1 //===- MipsISelLowering.cpp - Mips DAG Lowering Implementation ------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the interfaces that Mips uses to lower LLVM code into a
11 // selection DAG.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "MipsISelLowering.h"
16 #include "InstPrinter/MipsInstPrinter.h"
17 #include "MCTargetDesc/MipsBaseInfo.h"
18 #include "MCTargetDesc/MipsMCTargetDesc.h"
19 #include "MipsCCState.h"
20 #include "MipsInstrInfo.h"
21 #include "MipsMachineFunction.h"
22 #include "MipsRegisterInfo.h"
23 #include "MipsSubtarget.h"
24 #include "MipsTargetMachine.h"
25 #include "MipsTargetObjectFile.h"
26 #include "llvm/ADT/APFloat.h"
27 #include "llvm/ADT/ArrayRef.h"
28 #include "llvm/ADT/SmallVector.h"
29 #include "llvm/ADT/Statistic.h"
30 #include "llvm/ADT/StringRef.h"
31 #include "llvm/ADT/StringSwitch.h"
32 #include "llvm/CodeGen/CallingConvLower.h"
33 #include "llvm/CodeGen/FunctionLoweringInfo.h"
34 #include "llvm/CodeGen/ISDOpcodes.h"
35 #include "llvm/CodeGen/MachineBasicBlock.h"
36 #include "llvm/CodeGen/MachineFrameInfo.h"
37 #include "llvm/CodeGen/MachineFunction.h"
38 #include "llvm/CodeGen/MachineInstr.h"
39 #include "llvm/CodeGen/MachineInstrBuilder.h"
40 #include "llvm/CodeGen/MachineJumpTableInfo.h"
41 #include "llvm/CodeGen/MachineMemOperand.h"
42 #include "llvm/CodeGen/MachineOperand.h"
43 #include "llvm/CodeGen/MachineRegisterInfo.h"
44 #include "llvm/CodeGen/RuntimeLibcalls.h"
45 #include "llvm/CodeGen/SelectionDAG.h"
46 #include "llvm/CodeGen/SelectionDAGNodes.h"
47 #include "llvm/CodeGen/TargetFrameLowering.h"
48 #include "llvm/CodeGen/TargetInstrInfo.h"
49 #include "llvm/CodeGen/TargetRegisterInfo.h"
50 #include "llvm/CodeGen/ValueTypes.h"
51 #include "llvm/IR/CallingConv.h"
52 #include "llvm/IR/Constants.h"
53 #include "llvm/IR/DataLayout.h"
54 #include "llvm/IR/DebugLoc.h"
55 #include "llvm/IR/DerivedTypes.h"
56 #include "llvm/IR/Function.h"
57 #include "llvm/IR/GlobalValue.h"
58 #include "llvm/IR/Type.h"
59 #include "llvm/IR/Value.h"
60 #include "llvm/MC/MCRegisterInfo.h"
61 #include "llvm/Support/Casting.h"
62 #include "llvm/Support/CodeGen.h"
63 #include "llvm/Support/CommandLine.h"
64 #include "llvm/Support/Compiler.h"
65 #include "llvm/Support/ErrorHandling.h"
66 #include "llvm/Support/MachineValueType.h"
67 #include "llvm/Support/MathExtras.h"
68 #include "llvm/Target/TargetMachine.h"
69 #include "llvm/Target/TargetOptions.h"
70 #include <algorithm>
71 #include <cassert>
72 #include <cctype>
73 #include <cstdint>
74 #include <deque>
75 #include <iterator>
76 #include <utility>
77 #include <vector>
78 
79 using namespace llvm;
80 
81 #define DEBUG_TYPE "mips-lower"
82 
83 STATISTIC(NumTailCalls, "Number of tail calls");
84 
85 static cl::opt<bool>
86 LargeGOT("mxgot", cl::Hidden,
87          cl::desc("MIPS: Enable GOT larger than 64k."), cl::init(false));
88 
89 static cl::opt<bool>
90 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
91                cl::desc("MIPS: Don't trap on integer division by zero."),
92                cl::init(false));
93 
94 static const MCPhysReg Mips64DPRegs[8] = {
95   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
96   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
97 };
98 
99 // If I is a shifted mask, set the size (Size) and the first bit of the
100 // mask (Pos), and return true.
101 // For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
102 static bool isShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
103   if (!isShiftedMask_64(I))
104     return false;
105 
106   Size = countPopulation(I);
107   Pos = countTrailingZeros(I);
108   return true;
109 }
110 
111 // The MIPS MSA ABI passes vector arguments in the integer register set.
112 // The number of integer registers used is dependant on the ABI used.
113 MVT MipsTargetLowering::getRegisterTypeForCallingConv(MVT VT) const {
114   if (VT.isVector() && Subtarget.hasMSA())
115     return Subtarget.isABI_O32() ? MVT::i32 : MVT::i64;
116   return MipsTargetLowering::getRegisterType(VT);
117 }
118 
119 MVT MipsTargetLowering::getRegisterTypeForCallingConv(LLVMContext &Context,
120                                                       EVT VT) const {
121   if (VT.isVector()) {
122       if (Subtarget.isABI_O32()) {
123         return MVT::i32;
124       } else {
125         return (VT.getSizeInBits() == 32) ? MVT::i32 : MVT::i64;
126       }
127   }
128   return MipsTargetLowering::getRegisterType(Context, VT);
129 }
130 
131 unsigned MipsTargetLowering::getNumRegistersForCallingConv(LLVMContext &Context,
132                                                            EVT VT) const {
133   if (VT.isVector())
134     return std::max((VT.getSizeInBits() / (Subtarget.isABI_O32() ? 32 : 64)),
135                     1U);
136   return MipsTargetLowering::getNumRegisters(Context, VT);
137 }
138 
139 unsigned MipsTargetLowering::getVectorTypeBreakdownForCallingConv(
140     LLVMContext &Context, EVT VT, EVT &IntermediateVT,
141     unsigned &NumIntermediates, MVT &RegisterVT) const {
142   // Break down vector types to either 2 i64s or 4 i32s.
143   RegisterVT = getRegisterTypeForCallingConv(Context, VT) ;
144   IntermediateVT = RegisterVT;
145   NumIntermediates = VT.getSizeInBits() < RegisterVT.getSizeInBits()
146                          ? VT.getVectorNumElements()
147                          : VT.getSizeInBits() / RegisterVT.getSizeInBits();
148 
149   return NumIntermediates;
150 }
151 
152 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
153   MipsFunctionInfo *FI = DAG.getMachineFunction().getInfo<MipsFunctionInfo>();
154   return DAG.getRegister(FI->getGlobalBaseReg(), Ty);
155 }
156 
157 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
158                                           SelectionDAG &DAG,
159                                           unsigned Flag) const {
160   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
161 }
162 
163 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
164                                           SelectionDAG &DAG,
165                                           unsigned Flag) const {
166   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
167 }
168 
169 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
170                                           SelectionDAG &DAG,
171                                           unsigned Flag) const {
172   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
173 }
174 
175 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
176                                           SelectionDAG &DAG,
177                                           unsigned Flag) const {
178   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
179 }
180 
181 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
182                                           SelectionDAG &DAG,
183                                           unsigned Flag) const {
184   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlignment(),
185                                    N->getOffset(), Flag);
186 }
187 
188 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
189   switch ((MipsISD::NodeType)Opcode) {
190   case MipsISD::FIRST_NUMBER:      break;
191   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
192   case MipsISD::TailCall:          return "MipsISD::TailCall";
193   case MipsISD::Highest:           return "MipsISD::Highest";
194   case MipsISD::Higher:            return "MipsISD::Higher";
195   case MipsISD::Hi:                return "MipsISD::Hi";
196   case MipsISD::Lo:                return "MipsISD::Lo";
197   case MipsISD::GotHi:             return "MipsISD::GotHi";
198   case MipsISD::GPRel:             return "MipsISD::GPRel";
199   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
200   case MipsISD::Ret:               return "MipsISD::Ret";
201   case MipsISD::ERet:              return "MipsISD::ERet";
202   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
203   case MipsISD::FMS:               return "MipsISD::FMS";
204   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
205   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
206   case MipsISD::FSELECT:           return "MipsISD::FSELECT";
207   case MipsISD::MTC1_D64:          return "MipsISD::MTC1_D64";
208   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
209   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
210   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
211   case MipsISD::MFHI:              return "MipsISD::MFHI";
212   case MipsISD::MFLO:              return "MipsISD::MFLO";
213   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
214   case MipsISD::Mult:              return "MipsISD::Mult";
215   case MipsISD::Multu:             return "MipsISD::Multu";
216   case MipsISD::MAdd:              return "MipsISD::MAdd";
217   case MipsISD::MAddu:             return "MipsISD::MAddu";
218   case MipsISD::MSub:              return "MipsISD::MSub";
219   case MipsISD::MSubu:             return "MipsISD::MSubu";
220   case MipsISD::DivRem:            return "MipsISD::DivRem";
221   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
222   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
223   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
224   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
225   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
226   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
227   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
228   case MipsISD::Sync:              return "MipsISD::Sync";
229   case MipsISD::Ext:               return "MipsISD::Ext";
230   case MipsISD::Ins:               return "MipsISD::Ins";
231   case MipsISD::CIns:              return "MipsISD::CIns";
232   case MipsISD::LWL:               return "MipsISD::LWL";
233   case MipsISD::LWR:               return "MipsISD::LWR";
234   case MipsISD::SWL:               return "MipsISD::SWL";
235   case MipsISD::SWR:               return "MipsISD::SWR";
236   case MipsISD::LDL:               return "MipsISD::LDL";
237   case MipsISD::LDR:               return "MipsISD::LDR";
238   case MipsISD::SDL:               return "MipsISD::SDL";
239   case MipsISD::SDR:               return "MipsISD::SDR";
240   case MipsISD::EXTP:              return "MipsISD::EXTP";
241   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
242   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
243   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
244   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
245   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
246   case MipsISD::SHILO:             return "MipsISD::SHILO";
247   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
248   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
249   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
250   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
251   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
252   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
253   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
254   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
255   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
256   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
257   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
258   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
259   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
260   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
261   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
262   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
263   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
264   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
265   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
266   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
267   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
268   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
269   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
270   case MipsISD::MULT:              return "MipsISD::MULT";
271   case MipsISD::MULTU:             return "MipsISD::MULTU";
272   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
273   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
274   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
275   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
276   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
277   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
278   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
279   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
280   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
281   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
282   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
283   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
284   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
285   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
286   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
287   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
288   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
289   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
290   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
291   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
292   case MipsISD::VNOR:              return "MipsISD::VNOR";
293   case MipsISD::VSHF:              return "MipsISD::VSHF";
294   case MipsISD::SHF:               return "MipsISD::SHF";
295   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
296   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
297   case MipsISD::ILVL:              return "MipsISD::ILVL";
298   case MipsISD::ILVR:              return "MipsISD::ILVR";
299   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
300   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
301   case MipsISD::INSVE:             return "MipsISD::INSVE";
302   }
303   return nullptr;
304 }
305 
306 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
307                                        const MipsSubtarget &STI)
308     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
309   // Mips does not have i1 type, so use i32 for
310   // setcc operations results (slt, sgt, ...).
311   setBooleanContents(ZeroOrOneBooleanContent);
312   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
313   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
314   // does. Integer booleans still use 0 and 1.
315   if (Subtarget.hasMips32r6())
316     setBooleanContents(ZeroOrOneBooleanContent,
317                        ZeroOrNegativeOneBooleanContent);
318 
319   // Load extented operations for i1 types must be promoted
320   for (MVT VT : MVT::integer_valuetypes()) {
321     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
322     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
323     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
324   }
325 
326   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
327   // for f32, f16
328   for (MVT VT : MVT::fp_valuetypes()) {
329     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
330     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
331   }
332 
333   // Set LoadExtAction for f16 vectors to Expand
334   for (MVT VT : MVT::fp_vector_valuetypes()) {
335     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
336     if (F16VT.isValid())
337       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
338   }
339 
340   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
341   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
342 
343   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
344 
345   // Used by legalize types to correctly generate the setcc result.
346   // Without this, every float setcc comes with a AND/OR with the result,
347   // we don't want this, since the fpcmp result goes to a flag register,
348   // which is used implicitly by brcond and select operations.
349   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
350 
351   // Mips Custom Operations
352   setOperationAction(ISD::BR_JT,              MVT::Other, Expand);
353   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
354   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
355   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
356   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
357   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
358   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
359   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
360   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
361   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
362   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
363   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
364   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
365   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
366   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
367 
368   if (Subtarget.isGP64bit()) {
369     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
370     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
371     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
372     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
373     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
374     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
375     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
376     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
377     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
378     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
379     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
380     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
381   }
382 
383   if (!Subtarget.isGP64bit()) {
384     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
385     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
386     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
387   }
388 
389   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
390   if (Subtarget.isGP64bit())
391     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
392 
393   setOperationAction(ISD::SDIV, MVT::i32, Expand);
394   setOperationAction(ISD::SREM, MVT::i32, Expand);
395   setOperationAction(ISD::UDIV, MVT::i32, Expand);
396   setOperationAction(ISD::UREM, MVT::i32, Expand);
397   setOperationAction(ISD::SDIV, MVT::i64, Expand);
398   setOperationAction(ISD::SREM, MVT::i64, Expand);
399   setOperationAction(ISD::UDIV, MVT::i64, Expand);
400   setOperationAction(ISD::UREM, MVT::i64, Expand);
401 
402   if (!(Subtarget.hasDSP() && Subtarget.hasMips32r2())) {
403     setOperationAction(ISD::ADDC, MVT::i32, Expand);
404     setOperationAction(ISD::ADDE, MVT::i32, Expand);
405   }
406 
407   setOperationAction(ISD::ADDC, MVT::i64, Expand);
408   setOperationAction(ISD::ADDE, MVT::i64, Expand);
409   setOperationAction(ISD::SUBC, MVT::i32, Expand);
410   setOperationAction(ISD::SUBE, MVT::i32, Expand);
411   setOperationAction(ISD::SUBC, MVT::i64, Expand);
412   setOperationAction(ISD::SUBE, MVT::i64, Expand);
413 
414   // Operations not directly supported by Mips.
415   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
416   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
417   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
418   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
419   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
420   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
421   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
422   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
423   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
424   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
425   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
426   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
427   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
428   if (Subtarget.hasCnMips()) {
429     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
430     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
431   } else {
432     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
433     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
434   }
435   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
436   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
437   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
438   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
439   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
440   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
441 
442   if (!Subtarget.hasMips32r2())
443     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
444 
445   if (!Subtarget.hasMips64r2())
446     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
447 
448   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
449   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
450   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
451   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
452   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
453   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
454   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
455   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
456   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
457   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
458   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
459   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
460   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
461   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
462   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
463   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
464 
465   // Lower f16 conversion operations into library calls
466   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
467   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
468   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
469   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
470 
471   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
472 
473   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
474   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
475   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
476   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
477 
478   // Use the default for now
479   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
480   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
481 
482   if (!Subtarget.isGP64bit()) {
483     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
484     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
485   }
486 
487   if (!Subtarget.hasMips32r2()) {
488     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
489     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
490   }
491 
492   // MIPS16 lacks MIPS32's clz and clo instructions.
493   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
494     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
495   if (!Subtarget.hasMips64())
496     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
497 
498   if (!Subtarget.hasMips32r2())
499     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
500   if (!Subtarget.hasMips64r2())
501     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
502 
503   if (Subtarget.isGP64bit()) {
504     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
505     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
506     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
507     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
508   }
509 
510   setOperationAction(ISD::TRAP, MVT::Other, Legal);
511 
512   setTargetDAGCombine(ISD::SDIVREM);
513   setTargetDAGCombine(ISD::UDIVREM);
514   setTargetDAGCombine(ISD::SELECT);
515   setTargetDAGCombine(ISD::AND);
516   setTargetDAGCombine(ISD::OR);
517   setTargetDAGCombine(ISD::ADD);
518   setTargetDAGCombine(ISD::SUB);
519   setTargetDAGCombine(ISD::AssertZext);
520   setTargetDAGCombine(ISD::SHL);
521 
522   if (ABI.IsO32()) {
523     // These libcalls are not available in 32-bit.
524     setLibcallName(RTLIB::SHL_I128, nullptr);
525     setLibcallName(RTLIB::SRL_I128, nullptr);
526     setLibcallName(RTLIB::SRA_I128, nullptr);
527   }
528 
529   setMinFunctionAlignment(Subtarget.isGP64bit() ? 3 : 2);
530 
531   // The arguments on the stack are defined in terms of 4-byte slots on O32
532   // and 8-byte slots on N32/N64.
533   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? 8 : 4);
534 
535   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
536 
537   MaxStoresPerMemcpy = 16;
538 
539   isMicroMips = Subtarget.inMicroMipsMode();
540 }
541 
542 const MipsTargetLowering *MipsTargetLowering::create(const MipsTargetMachine &TM,
543                                                      const MipsSubtarget &STI) {
544   if (STI.inMips16Mode())
545     return createMips16TargetLowering(TM, STI);
546 
547   return createMipsSETargetLowering(TM, STI);
548 }
549 
550 // Create a fast isel object.
551 FastISel *
552 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
553                                   const TargetLibraryInfo *libInfo) const {
554   const MipsTargetMachine &TM =
555       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
556 
557   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
558   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
559                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
560                      !Subtarget.inMicroMipsMode();
561 
562   // Disable if either of the following is true:
563   // We do not generate PIC, the ABI is not O32, LargeGOT is being used.
