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 #include "MipsISelLowering.h"
15 #include "InstPrinter/MipsInstPrinter.h"
16 #include "MCTargetDesc/MipsBaseInfo.h"
17 #include "MipsCCState.h"
18 #include "MipsMachineFunction.h"
19 #include "MipsSubtarget.h"
20 #include "MipsTargetMachine.h"
21 #include "MipsTargetObjectFile.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringSwitch.h"
24 #include "llvm/CodeGen/CallingConvLower.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstrBuilder.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineRegisterInfo.h"
30 #include "llvm/CodeGen/FunctionLoweringInfo.h"
31 #include "llvm/CodeGen/SelectionDAGISel.h"
32 #include "llvm/CodeGen/ValueTypes.h"
33 #include "llvm/IR/CallingConv.h"
34 #include "llvm/IR/DerivedTypes.h"
35 #include "llvm/IR/GlobalVariable.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include <cctype>
41 
42 using namespace llvm;
43 
44 #define DEBUG_TYPE "mips-lower"
45 
46 STATISTIC(NumTailCalls, "Number of tail calls");
47 
48 static cl::opt<bool>
49 LargeGOT("mxgot", cl::Hidden,
50          cl::desc("MIPS: Enable GOT larger than 64k."), cl::init(false));
51 
52 static cl::opt<bool>
53 NoZeroDivCheck("mno-check-zero-division", cl::Hidden,
54                cl::desc("MIPS: Don't trap on integer division by zero."),
55                cl::init(false));
56 
57 static const MCPhysReg Mips64DPRegs[8] = {
58   Mips::D12_64, Mips::D13_64, Mips::D14_64, Mips::D15_64,
59   Mips::D16_64, Mips::D17_64, Mips::D18_64, Mips::D19_64
60 };
61 
62 // If I is a shifted mask, set the size (Size) and the first bit of the
63 // mask (Pos), and return true.
64 // For example, if I is 0x003ff800, (Pos, Size) = (11, 11).
65 static bool isShiftedMask(uint64_t I, uint64_t &Pos, uint64_t &Size) {
66   if (!isShiftedMask_64(I))
67     return false;
68 
69   Size = countPopulation(I);
70   Pos = countTrailingZeros(I);
71   return true;
72 }
73 
74 SDValue MipsTargetLowering::getGlobalReg(SelectionDAG &DAG, EVT Ty) const {
75   MipsFunctionInfo *FI = DAG.getMachineFunction().getInfo<MipsFunctionInfo>();
76   return DAG.getRegister(FI->getGlobalBaseReg(), Ty);
77 }
78 
79 SDValue MipsTargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
80                                           SelectionDAG &DAG,
81                                           unsigned Flag) const {
82   return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty, 0, Flag);
83 }
84 
85 SDValue MipsTargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
86                                           SelectionDAG &DAG,
87                                           unsigned Flag) const {
88   return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
89 }
90 
91 SDValue MipsTargetLowering::getTargetNode(BlockAddressSDNode *N, EVT Ty,
92                                           SelectionDAG &DAG,
93                                           unsigned Flag) const {
94   return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
95 }
96 
97 SDValue MipsTargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
98                                           SelectionDAG &DAG,
99                                           unsigned Flag) const {
100   return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
101 }
102 
103 SDValue MipsTargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
104                                           SelectionDAG &DAG,
105                                           unsigned Flag) const {
106   return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlignment(),
107                                    N->getOffset(), Flag);
108 }
109 
110 const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
111   switch ((MipsISD::NodeType)Opcode) {
112   case MipsISD::FIRST_NUMBER:      break;
113   case MipsISD::JmpLink:           return "MipsISD::JmpLink";
114   case MipsISD::TailCall:          return "MipsISD::TailCall";
115   case MipsISD::Hi:                return "MipsISD::Hi";
116   case MipsISD::Lo:                return "MipsISD::Lo";
117   case MipsISD::GPRel:             return "MipsISD::GPRel";
118   case MipsISD::ThreadPointer:     return "MipsISD::ThreadPointer";
119   case MipsISD::Ret:               return "MipsISD::Ret";
120   case MipsISD::ERet:              return "MipsISD::ERet";
121   case MipsISD::EH_RETURN:         return "MipsISD::EH_RETURN";
122   case MipsISD::FPBrcond:          return "MipsISD::FPBrcond";
123   case MipsISD::FPCmp:             return "MipsISD::FPCmp";
124   case MipsISD::CMovFP_T:          return "MipsISD::CMovFP_T";
125   case MipsISD::CMovFP_F:          return "MipsISD::CMovFP_F";
126   case MipsISD::TruncIntFP:        return "MipsISD::TruncIntFP";
127   case MipsISD::MFHI:              return "MipsISD::MFHI";
128   case MipsISD::MFLO:              return "MipsISD::MFLO";
129   case MipsISD::MTLOHI:            return "MipsISD::MTLOHI";
130   case MipsISD::Mult:              return "MipsISD::Mult";
131   case MipsISD::Multu:             return "MipsISD::Multu";
132   case MipsISD::MAdd:              return "MipsISD::MAdd";
133   case MipsISD::MAddu:             return "MipsISD::MAddu";
134   case MipsISD::MSub:              return "MipsISD::MSub";
135   case MipsISD::MSubu:             return "MipsISD::MSubu";
136   case MipsISD::DivRem:            return "MipsISD::DivRem";
137   case MipsISD::DivRemU:           return "MipsISD::DivRemU";
138   case MipsISD::DivRem16:          return "MipsISD::DivRem16";
139   case MipsISD::DivRemU16:         return "MipsISD::DivRemU16";
140   case MipsISD::BuildPairF64:      return "MipsISD::BuildPairF64";
141   case MipsISD::ExtractElementF64: return "MipsISD::ExtractElementF64";
142   case MipsISD::Wrapper:           return "MipsISD::Wrapper";
143   case MipsISD::DynAlloc:          return "MipsISD::DynAlloc";
144   case MipsISD::Sync:              return "MipsISD::Sync";
145   case MipsISD::Ext:               return "MipsISD::Ext";
146   case MipsISD::Ins:               return "MipsISD::Ins";
147   case MipsISD::LWL:               return "MipsISD::LWL";
148   case MipsISD::LWR:               return "MipsISD::LWR";
149   case MipsISD::SWL:               return "MipsISD::SWL";
150   case MipsISD::SWR:               return "MipsISD::SWR";
151   case MipsISD::LDL:               return "MipsISD::LDL";
152   case MipsISD::LDR:               return "MipsISD::LDR";
153   case MipsISD::SDL:               return "MipsISD::SDL";
154   case MipsISD::SDR:               return "MipsISD::SDR";
155   case MipsISD::EXTP:              return "MipsISD::EXTP";
156   case MipsISD::EXTPDP:            return "MipsISD::EXTPDP";
157   case MipsISD::EXTR_S_H:          return "MipsISD::EXTR_S_H";
158   case MipsISD::EXTR_W:            return "MipsISD::EXTR_W";
159   case MipsISD::EXTR_R_W:          return "MipsISD::EXTR_R_W";
160   case MipsISD::EXTR_RS_W:         return "MipsISD::EXTR_RS_W";
161   case MipsISD::SHILO:             return "MipsISD::SHILO";
162   case MipsISD::MTHLIP:            return "MipsISD::MTHLIP";
163   case MipsISD::MULSAQ_S_W_PH:     return "MipsISD::MULSAQ_S_W_PH";
164   case MipsISD::MAQ_S_W_PHL:       return "MipsISD::MAQ_S_W_PHL";
165   case MipsISD::MAQ_S_W_PHR:       return "MipsISD::MAQ_S_W_PHR";
166   case MipsISD::MAQ_SA_W_PHL:      return "MipsISD::MAQ_SA_W_PHL";
167   case MipsISD::MAQ_SA_W_PHR:      return "MipsISD::MAQ_SA_W_PHR";
168   case MipsISD::DPAU_H_QBL:        return "MipsISD::DPAU_H_QBL";
169   case MipsISD::DPAU_H_QBR:        return "MipsISD::DPAU_H_QBR";
170   case MipsISD::DPSU_H_QBL:        return "MipsISD::DPSU_H_QBL";
171   case MipsISD::DPSU_H_QBR:        return "MipsISD::DPSU_H_QBR";
172   case MipsISD::DPAQ_S_W_PH:       return "MipsISD::DPAQ_S_W_PH";
173   case MipsISD::DPSQ_S_W_PH:       return "MipsISD::DPSQ_S_W_PH";
174   case MipsISD::DPAQ_SA_L_W:       return "MipsISD::DPAQ_SA_L_W";
175   case MipsISD::DPSQ_SA_L_W:       return "MipsISD::DPSQ_SA_L_W";
176   case MipsISD::DPA_W_PH:          return "MipsISD::DPA_W_PH";
177   case MipsISD::DPS_W_PH:          return "MipsISD::DPS_W_PH";
178   case MipsISD::DPAQX_S_W_PH:      return "MipsISD::DPAQX_S_W_PH";
179   case MipsISD::DPAQX_SA_W_PH:     return "MipsISD::DPAQX_SA_W_PH";
180   case MipsISD::DPAX_W_PH:         return "MipsISD::DPAX_W_PH";
181   case MipsISD::DPSX_W_PH:         return "MipsISD::DPSX_W_PH";
182   case MipsISD::DPSQX_S_W_PH:      return "MipsISD::DPSQX_S_W_PH";
183   case MipsISD::DPSQX_SA_W_PH:     return "MipsISD::DPSQX_SA_W_PH";
184   case MipsISD::MULSA_W_PH:        return "MipsISD::MULSA_W_PH";
185   case MipsISD::MULT:              return "MipsISD::MULT";
186   case MipsISD::MULTU:             return "MipsISD::MULTU";
187   case MipsISD::MADD_DSP:          return "MipsISD::MADD_DSP";
188   case MipsISD::MADDU_DSP:         return "MipsISD::MADDU_DSP";
189   case MipsISD::MSUB_DSP:          return "MipsISD::MSUB_DSP";
190   case MipsISD::MSUBU_DSP:         return "MipsISD::MSUBU_DSP";
191   case MipsISD::SHLL_DSP:          return "MipsISD::SHLL_DSP";
192   case MipsISD::SHRA_DSP:          return "MipsISD::SHRA_DSP";
193   case MipsISD::SHRL_DSP:          return "MipsISD::SHRL_DSP";
194   case MipsISD::SETCC_DSP:         return "MipsISD::SETCC_DSP";
195   case MipsISD::SELECT_CC_DSP:     return "MipsISD::SELECT_CC_DSP";
196   case MipsISD::VALL_ZERO:         return "MipsISD::VALL_ZERO";
197   case MipsISD::VANY_ZERO:         return "MipsISD::VANY_ZERO";
198   case MipsISD::VALL_NONZERO:      return "MipsISD::VALL_NONZERO";
199   case MipsISD::VANY_NONZERO:      return "MipsISD::VANY_NONZERO";
200   case MipsISD::VCEQ:              return "MipsISD::VCEQ";
201   case MipsISD::VCLE_S:            return "MipsISD::VCLE_S";
202   case MipsISD::VCLE_U:            return "MipsISD::VCLE_U";
203   case MipsISD::VCLT_S:            return "MipsISD::VCLT_S";
204   case MipsISD::VCLT_U:            return "MipsISD::VCLT_U";
205   case MipsISD::VSMAX:             return "MipsISD::VSMAX";
206   case MipsISD::VSMIN:             return "MipsISD::VSMIN";
207   case MipsISD::VUMAX:             return "MipsISD::VUMAX";
208   case MipsISD::VUMIN:             return "MipsISD::VUMIN";
209   case MipsISD::VEXTRACT_SEXT_ELT: return "MipsISD::VEXTRACT_SEXT_ELT";
210   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
211   case MipsISD::VNOR:              return "MipsISD::VNOR";
212   case MipsISD::VSHF:              return "MipsISD::VSHF";
213   case MipsISD::SHF:               return "MipsISD::SHF";
214   case MipsISD::ILVEV:             return "MipsISD::ILVEV";
215   case MipsISD::ILVOD:             return "MipsISD::ILVOD";
216   case MipsISD::ILVL:              return "MipsISD::ILVL";
217   case MipsISD::ILVR:              return "MipsISD::ILVR";
218   case MipsISD::PCKEV:             return "MipsISD::PCKEV";
219   case MipsISD::PCKOD:             return "MipsISD::PCKOD";
220   case MipsISD::INSVE:             return "MipsISD::INSVE";
221   }
222   return nullptr;
223 }
224 
225 MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM,
226                                        const MipsSubtarget &STI)
227     : TargetLowering(TM), Subtarget(STI), ABI(TM.getABI()) {
228   // Mips does not have i1 type, so use i32 for
229   // setcc operations results (slt, sgt, ...).
230   setBooleanContents(ZeroOrOneBooleanContent);
231   setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
232   // The cmp.cond.fmt instruction in MIPS32r6/MIPS64r6 uses 0 and -1 like MSA
233   // does. Integer booleans still use 0 and 1.
234   if (Subtarget.hasMips32r6())
235     setBooleanContents(ZeroOrOneBooleanContent,
236                        ZeroOrNegativeOneBooleanContent);
237 
238   // Load extented operations for i1 types must be promoted
239   for (MVT VT : MVT::integer_valuetypes()) {
240     setLoadExtAction(ISD::EXTLOAD,  VT, MVT::i1,  Promote);
241     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1,  Promote);
242     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1,  Promote);
243   }
244 
245   // MIPS doesn't have extending float->double load/store.  Set LoadExtAction
246   // for f32, f16
247   for (MVT VT : MVT::fp_valuetypes()) {
248     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
249     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
250   }
251 
252   // Set LoadExtAction for f16 vectors to Expand
253   for (MVT VT : MVT::fp_vector_valuetypes()) {
254     MVT F16VT = MVT::getVectorVT(MVT::f16, VT.getVectorNumElements());
255     if (F16VT.isValid())
256       setLoadExtAction(ISD::EXTLOAD, VT, F16VT, Expand);
257   }
258 
259   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
260   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
261 
262   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
263 
264   // Used by legalize types to correctly generate the setcc result.
265   // Without this, every float setcc comes with a AND/OR with the result,
266   // we don't want this, since the fpcmp result goes to a flag register,
267   // which is used implicitly by brcond and select operations.
