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