564   if (!TM.isPositionIndependent() || !TM.getABI().IsO32() || LargeGOT)
565     UseFastISel = false;
566 
567   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
568 }
569 
570 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
571                                            EVT VT) const {
572   if (!VT.isVector())
573     return MVT::i32;
574   return VT.changeVectorElementTypeToInteger();
575 }
576 
577 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
578                                     TargetLowering::DAGCombinerInfo &DCI,
579                                     const MipsSubtarget &Subtarget) {
580   if (DCI.isBeforeLegalizeOps())
581     return SDValue();
582 
583   EVT Ty = N->getValueType(0);
584   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
585   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
586   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
587                                                   MipsISD::DivRemU16;
588   SDLoc DL(N);
589 
590   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
591                                N->getOperand(0), N->getOperand(1));
592   SDValue InChain = DAG.getEntryNode();
593   SDValue InGlue = DivRem;
594 
595   // insert MFLO
596   if (N->hasAnyUseOfValue(0)) {
597     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
598                                             InGlue);
599     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
600     InChain = CopyFromLo.getValue(1);
601     InGlue = CopyFromLo.getValue(2);
602   }
603 
604   // insert MFHI
605   if (N->hasAnyUseOfValue(1)) {
606     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
607                                             HI, Ty, InGlue);
608     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
609   }
610 
611   return SDValue();
612 }
613 
614 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
615   switch (CC) {
616   default: llvm_unreachable("Unknown fp condition code!");
617   case ISD::SETEQ:
618   case ISD::SETOEQ: return Mips::FCOND_OEQ;
619   case ISD::SETUNE: return Mips::FCOND_UNE;
620   case ISD::SETLT:
621   case ISD::SETOLT: return Mips::FCOND_OLT;
622   case ISD::SETGT:
623   case ISD::SETOGT: return Mips::FCOND_OGT;
624   case ISD::SETLE:
625   case ISD::SETOLE: return Mips::FCOND_OLE;
626   case ISD::SETGE:
627   case ISD::SETOGE: return Mips::FCOND_OGE;
628   case ISD::SETULT: return Mips::FCOND_ULT;
629   case ISD::SETULE: return Mips::FCOND_ULE;
630   case ISD::SETUGT: return Mips::FCOND_UGT;
631   case ISD::SETUGE: return Mips::FCOND_UGE;
632   case ISD::SETUO:  return Mips::FCOND_UN;
633   case ISD::SETO:   return Mips::FCOND_OR;
634   case ISD::SETNE:
635   case ISD::SETONE: return Mips::FCOND_ONE;
636   case ISD::SETUEQ: return Mips::FCOND_UEQ;
637   }
638 }
639 
640 /// This function returns true if the floating point conditional branches and
641 /// conditional moves which use condition code CC should be inverted.
642 static bool invertFPCondCodeUser(Mips::CondCode CC) {
643   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
644     return false;
645 
646   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
647          "Illegal Condition Code");
648 
649   return true;
650 }
651 
652 // Creates and returns an FPCmp node from a setcc node.
653 // Returns Op if setcc is not a floating point comparison.
654 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
655   // must be a SETCC node
656   if (Op.getOpcode() != ISD::SETCC)
657     return Op;
658 
659   SDValue LHS = Op.getOperand(0);
660 
661   if (!LHS.getValueType().isFloatingPoint())
662     return Op;
663 
664   SDValue RHS = Op.getOperand(1);
665   SDLoc DL(Op);
666 
667   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
668   // node if necessary.
669   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
670 
671   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
672                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
673 }
674 
675 // Creates and returns a CMovFPT/F node.
676 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
677                             SDValue False, const SDLoc &DL) {
678   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
679   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
680   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
681 
682   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
683                      True.getValueType(), True, FCC0, False, Cond);
684 }
685 
686 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
687                                     TargetLowering::DAGCombinerInfo &DCI,
688                                     const MipsSubtarget &Subtarget) {
689   if (DCI.isBeforeLegalizeOps())
690     return SDValue();
691 
692   SDValue SetCC = N->getOperand(0);
693 
694   if ((SetCC.getOpcode() != ISD::SETCC) ||
695       !SetCC.getOperand(0).getValueType().isInteger())
696     return SDValue();
697 
698   SDValue False = N->getOperand(2);
699   EVT FalseTy = False.getValueType();
700 
701   if (!FalseTy.isInteger())
702     return SDValue();
703 
704   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
705 
706   // If the RHS (False) is 0, we swap the order of the operands
707   // of ISD::SELECT (obviously also inverting the condition) so that we can
708   // take advantage of conditional moves using the $0 register.
709   // Example:
710   //   return (a != 0) ? x : 0;
711   //     load $reg, x
712   //     movz $reg, $0, a
713   if (!FalseC)
714     return SDValue();
715 
716   const SDLoc DL(N);
717 
718   if (!FalseC->getZExtValue()) {
719     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
720     SDValue True = N->getOperand(1);
721 
722     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
723                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
724 
725     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
726   }
727 
728   // If both operands are integer constants there's a possibility that we
729   // can do some interesting optimizations.
730   SDValue True = N->getOperand(1);
731   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
732 
733   if (!TrueC || !True.getValueType().isInteger())
734     return SDValue();
735 
736   // We'll also ignore MVT::i64 operands as this optimizations proves
737   // to be ineffective because of the required sign extensions as the result
738   // of a SETCC operator is always MVT::i32 for non-vector types.
739   if (True.getValueType() == MVT::i64)
740     return SDValue();
741 
742   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
743 
744   // 1)  (a < x) ? y : y-1
745   //  slti $reg1, a, x
746   //  addiu $reg2, $reg1, y-1
747   if (Diff == 1)
748     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
749 
750   // 2)  (a < x) ? y-1 : y
751   //  slti $reg1, a, x
752   //  xor $reg1, $reg1, 1
753   //  addiu $reg2, $reg1, y-1
754   if (Diff == -1) {
755     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
756     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
757                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
758     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
759   }
760 
761   // Couldn't optimize.
762   return SDValue();
763 }
764 
765 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
766                                     TargetLowering::DAGCombinerInfo &DCI,
767                                     const MipsSubtarget &Subtarget) {
768   if (DCI.isBeforeLegalizeOps())
769     return SDValue();
770 
771   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
772 
773   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
774   if (!FalseC || FalseC->getZExtValue())
775     return SDValue();
776 
777   // Since RHS (False) is 0, we swap the order of the True/False operands
778   // (obviously also inverting the condition) so that we can
779   // take advantage of conditional moves using the $0 register.
780   // Example:
781   //   return (a != 0) ? x : 0;
782   //     load $reg, x
783   //     movz $reg, $0, a
784   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
785                                                          MipsISD::CMovFP_T;
786 
787   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
788   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
789                      ValueIfFalse, FCC, ValueIfTrue, Glue);
790 }
791 
792 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
793                                  TargetLowering::DAGCombinerInfo &DCI,
794                                  const MipsSubtarget &Subtarget) {
795   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
796     return SDValue();
797 
798   SDValue FirstOperand = N->getOperand(0);
799   unsigned FirstOperandOpc = FirstOperand.getOpcode();
800   SDValue Mask = N->getOperand(1);
801   EVT ValTy = N->getValueType(0);
802   SDLoc DL(N);
803 
804   uint64_t Pos = 0, SMPos, SMSize;
805   ConstantSDNode *CN;
806   SDValue NewOperand;
807   unsigned Opc;
808 
809   // Op's second operand must be a shifted mask.
810   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
811       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
812     return SDValue();
813 
814   if (FirstOperandOpc == ISD::SRA || FirstOperandOpc == ISD::SRL) {
815     // Pattern match EXT.
816     //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
817     //  => ext $dst, $src, pos, size
818 
819     // The second operand of the shift must be an immediate.
820     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
821       return SDValue();
822 
823     Pos = CN->getZExtValue();
824 
825     // Return if the shifted mask does not start at bit 0 or the sum of its size
826     // and Pos exceeds the word's size.
827     if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
828       return SDValue();
829 
830     Opc = MipsISD::Ext;
831     NewOperand = FirstOperand.getOperand(0);
832   } else if (FirstOperandOpc == ISD::SHL && Subtarget.hasCnMips()) {
833     // Pattern match CINS.
834     //  $dst = and (shl $src , pos), mask
835     //  => cins $dst, $src, pos, size
836     // mask is a shifted mask with consecutive 1's, pos = shift amount,
837     // size = population count.
838 
839     // The second operand of the shift must be an immediate.
840     if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))))
841       return SDValue();
842 
843     Pos = CN->getZExtValue();
844 
845     if (SMPos != Pos || Pos >= ValTy.getSizeInBits() || SMSize >= 32 ||
846         Pos + SMSize > ValTy.getSizeInBits())
847       return SDValue();
848 
849     NewOperand = FirstOperand.getOperand(0);
850     // SMSize is 'location' (position) in this case, not size.
851     SMSize--;
852     Opc = MipsISD::CIns;
853   } else {
854     // Pattern match EXT.
855     //  $dst = and $src, (2**size - 1) , if size > 16
856     //  => ext $dst, $src, pos, size , pos = 0
857 
858     // If the mask is <= 0xffff, andi can be used instead.
859     if (CN->getZExtValue() <= 0xffff)
860       return SDValue();
861 
862     // Return if the mask doesn't start at position 0.
863     if (SMPos)
864       return SDValue();
865 
866     Opc = MipsISD::Ext;
867     NewOperand = FirstOperand;
868   }
869   return DAG.getNode(Opc, DL, ValTy, NewOperand,
870                      DAG.getConstant(Pos, DL, MVT::i32),
871                      DAG.getConstant(SMSize, DL, MVT::i32));
872 }
873 
874 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
875                                 TargetLowering::DAGCombinerInfo &DCI,
876                                 const MipsSubtarget &Subtarget) {
877   // Pattern match INS.
878   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
879   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
880   //  => ins $dst, $src, size, pos, $src1
881   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
882     return SDValue();
883 
884   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
885   uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
886   ConstantSDNode *CN, *CN1;
887 
888   // See if Op's first operand matches (and $src1 , mask0).
889   if (And0.getOpcode() != ISD::AND)
890     return SDValue();
891 
892   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
893       !isShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
894     return SDValue();
895 
896   // See if Op's second operand matches (and (shl $src, pos), mask1).
897   if (And1.getOpcode() == ISD::AND &&
898       And1.getOperand(0).getOpcode() == ISD::SHL) {
899 
900     if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
901         !isShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
902       return SDValue();
903 
904     // The shift masks must have the same position and size.
905     if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
906       return SDValue();
907 
908     SDValue Shl = And1.getOperand(0);
909 
910     if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
911       return SDValue();
912 
913     unsigned Shamt = CN->getZExtValue();
914 
915     // Return if the shift amount and the first bit position of mask are not the
916     // same.
917     EVT ValTy = N->getValueType(0);
918     if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
919       return SDValue();
920 
921     SDLoc DL(N);
922     return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
923                        DAG.getConstant(SMPos0, DL, MVT::i32),
924                        DAG.getConstant(SMSize0, DL, MVT::i32),
925                        And0.getOperand(0));
926   } else {
927     // Pattern match DINS.
928     //  $dst = or (and $src, mask0), mask1
929     //  where mask0 = ((1 << SMSize0) -1) << SMPos0
930     //  => dins $dst, $src, pos, size
931     if (~CN->getSExtValue() == ((((int64_t)1 << SMSize0) - 1) << SMPos0) &&
932         ((SMSize0 + SMPos0 <= 64 && Subtarget.hasMips64r2()) ||
933          (SMSize0 + SMPos0 <= 32))) {
934       // Check if AND instruction has constant as argument
935       bool isConstCase = And1.getOpcode() != ISD::AND;
936       if (And1.getOpcode() == ISD::AND) {
937         if (!(CN1 = dyn_cast<ConstantSDNode>(And1->getOperand(1))))
938           return SDValue();
939       } else {
940         if (!(CN1 = dyn_cast<ConstantSDNode>(N->getOperand(1))))
941           return SDValue();
942       }
943       // Don't generate INS if constant OR operand doesn't fit into bits
944       // cleared by constant AND operand.
945       if (CN->getSExtValue() & CN1->getSExtValue())
946         return SDValue();
947 
948       SDLoc DL(N);
949       EVT ValTy = N->getOperand(0)->getValueType(0);
950       SDValue Const1;
951       SDValue SrlX;
952       if (!isConstCase) {
953         Const1 = DAG.getConstant(SMPos0, DL, MVT::i32);
954         SrlX = DAG.getNode(ISD::SRL, DL, And1->getValueType(0), And1, Const1);
955       }
956       return DAG.getNode(
957           MipsISD::Ins, DL, N->getValueType(0),
958           isConstCase
959               ? DAG.getConstant(CN1->getSExtValue() >> SMPos0, DL, ValTy)
960               : SrlX,
961           DAG.getConstant(SMPos0, DL, MVT::i32),
962           DAG.getConstant(ValTy.getSizeInBits() / 8 < 8 ? SMSize0 & 31
963                                                         : SMSize0,
964                           DL, MVT::i32),
965           And0->getOperand(0));
966 
967     }
968     return SDValue();
969   }
970 }
971 
972 static SDValue performMADD_MSUBCombine(SDNode *ROOTNode, SelectionDAG &CurDAG,
973                                        const MipsSubtarget &Subtarget) {
974   // ROOTNode must have a multiplication as an operand for the match to be
975   // successful.
976   if (ROOTNode->getOperand(0).getOpcode() != ISD::MUL &&
977       ROOTNode->getOperand(1).getOpcode() != ISD::MUL)
978     return SDValue();
979 
980   // We don't handle vector types here.
981   if (ROOTNode->getValueType(0).isVector())
982     return SDValue();
983 
984   // For MIPS64, madd / msub instructions are inefficent to use with 64 bit
985   // arithmetic. E.g.
986   // (add (mul a b) c) =>
987   //   let res = (madd (mthi (drotr c 32))x(mtlo c) a b) in
988   //   MIPS64:   (or (dsll (mfhi res) 32) (dsrl (dsll (mflo res) 32) 32)
989   //   or
990   //   MIPS64R2: (dins (mflo res) (mfhi res) 32 32)
991   //
992   // The overhead of setting up the Hi/Lo registers and reassembling the
993   // result makes this a dubious optimzation for MIPS64. The core of the
994   // problem is that Hi/Lo contain the upper and lower 32 bits of the
995   // operand and result.
996   //
997   // It requires a chain of 4 add/mul for MIPS64R2 to get better code
998   // density than doing it naively, 5 for MIPS64. Additionally, using
999   // madd/msub on MIPS64 requires the operands actually be 32 bit sign
1000   // extended operands, not true 64 bit values.
1001   //
1002   // FIXME: For the moment, disable this completely for MIPS64.
1003   if (Subtarget.hasMips64())
1004     return SDValue();
1005 
1006   SDValue Mult = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1007                      ? ROOTNode->getOperand(0)
1008                      : ROOTNode->getOperand(1);
1009 
1010   SDValue AddOperand = ROOTNode->getOperand(0).getOpcode() == ISD::MUL
1011                      ? ROOTNode->getOperand(1)
1012                      : ROOTNode->getOperand(0);
1013 
1014   // Transform this to a MADD only if the user of this node is the add.
1015   // If there are other users of the mul, this function returns here.
1016   if (!Mult.hasOneUse())
1017     return SDValue();
1018 
1019   // maddu and madd are unusual instructions in that on MIPS64 bits 63..31
1020   // must be in canonical form, i.e. sign extended. For MIPS32, the operands
1021   // of the multiply must have 32 or more sign bits, otherwise we cannot
1022   // perform this optimization. We have to check this here as we're performing
1023   // this optimization pre-legalization.
1024   SDValue MultLHS = Mult->getOperand(0);
1025   SDValue MultRHS = Mult->getOperand(1);
1026 
1027   bool IsSigned = MultLHS->getOpcode() == ISD::SIGN_EXTEND &&
1028                   MultRHS->getOpcode() == ISD::SIGN_EXTEND;
1029   bool IsUnsigned = MultLHS->getOpcode() == ISD::ZERO_EXTEND &&
1030                     MultRHS->getOpcode() == ISD::ZERO_EXTEND;
1031 
1032   if (!IsSigned && !IsUnsigned)
1033     return SDValue();
1034 
1035   // Initialize accumulator.
1036   SDLoc DL(ROOTNode);
1037   SDValue TopHalf;
1038   SDValue BottomHalf;
1039   BottomHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1040                               CurDAG.getIntPtrConstant(0, DL));
1041 
1042   TopHalf = CurDAG.getNode(ISD::EXTRACT_ELEMENT, DL, MVT::i32, AddOperand,
1043                            CurDAG.getIntPtrConstant(1, DL));
1044   SDValue ACCIn = CurDAG.getNode(MipsISD::MTLOHI, DL, MVT::Untyped,
1045                                   BottomHalf,
1046                                   TopHalf);
1047 
1048   // Create MipsMAdd(u) / MipsMSub(u) node.
1049   bool IsAdd = ROOTNode->getOpcode() == ISD::ADD;
1050   unsigned Opcode = IsAdd ? (IsUnsigned ? MipsISD::MAddu : MipsISD::MAdd)
1051                           : (IsUnsigned ? MipsISD::MSubu : MipsISD::MSub);
1052   SDValue MAddOps[3] = {
1053       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(0)),
1054       CurDAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mult->getOperand(1)), ACCIn};
1055   EVT VTs[2] = {MVT::i32, MVT::i32};
1056   SDValue MAdd = CurDAG.getNode(Opcode, DL, VTs, MAddOps);
1057 
1058   SDValue ResLo = CurDAG.getNode(MipsISD::MFLO, DL, MVT::i32, MAdd);
1059   SDValue ResHi = CurDAG.getNode(MipsISD::MFHI, DL, MVT::i32, MAdd);
1060   SDValue Combined =
1061       CurDAG.getNode(ISD::BUILD_PAIR, DL, MVT::i64, ResLo, ResHi);
1062   return Combined;
1063 }
1064 
1065 static SDValue performSUBCombine(SDNode *N, SelectionDAG &DAG,
1066                                  TargetLowering::DAGCombinerInfo &DCI,
1067                                  const MipsSubtarget &Subtarget) {
1068   // (sub v0 (mul v1, v2)) => (msub v1, v2, v0)
1069   if (DCI.isBeforeLegalizeOps()) {
1070     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1071         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1072       return performMADD_MSUBCombine(N, DAG, Subtarget);
1073 
1074     return SDValue();
1075   }
1076 
1077   return SDValue();
1078 }
1079 
1080 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
1081                                  TargetLowering::DAGCombinerInfo &DCI,
1082                                  const MipsSubtarget &Subtarget) {
1083   // (add v0 (mul v1, v2)) => (madd v1, v2, v0)
1084   if (DCI.isBeforeLegalizeOps()) {
1085     if (Subtarget.hasMips32() && !Subtarget.hasMips32r6() &&
1086         !Subtarget.inMips16Mode() && N->getValueType(0) == MVT::i64)
1087       return performMADD_MSUBCombine(N, DAG, Subtarget);
1088 
1089     return SDValue();
1090   }
1091 
1092   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
1093   SDValue Add = N->getOperand(1);
1094 
1095   if (Add.getOpcode() != ISD::ADD)
1096     return SDValue();
1097 
1098   SDValue Lo = Add.getOperand(1);
1099 
1100   if ((Lo.getOpcode() != MipsISD::Lo) ||
1101       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
1102     return SDValue();
1103 
1104   EVT ValTy = N->getValueType(0);
1105   SDLoc DL(N);
1106 
1107   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
1108                              Add.getOperand(0));
1109   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
1110 }
1111 
1112 static SDValue performSHLCombine(SDNode *N, SelectionDAG &DAG,
1113                                  TargetLowering::DAGCombinerInfo &DCI,
1114                                  const MipsSubtarget &Subtarget) {
1115   // Pattern match CINS.