268   AddPromotedToType(ISD::SETCC, MVT::i1, MVT::i32);
269 
270   // Mips Custom Operations
271   setOperationAction(ISD::BR_JT,              MVT::Other, Custom);
272   setOperationAction(ISD::GlobalAddress,      MVT::i32,   Custom);
273   setOperationAction(ISD::BlockAddress,       MVT::i32,   Custom);
274   setOperationAction(ISD::GlobalTLSAddress,   MVT::i32,   Custom);
275   setOperationAction(ISD::JumpTable,          MVT::i32,   Custom);
276   setOperationAction(ISD::ConstantPool,       MVT::i32,   Custom);
277   setOperationAction(ISD::SELECT,             MVT::f32,   Custom);
278   setOperationAction(ISD::SELECT,             MVT::f64,   Custom);
279   setOperationAction(ISD::SELECT,             MVT::i32,   Custom);
280   setOperationAction(ISD::SETCC,              MVT::f32,   Custom);
281   setOperationAction(ISD::SETCC,              MVT::f64,   Custom);
282   setOperationAction(ISD::BRCOND,             MVT::Other, Custom);
283   setOperationAction(ISD::FCOPYSIGN,          MVT::f32,   Custom);
284   setOperationAction(ISD::FCOPYSIGN,          MVT::f64,   Custom);
285   setOperationAction(ISD::FP_TO_SINT,         MVT::i32,   Custom);
286 
287   if (Subtarget.isGP64bit()) {
288     setOperationAction(ISD::GlobalAddress,      MVT::i64,   Custom);
289     setOperationAction(ISD::BlockAddress,       MVT::i64,   Custom);
290     setOperationAction(ISD::GlobalTLSAddress,   MVT::i64,   Custom);
291     setOperationAction(ISD::JumpTable,          MVT::i64,   Custom);
292     setOperationAction(ISD::ConstantPool,       MVT::i64,   Custom);
293     setOperationAction(ISD::SELECT,             MVT::i64,   Custom);
294     setOperationAction(ISD::LOAD,               MVT::i64,   Custom);
295     setOperationAction(ISD::STORE,              MVT::i64,   Custom);
296     setOperationAction(ISD::FP_TO_SINT,         MVT::i64,   Custom);
297     setOperationAction(ISD::SHL_PARTS,          MVT::i64,   Custom);
298     setOperationAction(ISD::SRA_PARTS,          MVT::i64,   Custom);
299     setOperationAction(ISD::SRL_PARTS,          MVT::i64,   Custom);
300   }
301 
302   if (!Subtarget.isGP64bit()) {
303     setOperationAction(ISD::SHL_PARTS,          MVT::i32,   Custom);
304     setOperationAction(ISD::SRA_PARTS,          MVT::i32,   Custom);
305     setOperationAction(ISD::SRL_PARTS,          MVT::i32,   Custom);
306   }
307 
308   setOperationAction(ISD::EH_DWARF_CFA,         MVT::i32,   Custom);
309   if (Subtarget.isGP64bit())
310     setOperationAction(ISD::EH_DWARF_CFA,       MVT::i64,   Custom);
311 
312   setOperationAction(ISD::SDIV, MVT::i32, Expand);
313   setOperationAction(ISD::SREM, MVT::i32, Expand);
314   setOperationAction(ISD::UDIV, MVT::i32, Expand);
315   setOperationAction(ISD::UREM, MVT::i32, Expand);
316   setOperationAction(ISD::SDIV, MVT::i64, Expand);
317   setOperationAction(ISD::SREM, MVT::i64, Expand);
318   setOperationAction(ISD::UDIV, MVT::i64, Expand);
319   setOperationAction(ISD::UREM, MVT::i64, Expand);
320 
321   // Operations not directly supported by Mips.
322   setOperationAction(ISD::BR_CC,             MVT::f32,   Expand);
323   setOperationAction(ISD::BR_CC,             MVT::f64,   Expand);
324   setOperationAction(ISD::BR_CC,             MVT::i32,   Expand);
325   setOperationAction(ISD::BR_CC,             MVT::i64,   Expand);
326   setOperationAction(ISD::SELECT_CC,         MVT::i32,   Expand);
327   setOperationAction(ISD::SELECT_CC,         MVT::i64,   Expand);
328   setOperationAction(ISD::SELECT_CC,         MVT::f32,   Expand);
329   setOperationAction(ISD::SELECT_CC,         MVT::f64,   Expand);
330   setOperationAction(ISD::UINT_TO_FP,        MVT::i32,   Expand);
331   setOperationAction(ISD::UINT_TO_FP,        MVT::i64,   Expand);
332   setOperationAction(ISD::FP_TO_UINT,        MVT::i32,   Expand);
333   setOperationAction(ISD::FP_TO_UINT,        MVT::i64,   Expand);
334   setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i1,    Expand);
335   if (Subtarget.hasCnMips()) {
336     setOperationAction(ISD::CTPOP,           MVT::i32,   Legal);
337     setOperationAction(ISD::CTPOP,           MVT::i64,   Legal);
338   } else {
339     setOperationAction(ISD::CTPOP,           MVT::i32,   Expand);
340     setOperationAction(ISD::CTPOP,           MVT::i64,   Expand);
341   }
342   setOperationAction(ISD::CTTZ,              MVT::i32,   Expand);
343   setOperationAction(ISD::CTTZ,              MVT::i64,   Expand);
344   setOperationAction(ISD::ROTL,              MVT::i32,   Expand);
345   setOperationAction(ISD::ROTL,              MVT::i64,   Expand);
346   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32,  Expand);
347   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64,  Expand);
348 
349   if (!Subtarget.hasMips32r2())
350     setOperationAction(ISD::ROTR, MVT::i32,   Expand);
351 
352   if (!Subtarget.hasMips64r2())
353     setOperationAction(ISD::ROTR, MVT::i64,   Expand);
354 
355   setOperationAction(ISD::FSIN,              MVT::f32,   Expand);
356   setOperationAction(ISD::FSIN,              MVT::f64,   Expand);
357   setOperationAction(ISD::FCOS,              MVT::f32,   Expand);
358   setOperationAction(ISD::FCOS,              MVT::f64,   Expand);
359   setOperationAction(ISD::FSINCOS,           MVT::f32,   Expand);
360   setOperationAction(ISD::FSINCOS,           MVT::f64,   Expand);
361   setOperationAction(ISD::FPOWI,             MVT::f32,   Expand);
362   setOperationAction(ISD::FPOW,              MVT::f32,   Expand);
363   setOperationAction(ISD::FPOW,              MVT::f64,   Expand);
364   setOperationAction(ISD::FLOG,              MVT::f32,   Expand);
365   setOperationAction(ISD::FLOG2,             MVT::f32,   Expand);
366   setOperationAction(ISD::FLOG10,            MVT::f32,   Expand);
367   setOperationAction(ISD::FEXP,              MVT::f32,   Expand);
368   setOperationAction(ISD::FMA,               MVT::f32,   Expand);
369   setOperationAction(ISD::FMA,               MVT::f64,   Expand);
370   setOperationAction(ISD::FREM,              MVT::f32,   Expand);
371   setOperationAction(ISD::FREM,              MVT::f64,   Expand);
372 
373   // Lower f16 conversion operations into library calls
374   setOperationAction(ISD::FP16_TO_FP,        MVT::f32,   Expand);
375   setOperationAction(ISD::FP_TO_FP16,        MVT::f32,   Expand);
376   setOperationAction(ISD::FP16_TO_FP,        MVT::f64,   Expand);
377   setOperationAction(ISD::FP_TO_FP16,        MVT::f64,   Expand);
378 
379   setOperationAction(ISD::EH_RETURN, MVT::Other, Custom);
380 
381   setOperationAction(ISD::VASTART,           MVT::Other, Custom);
382   setOperationAction(ISD::VAARG,             MVT::Other, Custom);
383   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
384   setOperationAction(ISD::VAEND,             MVT::Other, Expand);
385 
386   // Use the default for now
387   setOperationAction(ISD::STACKSAVE,         MVT::Other, Expand);
388   setOperationAction(ISD::STACKRESTORE,      MVT::Other, Expand);
389 
390   if (!Subtarget.isGP64bit()) {
391     setOperationAction(ISD::ATOMIC_LOAD,     MVT::i64,   Expand);
392     setOperationAction(ISD::ATOMIC_STORE,    MVT::i64,   Expand);
393   }
394 
395 
396   if (!Subtarget.hasMips32r2()) {
397     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i8,  Expand);
398     setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16, Expand);
399   }
400 
401   // MIPS16 lacks MIPS32's clz and clo instructions.
402   if (!Subtarget.hasMips32() || Subtarget.inMips16Mode())
403     setOperationAction(ISD::CTLZ, MVT::i32, Expand);
404   if (!Subtarget.hasMips64())
405     setOperationAction(ISD::CTLZ, MVT::i64, Expand);
406 
407   if (!Subtarget.hasMips32r2())
408     setOperationAction(ISD::BSWAP, MVT::i32, Expand);
409   if (!Subtarget.hasMips64r2())
410     setOperationAction(ISD::BSWAP, MVT::i64, Expand);
411 
412   if (Subtarget.isGP64bit()) {
413     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, MVT::i32, Custom);
414     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, MVT::i32, Custom);
415     setLoadExtAction(ISD::EXTLOAD, MVT::i64, MVT::i32, Custom);
416     setTruncStoreAction(MVT::i64, MVT::i32, Custom);
417   }
418 
419   setOperationAction(ISD::TRAP, MVT::Other, Legal);
420 
421   setTargetDAGCombine(ISD::SDIVREM);
422   setTargetDAGCombine(ISD::UDIVREM);
423   setTargetDAGCombine(ISD::SELECT);
424   setTargetDAGCombine(ISD::AND);
425   setTargetDAGCombine(ISD::OR);
426   setTargetDAGCombine(ISD::ADD);
427   setTargetDAGCombine(ISD::AssertZext);
428 
429   if (ABI.IsO32()) {
430     // These libcalls are not available in 32-bit.
431     setLibcallName(RTLIB::SHL_I128, nullptr);
432     setLibcallName(RTLIB::SRL_I128, nullptr);
433     setLibcallName(RTLIB::SRA_I128, nullptr);
434   }
435 
436   setMinFunctionAlignment(Subtarget.isGP64bit() ? 3 : 2);
437 
438   // The arguments on the stack are defined in terms of 4-byte slots on O32
439   // and 8-byte slots on N32/N64.
440   setMinStackArgumentAlignment((ABI.IsN32() || ABI.IsN64()) ? 8 : 4);
441 
442   setStackPointerRegisterToSaveRestore(ABI.IsN64() ? Mips::SP_64 : Mips::SP);
443 
444   MaxStoresPerMemcpy = 16;
445 
446   isMicroMips = Subtarget.inMicroMipsMode();
447 }
448 
449 const MipsTargetLowering *MipsTargetLowering::create(const MipsTargetMachine &TM,
450                                                      const MipsSubtarget &STI) {
451   if (STI.inMips16Mode())
452     return llvm::createMips16TargetLowering(TM, STI);
453 
454   return llvm::createMipsSETargetLowering(TM, STI);
455 }
456 
457 // Create a fast isel object.
458 FastISel *
459 MipsTargetLowering::createFastISel(FunctionLoweringInfo &funcInfo,
460                                   const TargetLibraryInfo *libInfo) const {
461   const MipsTargetMachine &TM =
462       static_cast<const MipsTargetMachine &>(funcInfo.MF->getTarget());
463 
464   // We support only the standard encoding [MIPS32,MIPS32R5] ISAs.
465   bool UseFastISel = TM.Options.EnableFastISel && Subtarget.hasMips32() &&
466                      !Subtarget.hasMips32r6() && !Subtarget.inMips16Mode() &&
467                      !Subtarget.inMicroMipsMode();
468 
469   // Disable if we don't generate PIC or the ABI isn't O32.
470   if (!TM.isPositionIndependent() || !TM.getABI().IsO32())
471     UseFastISel = false;
472 
473   return UseFastISel ? Mips::createFastISel(funcInfo, libInfo) : nullptr;
474 }
475 
476 EVT MipsTargetLowering::getSetCCResultType(const DataLayout &, LLVMContext &,
477                                            EVT VT) const {
478   if (!VT.isVector())
479     return MVT::i32;
480   return VT.changeVectorElementTypeToInteger();
481 }
482 
483 static SDValue performDivRemCombine(SDNode *N, SelectionDAG &DAG,
484                                     TargetLowering::DAGCombinerInfo &DCI,
485                                     const MipsSubtarget &Subtarget) {
486   if (DCI.isBeforeLegalizeOps())
487     return SDValue();
488 
489   EVT Ty = N->getValueType(0);
490   unsigned LO = (Ty == MVT::i32) ? Mips::LO0 : Mips::LO0_64;
491   unsigned HI = (Ty == MVT::i32) ? Mips::HI0 : Mips::HI0_64;
492   unsigned Opc = N->getOpcode() == ISD::SDIVREM ? MipsISD::DivRem16 :
493                                                   MipsISD::DivRemU16;
494   SDLoc DL(N);
495 
496   SDValue DivRem = DAG.getNode(Opc, DL, MVT::Glue,
497                                N->getOperand(0), N->getOperand(1));
498   SDValue InChain = DAG.getEntryNode();
499   SDValue InGlue = DivRem;
500 
501   // insert MFLO
502   if (N->hasAnyUseOfValue(0)) {
503     SDValue CopyFromLo = DAG.getCopyFromReg(InChain, DL, LO, Ty,
504                                             InGlue);
505     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), CopyFromLo);
506     InChain = CopyFromLo.getValue(1);
507     InGlue = CopyFromLo.getValue(2);
508   }
509 
510   // insert MFHI
511   if (N->hasAnyUseOfValue(1)) {
512     SDValue CopyFromHi = DAG.getCopyFromReg(InChain, DL,
513                                             HI, Ty, InGlue);
514     DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), CopyFromHi);
515   }
516 
517   return SDValue();
518 }
519 
520 static Mips::CondCode condCodeToFCC(ISD::CondCode CC) {
521   switch (CC) {
522   default: llvm_unreachable("Unknown fp condition code!");
523   case ISD::SETEQ:
524   case ISD::SETOEQ: return Mips::FCOND_OEQ;
525   case ISD::SETUNE: return Mips::FCOND_UNE;
526   case ISD::SETLT:
527   case ISD::SETOLT: return Mips::FCOND_OLT;
528   case ISD::SETGT:
529   case ISD::SETOGT: return Mips::FCOND_OGT;
530   case ISD::SETLE:
531   case ISD::SETOLE: return Mips::FCOND_OLE;
532   case ISD::SETGE:
533   case ISD::SETOGE: return Mips::FCOND_OGE;
534   case ISD::SETULT: return Mips::FCOND_ULT;
535   case ISD::SETULE: return Mips::FCOND_ULE;
536   case ISD::SETUGT: return Mips::FCOND_UGT;
537   case ISD::SETUGE: return Mips::FCOND_UGE;
538   case ISD::SETUO:  return Mips::FCOND_UN;
539   case ISD::SETO:   return Mips::FCOND_OR;
540   case ISD::SETNE:
541   case ISD::SETONE: return Mips::FCOND_ONE;
542   case ISD::SETUEQ: return Mips::FCOND_UEQ;
543   }
544 }
545 
546 
547 /// This function returns true if the floating point conditional branches and
548 /// conditional moves which use condition code CC should be inverted.
549 static bool invertFPCondCodeUser(Mips::CondCode CC) {
550   if (CC >= Mips::FCOND_F && CC <= Mips::FCOND_NGT)
551     return false;
552 
553   assert((CC >= Mips::FCOND_T && CC <= Mips::FCOND_GT) &&
554          "Illegal Condition Code");
555 
556   return true;
557 }
558 
559 // Creates and returns an FPCmp node from a setcc node.
560 // Returns Op if setcc is not a floating point comparison.
561 static SDValue createFPCmp(SelectionDAG &DAG, const SDValue &Op) {
562   // must be a SETCC node
563   if (Op.getOpcode() != ISD::SETCC)
564     return Op;
565 
566   SDValue LHS = Op.getOperand(0);
567 
568   if (!LHS.getValueType().isFloatingPoint())
569     return Op;
570 
571   SDValue RHS = Op.getOperand(1);
572   SDLoc DL(Op);
573 
574   // Assume the 3rd operand is a CondCodeSDNode. Add code to check the type of
575   // node if necessary.
576   ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
577 
578   return DAG.getNode(MipsISD::FPCmp, DL, MVT::Glue, LHS, RHS,
579                      DAG.getConstant(condCodeToFCC(CC), DL, MVT::i32));
580 }
581 
582 // Creates and returns a CMovFPT/F node.