1116   //  $dst = shl (and $src , imm), pos
1117   //  => cins $dst, $src, pos, size
1118 
1119   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasCnMips())
1120     return SDValue();
1121 
1122   SDValue FirstOperand = N->getOperand(0);
1123   unsigned FirstOperandOpc = FirstOperand.getOpcode();
1124   SDValue SecondOperand = N->getOperand(1);
1125   EVT ValTy = N->getValueType(0);
1126   SDLoc DL(N);
1127 
1128   uint64_t Pos = 0, SMPos, SMSize;
1129   ConstantSDNode *CN;
1130   SDValue NewOperand;
1131 
1132   // The second operand of the shift must be an immediate.
1133   if (!(CN = dyn_cast<ConstantSDNode>(SecondOperand)))
1134     return SDValue();
1135 
1136   Pos = CN->getZExtValue();
1137 
1138   if (Pos >= ValTy.getSizeInBits())
1139     return SDValue();
1140 
1141   if (FirstOperandOpc != ISD::AND)
1142     return SDValue();
1143 
1144   // AND's second operand must be a shifted mask.
1145   if (!(CN = dyn_cast<ConstantSDNode>(FirstOperand.getOperand(1))) ||
1146       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
1147     return SDValue();
1148 
1149   // Return if the shifted mask does not start at bit 0 or the sum of its size
1150   // and Pos exceeds the word's size.
1151   if (SMPos != 0 || SMSize > 32 || Pos + SMSize > ValTy.getSizeInBits())
1152     return SDValue();
1153 
1154   NewOperand = FirstOperand.getOperand(0);
1155   // SMSize is 'location' (position) in this case, not size.
1156   SMSize--;
1157 
1158   return DAG.getNode(MipsISD::CIns, DL, ValTy, NewOperand,
1159                      DAG.getConstant(Pos, DL, MVT::i32),
1160                      DAG.getConstant(SMSize, DL, MVT::i32));
1161 }
1162 
1163 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
1164   const {
1165   SelectionDAG &DAG = DCI.DAG;
1166   unsigned Opc = N->getOpcode();
1167 
1168   switch (Opc) {
1169   default: break;
1170   case ISD::SDIVREM:
1171   case ISD::UDIVREM:
1172     return performDivRemCombine(N, DAG, DCI, Subtarget);
1173   case ISD::SELECT:
1174     return performSELECTCombine(N, DAG, DCI, Subtarget);
1175   case MipsISD::CMovFP_F:
1176   case MipsISD::CMovFP_T:
1177     return performCMovFPCombine(N, DAG, DCI, Subtarget);
1178   case ISD::AND:
1179     return performANDCombine(N, DAG, DCI, Subtarget);
1180   case ISD::OR:
1181     return performORCombine(N, DAG, DCI, Subtarget);
1182   case ISD::ADD:
1183     return performADDCombine(N, DAG, DCI, Subtarget);
1184   case ISD::SHL:
1185     return performSHLCombine(N, DAG, DCI, Subtarget);
1186   case ISD::SUB:
1187     return performSUBCombine(N, DAG, DCI, Subtarget);
1188   }
1189 
1190   return SDValue();
1191 }
1192 
1193 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
1194   return Subtarget.hasMips32();
1195 }
1196 
1197 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
1198   return Subtarget.hasMips32();
1199 }
1200 
1201 void
1202 MipsTargetLowering::LowerOperationWrapper(SDNode *N,
1203                                           SmallVectorImpl<SDValue> &Results,
1204                                           SelectionDAG &DAG) const {
1205   SDValue Res = LowerOperation(SDValue(N, 0), DAG);
1206 
1207   for (unsigned I = 0, E = Res->getNumValues(); I != E; ++I)
1208     Results.push_back(Res.getValue(I));
1209 }
1210 
1211 void
1212 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
1213                                        SmallVectorImpl<SDValue> &Results,
1214                                        SelectionDAG &DAG) const {
1215   return LowerOperationWrapper(N, Results, DAG);
1216 }
1217 
1218 SDValue MipsTargetLowering::
1219 LowerOperation(SDValue Op, SelectionDAG &DAG) const
1220 {
1221   switch (Op.getOpcode())
1222   {
1223   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
1224   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
1225   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
1226   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
1227   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
1228   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
1229   case ISD::SELECT:             return lowerSELECT(Op, DAG);
1230   case ISD::SETCC:              return lowerSETCC(Op, DAG);
1231   case ISD::VASTART:            return lowerVASTART(Op, DAG);
1232   case ISD::VAARG:              return lowerVAARG(Op, DAG);
1233   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
1234   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
1235   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
1236   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
1237   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
1238   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
1239   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
1240   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
1241   case ISD::LOAD:               return lowerLOAD(Op, DAG);
1242   case ISD::STORE:              return lowerSTORE(Op, DAG);
1243   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
1244   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
1245   }
1246   return SDValue();
1247 }
1248 
1249 //===----------------------------------------------------------------------===//
1250 //  Lower helper functions
1251 //===----------------------------------------------------------------------===//
1252 
1253 // addLiveIn - This helper function adds the specified physical register to the
1254 // MachineFunction as a live in value.  It also creates a corresponding
1255 // virtual register for it.
1256 static unsigned
1257 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
1258 {
1259   unsigned VReg = MF.getRegInfo().createVirtualRegister(RC);
1260   MF.getRegInfo().addLiveIn(PReg, VReg);
1261   return VReg;
1262 }
1263 
1264 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
1265                                               MachineBasicBlock &MBB,
1266                                               const TargetInstrInfo &TII,
1267                                               bool Is64Bit, bool IsMicroMips) {
1268   if (NoZeroDivCheck)
1269     return &MBB;
1270 
1271   // Insert instruction "teq $divisor_reg, $zero, 7".
1272   MachineBasicBlock::iterator I(MI);
1273   MachineInstrBuilder MIB;
1274   MachineOperand &Divisor = MI.getOperand(2);
1275   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
1276                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
1277             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
1278             .addReg(Mips::ZERO)
1279             .addImm(7);
1280 
1281   // Use the 32-bit sub-register if this is a 64-bit division.
1282   if (Is64Bit)
1283     MIB->getOperand(0).setSubReg(Mips::sub_32);
1284 
1285   // Clear Divisor's kill flag.
1286   Divisor.setIsKill(false);
1287 
1288   // We would normally delete the original instruction here but in this case
1289   // we only needed to inject an additional instruction rather than replace it.
1290 
1291   return &MBB;
1292 }
1293 
1294 MachineBasicBlock *
1295 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
1296                                                 MachineBasicBlock *BB) const {
1297   switch (MI.getOpcode()) {
1298   default:
1299     llvm_unreachable("Unexpected instr type to insert");
1300   case Mips::ATOMIC_LOAD_ADD_I8:
1301     return emitAtomicBinaryPartword(MI, BB, 1, Mips::ADDu);
1302   case Mips::ATOMIC_LOAD_ADD_I16:
1303     return emitAtomicBinaryPartword(MI, BB, 2, Mips::ADDu);
1304   case Mips::ATOMIC_LOAD_ADD_I32:
1305     return emitAtomicBinary(MI, BB, 4, Mips::ADDu);
1306   case Mips::ATOMIC_LOAD_ADD_I64:
1307     return emitAtomicBinary(MI, BB, 8, Mips::DADDu);
1308 
1309   case Mips::ATOMIC_LOAD_AND_I8:
1310     return emitAtomicBinaryPartword(MI, BB, 1, Mips::AND);
1311   case Mips::ATOMIC_LOAD_AND_I16:
1312     return emitAtomicBinaryPartword(MI, BB, 2, Mips::AND);
1313   case Mips::ATOMIC_LOAD_AND_I32:
1314     return emitAtomicBinary(MI, BB, 4, Mips::AND);
1315   case Mips::ATOMIC_LOAD_AND_I64:
1316     return emitAtomicBinary(MI, BB, 8, Mips::AND64);
1317 
1318   case Mips::ATOMIC_LOAD_OR_I8:
1319     return emitAtomicBinaryPartword(MI, BB, 1, Mips::OR);
1320   case Mips::ATOMIC_LOAD_OR_I16:
1321     return emitAtomicBinaryPartword(MI, BB, 2, Mips::OR);
1322   case Mips::ATOMIC_LOAD_OR_I32:
1323     return emitAtomicBinary(MI, BB, 4, Mips::OR);
1324   case Mips::ATOMIC_LOAD_OR_I64:
1325     return emitAtomicBinary(MI, BB, 8, Mips::OR64);
1326 
1327   case Mips::ATOMIC_LOAD_XOR_I8:
1328     return emitAtomicBinaryPartword(MI, BB, 1, Mips::XOR);
1329   case Mips::ATOMIC_LOAD_XOR_I16:
1330     return emitAtomicBinaryPartword(MI, BB, 2, Mips::XOR);
1331   case Mips::ATOMIC_LOAD_XOR_I32:
1332     return emitAtomicBinary(MI, BB, 4, Mips::XOR);
1333   case Mips::ATOMIC_LOAD_XOR_I64:
1334     return emitAtomicBinary(MI, BB, 8, Mips::XOR64);
1335 
1336   case Mips::ATOMIC_LOAD_NAND_I8:
1337     return emitAtomicBinaryPartword(MI, BB, 1, 0, true);
1338   case Mips::ATOMIC_LOAD_NAND_I16:
1339     return emitAtomicBinaryPartword(MI, BB, 2, 0, true);
1340   case Mips::ATOMIC_LOAD_NAND_I32:
1341     return emitAtomicBinary(MI, BB, 4, 0, true);
1342   case Mips::ATOMIC_LOAD_NAND_I64:
1343     return emitAtomicBinary(MI, BB, 8, 0, true);
1344 
1345   case Mips::ATOMIC_LOAD_SUB_I8:
1346     return emitAtomicBinaryPartword(MI, BB, 1, Mips::SUBu);
1347   case Mips::ATOMIC_LOAD_SUB_I16:
1348     return emitAtomicBinaryPartword(MI, BB, 2, Mips::SUBu);
1349   case Mips::ATOMIC_LOAD_SUB_I32:
1350     return emitAtomicBinary(MI, BB, 4, Mips::SUBu);
1351   case Mips::ATOMIC_LOAD_SUB_I64:
1352     return emitAtomicBinary(MI, BB, 8, Mips::DSUBu);
1353 
1354   case Mips::ATOMIC_SWAP_I8:
1355     return emitAtomicBinaryPartword(MI, BB, 1, 0);
1356   case Mips::ATOMIC_SWAP_I16:
1357     return emitAtomicBinaryPartword(MI, BB, 2, 0);
1358   case Mips::ATOMIC_SWAP_I32:
1359     return emitAtomicBinary(MI, BB, 4, 0);
1360   case Mips::ATOMIC_SWAP_I64:
1361     return emitAtomicBinary(MI, BB, 8, 0);
1362 
1363   case Mips::ATOMIC_CMP_SWAP_I8:
1364     return emitAtomicCmpSwapPartword(MI, BB, 1);
1365   case Mips::ATOMIC_CMP_SWAP_I16:
1366     return emitAtomicCmpSwapPartword(MI, BB, 2);
1367   case Mips::ATOMIC_CMP_SWAP_I32:
1368     return emitAtomicCmpSwap(MI, BB, 4);
1369   case Mips::ATOMIC_CMP_SWAP_I64:
1370     return emitAtomicCmpSwap(MI, BB, 8);
1371   case Mips::PseudoSDIV:
1372   case Mips::PseudoUDIV:
1373   case Mips::DIV:
1374   case Mips::DIVU:
1375   case Mips::MOD:
1376   case Mips::MODU:
1377     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1378                                false);
1379   case Mips::SDIV_MM_Pseudo:
1380   case Mips::UDIV_MM_Pseudo:
1381   case Mips::SDIV_MM:
1382   case Mips::UDIV_MM:
1383   case Mips::DIV_MMR6:
1384   case Mips::DIVU_MMR6:
1385   case Mips::MOD_MMR6:
1386   case Mips::MODU_MMR6:
1387     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1388   case Mips::PseudoDSDIV:
1389   case Mips::PseudoDUDIV:
1390   case Mips::DDIV:
1391   case Mips::DDIVU:
1392   case Mips::DMOD:
1393   case Mips::DMODU:
1394     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1395 
1396   case Mips::PseudoSELECT_I:
1397   case Mips::PseudoSELECT_I64:
1398   case Mips::PseudoSELECT_S:
1399   case Mips::PseudoSELECT_D32:
1400   case Mips::PseudoSELECT_D64:
1401     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1402   case Mips::PseudoSELECTFP_F_I:
1403   case Mips::PseudoSELECTFP_F_I64:
1404   case Mips::PseudoSELECTFP_F_S:
1405   case Mips::PseudoSELECTFP_F_D32:
1406   case Mips::PseudoSELECTFP_F_D64:
1407     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1408   case Mips::PseudoSELECTFP_T_I:
1409   case Mips::PseudoSELECTFP_T_I64:
1410   case Mips::PseudoSELECTFP_T_S:
1411   case Mips::PseudoSELECTFP_T_D32:
1412   case Mips::PseudoSELECTFP_T_D64:
1413     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1414   }
1415 }
1416 
1417 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1418 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1419 MachineBasicBlock *MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1420                                                         MachineBasicBlock *BB,
1421                                                         unsigned Size,
1422                                                         unsigned BinOpcode,
1423                                                         bool Nand) const {
1424   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicBinary.");
1425 
1426   MachineFunction *MF = BB->getParent();
1427   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1428   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1429   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1430   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1431   DebugLoc DL = MI.getDebugLoc();
1432   unsigned LL, SC, AND, NOR, ZERO, BEQ;
1433 
1434   if (Size == 4) {
1435     if (isMicroMips) {
1436       LL = Mips::LL_MM;
1437       SC = Mips::SC_MM;
1438     } else {
1439       LL = Subtarget.hasMips32r6()
1440                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1441                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1442       SC = Subtarget.hasMips32r6()
1443                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1444                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1445     }
1446 
1447     AND = Mips::AND;
1448     NOR = Mips::NOR;
1449     ZERO = Mips::ZERO;
1450     BEQ = Mips::BEQ;
1451   } else {
1452     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1453     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1454     AND = Mips::AND64;
1455     NOR = Mips::NOR64;
1456     ZERO = Mips::ZERO_64;
1457     BEQ = Mips::BEQ64;
1458   }
1459 
1460   unsigned OldVal = MI.getOperand(0).getReg();
1461   unsigned Ptr = MI.getOperand(1).getReg();
1462   unsigned Incr = MI.getOperand(2).getReg();
1463 
1464   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1465   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1466   unsigned Success = RegInfo.createVirtualRegister(RC);
1467 
1468   // insert new blocks after the current block
1469   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1470   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1471   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1472   MachineFunction::iterator It = ++BB->getIterator();
1473   MF->insert(It, loopMBB);
1474   MF->insert(It, exitMBB);
1475 
1476   // Transfer the remainder of BB and its successor edges to exitMBB.
1477   exitMBB->splice(exitMBB->begin(), BB,
1478                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1479   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1480 
1481   //  thisMBB:
1482   //    ...
1483   //    fallthrough --> loopMBB
1484   BB->addSuccessor(loopMBB);
1485   loopMBB->addSuccessor(loopMBB);
1486   loopMBB->addSuccessor(exitMBB);
1487 
1488   //  loopMBB:
1489   //    ll oldval, 0(ptr)
1490   //    <binop> storeval, oldval, incr
1491   //    sc success, storeval, 0(ptr)
1492   //    beq success, $0, loopMBB
1493   BB = loopMBB;
1494   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
1495   if (Nand) {
1496     //  and andres, oldval, incr
1497     //  nor storeval, $0, andres
1498     BuildMI(BB, DL, TII->get(AND), AndRes).addReg(OldVal).addReg(Incr);
1499     BuildMI(BB, DL, TII->get(NOR), StoreVal).addReg(ZERO).addReg(AndRes);
1500   } else if (BinOpcode) {
1501     //  <binop> storeval, oldval, incr
1502     BuildMI(BB, DL, TII->get(BinOpcode), StoreVal).addReg(OldVal).addReg(Incr);
1503   } else {
1504     StoreVal = Incr;
1505   }
1506   BuildMI(BB, DL, TII->get(SC), Success).addReg(StoreVal).addReg(Ptr).addImm(0);
1507   BuildMI(BB, DL, TII->get(BEQ)).addReg(Success).addReg(ZERO).addMBB(loopMBB);
1508 
1509   MI.eraseFromParent(); // The instruction is gone now.
1510 
1511   return exitMBB;
1512 }
1513 
1514 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1515     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1516     unsigned SrcReg) const {
1517   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1518   const DebugLoc &DL = MI.getDebugLoc();
1519 
1520   if (Subtarget.hasMips32r2() && Size == 1) {
1521     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1522     return BB;
1523   }
1524 
1525   if (Subtarget.hasMips32r2() && Size == 2) {
1526     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1527     return BB;
1528   }
1529 
1530   MachineFunction *MF = BB->getParent();
1531   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1532   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1533   unsigned ScrReg = RegInfo.createVirtualRegister(RC);
1534 
1535   assert(Size < 32);
1536   int64_t ShiftImm = 32 - (Size * 8);
1537 
1538   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1539   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1540 
1541   return BB;
1542 }
1543 
1544 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1545     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode,
1546     bool Nand) const {
1547   assert((Size == 1 || Size == 2) &&
1548          "Unsupported size for EmitAtomicBinaryPartial.");
1549 
1550   MachineFunction *MF = BB->getParent();
1551   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1552   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1553   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1554   const TargetRegisterClass *RCp =
1555     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1556   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1557   DebugLoc DL = MI.getDebugLoc();
1558 
1559   unsigned Dest = MI.getOperand(0).getReg();
1560   unsigned Ptr = MI.getOperand(1).getReg();
1561   unsigned Incr = MI.getOperand(2).getReg();
1562 
1563   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1564   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1565   unsigned Mask = RegInfo.createVirtualRegister(RC);
1566   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1567   unsigned NewVal = RegInfo.createVirtualRegister(RC);
1568   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1569   unsigned Incr2 = RegInfo.createVirtualRegister(RC);
1570   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1571   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1572   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1573   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1574   unsigned BinOpRes = RegInfo.createVirtualRegister(RC);
1575   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1576   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1577   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1578   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1579   unsigned Success = RegInfo.createVirtualRegister(RC);
1580 
1581   unsigned LL, SC;
1582   if (isMicroMips) {
1583     LL = Mips::LL_MM;
1584     SC = Mips::SC_MM;
1585   } else {
1586     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1587                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1588     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1589                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1590   }
1591 
1592   // insert new blocks after the current block
1593   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1594   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1595   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1596   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1597   MachineFunction::iterator It = ++BB->getIterator();
1598   MF->insert(It, loopMBB);
1599   MF->insert(It, sinkMBB);
1600   MF->insert(It, exitMBB);
1601 
1602   // Transfer the remainder of BB and its successor edges to exitMBB.