583 static SDValue createCMovFP(SelectionDAG &DAG, SDValue Cond, SDValue True,
584                             SDValue False, const SDLoc &DL) {
585   ConstantSDNode *CC = cast<ConstantSDNode>(Cond.getOperand(2));
586   bool invert = invertFPCondCodeUser((Mips::CondCode)CC->getSExtValue());
587   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
588 
589   return DAG.getNode((invert ? MipsISD::CMovFP_F : MipsISD::CMovFP_T), DL,
590                      True.getValueType(), True, FCC0, False, Cond);
591 }
592 
593 static SDValue performSELECTCombine(SDNode *N, SelectionDAG &DAG,
594                                     TargetLowering::DAGCombinerInfo &DCI,
595                                     const MipsSubtarget &Subtarget) {
596   if (DCI.isBeforeLegalizeOps())
597     return SDValue();
598 
599   SDValue SetCC = N->getOperand(0);
600 
601   if ((SetCC.getOpcode() != ISD::SETCC) ||
602       !SetCC.getOperand(0).getValueType().isInteger())
603     return SDValue();
604 
605   SDValue False = N->getOperand(2);
606   EVT FalseTy = False.getValueType();
607 
608   if (!FalseTy.isInteger())
609     return SDValue();
610 
611   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(False);
612 
613   // If the RHS (False) is 0, we swap the order of the operands
614   // of ISD::SELECT (obviously also inverting the condition) so that we can
615   // take advantage of conditional moves using the $0 register.
616   // Example:
617   //   return (a != 0) ? x : 0;
618   //     load $reg, x
619   //     movz $reg, $0, a
620   if (!FalseC)
621     return SDValue();
622 
623   const SDLoc DL(N);
624 
625   if (!FalseC->getZExtValue()) {
626     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
627     SDValue True = N->getOperand(1);
628 
629     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
630                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
631 
632     return DAG.getNode(ISD::SELECT, DL, FalseTy, SetCC, False, True);
633   }
634 
635   // If both operands are integer constants there's a possibility that we
636   // can do some interesting optimizations.
637   SDValue True = N->getOperand(1);
638   ConstantSDNode *TrueC = dyn_cast<ConstantSDNode>(True);
639 
640   if (!TrueC || !True.getValueType().isInteger())
641     return SDValue();
642 
643   // We'll also ignore MVT::i64 operands as this optimizations proves
644   // to be ineffective because of the required sign extensions as the result
645   // of a SETCC operator is always MVT::i32 for non-vector types.
646   if (True.getValueType() == MVT::i64)
647     return SDValue();
648 
649   int64_t Diff = TrueC->getSExtValue() - FalseC->getSExtValue();
650 
651   // 1)  (a < x) ? y : y-1
652   //  slti $reg1, a, x
653   //  addiu $reg2, $reg1, y-1
654   if (Diff == 1)
655     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, False);
656 
657   // 2)  (a < x) ? y-1 : y
658   //  slti $reg1, a, x
659   //  xor $reg1, $reg1, 1
660   //  addiu $reg2, $reg1, y-1
661   if (Diff == -1) {
662     ISD::CondCode CC = cast<CondCodeSDNode>(SetCC.getOperand(2))->get();
663     SetCC = DAG.getSetCC(DL, SetCC.getValueType(), SetCC.getOperand(0),
664                          SetCC.getOperand(1), ISD::getSetCCInverse(CC, true));
665     return DAG.getNode(ISD::ADD, DL, SetCC.getValueType(), SetCC, True);
666   }
667 
668   // Couldn't optimize.
669   return SDValue();
670 }
671 
672 static SDValue performCMovFPCombine(SDNode *N, SelectionDAG &DAG,
673                                     TargetLowering::DAGCombinerInfo &DCI,
674                                     const MipsSubtarget &Subtarget) {
675   if (DCI.isBeforeLegalizeOps())
676     return SDValue();
677 
678   SDValue ValueIfTrue = N->getOperand(0), ValueIfFalse = N->getOperand(2);
679 
680   ConstantSDNode *FalseC = dyn_cast<ConstantSDNode>(ValueIfFalse);
681   if (!FalseC || FalseC->getZExtValue())
682     return SDValue();
683 
684   // Since RHS (False) is 0, we swap the order of the True/False operands
685   // (obviously also inverting the condition) so that we can
686   // take advantage of conditional moves using the $0 register.
687   // Example:
688   //   return (a != 0) ? x : 0;
689   //     load $reg, x
690   //     movz $reg, $0, a
691   unsigned Opc = (N->getOpcode() == MipsISD::CMovFP_T) ? MipsISD::CMovFP_F :
692                                                          MipsISD::CMovFP_T;
693 
694   SDValue FCC = N->getOperand(1), Glue = N->getOperand(3);
695   return DAG.getNode(Opc, SDLoc(N), ValueIfFalse.getValueType(),
696                      ValueIfFalse, FCC, ValueIfTrue, Glue);
697 }
698 
699 static SDValue performANDCombine(SDNode *N, SelectionDAG &DAG,
700                                  TargetLowering::DAGCombinerInfo &DCI,
701                                  const MipsSubtarget &Subtarget) {
702   // Pattern match EXT.
703   //  $dst = and ((sra or srl) $src , pos), (2**size - 1)
704   //  => ext $dst, $src, size, pos
705   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
706     return SDValue();
707 
708   SDValue ShiftRight = N->getOperand(0), Mask = N->getOperand(1);
709   unsigned ShiftRightOpc = ShiftRight.getOpcode();
710 
711   // Op's first operand must be a shift right.
712   if (ShiftRightOpc != ISD::SRA && ShiftRightOpc != ISD::SRL)
713     return SDValue();
714 
715   // The second operand of the shift must be an immediate.
716   ConstantSDNode *CN;
717   if (!(CN = dyn_cast<ConstantSDNode>(ShiftRight.getOperand(1))))
718     return SDValue();
719 
720   uint64_t Pos = CN->getZExtValue();
721   uint64_t SMPos, SMSize;
722 
723   // Op's second operand must be a shifted mask.
724   if (!(CN = dyn_cast<ConstantSDNode>(Mask)) ||
725       !isShiftedMask(CN->getZExtValue(), SMPos, SMSize))
726     return SDValue();
727 
728   // Return if the shifted mask does not start at bit 0 or the sum of its size
729   // and Pos exceeds the word's size.
730   EVT ValTy = N->getValueType(0);
731   if (SMPos != 0 || Pos + SMSize > ValTy.getSizeInBits())
732     return SDValue();
733 
734   SDLoc DL(N);
735   return DAG.getNode(MipsISD::Ext, DL, ValTy,
736                      ShiftRight.getOperand(0),
737                      DAG.getConstant(Pos, DL, MVT::i32),
738                      DAG.getConstant(SMSize, DL, MVT::i32));
739 }
740 
741 static SDValue performORCombine(SDNode *N, SelectionDAG &DAG,
742                                 TargetLowering::DAGCombinerInfo &DCI,
743                                 const MipsSubtarget &Subtarget) {
744   // Pattern match INS.
745   //  $dst = or (and $src1 , mask0), (and (shl $src, pos), mask1),
746   //  where mask1 = (2**size - 1) << pos, mask0 = ~mask1
747   //  => ins $dst, $src, size, pos, $src1
748   if (DCI.isBeforeLegalizeOps() || !Subtarget.hasExtractInsert())
749     return SDValue();
750 
751   SDValue And0 = N->getOperand(0), And1 = N->getOperand(1);
752   uint64_t SMPos0, SMSize0, SMPos1, SMSize1;
753   ConstantSDNode *CN;
754 
755   // See if Op's first operand matches (and $src1 , mask0).
756   if (And0.getOpcode() != ISD::AND)
757     return SDValue();
758 
759   if (!(CN = dyn_cast<ConstantSDNode>(And0.getOperand(1))) ||
760       !isShiftedMask(~CN->getSExtValue(), SMPos0, SMSize0))
761     return SDValue();
762 
763   // See if Op's second operand matches (and (shl $src, pos), mask1).
764   if (And1.getOpcode() != ISD::AND)
765     return SDValue();
766 
767   if (!(CN = dyn_cast<ConstantSDNode>(And1.getOperand(1))) ||
768       !isShiftedMask(CN->getZExtValue(), SMPos1, SMSize1))
769     return SDValue();
770 
771   // The shift masks must have the same position and size.
772   if (SMPos0 != SMPos1 || SMSize0 != SMSize1)
773     return SDValue();
774 
775   SDValue Shl = And1.getOperand(0);
776   if (Shl.getOpcode() != ISD::SHL)
777     return SDValue();
778 
779   if (!(CN = dyn_cast<ConstantSDNode>(Shl.getOperand(1))))
780     return SDValue();
781 
782   unsigned Shamt = CN->getZExtValue();
783 
784   // Return if the shift amount and the first bit position of mask are not the
785   // same.
786   EVT ValTy = N->getValueType(0);
787   if ((Shamt != SMPos0) || (SMPos0 + SMSize0 > ValTy.getSizeInBits()))
788     return SDValue();
789 
790   SDLoc DL(N);
791   return DAG.getNode(MipsISD::Ins, DL, ValTy, Shl.getOperand(0),
792                      DAG.getConstant(SMPos0, DL, MVT::i32),
793                      DAG.getConstant(SMSize0, DL, MVT::i32),
794                      And0.getOperand(0));
795 }
796 
797 static SDValue performADDCombine(SDNode *N, SelectionDAG &DAG,
798                                  TargetLowering::DAGCombinerInfo &DCI,
799                                  const MipsSubtarget &Subtarget) {
800   // (add v0, (add v1, abs_lo(tjt))) => (add (add v0, v1), abs_lo(tjt))
801 
802   if (DCI.isBeforeLegalizeOps())
803     return SDValue();
804 
805   SDValue Add = N->getOperand(1);
806 
807   if (Add.getOpcode() != ISD::ADD)
808     return SDValue();
809 
810   SDValue Lo = Add.getOperand(1);
811 
812   if ((Lo.getOpcode() != MipsISD::Lo) ||
813       (Lo.getOperand(0).getOpcode() != ISD::TargetJumpTable))
814     return SDValue();
815 
816   EVT ValTy = N->getValueType(0);
817   SDLoc DL(N);
818 
819   SDValue Add1 = DAG.getNode(ISD::ADD, DL, ValTy, N->getOperand(0),
820                              Add.getOperand(0));
821   return DAG.getNode(ISD::ADD, DL, ValTy, Add1, Lo);
822 }
823 
824 static SDValue performAssertZextCombine(SDNode *N, SelectionDAG &DAG,
825                                         TargetLowering::DAGCombinerInfo &DCI,
826                                         const MipsSubtarget &Subtarget) {
827   SDValue N0 = N->getOperand(0);
828   EVT NarrowerVT = cast<VTSDNode>(N->getOperand(1))->getVT();
829 
830   if (N0.getOpcode() != ISD::TRUNCATE)
831     return SDValue();
832 
833   if (N0.getOperand(0).getOpcode() != ISD::AssertZext)
834     return SDValue();
835 
836   // fold (AssertZext (trunc (AssertZext x))) -> (trunc (AssertZext x))
837   // if the type of the extension of the innermost AssertZext node is
838   // smaller from that of the outermost node, eg:
839   // (AssertZext:i32 (trunc:i32 (AssertZext:i64 X, i32)), i8)
840   //   -> (trunc:i32 (AssertZext X, i8))
841   SDValue WiderAssertZext = N0.getOperand(0);
842   EVT WiderVT = cast<VTSDNode>(WiderAssertZext->getOperand(1))->getVT();
843 
844   if (NarrowerVT.bitsLT(WiderVT)) {
845     SDValue NewAssertZext = DAG.getNode(
846         ISD::AssertZext, SDLoc(N), WiderAssertZext.getValueType(),
847         WiderAssertZext.getOperand(0), DAG.getValueType(NarrowerVT));
848     return DAG.getNode(ISD::TRUNCATE, SDLoc(N), N->getValueType(0),
849                        NewAssertZext);
850   }
851 
852   return SDValue();
853 }
854 
855 SDValue  MipsTargetLowering::PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI)
856   const {
857   SelectionDAG &DAG = DCI.DAG;
858   unsigned Opc = N->getOpcode();
859 
860   switch (Opc) {
861   default: break;
862   case ISD::SDIVREM:
863   case ISD::UDIVREM:
864     return performDivRemCombine(N, DAG, DCI, Subtarget);
865   case ISD::SELECT:
866     return performSELECTCombine(N, DAG, DCI, Subtarget);
867   case MipsISD::CMovFP_F:
868   case MipsISD::CMovFP_T:
869     return performCMovFPCombine(N, DAG, DCI, Subtarget);
870   case ISD::AND:
871     return performANDCombine(N, DAG, DCI, Subtarget);
872   case ISD::OR:
873     return performORCombine(N, DAG, DCI, Subtarget);
874   case ISD::ADD:
875     return performADDCombine(N, DAG, DCI, Subtarget);
876   case ISD::AssertZext:
877     return performAssertZextCombine(N, DAG, DCI, Subtarget);
878   }
879 
880   return SDValue();
881 }
882 
883 bool MipsTargetLowering::isCheapToSpeculateCttz() const {
884   return Subtarget.hasMips32();
885 }
886 
887 bool MipsTargetLowering::isCheapToSpeculateCtlz() const {
888   return Subtarget.hasMips32();
889 }
890 
891 void
892 MipsTargetLowering::LowerOperationWrapper(SDNode *N,
893                                           SmallVectorImpl<SDValue> &Results,
894                                           SelectionDAG &DAG) const {
895   SDValue Res = LowerOperation(SDValue(N, 0), DAG);
896 
897   for (unsigned I = 0, E = Res->getNumValues(); I != E; ++I)
898     Results.push_back(Res.getValue(I));
899 }
900 
901 void
902 MipsTargetLowering::ReplaceNodeResults(SDNode *N,
903                                        SmallVectorImpl<SDValue> &Results,
904                                        SelectionDAG &DAG) const {
905   return LowerOperationWrapper(N, Results, DAG);
906 }
907 
908 SDValue MipsTargetLowering::
909 LowerOperation(SDValue Op, SelectionDAG &DAG) const
910 {
911   switch (Op.getOpcode())
912   {
913   case ISD::BR_JT:              return lowerBR_JT(Op, DAG);
914   case ISD::BRCOND:             return lowerBRCOND(Op, DAG);
915   case ISD::ConstantPool:       return lowerConstantPool(Op, DAG);
916   case ISD::GlobalAddress:      return lowerGlobalAddress(Op, DAG);
917   case ISD::BlockAddress:       return lowerBlockAddress(Op, DAG);
918   case ISD::GlobalTLSAddress:   return lowerGlobalTLSAddress(Op, DAG);
919   case ISD::JumpTable:          return lowerJumpTable(Op, DAG);
920   case ISD::SELECT:             return lowerSELECT(Op, DAG);
921   case ISD::SETCC:              return lowerSETCC(Op, DAG);
922   case ISD::VASTART:            return lowerVASTART(Op, DAG);
923   case ISD::VAARG:              return lowerVAARG(Op, DAG);
924   case ISD::FCOPYSIGN:          return lowerFCOPYSIGN(Op, DAG);
925   case ISD::FRAMEADDR:          return lowerFRAMEADDR(Op, DAG);
926   case ISD::RETURNADDR:         return lowerRETURNADDR(Op, DAG);
927   case ISD::EH_RETURN:          return lowerEH_RETURN(Op, DAG);
928   case ISD::ATOMIC_FENCE:       return lowerATOMIC_FENCE(Op, DAG);
929   case ISD::SHL_PARTS:          return lowerShiftLeftParts(Op, DAG);
930   case ISD::SRA_PARTS:          return lowerShiftRightParts(Op, DAG, true);
931   case ISD::SRL_PARTS:          return lowerShiftRightParts(Op, DAG, false);
932   case ISD::LOAD:               return lowerLOAD(Op, DAG);
933   case ISD::STORE:              return lowerSTORE(Op, DAG);
934   case ISD::EH_DWARF_CFA:       return lowerEH_DWARF_CFA(Op, DAG);
935   case ISD::FP_TO_SINT:         return lowerFP_TO_SINT(Op, DAG);
936   }
937   return SDValue();
938 }
939 
940 //===----------------------------------------------------------------------===//
941 //  Lower helper functions
942 //===----------------------------------------------------------------------===//
943 
944 // addLiveIn - This helper function adds the specified physical register to the
945 // MachineFunction as a live in value.  It also creates a corresponding
946 // virtual register for it.
947 static unsigned
948 addLiveIn(MachineFunction &MF, unsigned PReg, const TargetRegisterClass *RC)
949 {
950   unsigned VReg = MF.getRegInfo().createVirtualRegister(RC);
951   MF.getRegInfo().addLiveIn(PReg, VReg);
952   return VReg;
953 }
954 
955 static MachineBasicBlock *insertDivByZeroTrap(MachineInstr &MI,
956                                               MachineBasicBlock &MBB,
957                                               const TargetInstrInfo &TII,
958                                               bool Is64Bit, bool IsMicroMips) {
959   if (NoZeroDivCheck)
960     return &MBB;
961 
962   // Insert instruction "teq $divisor_reg, $zero, 7".
963   MachineBasicBlock::iterator I(MI);
964   MachineInstrBuilder MIB;
965   MachineOperand &Divisor = MI.getOperand(2);
966   MIB = BuildMI(MBB, std::next(I), MI.getDebugLoc(),
967                 TII.get(IsMicroMips ? Mips::TEQ_MM : Mips::TEQ))
968             .addReg(Divisor.getReg(), getKillRegState(Divisor.isKill()))
969             .addReg(Mips::ZERO)
970             .addImm(7);
971 
972   // Use the 32-bit sub-register if this is a 64-bit division.
973   if (Is64Bit)
974     MIB->getOperand(0).setSubReg(Mips::sub_32);
975 
976   // Clear Divisor's kill flag.
977   Divisor.setIsKill(false);
978 
979   // We would normally delete the original instruction here but in this case
980   // we only needed to inject an additional instruction rather than replace it.
981 
982   return &MBB;
983 }
984 
985 MachineBasicBlock *
986 MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
987                                                 MachineBasicBlock *BB) const {
988   switch (MI.getOpcode()) {
989   default:
990     llvm_unreachable("Unexpected instr type to insert");
991   case Mips::ATOMIC_LOAD_ADD_I8:
992     return emitAtomicBinaryPartword(MI, BB, 1, Mips::ADDu);
993   case Mips::ATOMIC_LOAD_ADD_I16:
994     return emitAtomicBinaryPartword(MI, BB, 2, Mips::ADDu);
995   case Mips::ATOMIC_LOAD_ADD_I32:
996     return emitAtomicBinary(MI, BB, 4, Mips::ADDu);
997   case Mips::ATOMIC_LOAD_ADD_I64:
998     return emitAtomicBinary(MI, BB, 8, Mips::DADDu);
999 
1000   case Mips::ATOMIC_LOAD_AND_I8:
1001     return emitAtomicBinaryPartword(MI, BB, 1, Mips::AND);
1002   case Mips::ATOMIC_LOAD_AND_I16:
1003     return emitAtomicBinaryPartword(MI, BB, 2, Mips::AND);
1004   case Mips::ATOMIC_LOAD_AND_I32:
1005     return emitAtomicBinary(MI, BB, 4, Mips::AND);
1006   case Mips::ATOMIC_LOAD_AND_I64:
1007     return emitAtomicBinary(MI, BB, 8, Mips::AND64);
1008 
1009   case Mips::ATOMIC_LOAD_OR_I8:
1010     return emitAtomicBinaryPartword(MI, BB, 1, Mips::OR);
1011   case Mips::ATOMIC_LOAD_OR_I16:
1012     return emitAtomicBinaryPartword(MI, BB, 2, Mips::OR);
1013   case Mips::ATOMIC_LOAD_OR_I32:
1014     return emitAtomicBinary(MI, BB, 4, Mips::OR);
1015   case Mips::ATOMIC_LOAD_OR_I64:
1016     return emitAtomicBinary(MI, BB, 8, Mips::OR64);
1017 
1018   case Mips::ATOMIC_LOAD_XOR_I8:
1019     return emitAtomicBinaryPartword(MI, BB, 1, Mips::XOR);
1020   case Mips::ATOMIC_LOAD_XOR_I16:
1021     return emitAtomicBinaryPartword(MI, BB, 2, Mips::XOR);
1022   case Mips::ATOMIC_LOAD_XOR_I32:
1023     return emitAtomicBinary(MI, BB, 4, Mips::XOR);
1024   case Mips::ATOMIC_LOAD_XOR_I64:
1025     return emitAtomicBinary(MI, BB, 8, Mips::XOR64);
1026 
1027   case Mips::ATOMIC_LOAD_NAND_I8:
1028     return emitAtomicBinaryPartword(MI, BB, 1, 0, true);
1029   case Mips::ATOMIC_LOAD_NAND_I16:
1030     return emitAtomicBinaryPartword(MI, BB, 2, 0, true);
1031   case Mips::ATOMIC_LOAD_NAND_I32:
1032     return emitAtomicBinary(MI, BB, 4, 0, true);
1033   case Mips::ATOMIC_LOAD_NAND_I64:
1034     return emitAtomicBinary(MI, BB, 8, 0, true);
1035 
1036   case Mips::ATOMIC_LOAD_SUB_I8:
1037     return emitAtomicBinaryPartword(MI, BB, 1, Mips::SUBu);
1038   case Mips::ATOMIC_LOAD_SUB_I16:
1039     return emitAtomicBinaryPartword(MI, BB, 2, Mips::SUBu);
1040   case Mips::ATOMIC_LOAD_SUB_I32:
1041     return emitAtomicBinary(MI, BB, 4, Mips::SUBu);
1042   case Mips::ATOMIC_LOAD_SUB_I64:
1043     return emitAtomicBinary(MI, BB, 8, Mips::DSUBu);
1044 
1045   case Mips::ATOMIC_SWAP_I8:
1046     return emitAtomicBinaryPartword(MI, BB, 1, 0);
1047   case Mips::ATOMIC_SWAP_I16:
1048     return emitAtomicBinaryPartword(MI, BB, 2, 0);
1049   case Mips::ATOMIC_SWAP_I32:
1050     return emitAtomicBinary(MI, BB, 4, 0);
1051   case Mips::ATOMIC_SWAP_I64:
1052     return emitAtomicBinary(MI, BB, 8, 0);
1053 
1054   case Mips::ATOMIC_CMP_SWAP_I8:
1055     return emitAtomicCmpSwapPartword(MI, BB, 1);
1056   case Mips::ATOMIC_CMP_SWAP_I16:
1057     return emitAtomicCmpSwapPartword(MI, BB, 2);
1058   case Mips::ATOMIC_CMP_SWAP_I32:
1059     return emitAtomicCmpSwap(MI, BB, 4);
1060   case Mips::ATOMIC_CMP_SWAP_I64:
1061     return emitAtomicCmpSwap(MI, BB, 8);
1062   case Mips::PseudoSDIV:
1063   case Mips::PseudoUDIV:
1064   case Mips::DIV:
1065   case Mips::DIVU:
1066   case Mips::MOD:
1067   case Mips::MODU:
1068     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false,
1069                                false);
1070   case Mips::SDIV_MM_Pseudo:
1071   case Mips::UDIV_MM_Pseudo:
1072   case Mips::SDIV_MM:
1073   case Mips::UDIV_MM:
1074   case Mips::DIV_MMR6:
1075   case Mips::DIVU_MMR6:
1076   case Mips::MOD_MMR6:
1077   case Mips::MODU_MMR6:
1078     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), false, true);
1079   case Mips::PseudoDSDIV:
1080   case Mips::PseudoDUDIV:
1081   case Mips::DDIV:
1082   case Mips::DDIVU:
1083   case Mips::DMOD:
1084   case Mips::DMODU:
1085     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, false);
1086   case Mips::DDIV_MM64R6:
1087   case Mips::DDIVU_MM64R6:
1088   case Mips::DMOD_MM64R6:
1089   case Mips::DMODU_MM64R6:
1090     return insertDivByZeroTrap(MI, *BB, *Subtarget.getInstrInfo(), true, true);
1091   case Mips::SEL_D:
1092   case Mips::SEL_D_MMR6:
1093     return emitSEL_D(MI, BB);
1094 
1095   case Mips::PseudoSELECT_I:
1096   case Mips::PseudoSELECT_I64:
1097   case Mips::PseudoSELECT_S:
1098   case Mips::PseudoSELECT_D32:
1099   case Mips::PseudoSELECT_D64:
1100     return emitPseudoSELECT(MI, BB, false, Mips::BNE);
1101   case Mips::PseudoSELECTFP_F_I:
1102   case Mips::PseudoSELECTFP_F_I64:
1103   case Mips::PseudoSELECTFP_F_S:
1104   case Mips::PseudoSELECTFP_F_D32:
1105   case Mips::PseudoSELECTFP_F_D64:
1106     return emitPseudoSELECT(MI, BB, true, Mips::BC1F);
1107   case Mips::PseudoSELECTFP_T_I:
1108   case Mips::PseudoSELECTFP_T_I64:
1109   case Mips::PseudoSELECTFP_T_S:
1110   case Mips::PseudoSELECTFP_T_D32:
1111   case Mips::PseudoSELECTFP_T_D64:
1112     return emitPseudoSELECT(MI, BB, true, Mips::BC1T);
1113   }
1114 }
1115 
1116 // This function also handles Mips::ATOMIC_SWAP_I32 (when BinOpcode == 0), and
1117 // Mips::ATOMIC_LOAD_NAND_I32 (when Nand == true)
1118 MachineBasicBlock *MipsTargetLowering::emitAtomicBinary(MachineInstr &MI,
1119                                                         MachineBasicBlock *BB,
1120                                                         unsigned Size,
1121                                                         unsigned BinOpcode,
1122                                                         bool Nand) const {
1123   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicBinary.");
1124 
1125   MachineFunction *MF = BB->getParent();
1126   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1127   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1128   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1129   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1130   DebugLoc DL = MI.getDebugLoc();
1131   unsigned LL, SC, AND, NOR, ZERO, BEQ;
1132 
1133   if (Size == 4) {
1134     if (isMicroMips) {
1135       LL = Mips::LL_MM;
1136       SC = Mips::SC_MM;
1137     } else {
1138       LL = Subtarget.hasMips32r6()
1139                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1140                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1141       SC = Subtarget.hasMips32r6()
1142                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1143                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1144     }
1145 
1146     AND = Mips::AND;
1147     NOR = Mips::NOR;
1148     ZERO = Mips::ZERO;
1149     BEQ = Mips::BEQ;
1150   } else {
1151     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1152     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1153     AND = Mips::AND64;
1154     NOR = Mips::NOR64;
1155     ZERO = Mips::ZERO_64;
1156     BEQ = Mips::BEQ64;
1157   }
1158 
1159   unsigned OldVal = MI.getOperand(0).getReg();
1160   unsigned Ptr = MI.getOperand(1).getReg();
1161   unsigned Incr = MI.getOperand(2).getReg();
1162 
1163   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1164   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1165   unsigned Success = RegInfo.createVirtualRegister(RC);
1166 
1167   // insert new blocks after the current block
1168   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1169   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1170   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1171   MachineFunction::iterator It = ++BB->getIterator();
1172   MF->insert(It, loopMBB);
1173   MF->insert(It, exitMBB);
1174 
1175   // Transfer the remainder of BB and its successor edges to exitMBB.
1176   exitMBB->splice(exitMBB->begin(), BB,
1177                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1178   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1179 
1180   //  thisMBB:
1181   //    ...
1182   //    fallthrough --> loopMBB
1183   BB->addSuccessor(loopMBB);
1184   loopMBB->addSuccessor(loopMBB);
1185   loopMBB->addSuccessor(exitMBB);
1186 
1187   //  loopMBB:
1188   //    ll oldval, 0(ptr)
1189   //    <binop> storeval, oldval, incr
1190   //    sc success, storeval, 0(ptr)
1191   //    beq success, $0, loopMBB
1192   BB = loopMBB;
1193   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(Ptr).addImm(0);
1194   if (Nand) {
1195     //  and andres, oldval, incr
1196     //  nor storeval, $0, andres
1197     BuildMI(BB, DL, TII->get(AND), AndRes).addReg(OldVal).addReg(Incr);
1198     BuildMI(BB, DL, TII->get(NOR), StoreVal).addReg(ZERO).addReg(AndRes);
1199   } else if (BinOpcode) {
1200     //  <binop> storeval, oldval, incr
1201     BuildMI(BB, DL, TII->get(BinOpcode), StoreVal).addReg(OldVal).addReg(Incr);
1202   } else {
1203     StoreVal = Incr;
1204   }
1205   BuildMI(BB, DL, TII->get(SC), Success).addReg(StoreVal).addReg(Ptr).addImm(0);
1206   BuildMI(BB, DL, TII->get(BEQ)).addReg(Success).addReg(ZERO).addMBB(loopMBB);
1207 
1208   MI.eraseFromParent(); // The instruction is gone now.
1209 
1210   return exitMBB;
1211 }
1212 
1213 MachineBasicBlock *MipsTargetLowering::emitSignExtendToI32InReg(
1214     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned DstReg,
1215     unsigned SrcReg) const {
1216   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1217   const DebugLoc &DL = MI.getDebugLoc();
1218 
1219   if (Subtarget.hasMips32r2() && Size == 1) {
1220     BuildMI(BB, DL, TII->get(Mips::SEB), DstReg).addReg(SrcReg);
1221     return BB;
1222   }
1223 
1224   if (Subtarget.hasMips32r2() && Size == 2) {
1225     BuildMI(BB, DL, TII->get(Mips::SEH), DstReg).addReg(SrcReg);
1226     return BB;
1227   }
1228 
1229   MachineFunction *MF = BB->getParent();
1230   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1231   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1232   unsigned ScrReg = RegInfo.createVirtualRegister(RC);
1233 
1234   assert(Size < 32);
1235   int64_t ShiftImm = 32 - (Size * 8);
1236 
1237   BuildMI(BB, DL, TII->get(Mips::SLL), ScrReg).addReg(SrcReg).addImm(ShiftImm);
1238   BuildMI(BB, DL, TII->get(Mips::SRA), DstReg).addReg(ScrReg).addImm(ShiftImm);
1239 
1240   return BB;
1241 }
1242 
1243 MachineBasicBlock *MipsTargetLowering::emitAtomicBinaryPartword(
1244     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode,
1245     bool Nand) const {
1246   assert((Size == 1 || Size == 2) &&
1247          "Unsupported size for EmitAtomicBinaryPartial.");
1248 
1249   MachineFunction *MF = BB->getParent();
1250   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1251   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1252   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1253   const TargetRegisterClass *RCp =
1254     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1255   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1256   DebugLoc DL = MI.getDebugLoc();
1257 
1258   unsigned Dest = MI.getOperand(0).getReg();
1259   unsigned Ptr = MI.getOperand(1).getReg();
1260   unsigned Incr = MI.getOperand(2).getReg();
1261 
1262   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1263   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1264   unsigned Mask = RegInfo.createVirtualRegister(RC);
1265   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1266   unsigned NewVal = RegInfo.createVirtualRegister(RC);
1267   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1268   unsigned Incr2 = RegInfo.createVirtualRegister(RC);
1269   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1270   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1271   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1272   unsigned AndRes = RegInfo.createVirtualRegister(RC);
1273   unsigned BinOpRes = RegInfo.createVirtualRegister(RC);
1274   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1275   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1276   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1277   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1278   unsigned Success = RegInfo.createVirtualRegister(RC);
1279 
1280   unsigned LL, SC;
1281   if (isMicroMips) {
1282     LL = Mips::LL_MM;
1283     SC = Mips::SC_MM;
1284   } else {
1285     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1286                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1287     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1288                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1289   }
1290 
1291   // insert new blocks after the current block
1292   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1293   MachineBasicBlock *loopMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1294   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1295   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1296   MachineFunction::iterator It = ++BB->getIterator();
1297   MF->insert(It, loopMBB);
1298   MF->insert(It, sinkMBB);
1299   MF->insert(It, exitMBB);
1300 
1301   // Transfer the remainder of BB and its successor edges to exitMBB.