1603   exitMBB->splice(exitMBB->begin(), BB,
1604                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1605   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1606 
1607   BB->addSuccessor(loopMBB);
1608   loopMBB->addSuccessor(loopMBB);
1609   loopMBB->addSuccessor(sinkMBB);
1610   sinkMBB->addSuccessor(exitMBB);
1611 
1612   //  thisMBB:
1613   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1614   //    and     alignedaddr,ptr,masklsb2
1615   //    andi    ptrlsb2,ptr,3
1616   //    sll     shiftamt,ptrlsb2,3
1617   //    ori     maskupper,$0,255               # 0xff
1618   //    sll     mask,maskupper,shiftamt
1619   //    nor     mask2,$0,mask
1620   //    sll     incr2,incr,shiftamt
1621 
1622   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1623   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1624     .addReg(ABI.GetNullPtr()).addImm(-4);
1625   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1626     .addReg(Ptr).addReg(MaskLSB2);
1627   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1628       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1629   if (Subtarget.isLittle()) {
1630     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1631   } else {
1632     unsigned Off = RegInfo.createVirtualRegister(RC);
1633     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1634       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1635     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1636   }
1637   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1638     .addReg(Mips::ZERO).addImm(MaskImm);
1639   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1640     .addReg(MaskUpper).addReg(ShiftAmt);
1641   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1642   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1643 
1644   // atomic.load.binop
1645   // loopMBB:
1646   //   ll      oldval,0(alignedaddr)
1647   //   binop   binopres,oldval,incr2
1648   //   and     newval,binopres,mask
1649   //   and     maskedoldval0,oldval,mask2
1650   //   or      storeval,maskedoldval0,newval
1651   //   sc      success,storeval,0(alignedaddr)
1652   //   beq     success,$0,loopMBB
1653 
1654   // atomic.swap
1655   // loopMBB:
1656   //   ll      oldval,0(alignedaddr)
1657   //   and     newval,incr2,mask
1658   //   and     maskedoldval0,oldval,mask2
1659   //   or      storeval,maskedoldval0,newval
1660   //   sc      success,storeval,0(alignedaddr)
1661   //   beq     success,$0,loopMBB
1662 
1663   BB = loopMBB;
1664   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1665   if (Nand) {
1666     //  and andres, oldval, incr2
1667     //  nor binopres, $0, andres
1668     //  and newval, binopres, mask
1669     BuildMI(BB, DL, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr2);
1670     BuildMI(BB, DL, TII->get(Mips::NOR), BinOpRes)
1671       .addReg(Mips::ZERO).addReg(AndRes);
1672     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1673   } else if (BinOpcode) {
1674     //  <binop> binopres, oldval, incr2
1675     //  and newval, binopres, mask
1676     BuildMI(BB, DL, TII->get(BinOpcode), BinOpRes).addReg(OldVal).addReg(Incr2);
1677     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1678   } else { // atomic.swap
1679     //  and newval, incr2, mask
1680     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(Incr2).addReg(Mask);
1681   }
1682 
1683   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1684     .addReg(OldVal).addReg(Mask2);
1685   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1686     .addReg(MaskedOldVal0).addReg(NewVal);
1687   BuildMI(BB, DL, TII->get(SC), Success)
1688     .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1689   BuildMI(BB, DL, TII->get(Mips::BEQ))
1690     .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB);
1691 
1692   //  sinkMBB:
1693   //    and     maskedoldval1,oldval,mask
1694   //    srl     srlres,maskedoldval1,shiftamt
1695   //    sign_extend dest,srlres
1696   BB = sinkMBB;
1697 
1698   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1699     .addReg(OldVal).addReg(Mask);
1700   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1701       .addReg(MaskedOldVal1).addReg(ShiftAmt);
1702   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1703 
1704   MI.eraseFromParent(); // The instruction is gone now.
1705 
1706   return exitMBB;
1707 }
1708 
1709 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1710                                                          MachineBasicBlock *BB,
1711                                                          unsigned Size) const {
1712   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicCmpSwap.");
1713 
1714   MachineFunction *MF = BB->getParent();
1715   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1716   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1717   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1718   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1719   DebugLoc DL = MI.getDebugLoc();
1720   unsigned LL, SC, ZERO, BNE, BEQ;
1721 
1722   if (Size == 4) {
1723     if (isMicroMips) {
1724       LL = Mips::LL_MM;
1725       SC = Mips::SC_MM;
1726     } else {
1727       LL = Subtarget.hasMips32r6()
1728                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1729                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1730       SC = Subtarget.hasMips32r6()
1731                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1732                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1733     }
1734 
1735     ZERO = Mips::ZERO;
1736     BNE = Mips::BNE;
1737     BEQ = Mips::BEQ;
1738   } else {
1739     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1740     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1741     ZERO = Mips::ZERO_64;
1742     BNE = Mips::BNE64;
1743     BEQ = Mips::BEQ64;
1744   }
1745 
1746   unsigned Dest = MI.getOperand(0).getReg();
1747   unsigned Ptr = MI.getOperand(1).getReg();
1748   unsigned OldVal = MI.getOperand(2).getReg();
1749   unsigned NewVal = MI.getOperand(3).getReg();
1750 
1751   unsigned Success = RegInfo.createVirtualRegister(RC);
1752 
1753   // insert new blocks after the current block
1754   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1755   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1756   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1757   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1758   MachineFunction::iterator It = ++BB->getIterator();
1759   MF->insert(It, loop1MBB);
1760   MF->insert(It, loop2MBB);
1761   MF->insert(It, exitMBB);
1762 
1763   // Transfer the remainder of BB and its successor edges to exitMBB.
1764   exitMBB->splice(exitMBB->begin(), BB,
1765                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1766   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1767 
1768   //  thisMBB:
1769   //    ...
1770   //    fallthrough --> loop1MBB
1771   BB->addSuccessor(loop1MBB);
1772   loop1MBB->addSuccessor(exitMBB);
1773   loop1MBB->addSuccessor(loop2MBB);
1774   loop2MBB->addSuccessor(loop1MBB);
1775   loop2MBB->addSuccessor(exitMBB);
1776 
1777   // loop1MBB:
1778   //   ll dest, 0(ptr)
1779   //   bne dest, oldval, exitMBB
1780   BB = loop1MBB;
1781   BuildMI(BB, DL, TII->get(LL), Dest).addReg(Ptr).addImm(0);
1782   BuildMI(BB, DL, TII->get(BNE))
1783     .addReg(Dest).addReg(OldVal).addMBB(exitMBB);
1784 
1785   // loop2MBB:
1786   //   sc success, newval, 0(ptr)
1787   //   beq success, $0, loop1MBB
1788   BB = loop2MBB;
1789   BuildMI(BB, DL, TII->get(SC), Success)
1790     .addReg(NewVal).addReg(Ptr).addImm(0);
1791   BuildMI(BB, DL, TII->get(BEQ))
1792     .addReg(Success).addReg(ZERO).addMBB(loop1MBB);
1793 
1794   MI.eraseFromParent(); // The instruction is gone now.
1795 
1796   return exitMBB;
1797 }
1798 
1799 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1800     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1801   assert((Size == 1 || Size == 2) &&
1802       "Unsupported size for EmitAtomicCmpSwapPartial.");
1803 
1804   MachineFunction *MF = BB->getParent();
1805   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1806   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1807   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1808   const TargetRegisterClass *RCp =
1809     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1810   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1811   DebugLoc DL = MI.getDebugLoc();
1812 
1813   unsigned Dest = MI.getOperand(0).getReg();
1814   unsigned Ptr = MI.getOperand(1).getReg();
1815   unsigned CmpVal = MI.getOperand(2).getReg();
1816   unsigned NewVal = MI.getOperand(3).getReg();
1817 
1818   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1819   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1820   unsigned Mask = RegInfo.createVirtualRegister(RC);
1821   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1822   unsigned ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1823   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1824   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1825   unsigned ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1826   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1827   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1828   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1829   unsigned MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1830   unsigned MaskedNewVal = RegInfo.createVirtualRegister(RC);
1831   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1832   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1833   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1834   unsigned Success = RegInfo.createVirtualRegister(RC);
1835   unsigned LL, SC;
1836 
1837   if (isMicroMips) {
1838     LL = Mips::LL_MM;
1839     SC = Mips::SC_MM;
1840   } else {
1841     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1842                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1843     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1844                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1845   }
1846 
1847   // insert new blocks after the current block
1848   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1849   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1850   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1851   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1852   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1853   MachineFunction::iterator It = ++BB->getIterator();
1854   MF->insert(It, loop1MBB);
1855   MF->insert(It, loop2MBB);
1856   MF->insert(It, sinkMBB);
1857   MF->insert(It, exitMBB);
1858 
1859   // Transfer the remainder of BB and its successor edges to exitMBB.
1860   exitMBB->splice(exitMBB->begin(), BB,
1861                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1862   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1863 
1864   BB->addSuccessor(loop1MBB);
1865   loop1MBB->addSuccessor(sinkMBB);
1866   loop1MBB->addSuccessor(loop2MBB);
1867   loop2MBB->addSuccessor(loop1MBB);
1868   loop2MBB->addSuccessor(sinkMBB);
1869   sinkMBB->addSuccessor(exitMBB);
1870 
1871   // FIXME: computation of newval2 can be moved to loop2MBB.
1872   //  thisMBB:
1873   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1874   //    and     alignedaddr,ptr,masklsb2
1875   //    andi    ptrlsb2,ptr,3
1876   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1877   //    sll     shiftamt,ptrlsb2,3
1878   //    ori     maskupper,$0,255               # 0xff
1879   //    sll     mask,maskupper,shiftamt
1880   //    nor     mask2,$0,mask
1881   //    andi    maskedcmpval,cmpval,255
1882   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1883   //    andi    maskednewval,newval,255
1884   //    sll     shiftednewval,maskednewval,shiftamt
1885   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1886   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1887     .addReg(ABI.GetNullPtr()).addImm(-4);
1888   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1889     .addReg(Ptr).addReg(MaskLSB2);
1890   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1891       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1892   if (Subtarget.isLittle()) {
1893     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1894   } else {
1895     unsigned Off = RegInfo.createVirtualRegister(RC);
1896     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1897       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1898     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1899   }
1900   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1901     .addReg(Mips::ZERO).addImm(MaskImm);
1902   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1903     .addReg(MaskUpper).addReg(ShiftAmt);
1904   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1905   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1906     .addReg(CmpVal).addImm(MaskImm);
1907   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1908     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1909   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1910     .addReg(NewVal).addImm(MaskImm);
1911   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1912     .addReg(MaskedNewVal).addReg(ShiftAmt);
1913 
1914   //  loop1MBB:
1915   //    ll      oldval,0(alginedaddr)
1916   //    and     maskedoldval0,oldval,mask
1917   //    bne     maskedoldval0,shiftedcmpval,sinkMBB
1918   BB = loop1MBB;
1919   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1920   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1921     .addReg(OldVal).addReg(Mask);
1922   BuildMI(BB, DL, TII->get(Mips::BNE))
1923     .addReg(MaskedOldVal0).addReg(ShiftedCmpVal).addMBB(sinkMBB);
1924 
1925   //  loop2MBB:
1926   //    and     maskedoldval1,oldval,mask2
1927   //    or      storeval,maskedoldval1,shiftednewval
1928   //    sc      success,storeval,0(alignedaddr)
1929   //    beq     success,$0,loop1MBB
1930   BB = loop2MBB;
1931   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1932     .addReg(OldVal).addReg(Mask2);
1933   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1934     .addReg(MaskedOldVal1).addReg(ShiftedNewVal);
1935   BuildMI(BB, DL, TII->get(SC), Success)
1936       .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1937   BuildMI(BB, DL, TII->get(Mips::BEQ))
1938       .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB);
1939 
1940   //  sinkMBB:
1941   //    srl     srlres,maskedoldval0,shiftamt
1942   //    sign_extend dest,srlres
1943   BB = sinkMBB;
1944 
1945   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1946       .addReg(MaskedOldVal0).addReg(ShiftAmt);
1947   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1948 
1949   MI.eraseFromParent(); // The instruction is gone now.
1950 
1951   return exitMBB;
1952 }
1953 
1954 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
1955   // The first operand is the chain, the second is the condition, the third is
1956   // the block to branch to if the condition is true.
1957   SDValue Chain = Op.getOperand(0);
1958   SDValue Dest = Op.getOperand(2);
1959   SDLoc DL(Op);
1960 
1961   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1962   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
1963 
1964   // Return if flag is not set by a floating point comparison.
1965   if (CondRes.getOpcode() != MipsISD::FPCmp)
1966     return Op;
1967 
1968   SDValue CCNode  = CondRes.getOperand(2);
1969   Mips::CondCode CC =
1970     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
1971   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
1972   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
1973   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
1974   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
1975                      FCC0, Dest, CondRes);
1976 }
1977 
1978 SDValue MipsTargetLowering::
1979 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
1980 {
1981   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1982   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
1983 
1984   // Return if flag is not set by a floating point comparison.
1985   if (Cond.getOpcode() != MipsISD::FPCmp)
1986     return Op;
1987 
1988   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
1989                       SDLoc(Op));
1990 }
1991 
1992 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
1993   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1994   SDValue Cond = createFPCmp(DAG, Op);
1995 
1996   assert(Cond.getOpcode() == MipsISD::FPCmp &&
1997          "Floating point operand expected.");
1998 
1999   SDLoc DL(Op);
2000   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
2001   SDValue False = DAG.getConstant(0, DL, MVT::i32);
2002 
2003   return createCMovFP(DAG, Cond, True, False, DL);
2004 }
2005 
2006 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
2007                                                SelectionDAG &DAG) const {
2008   EVT Ty = Op.getValueType();
2009   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
2010   const GlobalValue *GV = N->getGlobal();
2011 
2012   if (!isPositionIndependent()) {
2013     const MipsTargetObjectFile *TLOF =
2014         static_cast<const MipsTargetObjectFile *>(
2015             getTargetMachine().getObjFileLowering());
2016     const GlobalObject *GO = GV->getBaseObject();
2017     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
2018       // %gp_rel relocation
2019       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2020 
2021                                  // %hi/%lo relocation
2022     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2023                                  // %highest/%higher/%hi/%lo relocation
2024                                  : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2025   }
2026 
2027   // Every other architecture would use shouldAssumeDSOLocal in here, but
2028   // mips is special.
2029   // * In PIC code mips requires got loads even for local statics!
2030   // * To save on got entries, for local statics the got entry contains the
2031   //   page and an additional add instruction takes care of the low bits.
2032   // * It is legal to access a hidden symbol with a non hidden undefined,
2033   //   so one cannot guarantee that all access to a hidden symbol will know
2034   //   it is hidden.
2035   // * Mips linkers don't support creating a page and a full got entry for
2036   //   the same symbol.
2037   // * Given all that, we have to use a full got entry for hidden symbols :-(
2038   if (GV->hasLocalLinkage())
2039     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2040 
2041   if (LargeGOT)
2042     return getAddrGlobalLargeGOT(
2043         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
2044         DAG.getEntryNode(),
2045         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2046 
2047   return getAddrGlobal(
2048       N, SDLoc(N), Ty, DAG,
2049       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
2050       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
2051 }
2052 
2053 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
2054                                               SelectionDAG &DAG) const {
2055   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
2056   EVT Ty = Op.getValueType();
2057 
2058   if (!isPositionIndependent())
2059     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2060                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2061 
2062   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2063 }
2064 
2065 SDValue MipsTargetLowering::
2066 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
2067 {
2068   // If the relocation model is PIC, use the General Dynamic TLS Model or
2069   // Local Dynamic TLS model, otherwise use the Initial Exec or
2070   // Local Exec TLS Model.
2071 
2072   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
2073   if (DAG.getTarget().useEmulatedTLS())
2074     return LowerToTLSEmulatedModel(GA, DAG);
2075 
2076   SDLoc DL(GA);
2077   const GlobalValue *GV = GA->getGlobal();
2078   EVT PtrVT = getPointerTy(DAG.getDataLayout());
2079 
2080   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
2081 
2082   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
2083     // General Dynamic and Local Dynamic TLS Model.
2084     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
2085                                                       : MipsII::MO_TLSGD;
2086 
2087     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
2088     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
2089                                    getGlobalReg(DAG, PtrVT), TGA);
2090     unsigned PtrSize = PtrVT.getSizeInBits();
2091     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
2092 
2093     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
2094 
2095     ArgListTy Args;
2096     ArgListEntry Entry;
2097     Entry.Node = Argument;
2098     Entry.Ty = PtrTy;
2099     Args.push_back(Entry);
2100 
2101     TargetLowering::CallLoweringInfo CLI(DAG);
2102     CLI.setDebugLoc(DL)
2103         .setChain(DAG.getEntryNode())
2104         .setLibCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
2105     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
2106 
2107     SDValue Ret = CallResult.first;
2108 
2109     if (model != TLSModel::LocalDynamic)
2110       return Ret;
2111 
2112     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2113                                                MipsII::MO_DTPREL_HI);
2114     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
2115     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2116                                                MipsII::MO_DTPREL_LO);
2117     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2118     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
2119     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
2120   }
2121 
2122   SDValue Offset;
2123   if (model == TLSModel::InitialExec) {
2124     // Initial Exec TLS Model
2125     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2126                                              MipsII::MO_GOTTPREL);
2127     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
2128                       TGA);
2129     Offset =
2130         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
2131   } else {
2132     // Local Exec TLS Model
2133     assert(model == TLSModel::LocalExec);
2134     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2135                                                MipsII::MO_TPREL_HI);
2136     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
2137                                                MipsII::MO_TPREL_LO);
2138     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
2139     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
2140     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
2141   }
2142 
2143   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
2144   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
2145 }
2146 
2147 SDValue MipsTargetLowering::
2148 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
2149 {
2150   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
2151   EVT Ty = Op.getValueType();
2152 
2153   if (!isPositionIndependent())
2154     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2155                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2156 
2157   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2158 }
2159 
2160 SDValue MipsTargetLowering::
2161 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
2162 {
2163   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
2164   EVT Ty = Op.getValueType();
2165 
2166   if (!isPositionIndependent()) {
2167     const MipsTargetObjectFile *TLOF =
2168         static_cast<const MipsTargetObjectFile *>(
2169             getTargetMachine().getObjFileLowering());
2170 
2171     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
2172                                        getTargetMachine()))
2173       // %gp_rel relocation
2174       return getAddrGPRel(N, SDLoc(N), Ty, DAG, ABI.IsN64());
2175 
2176     return Subtarget.hasSym32() ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
2177                                 : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
2178   }
2179 
2180  return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
2181 }
2182 
2183 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
2184   MachineFunction &MF = DAG.getMachineFunction();
2185   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2186 
2187   SDLoc DL(Op);
2188   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
2189                                  getPointerTy(MF.getDataLayout()));
2190 
2191   // vastart just stores the address of the VarArgsFrameIndex slot into the
2192   // memory location argument.