1302   exitMBB->splice(exitMBB->begin(), BB,
1303                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1304   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1305 
1306   BB->addSuccessor(loopMBB);
1307   loopMBB->addSuccessor(loopMBB);
1308   loopMBB->addSuccessor(sinkMBB);
1309   sinkMBB->addSuccessor(exitMBB);
1310 
1311   //  thisMBB:
1312   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1313   //    and     alignedaddr,ptr,masklsb2
1314   //    andi    ptrlsb2,ptr,3
1315   //    sll     shiftamt,ptrlsb2,3
1316   //    ori     maskupper,$0,255               # 0xff
1317   //    sll     mask,maskupper,shiftamt
1318   //    nor     mask2,$0,mask
1319   //    sll     incr2,incr,shiftamt
1320 
1321   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1322   BuildMI(BB, DL, TII->get(ABI.GetPtrAddiuOp()), MaskLSB2)
1323     .addReg(ABI.GetNullPtr()).addImm(-4);
1324   BuildMI(BB, DL, TII->get(ABI.GetPtrAndOp()), AlignedAddr)
1325     .addReg(Ptr).addReg(MaskLSB2);
1326   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1327       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1328   if (Subtarget.isLittle()) {
1329     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1330   } else {
1331     unsigned Off = RegInfo.createVirtualRegister(RC);
1332     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1333       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1334     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1335   }
1336   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1337     .addReg(Mips::ZERO).addImm(MaskImm);
1338   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1339     .addReg(MaskUpper).addReg(ShiftAmt);
1340   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1341   BuildMI(BB, DL, TII->get(Mips::SLLV), Incr2).addReg(Incr).addReg(ShiftAmt);
1342 
1343   // atomic.load.binop
1344   // loopMBB:
1345   //   ll      oldval,0(alignedaddr)
1346   //   binop   binopres,oldval,incr2
1347   //   and     newval,binopres,mask
1348   //   and     maskedoldval0,oldval,mask2
1349   //   or      storeval,maskedoldval0,newval
1350   //   sc      success,storeval,0(alignedaddr)
1351   //   beq     success,$0,loopMBB
1352 
1353   // atomic.swap
1354   // loopMBB:
1355   //   ll      oldval,0(alignedaddr)
1356   //   and     newval,incr2,mask
1357   //   and     maskedoldval0,oldval,mask2
1358   //   or      storeval,maskedoldval0,newval
1359   //   sc      success,storeval,0(alignedaddr)
1360   //   beq     success,$0,loopMBB
1361 
1362   BB = loopMBB;
1363   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1364   if (Nand) {
1365     //  and andres, oldval, incr2
1366     //  nor binopres, $0, andres
1367     //  and newval, binopres, mask
1368     BuildMI(BB, DL, TII->get(Mips::AND), AndRes).addReg(OldVal).addReg(Incr2);
1369     BuildMI(BB, DL, TII->get(Mips::NOR), BinOpRes)
1370       .addReg(Mips::ZERO).addReg(AndRes);
1371     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1372   } else if (BinOpcode) {
1373     //  <binop> binopres, oldval, incr2
1374     //  and newval, binopres, mask
1375     BuildMI(BB, DL, TII->get(BinOpcode), BinOpRes).addReg(OldVal).addReg(Incr2);
1376     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(BinOpRes).addReg(Mask);
1377   } else { // atomic.swap
1378     //  and newval, incr2, mask
1379     BuildMI(BB, DL, TII->get(Mips::AND), NewVal).addReg(Incr2).addReg(Mask);
1380   }
1381 
1382   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1383     .addReg(OldVal).addReg(Mask2);
1384   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1385     .addReg(MaskedOldVal0).addReg(NewVal);
1386   BuildMI(BB, DL, TII->get(SC), Success)
1387     .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1388   BuildMI(BB, DL, TII->get(Mips::BEQ))
1389     .addReg(Success).addReg(Mips::ZERO).addMBB(loopMBB);
1390 
1391   //  sinkMBB:
1392   //    and     maskedoldval1,oldval,mask
1393   //    srl     srlres,maskedoldval1,shiftamt
1394   //    sign_extend dest,srlres
1395   BB = sinkMBB;
1396 
1397   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1398     .addReg(OldVal).addReg(Mask);
1399   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1400       .addReg(MaskedOldVal1).addReg(ShiftAmt);
1401   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1402 
1403   MI.eraseFromParent(); // The instruction is gone now.
1404 
1405   return exitMBB;
1406 }
1407 
1408 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwap(MachineInstr &MI,
1409                                                          MachineBasicBlock *BB,
1410                                                          unsigned Size) const {
1411   assert((Size == 4 || Size == 8) && "Unsupported size for EmitAtomicCmpSwap.");
1412 
1413   MachineFunction *MF = BB->getParent();
1414   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1415   const TargetRegisterClass *RC = getRegClassFor(MVT::getIntegerVT(Size * 8));
1416   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1417   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1418   DebugLoc DL = MI.getDebugLoc();
1419   unsigned LL, SC, ZERO, BNE, BEQ;
1420 
1421   if (Size == 4) {
1422     if (isMicroMips) {
1423       LL = Mips::LL_MM;
1424       SC = Mips::SC_MM;
1425     } else {
1426       LL = Subtarget.hasMips32r6()
1427                ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1428                : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1429       SC = Subtarget.hasMips32r6()
1430                ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1431                : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1432     }
1433 
1434     ZERO = Mips::ZERO;
1435     BNE = Mips::BNE;
1436     BEQ = Mips::BEQ;
1437   } else {
1438     LL = Subtarget.hasMips64r6() ? Mips::LLD_R6 : Mips::LLD;
1439     SC = Subtarget.hasMips64r6() ? Mips::SCD_R6 : Mips::SCD;
1440     ZERO = Mips::ZERO_64;
1441     BNE = Mips::BNE64;
1442     BEQ = Mips::BEQ64;
1443   }
1444 
1445   unsigned Dest = MI.getOperand(0).getReg();
1446   unsigned Ptr = MI.getOperand(1).getReg();
1447   unsigned OldVal = MI.getOperand(2).getReg();
1448   unsigned NewVal = MI.getOperand(3).getReg();
1449 
1450   unsigned Success = RegInfo.createVirtualRegister(RC);
1451 
1452   // insert new blocks after the current block
1453   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1454   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1455   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1456   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1457   MachineFunction::iterator It = ++BB->getIterator();
1458   MF->insert(It, loop1MBB);
1459   MF->insert(It, loop2MBB);
1460   MF->insert(It, exitMBB);
1461 
1462   // Transfer the remainder of BB and its successor edges to exitMBB.
1463   exitMBB->splice(exitMBB->begin(), BB,
1464                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1465   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1466 
1467   //  thisMBB:
1468   //    ...
1469   //    fallthrough --> loop1MBB
1470   BB->addSuccessor(loop1MBB);
1471   loop1MBB->addSuccessor(exitMBB);
1472   loop1MBB->addSuccessor(loop2MBB);
1473   loop2MBB->addSuccessor(loop1MBB);
1474   loop2MBB->addSuccessor(exitMBB);
1475 
1476   // loop1MBB:
1477   //   ll dest, 0(ptr)
1478   //   bne dest, oldval, exitMBB
1479   BB = loop1MBB;
1480   BuildMI(BB, DL, TII->get(LL), Dest).addReg(Ptr).addImm(0);
1481   BuildMI(BB, DL, TII->get(BNE))
1482     .addReg(Dest).addReg(OldVal).addMBB(exitMBB);
1483 
1484   // loop2MBB:
1485   //   sc success, newval, 0(ptr)
1486   //   beq success, $0, loop1MBB
1487   BB = loop2MBB;
1488   BuildMI(BB, DL, TII->get(SC), Success)
1489     .addReg(NewVal).addReg(Ptr).addImm(0);
1490   BuildMI(BB, DL, TII->get(BEQ))
1491     .addReg(Success).addReg(ZERO).addMBB(loop1MBB);
1492 
1493   MI.eraseFromParent(); // The instruction is gone now.
1494 
1495   return exitMBB;
1496 }
1497 
1498 MachineBasicBlock *MipsTargetLowering::emitAtomicCmpSwapPartword(
1499     MachineInstr &MI, MachineBasicBlock *BB, unsigned Size) const {
1500   assert((Size == 1 || Size == 2) &&
1501       "Unsupported size for EmitAtomicCmpSwapPartial.");
1502 
1503   MachineFunction *MF = BB->getParent();
1504   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1505   const TargetRegisterClass *RC = getRegClassFor(MVT::i32);
1506   const bool ArePtrs64bit = ABI.ArePtrs64bit();
1507   const TargetRegisterClass *RCp =
1508     getRegClassFor(ArePtrs64bit ? MVT::i64 : MVT::i32);
1509   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1510   DebugLoc DL = MI.getDebugLoc();
1511 
1512   unsigned Dest = MI.getOperand(0).getReg();
1513   unsigned Ptr = MI.getOperand(1).getReg();
1514   unsigned CmpVal = MI.getOperand(2).getReg();
1515   unsigned NewVal = MI.getOperand(3).getReg();
1516 
1517   unsigned AlignedAddr = RegInfo.createVirtualRegister(RCp);
1518   unsigned ShiftAmt = RegInfo.createVirtualRegister(RC);
1519   unsigned Mask = RegInfo.createVirtualRegister(RC);
1520   unsigned Mask2 = RegInfo.createVirtualRegister(RC);
1521   unsigned ShiftedCmpVal = RegInfo.createVirtualRegister(RC);
1522   unsigned OldVal = RegInfo.createVirtualRegister(RC);
1523   unsigned MaskedOldVal0 = RegInfo.createVirtualRegister(RC);
1524   unsigned ShiftedNewVal = RegInfo.createVirtualRegister(RC);
1525   unsigned MaskLSB2 = RegInfo.createVirtualRegister(RCp);
1526   unsigned PtrLSB2 = RegInfo.createVirtualRegister(RC);
1527   unsigned MaskUpper = RegInfo.createVirtualRegister(RC);
1528   unsigned MaskedCmpVal = RegInfo.createVirtualRegister(RC);
1529   unsigned MaskedNewVal = RegInfo.createVirtualRegister(RC);
1530   unsigned MaskedOldVal1 = RegInfo.createVirtualRegister(RC);
1531   unsigned StoreVal = RegInfo.createVirtualRegister(RC);
1532   unsigned SrlRes = RegInfo.createVirtualRegister(RC);
1533   unsigned Success = RegInfo.createVirtualRegister(RC);
1534   unsigned LL, SC;
1535 
1536   if (isMicroMips) {
1537     LL = Mips::LL_MM;
1538     SC = Mips::SC_MM;
1539   } else {
1540     LL = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::LL64_R6 : Mips::LL_R6)
1541                                  : (ArePtrs64bit ? Mips::LL64 : Mips::LL);
1542     SC = Subtarget.hasMips32r6() ? (ArePtrs64bit ? Mips::SC64_R6 : Mips::SC_R6)
1543                                  : (ArePtrs64bit ? Mips::SC64 : Mips::SC);
1544   }
1545 
1546   // insert new blocks after the current block
1547   const BasicBlock *LLVM_BB = BB->getBasicBlock();
1548   MachineBasicBlock *loop1MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1549   MachineBasicBlock *loop2MBB = MF->CreateMachineBasicBlock(LLVM_BB);
1550   MachineBasicBlock *sinkMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1551   MachineBasicBlock *exitMBB = MF->CreateMachineBasicBlock(LLVM_BB);
1552   MachineFunction::iterator It = ++BB->getIterator();
1553   MF->insert(It, loop1MBB);
1554   MF->insert(It, loop2MBB);
1555   MF->insert(It, sinkMBB);
1556   MF->insert(It, exitMBB);
1557 
1558   // Transfer the remainder of BB and its successor edges to exitMBB.
1559   exitMBB->splice(exitMBB->begin(), BB,
1560                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
1561   exitMBB->transferSuccessorsAndUpdatePHIs(BB);
1562 
1563   BB->addSuccessor(loop1MBB);
1564   loop1MBB->addSuccessor(sinkMBB);
1565   loop1MBB->addSuccessor(loop2MBB);
1566   loop2MBB->addSuccessor(loop1MBB);
1567   loop2MBB->addSuccessor(sinkMBB);
1568   sinkMBB->addSuccessor(exitMBB);
1569 
1570   // FIXME: computation of newval2 can be moved to loop2MBB.
1571   //  thisMBB:
1572   //    addiu   masklsb2,$0,-4                # 0xfffffffc
1573   //    and     alignedaddr,ptr,masklsb2
1574   //    andi    ptrlsb2,ptr,3
1575   //    xori    ptrlsb2,ptrlsb2,3              # Only for BE
1576   //    sll     shiftamt,ptrlsb2,3
1577   //    ori     maskupper,$0,255               # 0xff
1578   //    sll     mask,maskupper,shiftamt
1579   //    nor     mask2,$0,mask
1580   //    andi    maskedcmpval,cmpval,255
1581   //    sll     shiftedcmpval,maskedcmpval,shiftamt
1582   //    andi    maskednewval,newval,255
1583   //    sll     shiftednewval,maskednewval,shiftamt
1584   int64_t MaskImm = (Size == 1) ? 255 : 65535;
1585   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::DADDiu : Mips::ADDiu), MaskLSB2)
1586     .addReg(ABI.GetNullPtr()).addImm(-4);
1587   BuildMI(BB, DL, TII->get(ArePtrs64bit ? Mips::AND64 : Mips::AND), AlignedAddr)
1588     .addReg(Ptr).addReg(MaskLSB2);
1589   BuildMI(BB, DL, TII->get(Mips::ANDi), PtrLSB2)
1590       .addReg(Ptr, 0, ArePtrs64bit ? Mips::sub_32 : 0).addImm(3);
1591   if (Subtarget.isLittle()) {
1592     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(PtrLSB2).addImm(3);
1593   } else {
1594     unsigned Off = RegInfo.createVirtualRegister(RC);
1595     BuildMI(BB, DL, TII->get(Mips::XORi), Off)
1596       .addReg(PtrLSB2).addImm((Size == 1) ? 3 : 2);
1597     BuildMI(BB, DL, TII->get(Mips::SLL), ShiftAmt).addReg(Off).addImm(3);
1598   }
1599   BuildMI(BB, DL, TII->get(Mips::ORi), MaskUpper)
1600     .addReg(Mips::ZERO).addImm(MaskImm);
1601   BuildMI(BB, DL, TII->get(Mips::SLLV), Mask)
1602     .addReg(MaskUpper).addReg(ShiftAmt);
1603   BuildMI(BB, DL, TII->get(Mips::NOR), Mask2).addReg(Mips::ZERO).addReg(Mask);
1604   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedCmpVal)
1605     .addReg(CmpVal).addImm(MaskImm);
1606   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedCmpVal)
1607     .addReg(MaskedCmpVal).addReg(ShiftAmt);
1608   BuildMI(BB, DL, TII->get(Mips::ANDi), MaskedNewVal)
1609     .addReg(NewVal).addImm(MaskImm);
1610   BuildMI(BB, DL, TII->get(Mips::SLLV), ShiftedNewVal)
1611     .addReg(MaskedNewVal).addReg(ShiftAmt);
1612 
1613   //  loop1MBB:
1614   //    ll      oldval,0(alginedaddr)
1615   //    and     maskedoldval0,oldval,mask
1616   //    bne     maskedoldval0,shiftedcmpval,sinkMBB
1617   BB = loop1MBB;
1618   BuildMI(BB, DL, TII->get(LL), OldVal).addReg(AlignedAddr).addImm(0);
1619   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal0)
1620     .addReg(OldVal).addReg(Mask);
1621   BuildMI(BB, DL, TII->get(Mips::BNE))
1622     .addReg(MaskedOldVal0).addReg(ShiftedCmpVal).addMBB(sinkMBB);
1623 
1624   //  loop2MBB:
1625   //    and     maskedoldval1,oldval,mask2
1626   //    or      storeval,maskedoldval1,shiftednewval
1627   //    sc      success,storeval,0(alignedaddr)
1628   //    beq     success,$0,loop1MBB
1629   BB = loop2MBB;
1630   BuildMI(BB, DL, TII->get(Mips::AND), MaskedOldVal1)
1631     .addReg(OldVal).addReg(Mask2);
1632   BuildMI(BB, DL, TII->get(Mips::OR), StoreVal)
1633     .addReg(MaskedOldVal1).addReg(ShiftedNewVal);
1634   BuildMI(BB, DL, TII->get(SC), Success)
1635       .addReg(StoreVal).addReg(AlignedAddr).addImm(0);
1636   BuildMI(BB, DL, TII->get(Mips::BEQ))
1637       .addReg(Success).addReg(Mips::ZERO).addMBB(loop1MBB);
1638 
1639   //  sinkMBB:
1640   //    srl     srlres,maskedoldval0,shiftamt
1641   //    sign_extend dest,srlres
1642   BB = sinkMBB;
1643 
1644   BuildMI(BB, DL, TII->get(Mips::SRLV), SrlRes)
1645       .addReg(MaskedOldVal0).addReg(ShiftAmt);