2193   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
2194   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
2195                       MachinePointerInfo(SV));
2196 }
2197 
2198 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
2199   SDNode *Node = Op.getNode();
2200   EVT VT = Node->getValueType(0);
2201   SDValue Chain = Node->getOperand(0);
2202   SDValue VAListPtr = Node->getOperand(1);
2203   unsigned Align = Node->getConstantOperandVal(3);
2204   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
2205   SDLoc DL(Node);
2206   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
2207 
2208   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
2209                                    VAListPtr, MachinePointerInfo(SV));
2210   SDValue VAList = VAListLoad;
2211 
2212   // Re-align the pointer if necessary.
2213   // It should only ever be necessary for 64-bit types on O32 since the minimum
2214   // argument alignment is the same as the maximum type alignment for N32/N64.
2215   //
2216   // FIXME: We currently align too often. The code generator doesn't notice
2217   //        when the pointer is still aligned from the last va_arg (or pair of
2218   //        va_args for the i64 on O32 case).
2219   if (Align > getMinStackArgumentAlignment()) {
2220     assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
2221 
2222     VAList = DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2223                          DAG.getConstant(Align - 1, DL, VAList.getValueType()));
2224 
2225     VAList = DAG.getNode(ISD::AND, DL, VAList.getValueType(), VAList,
2226                          DAG.getConstant(-(int64_t)Align, DL,
2227                                          VAList.getValueType()));
2228   }
2229 
2230   // Increment the pointer, VAList, to the next vaarg.
2231   auto &TD = DAG.getDataLayout();
2232   unsigned ArgSizeInBytes =
2233       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
2234   SDValue Tmp3 =
2235       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
2236                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
2237                                   DL, VAList.getValueType()));
2238   // Store the incremented VAList to the legalized pointer
2239   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
2240                        MachinePointerInfo(SV));
2241 
2242   // In big-endian mode we must adjust the pointer when the load size is smaller
2243   // than the argument slot size. We must also reduce the known alignment to
2244   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
2245   // the correct half of the slot, and reduce the alignment from 8 (slot
2246   // alignment) down to 4 (type alignment).
2247   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2248     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2249     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2250                          DAG.getIntPtrConstant(Adjustment, DL));
2251   }
2252   // Load the actual argument out of the pointer VAList
2253   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2254 }
2255 
2256 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2257                                 bool HasExtractInsert) {
2258   EVT TyX = Op.getOperand(0).getValueType();
2259   EVT TyY = Op.getOperand(1).getValueType();
2260   SDLoc DL(Op);
2261   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2262   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2263   SDValue Res;
2264 
2265   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2266   // to i32.
2267   SDValue X = (TyX == MVT::f32) ?
2268     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2269     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2270                 Const1);
2271   SDValue Y = (TyY == MVT::f32) ?
2272     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2273     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2274                 Const1);
2275 
2276   if (HasExtractInsert) {
2277     // ext  E, Y, 31, 1  ; extract bit31 of Y
2278     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2279     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2280     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2281   } else {
2282     // sll SllX, X, 1
2283     // srl SrlX, SllX, 1
2284     // srl SrlY, Y, 31
2285     // sll SllY, SrlX, 31
2286     // or  Or, SrlX, SllY
2287     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2288     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2289     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2290     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2291     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2292   }
2293 
2294   if (TyX == MVT::f32)
2295     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2296 
2297   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2298                              Op.getOperand(0),
2299                              DAG.getConstant(0, DL, MVT::i32));
2300   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2301 }
2302 
2303 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2304                                 bool HasExtractInsert) {
2305   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2306   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2307   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2308   SDLoc DL(Op);
2309   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2310 
2311   // Bitcast to integer nodes.
2312   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2313   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2314 
2315   if (HasExtractInsert) {
2316     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2317     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2318     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2319                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2320 
2321     if (WidthX > WidthY)
2322       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2323     else if (WidthY > WidthX)
2324       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2325 
2326     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2327                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2328                             X);
2329     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2330   }
2331 
2332   // (d)sll SllX, X, 1
2333   // (d)srl SrlX, SllX, 1
2334   // (d)srl SrlY, Y, width(Y)-1
2335   // (d)sll SllY, SrlX, width(Y)-1
2336   // or     Or, SrlX, SllY
2337   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2338   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2339   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2340                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2341 
2342   if (WidthX > WidthY)
2343     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2344   else if (WidthY > WidthX)
2345     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2346 
2347   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2348                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2349   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2350   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2351 }
2352 
2353 SDValue
2354 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2355   if (Subtarget.isGP64bit())
2356     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2357 
2358   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2359 }
2360 
2361 SDValue MipsTargetLowering::
2362 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2363   // check the depth
2364   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2365          "Frame address can only be determined for current frame.");
2366 
2367   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2368   MFI.setFrameAddressIsTaken(true);
2369   EVT VT = Op.getValueType();
2370   SDLoc DL(Op);
2371   SDValue FrameAddr = DAG.getCopyFromReg(
2372       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2373   return FrameAddr;
2374 }
2375 
2376 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2377                                             SelectionDAG &DAG) const {
2378   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2379     return SDValue();
2380 
2381   // check the depth
2382   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2383          "Return address can be determined only for current frame.");
2384 
2385   MachineFunction &MF = DAG.getMachineFunction();
2386   MachineFrameInfo &MFI = MF.getFrameInfo();
2387   MVT VT = Op.getSimpleValueType();
2388   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2389   MFI.setReturnAddressIsTaken(true);
2390 
2391   // Return RA, which contains the return address. Mark it an implicit live-in.
2392   unsigned Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2393   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2394 }
2395 
2396 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2397 // generated from __builtin_eh_return (offset, handler)
2398 // The effect of this is to adjust the stack pointer by "offset"
2399 // and then branch to "handler".
2400 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2401                                                                      const {
2402   MachineFunction &MF = DAG.getMachineFunction();
2403   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2404 
2405   MipsFI->setCallsEhReturn();
2406   SDValue Chain     = Op.getOperand(0);
2407   SDValue Offset    = Op.getOperand(1);
2408   SDValue Handler   = Op.getOperand(2);
2409   SDLoc DL(Op);
2410   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2411 
2412   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2413   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2414   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2415   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2416   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2417   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2418   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2419                      DAG.getRegister(OffsetReg, Ty),
2420                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2421                      Chain.getValue(1));
2422 }
2423 
2424 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2425                                               SelectionDAG &DAG) const {
2426   // FIXME: Need pseudo-fence for 'singlethread' fences
2427   // FIXME: Set SType for weaker fences where supported/appropriate.
2428   unsigned SType = 0;
2429   SDLoc DL(Op);
2430   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2431                      DAG.getConstant(SType, DL, MVT::i32));
2432 }
2433 
2434 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2435                                                 SelectionDAG &DAG) const {
2436   SDLoc DL(Op);
2437   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2438 
2439   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2440   SDValue Shamt = Op.getOperand(2);
2441   // if shamt < (VT.bits):
2442   //  lo = (shl lo, shamt)
2443   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2444   // else:
2445   //  lo = 0
2446   //  hi = (shl lo, shamt[4:0])
2447   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2448                             DAG.getConstant(-1, DL, MVT::i32));
2449   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2450                                       DAG.getConstant(1, DL, VT));
2451   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2452   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2453   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2454   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2455   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2456                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2457   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2458                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2459   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2460 
2461   SDValue Ops[2] = {Lo, Hi};
2462   return DAG.getMergeValues(Ops, DL);
2463 }
2464 
2465 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2466                                                  bool IsSRA) const {
2467   SDLoc DL(Op);
2468   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2469   SDValue Shamt = Op.getOperand(2);
2470   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2471 
2472   // if shamt < (VT.bits):
2473   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2474   //  if isSRA:
2475   //    hi = (sra hi, shamt)
2476   //  else:
2477   //    hi = (srl hi, shamt)
2478   // else:
2479   //  if isSRA:
2480   //   lo = (sra hi, shamt[4:0])
2481   //   hi = (sra hi, 31)
2482   //  else:
2483   //   lo = (srl hi, shamt[4:0])
2484   //   hi = 0
2485   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2486                             DAG.getConstant(-1, DL, MVT::i32));
2487   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2488                                      DAG.getConstant(1, DL, VT));
2489   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2490   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2491   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2492   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2493                                      DL, VT, Hi, Shamt);
2494   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2495                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2496   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2497                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2498   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2499   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2500                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2501 
2502   SDValue Ops[2] = {Lo, Hi};
2503   return DAG.getMergeValues(Ops, DL);
2504 }
2505 
2506 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2507                             SDValue Chain, SDValue Src, unsigned Offset) {
2508   SDValue Ptr = LD->getBasePtr();
2509   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2510   EVT BasePtrVT = Ptr.getValueType();
2511   SDLoc DL(LD);
2512   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2513 
2514   if (Offset)
2515     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2516                       DAG.getConstant(Offset, DL, BasePtrVT));
2517 
2518   SDValue Ops[] = { Chain, Ptr, Src };
2519   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2520                                  LD->getMemOperand());
2521 }
2522 
2523 // Expand an unaligned 32 or 64-bit integer load node.
2524 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2525   LoadSDNode *LD = cast<LoadSDNode>(Op);
2526   EVT MemVT = LD->getMemoryVT();
2527 
2528   if (Subtarget.systemSupportsUnalignedAccess())
2529     return Op;
2530 
2531   // Return if load is aligned or if MemVT is neither i32 nor i64.
2532   if ((LD->getAlignment() >= MemVT.getSizeInBits() / 8) ||
2533       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2534     return SDValue();
2535 
2536   bool IsLittle = Subtarget.isLittle();
2537   EVT VT = Op.getValueType();
2538   ISD::LoadExtType ExtType = LD->getExtensionType();
2539   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2540 
2541   assert((VT == MVT::i32) || (VT == MVT::i64));
2542 
2543   // Expand
2544   //  (set dst, (i64 (load baseptr)))
2545   // to
2546   //  (set tmp, (ldl (add baseptr, 7), undef))
2547   //  (set dst, (ldr baseptr, tmp))
2548   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2549     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2550                                IsLittle ? 7 : 0);
2551     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2552                         IsLittle ? 0 : 7);
2553   }
2554 
2555   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2556                              IsLittle ? 3 : 0);
2557   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2558                              IsLittle ? 0 : 3);
2559 
2560   // Expand
2561   //  (set dst, (i32 (load baseptr))) or
2562   //  (set dst, (i64 (sextload baseptr))) or
2563   //  (set dst, (i64 (extload baseptr)))
2564   // to
2565   //  (set tmp, (lwl (add baseptr, 3), undef))
2566   //  (set dst, (lwr baseptr, tmp))
2567   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2568       (ExtType == ISD::EXTLOAD))
2569     return LWR;
2570 
2571   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2572 
2573   // Expand
2574   //  (set dst, (i64 (zextload baseptr)))
2575   // to
2576   //  (set tmp0, (lwl (add baseptr, 3), undef))
2577   //  (set tmp1, (lwr baseptr, tmp0))
2578   //  (set tmp2, (shl tmp1, 32))
2579   //  (set dst, (srl tmp2, 32))
2580   SDLoc DL(LD);
2581   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2582   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2583   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2584   SDValue Ops[] = { SRL, LWR.getValue(1) };
2585   return DAG.getMergeValues(Ops, DL);
2586 }
2587 
2588 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2589                              SDValue Chain, unsigned Offset) {
2590   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2591   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2592   SDLoc DL(SD);
2593   SDVTList VTList = DAG.getVTList(MVT::Other);
2594 
2595   if (Offset)
2596     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2597                       DAG.getConstant(Offset, DL, BasePtrVT));
2598 
2599   SDValue Ops[] = { Chain, Value, Ptr };
2600   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2601                                  SD->getMemOperand());
2602 }
2603 
2604 // Expand an unaligned 32 or 64-bit integer store node.
2605 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2606                                       bool IsLittle) {
2607   SDValue Value = SD->getValue(), Chain = SD->getChain();
2608   EVT VT = Value.getValueType();
2609 
2610   // Expand
2611   //  (store val, baseptr) or
2612   //  (truncstore val, baseptr)
2613   // to
2614   //  (swl val, (add baseptr, 3))
2615   //  (swr val, baseptr)
2616   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2617     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2618                                 IsLittle ? 3 : 0);
2619     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2620   }
2621 
2622   assert(VT == MVT::i64);
2623 
2624   // Expand
2625   //  (store val, baseptr)
2626   // to
2627   //  (sdl val, (add baseptr, 7))
2628   //  (sdr val, baseptr)
2629   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2630   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2631 }
2632 
2633 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2634 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG) {
2635   SDValue Val = SD->getValue();
2636 
2637   if (Val.getOpcode() != ISD::FP_TO_SINT)
2638     return SDValue();
2639 
2640   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2641   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2642                            Val.getOperand(0));
2643   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2644                       SD->getPointerInfo(), SD->getAlignment(),
2645                       SD->getMemOperand()->getFlags());
2646 }
2647 
2648 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2649   StoreSDNode *SD = cast<StoreSDNode>(Op);
2650   EVT MemVT = SD->getMemoryVT();
2651 
2652   // Lower unaligned integer stores.
2653   if (!Subtarget.systemSupportsUnalignedAccess() &&
2654       (SD->getAlignment() < MemVT.getSizeInBits() / 8) &&
2655       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2656     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2657 
2658   return lowerFP_TO_SINT_STORE(SD, DAG);
2659 }
2660 
2661 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2662                                               SelectionDAG &DAG) const {
2663 
2664   // Return a fixed StackObject with offset 0 which points to the old stack
2665   // pointer.
2666   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2667   EVT ValTy = Op->getValueType(0);
2668   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2669   return DAG.getFrameIndex(FI, ValTy);
2670 }
2671 
2672 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2673                                             SelectionDAG &DAG) const {
2674   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2675   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2676                               Op.getOperand(0));
2677   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2678 }
2679 
2680 //===----------------------------------------------------------------------===//
2681 //                      Calling Convention Implementation
2682 //===----------------------------------------------------------------------===//
2683 
2684 //===----------------------------------------------------------------------===//
2685 // TODO: Implement a generic logic using tblgen that can support this.
2686 // Mips O32 ABI rules:
2687 // ---
2688 // i32 - Passed in A0, A1, A2, A3 and stack
2689 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2690 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2691 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2692 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2693 //       not used, it must be shadowed. If only A3 is available, shadow it and
2694 //       go to stack.
2695 // vXiX - Received as scalarized i32s, passed in A0 - A3 and the stack.
2696 // vXf32 - Passed in either a pair of registers {A0, A1}, {A2, A3} or {A0 - A3}
2697 //         with the remainder spilled to the stack.
2698 // vXf64 - Passed in either {A0, A1, A2, A3} or {A2, A3} and in both cases
2699 //         spilling the remainder to the stack.
2700 //
2701 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2702 //===----------------------------------------------------------------------===//
2703 
2704 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2705                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2706                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2707   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2708       State.getMachineFunction().getSubtarget());
2709 
2710   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2711 
2712   const MipsCCState * MipsState = static_cast<MipsCCState *>(&State);
2713 
2714   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2715 
2716   static const MCPhysReg FloatVectorIntRegs[] = { Mips::A0, Mips::A2 };
2717 
2718   // Do not process byval args here.
2719   if (ArgFlags.isByVal())
2720     return true;
2721 
2722   // Promote i8 and i16
2723   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2724     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2725       LocVT = MVT::i32;
2726       if (ArgFlags.isSExt())
2727         LocInfo = CCValAssign::SExtUpper;
2728       else if (ArgFlags.isZExt())
2729         LocInfo = CCValAssign::ZExtUpper;
2730       else
2731         LocInfo = CCValAssign::AExtUpper;
2732     }
2733   }
2734 
2735   // Promote i8 and i16
2736   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2737     LocVT = MVT::i32;
2738     if (ArgFlags.isSExt())
2739       LocInfo = CCValAssign::SExt;
2740     else if (ArgFlags.isZExt())
2741       LocInfo = CCValAssign::ZExt;
2742     else
2743       LocInfo = CCValAssign::AExt;
2744   }
2745 
2746   unsigned Reg;
2747 
2748   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2749   // is true: function is vararg, argument is 3rd or higher, there is previous
2750   // argument which is not f32 or f64.
2751   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2752                                 State.getFirstUnallocated(F32Regs) != ValNo;
2753   unsigned OrigAlign = ArgFlags.getOrigAlign();
2754   bool isI64 = (ValVT == MVT::i32 && OrigAlign == 8);
2755   bool isVectorFloat = MipsState->WasOriginalArgVectorFloat(ValNo);
2756 
2757   // The MIPS vector ABI for floats passes them in a pair of registers
2758   if (ValVT == MVT::i32 && isVectorFloat) {
2759     // This is the start of an vector that was scalarized into an unknown number
2760     // of components. It doesn't matter how many there are. Allocate one of the
2761     // notional 8 byte aligned registers which map onto the argument stack, and
2762     // shadow the register lost to alignment requirements.
2763     if (ArgFlags.isSplit()) {
2764       Reg = State.AllocateReg(FloatVectorIntRegs);
2765       if (Reg == Mips::A2)
2766         State.AllocateReg(Mips::A1);
2767       else if (Reg == 0)
2768         State.AllocateReg(Mips::A3);
2769     } else {
2770       // If we're an intermediate component of the split, we can just attempt to
2771       // allocate a register directly.