1646   BB = emitSignExtendToI32InReg(MI, BB, Size, Dest, SrlRes);
1647 
1648   MI.eraseFromParent(); // The instruction is gone now.
1649 
1650   return exitMBB;
1651 }
1652 
1653 MachineBasicBlock *MipsTargetLowering::emitSEL_D(MachineInstr &MI,
1654                                                  MachineBasicBlock *BB) const {
1655   MachineFunction *MF = BB->getParent();
1656   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
1657   const TargetInstrInfo *TII = Subtarget.getInstrInfo();
1658   MachineRegisterInfo &RegInfo = MF->getRegInfo();
1659   DebugLoc DL = MI.getDebugLoc();
1660   MachineBasicBlock::iterator II(MI);
1661 
1662   unsigned Fc = MI.getOperand(1).getReg();
1663   const auto &FGR64RegClass = TRI->getRegClass(Mips::FGR64RegClassID);
1664 
1665   unsigned Fc2 = RegInfo.createVirtualRegister(FGR64RegClass);
1666 
1667   BuildMI(*BB, II, DL, TII->get(Mips::SUBREG_TO_REG), Fc2)
1668       .addImm(0)
1669       .addReg(Fc)
1670       .addImm(Mips::sub_lo);
1671 
1672   // We don't erase the original instruction, we just replace the condition
1673   // register with the 64-bit super-register.
1674   MI.getOperand(1).setReg(Fc2);
1675 
1676   return BB;
1677 }
1678 
1679 //===----------------------------------------------------------------------===//
1680 //  Misc Lower Operation implementation
1681 //===----------------------------------------------------------------------===//
1682 SDValue MipsTargetLowering::lowerBR_JT(SDValue Op, SelectionDAG &DAG) const {
1683   SDValue Chain = Op.getOperand(0);
1684   SDValue Table = Op.getOperand(1);
1685   SDValue Index = Op.getOperand(2);
1686   SDLoc DL(Op);
1687   auto &TD = DAG.getDataLayout();
1688   EVT PTy = getPointerTy(TD);
1689   unsigned EntrySize =
1690       DAG.getMachineFunction().getJumpTableInfo()->getEntrySize(TD);
1691 
1692   Index = DAG.getNode(ISD::MUL, DL, PTy, Index,
1693                       DAG.getConstant(EntrySize, DL, PTy));
1694   SDValue Addr = DAG.getNode(ISD::ADD, DL, PTy, Index, Table);
1695 
1696   EVT MemVT = EVT::getIntegerVT(*DAG.getContext(), EntrySize * 8);
1697   Addr = DAG.getExtLoad(
1698       ISD::SEXTLOAD, DL, PTy, Chain, Addr,
1699       MachinePointerInfo::getJumpTable(DAG.getMachineFunction()), MemVT);
1700   Chain = Addr.getValue(1);
1701 
1702   if (isPositionIndependent() || ABI.IsN64()) {
1703     // For PIC, the sequence is:
1704     // BRIND(load(Jumptable + index) + RelocBase)
1705     // RelocBase can be JumpTable, GOT or some sort of global base.
1706     Addr = DAG.getNode(ISD::ADD, DL, PTy, Addr,
1707                        getPICJumpTableRelocBase(Table, DAG));
1708   }
1709 
1710   return DAG.getNode(ISD::BRIND, DL, MVT::Other, Chain, Addr);
1711 }
1712 
1713 SDValue MipsTargetLowering::lowerBRCOND(SDValue Op, SelectionDAG &DAG) const {
1714   // The first operand is the chain, the second is the condition, the third is
1715   // the block to branch to if the condition is true.
1716   SDValue Chain = Op.getOperand(0);
1717   SDValue Dest = Op.getOperand(2);
1718   SDLoc DL(Op);
1719 
1720   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1721   SDValue CondRes = createFPCmp(DAG, Op.getOperand(1));
1722 
1723   // Return if flag is not set by a floating point comparison.
1724   if (CondRes.getOpcode() != MipsISD::FPCmp)
1725     return Op;
1726 
1727   SDValue CCNode  = CondRes.getOperand(2);
1728   Mips::CondCode CC =
1729     (Mips::CondCode)cast<ConstantSDNode>(CCNode)->getZExtValue();
1730   unsigned Opc = invertFPCondCodeUser(CC) ? Mips::BRANCH_F : Mips::BRANCH_T;
1731   SDValue BrCode = DAG.getConstant(Opc, DL, MVT::i32);
1732   SDValue FCC0 = DAG.getRegister(Mips::FCC0, MVT::i32);
1733   return DAG.getNode(MipsISD::FPBrcond, DL, Op.getValueType(), Chain, BrCode,
1734                      FCC0, Dest, CondRes);
1735 }
1736 
1737 SDValue MipsTargetLowering::
1738 lowerSELECT(SDValue Op, SelectionDAG &DAG) const
1739 {
1740   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1741   SDValue Cond = createFPCmp(DAG, Op.getOperand(0));
1742 
1743   // Return if flag is not set by a floating point comparison.
1744   if (Cond.getOpcode() != MipsISD::FPCmp)
1745     return Op;
1746 
1747   return createCMovFP(DAG, Cond, Op.getOperand(1), Op.getOperand(2),
1748                       SDLoc(Op));
1749 }
1750 
1751 SDValue MipsTargetLowering::lowerSETCC(SDValue Op, SelectionDAG &DAG) const {
1752   assert(!Subtarget.hasMips32r6() && !Subtarget.hasMips64r6());
1753   SDValue Cond = createFPCmp(DAG, Op);
1754 
1755   assert(Cond.getOpcode() == MipsISD::FPCmp &&
1756          "Floating point operand expected.");
1757 
1758   SDLoc DL(Op);
1759   SDValue True  = DAG.getConstant(1, DL, MVT::i32);
1760   SDValue False = DAG.getConstant(0, DL, MVT::i32);
1761 
1762   return createCMovFP(DAG, Cond, True, False, DL);
1763 }
1764 
1765 SDValue MipsTargetLowering::lowerGlobalAddress(SDValue Op,
1766                                                SelectionDAG &DAG) const {
1767   EVT Ty = Op.getValueType();
1768   GlobalAddressSDNode *N = cast<GlobalAddressSDNode>(Op);
1769   const GlobalValue *GV = N->getGlobal();
1770 
1771   if (!isPositionIndependent() && !ABI.IsN64()) {
1772     const MipsTargetObjectFile *TLOF =
1773         static_cast<const MipsTargetObjectFile *>(
1774             getTargetMachine().getObjFileLowering());
1775     const GlobalObject *GO = GV->getBaseObject();
1776     if (GO && TLOF->IsGlobalInSmallSection(GO, getTargetMachine()))
1777       // %gp_rel relocation
1778       return getAddrGPRel(N, SDLoc(N), Ty, DAG);
1779 
1780     // %hi/%lo relocation
1781     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1782   }
1783 
1784   // Every other architecture would use shouldAssumeDSOLocal in here, but
1785   // mips is special.
1786   // * In PIC code mips requires got loads even for local statics!
1787   // * To save on got entries, for local statics the got entry contains the
1788   //   page and an additional add instruction takes care of the low bits.
1789   // * It is legal to access a hidden symbol with a non hidden undefined,
1790   //   so one cannot guarantee that all access to a hidden symbol will know
1791   //   it is hidden.
1792   // * Mips linkers don't support creating a page and a full got entry for
1793   //   the same symbol.
1794   // * Given all that, we have to use a full got entry for hidden symbols :-(
1795   if (GV->hasLocalLinkage())
1796     return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1797 
1798   if (LargeGOT)
1799     return getAddrGlobalLargeGOT(
1800         N, SDLoc(N), Ty, DAG, MipsII::MO_GOT_HI16, MipsII::MO_GOT_LO16,
1801         DAG.getEntryNode(),
1802         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
1803 
1804   return getAddrGlobal(
1805       N, SDLoc(N), Ty, DAG,
1806       (ABI.IsN32() || ABI.IsN64()) ? MipsII::MO_GOT_DISP : MipsII::MO_GOT,
1807       DAG.getEntryNode(), MachinePointerInfo::getGOT(DAG.getMachineFunction()));
1808 }
1809 
1810 SDValue MipsTargetLowering::lowerBlockAddress(SDValue Op,
1811                                               SelectionDAG &DAG) const {
1812   BlockAddressSDNode *N = cast<BlockAddressSDNode>(Op);
1813   EVT Ty = Op.getValueType();
1814 
1815   if (!isPositionIndependent() && !ABI.IsN64())
1816     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1817 
1818   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1819 }
1820 
1821 SDValue MipsTargetLowering::
1822 lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const
1823 {
1824   // If the relocation model is PIC, use the General Dynamic TLS Model or
1825   // Local Dynamic TLS model, otherwise use the Initial Exec or
1826   // Local Exec TLS Model.
1827 
1828   GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
1829   if (DAG.getTarget().Options.EmulatedTLS)
1830     return LowerToTLSEmulatedModel(GA, DAG);
1831 
1832   SDLoc DL(GA);
1833   const GlobalValue *GV = GA->getGlobal();
1834   EVT PtrVT = getPointerTy(DAG.getDataLayout());
1835 
1836   TLSModel::Model model = getTargetMachine().getTLSModel(GV);
1837 
1838   if (model == TLSModel::GeneralDynamic || model == TLSModel::LocalDynamic) {
1839     // General Dynamic and Local Dynamic TLS Model.
1840     unsigned Flag = (model == TLSModel::LocalDynamic) ? MipsII::MO_TLSLDM
1841                                                       : MipsII::MO_TLSGD;
1842 
1843     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, Flag);
1844     SDValue Argument = DAG.getNode(MipsISD::Wrapper, DL, PtrVT,
1845                                    getGlobalReg(DAG, PtrVT), TGA);
1846     unsigned PtrSize = PtrVT.getSizeInBits();
1847     IntegerType *PtrTy = Type::getIntNTy(*DAG.getContext(), PtrSize);
1848 
1849     SDValue TlsGetAddr = DAG.getExternalSymbol("__tls_get_addr", PtrVT);
1850 
1851     ArgListTy Args;
1852     ArgListEntry Entry;
1853     Entry.Node = Argument;
1854     Entry.Ty = PtrTy;
1855     Args.push_back(Entry);
1856 
1857     TargetLowering::CallLoweringInfo CLI(DAG);
1858     CLI.setDebugLoc(DL).setChain(DAG.getEntryNode())
1859       .setCallee(CallingConv::C, PtrTy, TlsGetAddr, std::move(Args));
1860     std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
1861 
1862     SDValue Ret = CallResult.first;
1863 
1864     if (model != TLSModel::LocalDynamic)
1865       return Ret;
1866 
1867     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1868                                                MipsII::MO_DTPREL_HI);
1869     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
1870     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1871                                                MipsII::MO_DTPREL_LO);
1872     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
1873     SDValue Add = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Ret);
1874     return DAG.getNode(ISD::ADD, DL, PtrVT, Add, Lo);
1875   }
1876 
1877   SDValue Offset;
1878   if (model == TLSModel::InitialExec) {
1879     // Initial Exec TLS Model
1880     SDValue TGA = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1881                                              MipsII::MO_GOTTPREL);
1882     TGA = DAG.getNode(MipsISD::Wrapper, DL, PtrVT, getGlobalReg(DAG, PtrVT),
1883                       TGA);
1884     Offset =
1885         DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), TGA, MachinePointerInfo());
1886   } else {
1887     // Local Exec TLS Model
1888     assert(model == TLSModel::LocalExec);
1889     SDValue TGAHi = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1890                                                MipsII::MO_TPREL_HI);
1891     SDValue TGALo = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0,
1892                                                MipsII::MO_TPREL_LO);
1893     SDValue Hi = DAG.getNode(MipsISD::Hi, DL, PtrVT, TGAHi);
1894     SDValue Lo = DAG.getNode(MipsISD::Lo, DL, PtrVT, TGALo);
1895     Offset = DAG.getNode(ISD::ADD, DL, PtrVT, Hi, Lo);
1896   }
1897 
1898   SDValue ThreadPointer = DAG.getNode(MipsISD::ThreadPointer, DL, PtrVT);
1899   return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadPointer, Offset);
1900 }
1901 
1902 SDValue MipsTargetLowering::
1903 lowerJumpTable(SDValue Op, SelectionDAG &DAG) const
1904 {
1905   JumpTableSDNode *N = cast<JumpTableSDNode>(Op);
1906   EVT Ty = Op.getValueType();
1907 
1908   if (!isPositionIndependent() && !ABI.IsN64())
1909     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1910 
1911   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1912 }
1913 
1914 SDValue MipsTargetLowering::
1915 lowerConstantPool(SDValue Op, SelectionDAG &DAG) const
1916 {
1917   ConstantPoolSDNode *N = cast<ConstantPoolSDNode>(Op);
1918   EVT Ty = Op.getValueType();
1919 
1920   if (!isPositionIndependent() && !ABI.IsN64()) {
1921     const MipsTargetObjectFile *TLOF =
1922         static_cast<const MipsTargetObjectFile *>(
1923             getTargetMachine().getObjFileLowering());
1924 
1925     if (TLOF->IsConstantInSmallSection(DAG.getDataLayout(), N->getConstVal(),
1926                                        getTargetMachine()))
1927       // %gp_rel relocation
1928       return getAddrGPRel(N, SDLoc(N), Ty, DAG);
1929 
1930     return getAddrNonPIC(N, SDLoc(N), Ty, DAG);
1931   }
1932 
1933   return getAddrLocal(N, SDLoc(N), Ty, DAG, ABI.IsN32() || ABI.IsN64());
1934 }
1935 
1936 SDValue MipsTargetLowering::lowerVASTART(SDValue Op, SelectionDAG &DAG) const {
1937   MachineFunction &MF = DAG.getMachineFunction();
1938   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
1939 
1940   SDLoc DL(Op);
1941   SDValue FI = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(),
1942                                  getPointerTy(MF.getDataLayout()));
1943 
1944   // vastart just stores the address of the VarArgsFrameIndex slot into the
1945   // memory location argument.
1946   const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
1947   return DAG.getStore(Op.getOperand(0), DL, FI, Op.getOperand(1),
1948                       MachinePointerInfo(SV));
1949 }
1950 
1951 SDValue MipsTargetLowering::lowerVAARG(SDValue Op, SelectionDAG &DAG) const {
1952   SDNode *Node = Op.getNode();
1953   EVT VT = Node->getValueType(0);
1954   SDValue Chain = Node->getOperand(0);
1955   SDValue VAListPtr = Node->getOperand(1);
1956   unsigned Align = Node->getConstantOperandVal(3);
1957   const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
1958   SDLoc DL(Node);
1959   unsigned ArgSlotSizeInBytes = (ABI.IsN32() || ABI.IsN64()) ? 8 : 4;
1960 
1961   SDValue VAListLoad = DAG.getLoad(getPointerTy(DAG.getDataLayout()), DL, Chain,
1962                                    VAListPtr, MachinePointerInfo(SV));
1963   SDValue VAList = VAListLoad;
1964 
1965   // Re-align the pointer if necessary.
1966   // It should only ever be necessary for 64-bit types on O32 since the minimum
1967   // argument alignment is the same as the maximum type alignment for N32/N64.
1968   //
1969   // FIXME: We currently align too often. The code generator doesn't notice
1970   //        when the pointer is still aligned from the last va_arg (or pair of
1971   //        va_args for the i64 on O32 case).
1972   if (Align > getMinStackArgumentAlignment()) {
1973     assert(((Align & (Align-1)) == 0) && "Expected Align to be a power of 2");
1974 
1975     VAList = DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
1976                          DAG.getConstant(Align - 1, DL, VAList.getValueType()));
1977 
1978     VAList = DAG.getNode(ISD::AND, DL, VAList.getValueType(), VAList,
1979                          DAG.getConstant(-(int64_t)Align, DL,
1980                                          VAList.getValueType()));
1981   }
1982 
1983   // Increment the pointer, VAList, to the next vaarg.
1984   auto &TD = DAG.getDataLayout();
1985   unsigned ArgSizeInBytes =
1986       TD.getTypeAllocSize(VT.getTypeForEVT(*DAG.getContext()));
1987   SDValue Tmp3 =
1988       DAG.getNode(ISD::ADD, DL, VAList.getValueType(), VAList,
1989                   DAG.getConstant(alignTo(ArgSizeInBytes, ArgSlotSizeInBytes),
1990                                   DL, VAList.getValueType()));
1991   // Store the incremented VAList to the legalized pointer
1992   Chain = DAG.getStore(VAListLoad.getValue(1), DL, Tmp3, VAListPtr,
1993                        MachinePointerInfo(SV));
1994 
1995   // In big-endian mode we must adjust the pointer when the load size is smaller
1996   // than the argument slot size. We must also reduce the known alignment to
1997   // match. For example in the N64 ABI, we must add 4 bytes to the offset to get
1998   // the correct half of the slot, and reduce the alignment from 8 (slot
1999   // alignment) down to 4 (type alignment).
2000   if (!Subtarget.isLittle() && ArgSizeInBytes < ArgSlotSizeInBytes) {
2001     unsigned Adjustment = ArgSlotSizeInBytes - ArgSizeInBytes;
2002     VAList = DAG.getNode(ISD::ADD, DL, VAListPtr.getValueType(), VAList,
2003                          DAG.getIntPtrConstant(Adjustment, DL));
2004   }
2005   // Load the actual argument out of the pointer VAList
2006   return DAG.getLoad(VT, DL, Chain, VAList, MachinePointerInfo());
2007 }
2008 
2009 static SDValue lowerFCOPYSIGN32(SDValue Op, SelectionDAG &DAG,
2010                                 bool HasExtractInsert) {
2011   EVT TyX = Op.getOperand(0).getValueType();
2012   EVT TyY = Op.getOperand(1).getValueType();
2013   SDLoc DL(Op);
2014   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2015   SDValue Const31 = DAG.getConstant(31, DL, MVT::i32);
2016   SDValue Res;
2017 
2018   // If operand is of type f64, extract the upper 32-bit. Otherwise, bitcast it
2019   // to i32.
2020   SDValue X = (TyX == MVT::f32) ?
2021     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(0)) :
2022     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(0),
2023                 Const1);
2024   SDValue Y = (TyY == MVT::f32) ?
2025     DAG.getNode(ISD::BITCAST, DL, MVT::i32, Op.getOperand(1)) :
2026     DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32, Op.getOperand(1),
2027                 Const1);
2028 
2029   if (HasExtractInsert) {
2030     // ext  E, Y, 31, 1  ; extract bit31 of Y
2031     // ins  X, E, 31, 1  ; insert extracted bit at bit31 of X
2032     SDValue E = DAG.getNode(MipsISD::Ext, DL, MVT::i32, Y, Const31, Const1);
2033     Res = DAG.getNode(MipsISD::Ins, DL, MVT::i32, E, Const31, Const1, X);
2034   } else {
2035     // sll SllX, X, 1
2036     // srl SrlX, SllX, 1
2037     // srl SrlY, Y, 31
2038     // sll SllY, SrlX, 31
2039     // or  Or, SrlX, SllY
2040     SDValue SllX = DAG.getNode(ISD::SHL, DL, MVT::i32, X, Const1);
2041     SDValue SrlX = DAG.getNode(ISD::SRL, DL, MVT::i32, SllX, Const1);
2042     SDValue SrlY = DAG.getNode(ISD::SRL, DL, MVT::i32, Y, Const31);
2043     SDValue SllY = DAG.getNode(ISD::SHL, DL, MVT::i32, SrlY, Const31);
2044     Res = DAG.getNode(ISD::OR, DL, MVT::i32, SrlX, SllY);
2045   }
2046 
2047   if (TyX == MVT::f32)
2048     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Res);
2049 
2050   SDValue LowX = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2051                              Op.getOperand(0),
2052                              DAG.getConstant(0, DL, MVT::i32));
2053   return DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64, LowX, Res);
2054 }
2055 
2056 static SDValue lowerFCOPYSIGN64(SDValue Op, SelectionDAG &DAG,
2057                                 bool HasExtractInsert) {
2058   unsigned WidthX = Op.getOperand(0).getValueSizeInBits();
2059   unsigned WidthY = Op.getOperand(1).getValueSizeInBits();
2060   EVT TyX = MVT::getIntegerVT(WidthX), TyY = MVT::getIntegerVT(WidthY);
2061   SDLoc DL(Op);
2062   SDValue Const1 = DAG.getConstant(1, DL, MVT::i32);
2063 
2064   // Bitcast to integer nodes.
2065   SDValue X = DAG.getNode(ISD::BITCAST, DL, TyX, Op.getOperand(0));
2066   SDValue Y = DAG.getNode(ISD::BITCAST, DL, TyY, Op.getOperand(1));
2067 
2068   if (HasExtractInsert) {
2069     // ext  E, Y, width(Y) - 1, 1  ; extract bit width(Y)-1 of Y
2070     // ins  X, E, width(X) - 1, 1  ; insert extracted bit at bit width(X)-1 of X
2071     SDValue E = DAG.getNode(MipsISD::Ext, DL, TyY, Y,
2072                             DAG.getConstant(WidthY - 1, DL, MVT::i32), Const1);
2073 
2074     if (WidthX > WidthY)
2075       E = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, E);
2076     else if (WidthY > WidthX)
2077       E = DAG.getNode(ISD::TRUNCATE, DL, TyX, E);
2078 
2079     SDValue I = DAG.getNode(MipsISD::Ins, DL, TyX, E,
2080                             DAG.getConstant(WidthX - 1, DL, MVT::i32), Const1,
2081                             X);
2082     return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), I);
2083   }
2084 
2085   // (d)sll SllX, X, 1
2086   // (d)srl SrlX, SllX, 1
2087   // (d)srl SrlY, Y, width(Y)-1
2088   // (d)sll SllY, SrlX, width(Y)-1
2089   // or     Or, SrlX, SllY
2090   SDValue SllX = DAG.getNode(ISD::SHL, DL, TyX, X, Const1);
2091   SDValue SrlX = DAG.getNode(ISD::SRL, DL, TyX, SllX, Const1);
2092   SDValue SrlY = DAG.getNode(ISD::SRL, DL, TyY, Y,
2093                              DAG.getConstant(WidthY - 1, DL, MVT::i32));
2094 
2095   if (WidthX > WidthY)
2096     SrlY = DAG.getNode(ISD::ZERO_EXTEND, DL, TyX, SrlY);
2097   else if (WidthY > WidthX)
2098     SrlY = DAG.getNode(ISD::TRUNCATE, DL, TyX, SrlY);
2099 
2100   SDValue SllY = DAG.getNode(ISD::SHL, DL, TyX, SrlY,
2101                              DAG.getConstant(WidthX - 1, DL, MVT::i32));
2102   SDValue Or = DAG.getNode(ISD::OR, DL, TyX, SrlX, SllY);
2103   return DAG.getNode(ISD::BITCAST, DL, Op.getOperand(0).getValueType(), Or);
2104 }
2105 
2106 SDValue
2107 MipsTargetLowering::lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const {
2108   if (Subtarget.isGP64bit())
2109     return lowerFCOPYSIGN64(Op, DAG, Subtarget.hasExtractInsert());
2110 
2111   return lowerFCOPYSIGN32(Op, DAG, Subtarget.hasExtractInsert());
2112 }
2113 
2114 SDValue MipsTargetLowering::
2115 lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const {
2116   // check the depth
2117   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2118          "Frame address can only be determined for current frame.");
2119 
2120   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2121   MFI.setFrameAddressIsTaken(true);
2122   EVT VT = Op.getValueType();
2123   SDLoc DL(Op);
2124   SDValue FrameAddr = DAG.getCopyFromReg(
2125       DAG.getEntryNode(), DL, ABI.IsN64() ? Mips::FP_64 : Mips::FP, VT);
2126   return FrameAddr;
2127 }
2128 
2129 SDValue MipsTargetLowering::lowerRETURNADDR(SDValue Op,
2130                                             SelectionDAG &DAG) const {
2131   if (verifyReturnAddressArgumentIsConstant(Op, DAG))
2132     return SDValue();
2133 
2134   // check the depth
2135   assert((cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue() == 0) &&
2136          "Return address can be determined only for current frame.");
2137 
2138   MachineFunction &MF = DAG.getMachineFunction();
2139   MachineFrameInfo &MFI = MF.getFrameInfo();
2140   MVT VT = Op.getSimpleValueType();
2141   unsigned RA = ABI.IsN64() ? Mips::RA_64 : Mips::RA;
2142   MFI.setReturnAddressIsTaken(true);
2143 
2144   // Return RA, which contains the return address. Mark it an implicit live-in.
2145   unsigned Reg = MF.addLiveIn(RA, getRegClassFor(VT));
2146   return DAG.getCopyFromReg(DAG.getEntryNode(), SDLoc(Op), Reg, VT);
2147 }
2148 
2149 // An EH_RETURN is the result of lowering llvm.eh.return which in turn is
2150 // generated from __builtin_eh_return (offset, handler)
2151 // The effect of this is to adjust the stack pointer by "offset"
2152 // and then branch to "handler".
2153 SDValue MipsTargetLowering::lowerEH_RETURN(SDValue Op, SelectionDAG &DAG)
2154                                                                      const {
2155   MachineFunction &MF = DAG.getMachineFunction();
2156   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
2157 
2158   MipsFI->setCallsEhReturn();
2159   SDValue Chain     = Op.getOperand(0);
2160   SDValue Offset    = Op.getOperand(1);
2161   SDValue Handler   = Op.getOperand(2);
2162   SDLoc DL(Op);
2163   EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2164 
2165   // Store stack offset in V1, store jump target in V0. Glue CopyToReg and
2166   // EH_RETURN nodes, so that instructions are emitted back-to-back.
2167   unsigned OffsetReg = ABI.IsN64() ? Mips::V1_64 : Mips::V1;
2168   unsigned AddrReg = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
2169   Chain = DAG.getCopyToReg(Chain, DL, OffsetReg, Offset, SDValue());
2170   Chain = DAG.getCopyToReg(Chain, DL, AddrReg, Handler, Chain.getValue(1));
2171   return DAG.getNode(MipsISD::EH_RETURN, DL, MVT::Other, Chain,
2172                      DAG.getRegister(OffsetReg, Ty),
2173                      DAG.getRegister(AddrReg, getPointerTy(MF.getDataLayout())),
2174                      Chain.getValue(1));
2175 }
2176 
2177 SDValue MipsTargetLowering::lowerATOMIC_FENCE(SDValue Op,
2178                                               SelectionDAG &DAG) const {
2179   // FIXME: Need pseudo-fence for 'singlethread' fences
2180   // FIXME: Set SType for weaker fences where supported/appropriate.
2181   unsigned SType = 0;
2182   SDLoc DL(Op);
2183   return DAG.getNode(MipsISD::Sync, DL, MVT::Other, Op.getOperand(0),
2184                      DAG.getConstant(SType, DL, MVT::i32));
2185 }
2186 
2187 SDValue MipsTargetLowering::lowerShiftLeftParts(SDValue Op,
2188                                                 SelectionDAG &DAG) const {
2189   SDLoc DL(Op);
2190   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2191 
2192   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2193   SDValue Shamt = Op.getOperand(2);
2194   // if shamt < (VT.bits):
2195   //  lo = (shl lo, shamt)
2196   //  hi = (or (shl hi, shamt) (srl (srl lo, 1), ~shamt))
2197   // else:
2198   //  lo = 0
2199   //  hi = (shl lo, shamt[4:0])
2200   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2201                             DAG.getConstant(-1, DL, MVT::i32));
2202   SDValue ShiftRight1Lo = DAG.getNode(ISD::SRL, DL, VT, Lo,
2203                                       DAG.getConstant(1, DL, VT));
2204   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, ShiftRight1Lo, Not);
2205   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, Hi, Shamt);
2206   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2207   SDValue ShiftLeftLo = DAG.getNode(ISD::SHL, DL, VT, Lo, Shamt);
2208   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2209                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2210   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2211                    DAG.getConstant(0, DL, VT), ShiftLeftLo);
2212   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftLeftLo, Or);
2213 
2214   SDValue Ops[2] = {Lo, Hi};
2215   return DAG.getMergeValues(Ops, DL);
2216 }
2217 
2218 SDValue MipsTargetLowering::lowerShiftRightParts(SDValue Op, SelectionDAG &DAG,
2219                                                  bool IsSRA) const {
2220   SDLoc DL(Op);
2221   SDValue Lo = Op.getOperand(0), Hi = Op.getOperand(1);
2222   SDValue Shamt = Op.getOperand(2);
2223   MVT VT = Subtarget.isGP64bit() ? MVT::i64 : MVT::i32;
2224 
2225   // if shamt < (VT.bits):
2226   //  lo = (or (shl (shl hi, 1), ~shamt) (srl lo, shamt))
2227   //  if isSRA:
2228   //    hi = (sra hi, shamt)
2229   //  else:
2230   //    hi = (srl hi, shamt)
2231   // else:
2232   //  if isSRA:
2233   //   lo = (sra hi, shamt[4:0])
2234   //   hi = (sra hi, 31)
2235   //  else:
2236   //   lo = (srl hi, shamt[4:0])
2237   //   hi = 0
2238   SDValue Not = DAG.getNode(ISD::XOR, DL, MVT::i32, Shamt,
2239                             DAG.getConstant(-1, DL, MVT::i32));
2240   SDValue ShiftLeft1Hi = DAG.getNode(ISD::SHL, DL, VT, Hi,
2241                                      DAG.getConstant(1, DL, VT));
2242   SDValue ShiftLeftHi = DAG.getNode(ISD::SHL, DL, VT, ShiftLeft1Hi, Not);
2243   SDValue ShiftRightLo = DAG.getNode(ISD::SRL, DL, VT, Lo, Shamt);
2244   SDValue Or = DAG.getNode(ISD::OR, DL, VT, ShiftLeftHi, ShiftRightLo);
2245   SDValue ShiftRightHi = DAG.getNode(IsSRA ? ISD::SRA : ISD::SRL,
2246                                      DL, VT, Hi, Shamt);
2247   SDValue Cond = DAG.getNode(ISD::AND, DL, MVT::i32, Shamt,
2248                              DAG.getConstant(VT.getSizeInBits(), DL, MVT::i32));
2249   SDValue Ext = DAG.getNode(ISD::SRA, DL, VT, Hi,
2250                             DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
2251   Lo = DAG.getNode(ISD::SELECT, DL, VT, Cond, ShiftRightHi, Or);
2252   Hi = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2253                    IsSRA ? Ext : DAG.getConstant(0, DL, VT), ShiftRightHi);
2254 
2255   SDValue Ops[2] = {Lo, Hi};
2256   return DAG.getMergeValues(Ops, DL);
2257 }
2258 
2259 static SDValue createLoadLR(unsigned Opc, SelectionDAG &DAG, LoadSDNode *LD,
2260                             SDValue Chain, SDValue Src, unsigned Offset) {
2261   SDValue Ptr = LD->getBasePtr();
2262   EVT VT = LD->getValueType(0), MemVT = LD->getMemoryVT();
2263   EVT BasePtrVT = Ptr.getValueType();
2264   SDLoc DL(LD);
2265   SDVTList VTList = DAG.getVTList(VT, MVT::Other);
2266 
2267   if (Offset)
2268     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2269                       DAG.getConstant(Offset, DL, BasePtrVT));
2270 
2271   SDValue Ops[] = { Chain, Ptr, Src };
2272   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2273                                  LD->getMemOperand());
2274 }
2275 
2276 // Expand an unaligned 32 or 64-bit integer load node.