2772       Reg = State.AllocateReg(IntRegs);
2773     }
2774   } else if (ValVT == MVT::i32 || (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2775     Reg = State.AllocateReg(IntRegs);
2776     // If this is the first part of an i64 arg,
2777     // the allocated register must be either A0 or A2.
2778     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2779       Reg = State.AllocateReg(IntRegs);
2780     LocVT = MVT::i32;
2781   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2782     // Allocate int register and shadow next int register. If first
2783     // available register is Mips::A1 or Mips::A3, shadow it too.
2784     Reg = State.AllocateReg(IntRegs);
2785     if (Reg == Mips::A1 || Reg == Mips::A3)
2786       Reg = State.AllocateReg(IntRegs);
2787     State.AllocateReg(IntRegs);
2788     LocVT = MVT::i32;
2789   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2790     // we are guaranteed to find an available float register
2791     if (ValVT == MVT::f32) {
2792       Reg = State.AllocateReg(F32Regs);
2793       // Shadow int register
2794       State.AllocateReg(IntRegs);
2795     } else {
2796       Reg = State.AllocateReg(F64Regs);
2797       // Shadow int registers
2798       unsigned Reg2 = State.AllocateReg(IntRegs);
2799       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2800         State.AllocateReg(IntRegs);
2801       State.AllocateReg(IntRegs);
2802     }
2803   } else
2804     llvm_unreachable("Cannot handle this ValVT.");
2805 
2806   if (!Reg) {
2807     unsigned Offset = State.AllocateStack(ValVT.getStoreSize(), OrigAlign);
2808     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2809   } else
2810     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2811 
2812   return false;
2813 }
2814 
2815 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2816                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2817                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2818   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2819 
2820   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2821 }
2822 
2823 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2824                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2825                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2826   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2827 
2828   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2829 }
2830 
2831 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2832                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2833                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2834 
2835 #include "MipsGenCallingConv.inc"
2836 
2837  CCAssignFn *MipsTargetLowering::CCAssignFnForCall() const{
2838    return CC_Mips;
2839  }
2840 
2841  CCAssignFn *MipsTargetLowering::CCAssignFnForReturn() const{
2842    return RetCC_Mips;
2843  }
2844 //===----------------------------------------------------------------------===//
2845 //                  Call Calling Convention Implementation
2846 //===----------------------------------------------------------------------===//
2847 
2848 // Return next O32 integer argument register.
2849 static unsigned getNextIntArgReg(unsigned Reg) {
2850   assert((Reg == Mips::A0) || (Reg == Mips::A2));
2851   return (Reg == Mips::A0) ? Mips::A1 : Mips::A3;
2852 }
2853 
2854 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
2855                                            SDValue Chain, SDValue Arg,
2856                                            const SDLoc &DL, bool IsTailCall,
2857                                            SelectionDAG &DAG) const {
2858   if (!IsTailCall) {
2859     SDValue PtrOff =
2860         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
2861                     DAG.getIntPtrConstant(Offset, DL));
2862     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
2863   }
2864 
2865   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2866   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
2867   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
2868   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(),
2869                       /* Alignment = */ 0, MachineMemOperand::MOVolatile);
2870 }
2871 
2872 void MipsTargetLowering::
2873 getOpndList(SmallVectorImpl<SDValue> &Ops,
2874             std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
2875             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
2876             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
2877             SDValue Chain) const {
2878   // Insert node "GP copy globalreg" before call to function.
2879   //
2880   // R_MIPS_CALL* operators (emitted when non-internal functions are called
2881   // in PIC mode) allow symbols to be resolved via lazy binding.
2882   // The lazy binding stub requires GP to point to the GOT.
2883   // Note that we don't need GP to point to the GOT for indirect calls
2884   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
2885   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
2886   // used for the function (that is, Mips linker doesn't generate lazy binding
2887   // stub for a function whose address is taken in the program).
2888   if (IsPICCall && !InternalLinkage && IsCallReloc) {
2889     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
2890     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2891     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
2892   }
2893 
2894   // Build a sequence of copy-to-reg nodes chained together with token
2895   // chain and flag operands which copy the outgoing args into registers.
2896   // The InFlag in necessary since all emitted instructions must be
2897   // stuck together.
2898   SDValue InFlag;
2899 
2900   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2901     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, RegsToPass[i].first,
2902                                  RegsToPass[i].second, InFlag);
2903     InFlag = Chain.getValue(1);
2904   }
2905 
2906   // Add argument registers to the end of the list so that they are
2907   // known live into the call.
2908   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2909     Ops.push_back(CLI.DAG.getRegister(RegsToPass[i].first,
2910                                       RegsToPass[i].second.getValueType()));
2911 
2912   // Add a register mask operand representing the call-preserved registers.
2913   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
2914   const uint32_t *Mask =
2915       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
2916   assert(Mask && "Missing call preserved mask for calling convention");
2917   if (Subtarget.inMips16HardFloat()) {
2918     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
2919       StringRef Sym = G->getGlobal()->getName();
2920       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
2921       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
2922         Mask = MipsRegisterInfo::getMips16RetHelperMask();
2923       }
2924     }
2925   }
2926   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
2927 
2928   if (InFlag.getNode())
2929     Ops.push_back(InFlag);
2930 }
2931 
2932 /// LowerCall - functions arguments are copied from virtual regs to
2933 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
2934 SDValue
2935 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
2936                               SmallVectorImpl<SDValue> &InVals) const {
2937   SelectionDAG &DAG                     = CLI.DAG;
2938   SDLoc DL                              = CLI.DL;
2939   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
2940   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
2941   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
2942   SDValue Chain                         = CLI.Chain;
2943   SDValue Callee                        = CLI.Callee;
2944   bool &IsTailCall                      = CLI.IsTailCall;
2945   CallingConv::ID CallConv              = CLI.CallConv;
2946   bool IsVarArg                         = CLI.IsVarArg;
2947 
2948   MachineFunction &MF = DAG.getMachineFunction();
2949   MachineFrameInfo &MFI = MF.getFrameInfo();
2950   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
2951   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2952   bool IsPIC = isPositionIndependent();
2953 
2954   // Analyze operands of the call, assigning locations to each operand.
2955   SmallVector<CCValAssign, 16> ArgLocs;
2956   MipsCCState CCInfo(
2957       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
2958       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
2959 
2960   const ExternalSymbolSDNode *ES =
2961       dyn_cast_or_null<const ExternalSymbolSDNode>(Callee.getNode());
2962 
2963   // There is one case where CALLSEQ_START..CALLSEQ_END can be nested, which
2964   // is during the lowering of a call with a byval argument which produces
2965   // a call to memcpy. For the O32 case, this causes the caller to allocate
2966   // stack space for the reserved argument area for the callee, then recursively
2967   // again for the memcpy call. In the NEWABI case, this doesn't occur as those
2968   // ABIs mandate that the callee allocates the reserved argument area. We do
2969   // still produce nested CALLSEQ_START..CALLSEQ_END with zero space though.
2970   //
2971   // If the callee has a byval argument and memcpy is used, we are mandated
2972   // to already have produced a reserved argument area for the callee for O32.
2973   // Therefore, the reserved argument area can be reused for both calls.
2974   //
2975   // Other cases of calling memcpy cannot have a chain with a CALLSEQ_START
2976   // present, as we have yet to hook that node onto the chain.
2977   //
2978   // Hence, the CALLSEQ_START and CALLSEQ_END nodes can be eliminated in this
2979   // case. GCC does a similar trick, in that wherever possible, it calculates
2980   // the maximum out going argument area (including the reserved area), and
2981   // preallocates the stack space on entrance to the caller.
2982   //
2983   // FIXME: We should do the same for efficency and space.
2984 
2985   // Note: The check on the calling convention below must match
2986   //       MipsABIInfo::GetCalleeAllocdArgSizeInBytes().
2987   bool MemcpyInByVal = ES &&
2988                        StringRef(ES->getSymbol()) == StringRef("memcpy") &&
2989                        CallConv != CallingConv::Fast &&
2990                        Chain.getOpcode() == ISD::CALLSEQ_START;
2991 
2992   // Allocate the reserved argument area. It seems strange to do this from the
2993   // caller side but removing it breaks the frame size calculation.
2994   unsigned ReservedArgArea =
2995       MemcpyInByVal ? 0 : ABI.GetCalleeAllocdArgSizeInBytes(CallConv);
2996   CCInfo.AllocateStack(ReservedArgArea, 1);
2997 
2998   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(),
2999                              ES ? ES->getSymbol() : nullptr);
3000 
3001   // Get a count of how many bytes are to be pushed on the stack.
3002   unsigned NextStackOffset = CCInfo.getNextStackOffset();
3003 
3004   // Check if it's really possible to do a tail call. Restrict it to functions
3005   // that are part of this compilation unit.
3006   bool InternalLinkage = false;
3007   if (IsTailCall) {
3008     IsTailCall = isEligibleForTailCallOptimization(
3009         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
3010      if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3011       InternalLinkage = G->getGlobal()->hasInternalLinkage();
3012       IsTailCall &= (InternalLinkage || G->getGlobal()->hasLocalLinkage() ||
3013                      G->getGlobal()->hasPrivateLinkage() ||
3014                      G->getGlobal()->hasHiddenVisibility() ||
3015                      G->getGlobal()->hasProtectedVisibility());
3016      }
3017   }
3018   if (!IsTailCall && CLI.CS && CLI.CS.isMustTailCall())
3019     report_fatal_error("failed to perform tail call elimination on a call "
3020                        "site marked musttail");
3021 
3022   if (IsTailCall)
3023     ++NumTailCalls;
3024 
3025   // Chain is the output chain of the last Load/Store or CopyToReg node.
3026   // ByValChain is the output chain of the last Memcpy node created for copying
3027   // byval arguments to the stack.
3028   unsigned StackAlignment = TFL->getStackAlignment();
3029   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
3030   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
3031 
3032   if (!(IsTailCall || MemcpyInByVal))
3033     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffset, 0, DL);
3034 
3035   SDValue StackPtr =
3036       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
3037                          getPointerTy(DAG.getDataLayout()));
3038 
3039   std::deque<std::pair<unsigned, SDValue>> RegsToPass;
3040   SmallVector<SDValue, 8> MemOpChains;
3041 
3042   CCInfo.rewindByValRegsInfo();
3043 
3044   // Walk the register/memloc assignments, inserting copies/loads.
3045   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3046     SDValue Arg = OutVals[i];
3047     CCValAssign &VA = ArgLocs[i];
3048     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
3049     ISD::ArgFlagsTy Flags = Outs[i].Flags;
3050     bool UseUpperBits = false;
3051 
3052     // ByVal Arg.
3053     if (Flags.isByVal()) {
3054       unsigned FirstByValReg, LastByValReg;
3055       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3056       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3057 
3058       assert(Flags.getByValSize() &&
3059              "ByVal args of size 0 should have been ignored by front-end.");
3060       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3061       assert(!IsTailCall &&
3062              "Do not tail-call optimize if there is a byval argument.");
3063       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
3064                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
3065                    VA);
3066       CCInfo.nextInRegsParam();
3067       continue;
3068     }
3069 
3070     // Promote the value if needed.
3071     switch (VA.getLocInfo()) {
3072     default:
3073       llvm_unreachable("Unknown loc info!");
3074     case CCValAssign::Full:
3075       if (VA.isRegLoc()) {
3076         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
3077             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
3078             (ValVT == MVT::i64 && LocVT == MVT::f64))
3079           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3080         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
3081           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3082                                    Arg, DAG.getConstant(0, DL, MVT::i32));
3083           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
3084                                    Arg, DAG.getConstant(1, DL, MVT::i32));
3085           if (!Subtarget.isLittle())
3086             std::swap(Lo, Hi);
3087           unsigned LocRegLo = VA.getLocReg();
3088           unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
3089           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
3090           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
3091           continue;
3092         }
3093       }
3094       break;
3095     case CCValAssign::BCvt:
3096       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
3097       break;
3098     case CCValAssign::SExtUpper:
3099       UseUpperBits = true;
3100       LLVM_FALLTHROUGH;
3101     case CCValAssign::SExt:
3102       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
3103       break;
3104     case CCValAssign::ZExtUpper:
3105       UseUpperBits = true;
3106       LLVM_FALLTHROUGH;
3107     case CCValAssign::ZExt:
3108       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
3109       break;
3110     case CCValAssign::AExtUpper:
3111       UseUpperBits = true;
3112       LLVM_FALLTHROUGH;
3113     case CCValAssign::AExt:
3114       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
3115       break;
3116     }
3117 
3118     if (UseUpperBits) {
3119       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3120       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3121       Arg = DAG.getNode(
3122           ISD::SHL, DL, VA.getLocVT(), Arg,
3123           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3124     }
3125 
3126     // Arguments that can be passed on register must be kept at
3127     // RegsToPass vector
3128     if (VA.isRegLoc()) {
3129       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
3130       continue;
3131     }
3132 
3133     // Register can't get to this point...
3134     assert(VA.isMemLoc());
3135 
3136     // emit ISD::STORE whichs stores the
3137     // parameter value to a stack Location
3138     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
3139                                          Chain, Arg, DL, IsTailCall, DAG));
3140   }
3141 
3142   // Transform all store nodes into one single node because all store
3143   // nodes are independent of each other.
3144   if (!MemOpChains.empty())
3145     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
3146 
3147   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
3148   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
3149   // node so that legalize doesn't hack it.
3150 
3151   EVT Ty = Callee.getValueType();
3152   bool GlobalOrExternal = false, IsCallReloc = false;
3153 
3154   // The long-calls feature is ignored in case of PIC.
3155   // While we do not support -mshared / -mno-shared properly,
3156   // ignore long-calls in case of -mabicalls too.
3157   if (!Subtarget.isABICalls() && !IsPIC) {
3158     // If the function should be called using "long call",
3159     // get its address into a register to prevent using
3160     // of the `jal` instruction for the direct call.
3161     if (auto *N = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3162       if (Subtarget.useLongCalls())
3163         Callee = Subtarget.hasSym32()
3164                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3165                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3166     } else if (auto *N = dyn_cast<GlobalAddressSDNode>(Callee)) {
3167       bool UseLongCalls = Subtarget.useLongCalls();
3168       // If the function has long-call/far/near attribute
3169       // it overrides command line switch pased to the backend.
3170       if (auto *F = dyn_cast<Function>(N->getGlobal())) {
3171         if (F->hasFnAttribute("long-call"))
3172           UseLongCalls = true;
3173         else if (F->hasFnAttribute("short-call"))
3174           UseLongCalls = false;
3175       }
3176       if (UseLongCalls)
3177         Callee = Subtarget.hasSym32()
3178                      ? getAddrNonPIC(N, SDLoc(N), Ty, DAG)
3179                      : getAddrNonPICSym64(N, SDLoc(N), Ty, DAG);
3180     }
3181   }
3182 
3183   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
3184     if (IsPIC) {
3185       const GlobalValue *Val = G->getGlobal();
3186       InternalLinkage = Val->hasInternalLinkage();
3187 
3188       if (InternalLinkage)
3189         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
3190       else if (LargeGOT) {
3191         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3192                                        MipsII::MO_CALL_LO16, Chain,
3193                                        FuncInfo->callPtrInfo(Val));
3194         IsCallReloc = true;
3195       } else {
3196         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3197                                FuncInfo->callPtrInfo(Val));
3198         IsCallReloc = true;
3199       }
3200     } else
3201       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
3202                                           getPointerTy(DAG.getDataLayout()), 0,
3203                                           MipsII::MO_NO_FLAG);
3204     GlobalOrExternal = true;
3205   }
3206   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
3207     const char *Sym = S->getSymbol();
3208 
3209     if (!IsPIC) // static
3210       Callee = DAG.getTargetExternalSymbol(
3211           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
3212     else if (LargeGOT) {
3213       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
3214                                      MipsII::MO_CALL_LO16, Chain,
3215                                      FuncInfo->callPtrInfo(Sym));
3216       IsCallReloc = true;
3217     } else { // PIC
3218       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
3219                              FuncInfo->callPtrInfo(Sym));
3220       IsCallReloc = true;
3221     }
3222 
3223     GlobalOrExternal = true;
3224   }
3225 
3226   SmallVector<SDValue, 8> Ops(1, Chain);
3227   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
3228 
3229   getOpndList(Ops, RegsToPass, IsPIC, GlobalOrExternal, InternalLinkage,
3230               IsCallReloc, CLI, Callee, Chain);
3231 
3232   if (IsTailCall) {
3233     MF.getFrameInfo().setHasTailCall();
3234     return DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
3235   }
3236 
3237   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
3238   SDValue InFlag = Chain.getValue(1);
3239 
3240   // Create the CALLSEQ_END node in the case of where it is not a call to
3241   // memcpy.
3242   if (!(MemcpyInByVal)) {
3243     Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
3244                                DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
3245     InFlag = Chain.getValue(1);
3246   }
3247 
3248   // Handle result values, copying them out of physregs into vregs that we
3249   // return.
3250   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
3251                          InVals, CLI);
3252 }
3253 
3254 /// LowerCallResult - Lower the result values of a call into the
3255 /// appropriate copies out of appropriate physical registers.
3256 SDValue MipsTargetLowering::LowerCallResult(
3257     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
3258     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3259     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
3260     TargetLowering::CallLoweringInfo &CLI) const {
3261   // Assign locations to each value returned by this call.
3262   SmallVector<CCValAssign, 16> RVLocs;
3263   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
3264                      *DAG.getContext());
3265 
3266   const ExternalSymbolSDNode *ES =
3267       dyn_cast_or_null<const ExternalSymbolSDNode>(CLI.Callee.getNode());
3268   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI.RetTy,
3269                            ES ? ES->getSymbol() : nullptr);
3270 
3271   // Copy all of the result registers out of their specified physreg.
3272   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3273     CCValAssign &VA = RVLocs[i];
3274     assert(VA.isRegLoc() && "Can only return in registers!");
3275 
3276     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
3277                                      RVLocs[i].getLocVT(), InFlag);
3278     Chain = Val.getValue(1);
3279     InFlag = Val.getValue(2);
3280 
3281     if (VA.isUpperBitsInLoc()) {
3282       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
3283       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3284       unsigned Shift =
3285           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3286       Val = DAG.getNode(
3287           Shift, DL, VA.getLocVT(), Val,
3288           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3289     }
3290 
3291     switch (VA.getLocInfo()) {
3292     default:
3293       llvm_unreachable("Unknown loc info!");
3294     case CCValAssign::Full:
3295       break;
3296     case CCValAssign::BCvt:
3297       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
3298       break;
3299     case CCValAssign::AExt:
3300     case CCValAssign::AExtUpper:
3301       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3302       break;
3303     case CCValAssign::ZExt:
3304     case CCValAssign::ZExtUpper:
3305       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
3306                         DAG.getValueType(VA.getValVT()));
3307       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3308       break;
3309     case CCValAssign::SExt:
3310     case CCValAssign::SExtUpper:
3311       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
3312                         DAG.getValueType(VA.getValVT()));
3313       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
3314       break;
3315     }
3316 
3317     InVals.push_back(Val);
3318   }
3319 
3320   return Chain;
3321 }
3322 
3323 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
3324                                       EVT ArgVT, const SDLoc &DL,
3325                                       SelectionDAG &DAG) {
3326   MVT LocVT = VA.getLocVT();
3327   EVT ValVT = VA.getValVT();
3328 
3329   // Shift into the upper bits if necessary.
3330   switch (VA.getLocInfo()) {
3331   default:
3332     break;
3333   case CCValAssign::AExtUpper:
3334   case CCValAssign::SExtUpper:
3335   case CCValAssign::ZExtUpper: {
3336     unsigned ValSizeInBits = ArgVT.getSizeInBits();
3337     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3338     unsigned Opcode =
3339         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
3340     Val = DAG.getNode(
3341         Opcode, DL, VA.getLocVT(), Val,
3342         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3343     break;
3344   }
3345   }
3346 
3347   // If this is an value smaller than the argument slot size (32-bit for O32,
3348   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
3349   // size. Extract the value and insert any appropriate assertions regarding
3350   // sign/zero extension.
3351   switch (VA.getLocInfo()) {
3352   default:
3353     llvm_unreachable("Unknown loc info!");
3354   case CCValAssign::Full:
3355     break;
3356   case CCValAssign::AExtUpper:
3357   case CCValAssign::AExt:
3358     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3359     break;
3360   case CCValAssign::SExtUpper:
3361   case CCValAssign::SExt:
3362     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3363     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3364     break;
3365   case CCValAssign::ZExtUpper:
3366   case CCValAssign::ZExt:
3367     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3368     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3369     break;
3370   case CCValAssign::BCvt:
3371     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3372     break;
3373   }
3374 
3375   return Val;
3376 }
3377 
3378 //===----------------------------------------------------------------------===//
3379 //             Formal Arguments Calling Convention Implementation
3380 //===----------------------------------------------------------------------===//
3381 /// LowerFormalArguments - transform physical registers into virtual registers
3382 /// and generate load operations for arguments places on the stack.
3383 SDValue MipsTargetLowering::LowerFormalArguments(
3384     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3385     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3386     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3387   MachineFunction &MF = DAG.getMachineFunction();
3388   MachineFrameInfo &MFI = MF.getFrameInfo();
3389   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3390 
3391   MipsFI->setVarArgsFrameIndex(0);
3392 
3393   // Used with vargs to acumulate store chains.
3394   std::vector<SDValue> OutChains;
3395 
3396   // Assign locations to all of the incoming arguments.
3397   SmallVector<CCValAssign, 16> ArgLocs;
3398   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3399                      *DAG.getContext());
3400   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), 1);
3401   const Function &Func = DAG.getMachineFunction().getFunction();
3402   Function::const_arg_iterator FuncArg = Func.arg_begin();
3403 
3404   if (Func.hasFnAttribute("interrupt") && !Func.arg_empty())
3405     report_fatal_error(
3406         "Functions with the interrupt attribute cannot have arguments!");
3407 
3408   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3409   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3410                            CCInfo.getInRegsParamsCount() > 0);
3411 
3412   unsigned CurArgIdx = 0;
3413   CCInfo.rewindByValRegsInfo();
3414 
3415   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3416     CCValAssign &VA = ArgLocs[i];
3417     if (Ins[i].isOrigArg()) {
3418       std::advance(FuncArg, Ins[i].getOrigArgIndex() - CurArgIdx);
3419       CurArgIdx = Ins[i].getOrigArgIndex();
3420     }
3421     EVT ValVT = VA.getValVT();
3422     ISD::ArgFlagsTy Flags = Ins[i].Flags;
3423     bool IsRegLoc = VA.isRegLoc();
3424 
3425     if (Flags.isByVal()) {
3426       assert(Ins[i].isOrigArg() && "Byval arguments cannot be implicit");
3427       unsigned FirstByValReg, LastByValReg;
3428       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3429       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3430 
3431       assert(Flags.getByValSize() &&
3432              "ByVal args of size 0 should have been ignored by front-end.");
3433       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3434       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3435                     FirstByValReg, LastByValReg, VA, CCInfo);
3436       CCInfo.nextInRegsParam();
3437       continue;
3438     }
3439 
3440     // Arguments stored on registers
3441     if (IsRegLoc) {
3442       MVT RegVT = VA.getLocVT();
3443       unsigned ArgReg = VA.getLocReg();
3444       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3445 
3446       // Transform the arguments stored on
3447       // physical registers into virtual ones
3448       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3449       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3450 
3451       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3452 
3453       // Handle floating point arguments passed in integer registers and
3454       // long double arguments passed in floating point registers.
3455       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3456           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3457           (RegVT == MVT::f64 && ValVT == MVT::i64))
3458         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3459       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3460                ValVT == MVT::f64) {
3461         unsigned Reg2 = addLiveIn(DAG.getMachineFunction(),
3462                                   getNextIntArgReg(ArgReg), RC);
3463         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3464         if (!Subtarget.isLittle())
3465           std::swap(ArgValue, ArgValue2);
3466         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3467                                ArgValue, ArgValue2);
3468       }
3469 
3470       InVals.push_back(ArgValue);
3471     } else { // VA.isRegLoc()
3472       MVT LocVT = VA.getLocVT();
3473 
3474       if (ABI.IsO32()) {
3475         // We ought to be able to use LocVT directly but O32 sets it to i32
3476         // when allocating floating point values to integer registers.
3477         // This shouldn't influence how we load the value into registers unless
3478         // we are targeting softfloat.
3479         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3480           LocVT = VA.getValVT();
3481       }
3482 
3483       // sanity check
3484       assert(VA.isMemLoc());
3485 
3486       // The stack pointer offset is relative to the caller stack frame.
3487       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3488                                      VA.getLocMemOffset(), true);
3489 
3490       // Create load nodes to retrieve arguments from the stack
3491       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3492       SDValue ArgValue = DAG.getLoad(
3493           LocVT, DL, Chain, FIN,
3494           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3495       OutChains.push_back(ArgValue.getValue(1));
3496 
3497       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3498 
3499       InVals.push_back(ArgValue);
3500     }
3501   }
3502 
3503   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3504     // The mips ABIs for returning structs by value requires that we copy
3505     // the sret argument into $v0 for the return. Save the argument into
3506     // a virtual register so that we can access it from the return points.
3507     if (Ins[i].Flags.isSRet()) {
3508       unsigned Reg = MipsFI->getSRetReturnReg();
3509       if (!Reg) {
3510         Reg = MF.getRegInfo().createVirtualRegister(
3511             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3512         MipsFI->setSRetReturnReg(Reg);
3513       }
3514       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3515       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3516       break;
3517     }
3518   }
3519 
3520   if (IsVarArg)
3521     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3522 
3523   // All stores are grouped in one node to allow the matching between
3524   // the size of Ins and InVals. This only happens when on varg functions
3525   if (!OutChains.empty()) {
3526     OutChains.push_back(Chain);
3527     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3528   }
3529 
3530   return Chain;
3531 }
3532 
3533 //===----------------------------------------------------------------------===//
3534 //               Return Value Calling Convention Implementation
3535 //===----------------------------------------------------------------------===//
3536 
3537 bool
3538 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3539                                    MachineFunction &MF, bool IsVarArg,
3540                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3541                                    LLVMContext &Context) const {
3542   SmallVector<CCValAssign, 16> RVLocs;
3543   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3544   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3545 }
3546 
3547 bool
3548 MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const {
3549   if ((ABI.IsN32() || ABI.IsN64()) && Type == MVT::i32)
3550       return true;
3551 
3552   return IsSigned;
3553 }
3554 
3555 SDValue
3556 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3557                                          const SDLoc &DL,
3558                                          SelectionDAG &DAG) const {
3559   MachineFunction &MF = DAG.getMachineFunction();
3560   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3561 
3562   MipsFI->setISR();
3563 
3564   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3565 }
3566 
3567 SDValue
3568 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3569                                 bool IsVarArg,
3570                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3571                                 const SmallVectorImpl<SDValue> &OutVals,
3572                                 const SDLoc &DL, SelectionDAG &DAG) const {
3573   // CCValAssign - represent the assignment of
3574   // the return value to a location
3575   SmallVector<CCValAssign, 16> RVLocs;
3576   MachineFunction &MF = DAG.getMachineFunction();
3577 
3578   // CCState - Info about the registers and stack slot.
3579   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3580 
3581   // Analyze return values.
3582   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3583 
3584   SDValue Flag;
3585   SmallVector<SDValue, 4> RetOps(1, Chain);
3586 
3587   // Copy the result values into the output registers.
3588   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3589     SDValue Val = OutVals[i];
3590     CCValAssign &VA = RVLocs[i];
3591     assert(VA.isRegLoc() && "Can only return in registers!");
3592     bool UseUpperBits = false;
3593 
3594     switch (VA.getLocInfo()) {
3595     default:
3596       llvm_unreachable("Unknown loc info!");
3597     case CCValAssign::Full:
3598       break;
3599     case CCValAssign::BCvt:
3600       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3601       break;
3602     case CCValAssign::AExtUpper:
3603       UseUpperBits = true;
3604       LLVM_FALLTHROUGH;
3605     case CCValAssign::AExt:
3606       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3607       break;
3608     case CCValAssign::ZExtUpper:
3609       UseUpperBits = true;
3610       LLVM_FALLTHROUGH;
3611     case CCValAssign::ZExt:
3612       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3613       break;
3614     case CCValAssign::SExtUpper:
3615       UseUpperBits = true;
3616       LLVM_FALLTHROUGH;
3617     case CCValAssign::SExt:
3618       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3619       break;
3620     }
3621 
3622     if (UseUpperBits) {
3623       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3624       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3625       Val = DAG.getNode(
3626           ISD::SHL, DL, VA.getLocVT(), Val,
3627           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3628     }
3629 
3630     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3631 
3632     // Guarantee that all emitted copies are stuck together with flags.
3633     Flag = Chain.getValue(1);
3634     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3635   }
3636 
3637   // The mips ABIs for returning structs by value requires that we copy
3638   // the sret argument into $v0 for the return. We saved the argument into
3639   // a virtual register in the entry block, so now we copy the value out
3640   // and into $v0.
3641   if (MF.getFunction().hasStructRetAttr()) {
3642     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3643     unsigned Reg = MipsFI->getSRetReturnReg();
3644 
3645     if (!Reg)
3646       llvm_unreachable("sret virtual register not created in the entry block");
3647     SDValue Val =
3648         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3649     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3650 
3651     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3652     Flag = Chain.getValue(1);
3653     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3654   }
3655 
3656   RetOps[0] = Chain;  // Update chain.
3657 
3658   // Add the flag if we have it.
3659   if (Flag.getNode())
3660     RetOps.push_back(Flag);
3661 
3662   // ISRs must use "eret".
3663   if (DAG.getMachineFunction().getFunction().hasFnAttribute("interrupt"))
3664     return LowerInterruptReturn(RetOps, DL, DAG);
3665 
3666   // Standard return on Mips is a "jr $ra"
3667   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3668 }
3669 
3670 //===----------------------------------------------------------------------===//
3671 //                           Mips Inline Assembly Support
3672 //===----------------------------------------------------------------------===//
3673 
3674 /// getConstraintType - Given a constraint letter, return the type of
3675 /// constraint it is for this target.
3676 MipsTargetLowering::ConstraintType
3677 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3678   // Mips specific constraints
3679   // GCC config/mips/constraints.md
3680   //
3681   // 'd' : An address register. Equivalent to r
3682   //       unless generating MIPS16 code.
3683   // 'y' : Equivalent to r; retained for
3684   //       backwards compatibility.
3685   // 'c' : A register suitable for use in an indirect
3686   //       jump. This will always be $25 for -mabicalls.
3687   // 'l' : The lo register. 1 word storage.
3688   // 'x' : The hilo register pair. Double word storage.
3689   if (Constraint.size() == 1) {
3690     switch (Constraint[0]) {
3691       default : break;
3692       case 'd':
3693       case 'y':
3694       case 'f':
3695       case 'c':
3696       case 'l':
3697       case 'x':
3698         return C_RegisterClass;
3699       case 'R':
3700         return C_Memory;
3701     }
3702   }
3703 
3704   if (Constraint == "ZC")
3705     return C_Memory;
3706 
3707   return TargetLowering::getConstraintType(Constraint);
3708 }
3709 
3710 /// Examine constraint type and operand type and determine a weight value.
3711 /// This object must already have been set up with the operand type
3712 /// and the current alternative constraint selected.
3713 TargetLowering::ConstraintWeight
3714 MipsTargetLowering::getSingleConstraintMatchWeight(
3715     AsmOperandInfo &info, const char *constraint) const {
3716   ConstraintWeight weight = CW_Invalid;
3717   Value *CallOperandVal = info.CallOperandVal;
3718     // If we don't have a value, we can't do a match,
3719     // but allow it at the lowest weight.
3720   if (!CallOperandVal)
3721     return CW_Default;
3722   Type *type = CallOperandVal->getType();
3723   // Look at the constraint type.
3724   switch (*constraint) {
3725   default:
3726     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3727     break;
3728   case 'd':
3729   case 'y':
3730     if (type->isIntegerTy())
3731       weight = CW_Register;
3732     break;
3733   case 'f': // FPU or MSA register
3734     if (Subtarget.hasMSA() && type->isVectorTy() &&
3735         cast<VectorType>(type)->getBitWidth() == 128)
3736       weight = CW_Register;
3737     else if (type->isFloatTy())
3738       weight = CW_Register;
3739     break;
3740   case 'c': // $25 for indirect jumps
3741   case 'l': // lo register
3742   case 'x': // hilo register pair
3743     if (type->isIntegerTy())
3744       weight = CW_SpecificReg;
3745     break;
3746   case 'I': // signed 16 bit immediate
3747   case 'J': // integer zero
3748   case 'K': // unsigned 16 bit immediate
3749   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3750   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3751   case 'O': // signed 15 bit immediate (+- 16383)
3752   case 'P': // immediate in the range of 65535 to 1 (inclusive)
3753     if (isa<ConstantInt>(CallOperandVal))
3754       weight = CW_Constant;
3755     break;
3756   case 'R':
3757     weight = CW_Memory;
3758     break;
3759   }
3760   return weight;
3761 }
3762 
3763 /// This is a helper function to parse a physical register string and split it
3764 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
3765 /// that is returned indicates whether parsing was successful. The second flag
3766 /// is true if the numeric part exists.
3767 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
3768                                               unsigned long long &Reg) {
3769   if (C.front() != '{' || C.back() != '}')
3770     return std::make_pair(false, false);
3771 
3772   // Search for the first numeric character.
3773   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
3774   I = std::find_if(B, E, isdigit);
3775 
3776   Prefix = StringRef(B, I - B);
3777 
3778   // The second flag is set to false if no numeric characters were found.
3779   if (I == E)
3780     return std::make_pair(true, false);
3781 
3782   // Parse the numeric characters.
3783   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
3784                         true);
3785 }
3786 
3787 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
3788 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
3789   const TargetRegisterInfo *TRI =
3790       Subtarget.getRegisterInfo();
3791   const TargetRegisterClass *RC;
3792   StringRef Prefix;
3793   unsigned long long Reg;
3794 
3795   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
3796 
3797   if (!R.first)
3798     return std::make_pair(0U, nullptr);
3799 
3800   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
3801     // No numeric characters follow "hi" or "lo".
3802     if (R.second)
3803       return std::make_pair(0U, nullptr);
3804 
3805     RC = TRI->getRegClass(Prefix == "hi" ?
3806                           Mips::HI32RegClassID : Mips::LO32RegClassID);
3807     return std::make_pair(*(RC->begin()), RC);
3808   } else if (Prefix.startswith("$msa")) {
3809     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
3810 
3811     // No numeric characters follow the name.
3812     if (R.second)
3813       return std::make_pair(0U, nullptr);
3814 
3815     Reg = StringSwitch<unsigned long long>(Prefix)
3816               .Case("$msair", Mips::MSAIR)
3817               .Case("$msacsr", Mips::MSACSR)
3818               .Case("$msaaccess", Mips::MSAAccess)
3819               .Case("$msasave", Mips::MSASave)
3820               .Case("$msamodify", Mips::MSAModify)
3821               .Case("$msarequest", Mips::MSARequest)
3822               .Case("$msamap", Mips::MSAMap)
3823               .Case("$msaunmap", Mips::MSAUnmap)
3824               .Default(0);
3825 
3826     if (!Reg)
3827       return std::make_pair(0U, nullptr);
3828 
3829     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
3830     return std::make_pair(Reg, RC);
3831   }
3832 
3833   if (!R.second)
3834     return std::make_pair(0U, nullptr);
3835 
3836   if (Prefix == "$f") { // Parse $f0-$f31.
3837     // If the size of FP registers is 64-bit or Reg is an even number, select
3838     // the 64-bit register class. Otherwise, select the 32-bit register class.
3839     if (VT == MVT::Other)
3840       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
3841 
3842     RC = getRegClassFor(VT);
3843 
3844     if (RC == &Mips::AFGR64RegClass) {
3845       assert(Reg % 2 == 0);
3846       Reg >>= 1;
3847     }
3848   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
3849     RC = TRI->getRegClass(Mips::FCCRegClassID);
3850   else if (Prefix == "$w") { // Parse $w0-$w31.
3851     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
3852   } else { // Parse $0-$31.
3853     assert(Prefix == "$");
3854     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
3855   }
3856 
3857   assert(Reg < RC->getNumRegs());
3858   return std::make_pair(*(RC->begin() + Reg), RC);
3859 }
3860 
3861 /// Given a register class constraint, like 'r', if this corresponds directly
3862 /// to an LLVM register class, return a register of 0 and the register class
3863 /// pointer.
3864 std::pair<unsigned, const TargetRegisterClass *>
3865 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
3866                                                  StringRef Constraint,
3867                                                  MVT VT) const {
3868   if (Constraint.size() == 1) {
3869     switch (Constraint[0]) {
3870     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
3871     case 'y': // Same as 'r'. Exists for compatibility.
3872     case 'r':
3873       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) {
3874         if (Subtarget.inMips16Mode())
3875           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
3876         return std::make_pair(0U, &Mips::GPR32RegClass);
3877       }
3878       if (VT == MVT::i64 && !Subtarget.isGP64bit())
3879         return std::make_pair(0U, &Mips::GPR32RegClass);
3880       if (VT == MVT::i64 && Subtarget.isGP64bit())
3881         return std::make_pair(0U, &Mips::GPR64RegClass);
3882       // This will generate an error message
3883       return std::make_pair(0U, nullptr);
3884     case 'f': // FPU or MSA register
3885       if (VT == MVT::v16i8)
3886         return std::make_pair(0U, &Mips::MSA128BRegClass);
3887       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
3888         return std::make_pair(0U, &Mips::MSA128HRegClass);
3889       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
3890         return std::make_pair(0U, &Mips::MSA128WRegClass);
3891       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
3892         return std::make_pair(0U, &Mips::MSA128DRegClass);
3893       else if (VT == MVT::f32)
3894         return std::make_pair(0U, &Mips::FGR32RegClass);
3895       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
3896         if (Subtarget.isFP64bit())
3897           return std::make_pair(0U, &Mips::FGR64RegClass);
3898         return std::make_pair(0U, &Mips::AFGR64RegClass);
3899       }
3900       break;
3901     case 'c': // register suitable for indirect jump
3902       if (VT == MVT::i32)
3903         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
3904       if (VT == MVT::i64)
3905         return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
3906       // This will generate an error message
3907       return std::make_pair(0U, nullptr);
3908     case 'l': // use the `lo` register to store values
3909               // that are no bigger than a word
3910       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8)
3911         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
3912       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
3913     case 'x': // use the concatenated `hi` and `lo` registers
3914               // to store doubleword values
3915       // Fixme: Not triggering the use of both hi and low
3916       // This will generate an error message
3917       return std::make_pair(0U, nullptr);
3918     }
3919   }
3920 
3921   std::pair<unsigned, const TargetRegisterClass *> R;
3922   R = parseRegForInlineAsmConstraint(Constraint, VT);
3923 
3924   if (R.second)
3925     return R;
3926 
3927   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
3928 }
3929 
3930 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3931 /// vector.  If it is invalid, don't add anything to Ops.
3932 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
3933                                                      std::string &Constraint,
3934                                                      std::vector<SDValue>&Ops,
3935                                                      SelectionDAG &DAG) const {
3936   SDLoc DL(Op);
3937   SDValue Result;
3938 
3939   // Only support length 1 constraints for now.
3940   if (Constraint.length() > 1) return;
3941 
3942   char ConstraintLetter = Constraint[0];
3943   switch (ConstraintLetter) {
3944   default: break; // This will fall through to the generic implementation
3945   case 'I': // Signed 16 bit constant
3946     // If this fails, the parent routine will give an error
3947     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3948       EVT Type = Op.getValueType();
3949       int64_t Val = C->getSExtValue();
3950       if (isInt<16>(Val)) {
3951         Result = DAG.getTargetConstant(Val, DL, Type);
3952         break;
3953       }
3954     }
3955     return;
3956   case 'J': // integer zero
3957     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3958       EVT Type = Op.getValueType();
3959       int64_t Val = C->getZExtValue();
3960       if (Val == 0) {
3961         Result = DAG.getTargetConstant(0, DL, Type);
3962         break;
3963       }
3964     }
3965     return;
3966   case 'K': // unsigned 16 bit immediate
3967     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3968       EVT Type = Op.getValueType();
3969       uint64_t Val = (uint64_t)C->getZExtValue();
3970       if (isUInt<16>(Val)) {
3971         Result = DAG.getTargetConstant(Val, DL, Type);
3972         break;
3973       }
3974     }
3975     return;
3976   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3977     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3978       EVT Type = Op.getValueType();
3979       int64_t Val = C->getSExtValue();
3980       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
3981         Result = DAG.getTargetConstant(Val, DL, Type);
3982         break;
3983       }
3984     }
3985     return;
3986   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3987     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3988       EVT Type = Op.getValueType();
3989       int64_t Val = C->getSExtValue();
3990       if ((Val >= -65535) && (Val <= -1)) {
3991         Result = DAG.getTargetConstant(Val, DL, Type);
3992         break;
3993       }
3994     }
3995     return;
3996   case 'O': // signed 15 bit immediate
3997     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3998       EVT Type = Op.getValueType();
3999       int64_t Val = C->getSExtValue();
4000       if ((isInt<15>(Val))) {
4001         Result = DAG.getTargetConstant(Val, DL, Type);
4002         break;
4003       }
4004     }
4005     return;
4006   case 'P': // immediate in the range of 1 to 65535 (inclusive)
4007     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
4008       EVT Type = Op.getValueType();
4009       int64_t Val = C->getSExtValue();
4010       if ((Val <= 65535) && (Val >= 1)) {
4011         Result = DAG.getTargetConstant(Val, DL, Type);
4012         break;
4013       }
4014     }
4015     return;
4016   }
4017 
4018   if (Result.getNode()) {
4019     Ops.push_back(Result);
4020     return;
4021   }
4022 
4023   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
4024 }
4025 
4026 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
4027                                                const AddrMode &AM, Type *Ty,
4028                                                unsigned AS, Instruction *I) const {
4029   // No global is ever allowed as a base.
4030   if (AM.BaseGV)
4031     return false;
4032 
4033   switch (AM.Scale) {
4034   case 0: // "r+i" or just "i", depending on HasBaseReg.
4035     break;
4036   case 1:
4037     if (!AM.HasBaseReg) // allow "r+i".
4038       break;
4039     return false; // disallow "r+r" or "r+r+i".
4040   default:
4041     return false;
4042   }
4043 
4044   return true;
4045 }
4046 
4047 bool
4048 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
4049   // The Mips target isn't yet aware of offsets.
4050   return false;
4051 }
4052 
4053 EVT MipsTargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
4054                                             unsigned SrcAlign,
4055                                             bool IsMemset, bool ZeroMemset,
4056                                             bool MemcpyStrSrc,
4057                                             MachineFunction &MF) const {
4058   if (Subtarget.hasMips64())
4059     return MVT::i64;
4060 
4061   return MVT::i32;
4062 }
4063 
4064 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
4065   if (VT != MVT::f32 && VT != MVT::f64)
4066     return false;
4067   if (Imm.isNegZero())
4068     return false;
4069   return Imm.isZero();
4070 }
4071 
4072 unsigned MipsTargetLowering::getJumpTableEncoding() const {
4073 
4074   // FIXME: For space reasons this should be: EK_GPRel32BlockAddress.
4075   if (ABI.IsN64() && isPositionIndependent())
4076     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
4077 
4078   return TargetLowering::getJumpTableEncoding();
4079 }
4080 
4081 bool MipsTargetLowering::useSoftFloat() const {
4082   return Subtarget.useSoftFloat();
4083 }
4084 
4085 void MipsTargetLowering::copyByValRegs(
4086     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
4087     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
4088     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
4089     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
4090     MipsCCState &State) const {
4091   MachineFunction &MF = DAG.getMachineFunction();
4092   MachineFrameInfo &MFI = MF.getFrameInfo();
4093   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
4094   unsigned NumRegs = LastReg - FirstReg;
4095   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
4096   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
4097   int FrameObjOffset;
4098   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
4099 
4100   if (RegAreaSize)
4101     FrameObjOffset =
4102         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4103         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
4104   else
4105     FrameObjOffset = VA.getLocMemOffset();
4106 
4107   // Create frame object.
4108   EVT PtrTy = getPointerTy(DAG.getDataLayout());
4109   // Make the fixed object stored to mutable so that the load instructions
4110   // referencing it have their memory dependencies added.
4111   // Set the frame object as isAliased which clears the underlying objects
4112   // vector in ScheduleDAGInstrs::buildSchedGraph() resulting in addition of all
4113   // stores as dependencies for loads referencing this fixed object.
4114   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, false, true);
4115   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
4116   InVals.push_back(FIN);
4117 
4118   if (!NumRegs)
4119     return;
4120 
4121   // Copy arg registers.
4122   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
4123   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4124 
4125   for (unsigned I = 0; I < NumRegs; ++I) {
4126     unsigned ArgReg = ByValArgRegs[FirstReg + I];
4127     unsigned VReg = addLiveIn(MF, ArgReg, RC);
4128     unsigned Offset = I * GPRSizeInBytes;
4129     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
4130                                    DAG.getConstant(Offset, DL, PtrTy));
4131     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
4132                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
4133     OutChains.push_back(Store);
4134   }
4135 }
4136 
4137 // Copy byVal arg to registers and stack.
4138 void MipsTargetLowering::passByValArg(
4139     SDValue Chain, const SDLoc &DL,
4140     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
4141     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
4142     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
4143     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
4144     const CCValAssign &VA) const {
4145   unsigned ByValSizeInBytes = Flags.getByValSize();
4146   unsigned OffsetInBytes = 0; // From beginning of struct
4147   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4148   unsigned Alignment = std::min(Flags.getByValAlign(), RegSizeInBytes);
4149   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
4150       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4151   unsigned NumRegs = LastReg - FirstReg;
4152 
4153   if (NumRegs) {
4154     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
4155     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
4156     unsigned I = 0;
4157 
4158     // Copy words to registers.
4159     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
4160       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4161                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
4162       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
4163                                     MachinePointerInfo(), Alignment);
4164       MemOpChains.push_back(LoadVal.getValue(1));
4165       unsigned ArgReg = ArgRegs[FirstReg + I];
4166       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
4167     }
4168 
4169     // Return if the struct has been fully copied.
4170     if (ByValSizeInBytes == OffsetInBytes)
4171       return;
4172 
4173     // Copy the remainder of the byval argument with sub-word loads and shifts.
4174     if (LeftoverBytes) {
4175       SDValue Val;
4176 
4177       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
4178            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
4179         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
4180 
4181         if (RemainingSizeInBytes < LoadSizeInBytes)
4182           continue;
4183 
4184         // Load subword.
4185         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4186                                       DAG.getConstant(OffsetInBytes, DL,
4187                                                       PtrTy));
4188         SDValue LoadVal = DAG.getExtLoad(
4189             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
4190             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
4191         MemOpChains.push_back(LoadVal.getValue(1));
4192 
4193         // Shift the loaded value.
4194         unsigned Shamt;
4195 
4196         if (isLittle)
4197           Shamt = TotalBytesLoaded * 8;
4198         else
4199           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
4200 
4201         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
4202                                     DAG.getConstant(Shamt, DL, MVT::i32));
4203 
4204         if (Val.getNode())
4205           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
4206         else
4207           Val = Shift;
4208 
4209         OffsetInBytes += LoadSizeInBytes;
4210         TotalBytesLoaded += LoadSizeInBytes;
4211         Alignment = std::min(Alignment, LoadSizeInBytes);
4212       }
4213 
4214       unsigned ArgReg = ArgRegs[FirstReg + I];
4215       RegsToPass.push_back(std::make_pair(ArgReg, Val));
4216       return;
4217     }
4218   }
4219 
4220   // Copy remainder of byval arg to it with memcpy.
4221   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
4222   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
4223                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
4224   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
4225                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
4226   Chain = DAG.getMemcpy(Chain, DL, Dst, Src,
4227                         DAG.getConstant(MemCpySize, DL, PtrTy),
4228                         Alignment, /*isVolatile=*/false, /*AlwaysInline=*/false,
4229                         /*isTailCall=*/false,
4230                         MachinePointerInfo(), MachinePointerInfo());
4231   MemOpChains.push_back(Chain);
4232 }
4233 
4234 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
4235                                          SDValue Chain, const SDLoc &DL,
4236                                          SelectionDAG &DAG,
4237                                          CCState &State) const {
4238   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
4239   unsigned Idx = State.getFirstUnallocated(ArgRegs);
4240   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4241   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
4242   const TargetRegisterClass *RC = getRegClassFor(RegTy);
4243   MachineFunction &MF = DAG.getMachineFunction();
4244   MachineFrameInfo &MFI = MF.getFrameInfo();
4245   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
4246 
4247   // Offset of the first variable argument from stack pointer.
4248   int VaArgOffset;
4249 
4250   if (ArgRegs.size() == Idx)
4251     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
4252   else {
4253     VaArgOffset =
4254         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
4255         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
4256   }
4257 
4258   // Record the frame index of the first variable argument
4259   // which is a value necessary to VASTART.
4260   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4261   MipsFI->setVarArgsFrameIndex(FI);
4262 
4263   // Copy the integer registers that have not been used for argument passing
4264   // to the argument register save area. For O32, the save area is allocated
4265   // in the caller's stack frame, while for N32/64, it is allocated in the
4266   // callee's stack frame.
4267   for (unsigned I = Idx; I < ArgRegs.size();
4268        ++I, VaArgOffset += RegSizeInBytes) {
4269     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
4270     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
4271     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
4272     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
4273     SDValue Store =
4274         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
4275     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
4276         (Value *)nullptr);
4277     OutChains.push_back(Store);
4278   }
4279 }
4280 
4281 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
4282                                      unsigned Align) const {
4283   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
4284 
4285   assert(Size && "Byval argument's size shouldn't be 0.");
4286 
4287   Align = std::min(Align, TFL->getStackAlignment());
4288 
4289   unsigned FirstReg = 0;
4290   unsigned NumRegs = 0;
4291 
4292   if (State->getCallingConv() != CallingConv::Fast) {
4293     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
4294     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
4295     // FIXME: The O32 case actually describes no shadow registers.
4296     const MCPhysReg *ShadowRegs =
4297         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
4298 
4299     // We used to check the size as well but we can't do that anymore since
4300     // CCState::HandleByVal() rounds up the size after calling this function.
4301     assert(!(Align % RegSizeInBytes) &&
4302            "Byval argument's alignment should be a multiple of"
4303            "RegSizeInBytes.");
4304 
4305     FirstReg = State->getFirstUnallocated(IntArgRegs);
4306 
4307     // If Align > RegSizeInBytes, the first arg register must be even.
4308     // FIXME: This condition happens to do the right thing but it's not the
4309     //        right way to test it. We want to check that the stack frame offset
4310     //        of the register is aligned.
4311     if ((Align > RegSizeInBytes) && (FirstReg % 2)) {
4312       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
4313       ++FirstReg;
4314     }
4315 
4316     // Mark the registers allocated.
4317     Size = alignTo(Size, RegSizeInBytes);
4318     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
4319          Size -= RegSizeInBytes, ++I, ++NumRegs)
4320       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
4321   }
4322 
4323   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
4324 }
4325 
4326 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
4327                                                         MachineBasicBlock *BB,
4328                                                         bool isFPCmp,
4329                                                         unsigned Opc) const {
4330   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
4331          "Subtarget already supports SELECT nodes with the use of"
4332          "conditional-move instructions.");
4333 
4334   const TargetInstrInfo *TII =
4335       Subtarget.getInstrInfo();
4336   DebugLoc DL = MI.getDebugLoc();
4337 
4338   // To "insert" a SELECT instruction, we actually have to insert the
4339   // diamond control-flow pattern.  The incoming instruction knows the
4340   // destination vreg to set, the condition code register to branch on, the
4341   // true/false values to select between, and a branch opcode to use.
4342   const BasicBlock *LLVM_BB = BB->getBasicBlock();
4343   MachineFunction::iterator It = ++BB->getIterator();
4344 
4345   //  thisMBB:
4346   //  ...
4347   //   TrueVal = ...
4348   //   setcc r1, r2, r3
4349   //   bNE   r1, r0, copy1MBB
4350   //   fallthrough --> copy0MBB
4351   MachineBasicBlock *thisMBB  = BB;
4352   MachineFunction *F = BB->getParent();
4353   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
4354   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
4355   F->insert(It, copy0MBB);
4356   F->insert(It, sinkMBB);
4357 
4358   // Transfer the remainder of BB and its successor edges to sinkMBB.
4359   sinkMBB->splice(sinkMBB->begin(), BB,
4360                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
4361   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
4362 
4363   // Next, add the true and fallthrough blocks as its successors.
4364   BB->addSuccessor(copy0MBB);
4365   BB->addSuccessor(sinkMBB);
4366 
4367   if (isFPCmp) {
4368     // bc1[tf] cc, sinkMBB
4369     BuildMI(BB, DL, TII->get(Opc))
4370         .addReg(MI.getOperand(1).getReg())
4371         .addMBB(sinkMBB);
4372   } else {
4373     // bne rs, $0, sinkMBB
4374     BuildMI(BB, DL, TII->get(Opc))
4375         .addReg(MI.getOperand(1).getReg())
4376         .addReg(Mips::ZERO)
4377         .addMBB(sinkMBB);
4378   }
4379 
4380   //  copy0MBB:
4381   //   %FalseValue = ...
4382   //   # fallthrough to sinkMBB
4383   BB = copy0MBB;
4384 
4385   // Update machine-CFG edges
4386   BB->addSuccessor(sinkMBB);
4387 
4388   //  sinkMBB:
4389   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4390   //  ...
4391   BB = sinkMBB;
4392 
4393   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4394       .addReg(MI.getOperand(2).getReg())
4395       .addMBB(thisMBB)
4396       .addReg(MI.getOperand(3).getReg())
4397       .addMBB(copy0MBB);
4398 
4399   MI.eraseFromParent(); // The pseudo instruction is gone now.
4400 
4401   return BB;
4402 }
4403 
4404 // FIXME? Maybe this could be a TableGen attribute on some registers and
4405 // this table could be generated automatically from RegInfo.
4406 unsigned MipsTargetLowering::getRegisterByName(const char* RegName, EVT VT,
4407                                                SelectionDAG &DAG) const {
4408   // Named registers is expected to be fairly rare. For now, just support $28
4409   // since the linux kernel uses it.
4410   if (Subtarget.isGP64bit()) {
4411     unsigned Reg = StringSwitch<unsigned>(RegName)
4412                          .Case("$28", Mips::GP_64)
4413                          .Default(0);
4414     if (Reg)
4415       return Reg;
4416   } else {
4417     unsigned Reg = StringSwitch<unsigned>(RegName)
4418                          .Case("$28", Mips::GP)
4419                          .Default(0);
4420     if (Reg)
4421       return Reg;
4422   }
4423   report_fatal_error("Invalid register name global variable");
4424 }
4425