2277 SDValue MipsTargetLowering::lowerLOAD(SDValue Op, SelectionDAG &DAG) const {
2278   LoadSDNode *LD = cast<LoadSDNode>(Op);
2279   EVT MemVT = LD->getMemoryVT();
2280 
2281   if (Subtarget.systemSupportsUnalignedAccess())
2282     return Op;
2283 
2284   // Return if load is aligned or if MemVT is neither i32 nor i64.
2285   if ((LD->getAlignment() >= MemVT.getSizeInBits() / 8) ||
2286       ((MemVT != MVT::i32) && (MemVT != MVT::i64)))
2287     return SDValue();
2288 
2289   bool IsLittle = Subtarget.isLittle();
2290   EVT VT = Op.getValueType();
2291   ISD::LoadExtType ExtType = LD->getExtensionType();
2292   SDValue Chain = LD->getChain(), Undef = DAG.getUNDEF(VT);
2293 
2294   assert((VT == MVT::i32) || (VT == MVT::i64));
2295 
2296   // Expand
2297   //  (set dst, (i64 (load baseptr)))
2298   // to
2299   //  (set tmp, (ldl (add baseptr, 7), undef))
2300   //  (set dst, (ldr baseptr, tmp))
2301   if ((VT == MVT::i64) && (ExtType == ISD::NON_EXTLOAD)) {
2302     SDValue LDL = createLoadLR(MipsISD::LDL, DAG, LD, Chain, Undef,
2303                                IsLittle ? 7 : 0);
2304     return createLoadLR(MipsISD::LDR, DAG, LD, LDL.getValue(1), LDL,
2305                         IsLittle ? 0 : 7);
2306   }
2307 
2308   SDValue LWL = createLoadLR(MipsISD::LWL, DAG, LD, Chain, Undef,
2309                              IsLittle ? 3 : 0);
2310   SDValue LWR = createLoadLR(MipsISD::LWR, DAG, LD, LWL.getValue(1), LWL,
2311                              IsLittle ? 0 : 3);
2312 
2313   // Expand
2314   //  (set dst, (i32 (load baseptr))) or
2315   //  (set dst, (i64 (sextload baseptr))) or
2316   //  (set dst, (i64 (extload baseptr)))
2317   // to
2318   //  (set tmp, (lwl (add baseptr, 3), undef))
2319   //  (set dst, (lwr baseptr, tmp))
2320   if ((VT == MVT::i32) || (ExtType == ISD::SEXTLOAD) ||
2321       (ExtType == ISD::EXTLOAD))
2322     return LWR;
2323 
2324   assert((VT == MVT::i64) && (ExtType == ISD::ZEXTLOAD));
2325 
2326   // Expand
2327   //  (set dst, (i64 (zextload baseptr)))
2328   // to
2329   //  (set tmp0, (lwl (add baseptr, 3), undef))
2330   //  (set tmp1, (lwr baseptr, tmp0))
2331   //  (set tmp2, (shl tmp1, 32))
2332   //  (set dst, (srl tmp2, 32))
2333   SDLoc DL(LD);
2334   SDValue Const32 = DAG.getConstant(32, DL, MVT::i32);
2335   SDValue SLL = DAG.getNode(ISD::SHL, DL, MVT::i64, LWR, Const32);
2336   SDValue SRL = DAG.getNode(ISD::SRL, DL, MVT::i64, SLL, Const32);
2337   SDValue Ops[] = { SRL, LWR.getValue(1) };
2338   return DAG.getMergeValues(Ops, DL);
2339 }
2340 
2341 static SDValue createStoreLR(unsigned Opc, SelectionDAG &DAG, StoreSDNode *SD,
2342                              SDValue Chain, unsigned Offset) {
2343   SDValue Ptr = SD->getBasePtr(), Value = SD->getValue();
2344   EVT MemVT = SD->getMemoryVT(), BasePtrVT = Ptr.getValueType();
2345   SDLoc DL(SD);
2346   SDVTList VTList = DAG.getVTList(MVT::Other);
2347 
2348   if (Offset)
2349     Ptr = DAG.getNode(ISD::ADD, DL, BasePtrVT, Ptr,
2350                       DAG.getConstant(Offset, DL, BasePtrVT));
2351 
2352   SDValue Ops[] = { Chain, Value, Ptr };
2353   return DAG.getMemIntrinsicNode(Opc, DL, VTList, Ops, MemVT,
2354                                  SD->getMemOperand());
2355 }
2356 
2357 // Expand an unaligned 32 or 64-bit integer store node.
2358 static SDValue lowerUnalignedIntStore(StoreSDNode *SD, SelectionDAG &DAG,
2359                                       bool IsLittle) {
2360   SDValue Value = SD->getValue(), Chain = SD->getChain();
2361   EVT VT = Value.getValueType();
2362 
2363   // Expand
2364   //  (store val, baseptr) or
2365   //  (truncstore val, baseptr)
2366   // to
2367   //  (swl val, (add baseptr, 3))
2368   //  (swr val, baseptr)
2369   if ((VT == MVT::i32) || SD->isTruncatingStore()) {
2370     SDValue SWL = createStoreLR(MipsISD::SWL, DAG, SD, Chain,
2371                                 IsLittle ? 3 : 0);
2372     return createStoreLR(MipsISD::SWR, DAG, SD, SWL, IsLittle ? 0 : 3);
2373   }
2374 
2375   assert(VT == MVT::i64);
2376 
2377   // Expand
2378   //  (store val, baseptr)
2379   // to
2380   //  (sdl val, (add baseptr, 7))
2381   //  (sdr val, baseptr)
2382   SDValue SDL = createStoreLR(MipsISD::SDL, DAG, SD, Chain, IsLittle ? 7 : 0);
2383   return createStoreLR(MipsISD::SDR, DAG, SD, SDL, IsLittle ? 0 : 7);
2384 }
2385 
2386 // Lower (store (fp_to_sint $fp) $ptr) to (store (TruncIntFP $fp), $ptr).
2387 static SDValue lowerFP_TO_SINT_STORE(StoreSDNode *SD, SelectionDAG &DAG) {
2388   SDValue Val = SD->getValue();
2389 
2390   if (Val.getOpcode() != ISD::FP_TO_SINT)
2391     return SDValue();
2392 
2393   EVT FPTy = EVT::getFloatingPointVT(Val.getValueSizeInBits());
2394   SDValue Tr = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Val), FPTy,
2395                            Val.getOperand(0));
2396   return DAG.getStore(SD->getChain(), SDLoc(SD), Tr, SD->getBasePtr(),
2397                       SD->getPointerInfo(), SD->getAlignment(),
2398                       SD->getMemOperand()->getFlags());
2399 }
2400 
2401 SDValue MipsTargetLowering::lowerSTORE(SDValue Op, SelectionDAG &DAG) const {
2402   StoreSDNode *SD = cast<StoreSDNode>(Op);
2403   EVT MemVT = SD->getMemoryVT();
2404 
2405   // Lower unaligned integer stores.
2406   if (!Subtarget.systemSupportsUnalignedAccess() &&
2407       (SD->getAlignment() < MemVT.getSizeInBits() / 8) &&
2408       ((MemVT == MVT::i32) || (MemVT == MVT::i64)))
2409     return lowerUnalignedIntStore(SD, DAG, Subtarget.isLittle());
2410 
2411   return lowerFP_TO_SINT_STORE(SD, DAG);
2412 }
2413 
2414 SDValue MipsTargetLowering::lowerEH_DWARF_CFA(SDValue Op,
2415                                               SelectionDAG &DAG) const {
2416 
2417   // Return a fixed StackObject with offset 0 which points to the old stack
2418   // pointer.
2419   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2420   EVT ValTy = Op->getValueType(0);
2421   int FI = MFI.CreateFixedObject(Op.getValueSizeInBits() / 8, 0, false);
2422   return DAG.getFrameIndex(FI, ValTy);
2423 }
2424 
2425 SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op,
2426                                             SelectionDAG &DAG) const {
2427   EVT FPTy = EVT::getFloatingPointVT(Op.getValueSizeInBits());
2428   SDValue Trunc = DAG.getNode(MipsISD::TruncIntFP, SDLoc(Op), FPTy,
2429                               Op.getOperand(0));
2430   return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc);
2431 }
2432 
2433 //===----------------------------------------------------------------------===//
2434 //                      Calling Convention Implementation
2435 //===----------------------------------------------------------------------===//
2436 
2437 //===----------------------------------------------------------------------===//
2438 // TODO: Implement a generic logic using tblgen that can support this.
2439 // Mips O32 ABI rules:
2440 // ---
2441 // i32 - Passed in A0, A1, A2, A3 and stack
2442 // f32 - Only passed in f32 registers if no int reg has been used yet to hold
2443 //       an argument. Otherwise, passed in A1, A2, A3 and stack.
2444 // f64 - Only passed in two aliased f32 registers if no int reg has been used
2445 //       yet to hold an argument. Otherwise, use A2, A3 and stack. If A1 is
2446 //       not used, it must be shadowed. If only A3 is available, shadow it and
2447 //       go to stack.
2448 //
2449 //  For vararg functions, all arguments are passed in A0, A1, A2, A3 and stack.
2450 //===----------------------------------------------------------------------===//
2451 
2452 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2453                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2454                        CCState &State, ArrayRef<MCPhysReg> F64Regs) {
2455   const MipsSubtarget &Subtarget = static_cast<const MipsSubtarget &>(
2456       State.getMachineFunction().getSubtarget());
2457 
2458   static const MCPhysReg IntRegs[] = { Mips::A0, Mips::A1, Mips::A2, Mips::A3 };
2459   static const MCPhysReg F32Regs[] = { Mips::F12, Mips::F14 };
2460 
2461   // Do not process byval args here.
2462   if (ArgFlags.isByVal())
2463     return true;
2464 
2465   // Promote i8 and i16
2466   if (ArgFlags.isInReg() && !Subtarget.isLittle()) {
2467     if (LocVT == MVT::i8 || LocVT == MVT::i16 || LocVT == MVT::i32) {
2468       LocVT = MVT::i32;
2469       if (ArgFlags.isSExt())
2470         LocInfo = CCValAssign::SExtUpper;
2471       else if (ArgFlags.isZExt())
2472         LocInfo = CCValAssign::ZExtUpper;
2473       else
2474         LocInfo = CCValAssign::AExtUpper;
2475     }
2476   }
2477 
2478   // Promote i8 and i16
2479   if (LocVT == MVT::i8 || LocVT == MVT::i16) {
2480     LocVT = MVT::i32;
2481     if (ArgFlags.isSExt())
2482       LocInfo = CCValAssign::SExt;
2483     else if (ArgFlags.isZExt())
2484       LocInfo = CCValAssign::ZExt;
2485     else
2486       LocInfo = CCValAssign::AExt;
2487   }
2488 
2489   unsigned Reg;
2490 
2491   // f32 and f64 are allocated in A0, A1, A2, A3 when either of the following
2492   // is true: function is vararg, argument is 3rd or higher, there is previous
2493   // argument which is not f32 or f64.
2494   bool AllocateFloatsInIntReg = State.isVarArg() || ValNo > 1 ||
2495                                 State.getFirstUnallocated(F32Regs) != ValNo;
2496   unsigned OrigAlign = ArgFlags.getOrigAlign();
2497   bool isI64 = (ValVT == MVT::i32 && OrigAlign == 8);
2498 
2499   if (ValVT == MVT::i32 || (ValVT == MVT::f32 && AllocateFloatsInIntReg)) {
2500     Reg = State.AllocateReg(IntRegs);
2501     // If this is the first part of an i64 arg,
2502     // the allocated register must be either A0 or A2.
2503     if (isI64 && (Reg == Mips::A1 || Reg == Mips::A3))
2504       Reg = State.AllocateReg(IntRegs);
2505     LocVT = MVT::i32;
2506   } else if (ValVT == MVT::f64 && AllocateFloatsInIntReg) {
2507     // Allocate int register and shadow next int register. If first
2508     // available register is Mips::A1 or Mips::A3, shadow it too.
2509     Reg = State.AllocateReg(IntRegs);
2510     if (Reg == Mips::A1 || Reg == Mips::A3)
2511       Reg = State.AllocateReg(IntRegs);
2512     State.AllocateReg(IntRegs);
2513     LocVT = MVT::i32;
2514   } else if (ValVT.isFloatingPoint() && !AllocateFloatsInIntReg) {
2515     // we are guaranteed to find an available float register
2516     if (ValVT == MVT::f32) {
2517       Reg = State.AllocateReg(F32Regs);
2518       // Shadow int register
2519       State.AllocateReg(IntRegs);
2520     } else {
2521       Reg = State.AllocateReg(F64Regs);
2522       // Shadow int registers
2523       unsigned Reg2 = State.AllocateReg(IntRegs);
2524       if (Reg2 == Mips::A1 || Reg2 == Mips::A3)
2525         State.AllocateReg(IntRegs);
2526       State.AllocateReg(IntRegs);
2527     }
2528   } else
2529     llvm_unreachable("Cannot handle this ValVT.");
2530 
2531   if (!Reg) {
2532     unsigned Offset = State.AllocateStack(ValVT.getSizeInBits() >> 3,
2533                                           OrigAlign);
2534     State.addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
2535   } else
2536     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
2537 
2538   return false;
2539 }
2540 
2541 static bool CC_MipsO32_FP32(unsigned ValNo, MVT ValVT,
2542                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2543                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2544   static const MCPhysReg F64Regs[] = { Mips::D6, Mips::D7 };
2545 
2546   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2547 }
2548 
2549 static bool CC_MipsO32_FP64(unsigned ValNo, MVT ValVT,
2550                             MVT LocVT, CCValAssign::LocInfo LocInfo,
2551                             ISD::ArgFlagsTy ArgFlags, CCState &State) {
2552   static const MCPhysReg F64Regs[] = { Mips::D12_64, Mips::D14_64 };
2553 
2554   return CC_MipsO32(ValNo, ValVT, LocVT, LocInfo, ArgFlags, State, F64Regs);
2555 }
2556 
2557 static bool CC_MipsO32(unsigned ValNo, MVT ValVT, MVT LocVT,
2558                        CCValAssign::LocInfo LocInfo, ISD::ArgFlagsTy ArgFlags,
2559                        CCState &State) LLVM_ATTRIBUTE_UNUSED;
2560 
2561 #include "MipsGenCallingConv.inc"
2562 
2563 //===----------------------------------------------------------------------===//
2564 //                  Call Calling Convention Implementation
2565 //===----------------------------------------------------------------------===//
2566 
2567 // Return next O32 integer argument register.
2568 static unsigned getNextIntArgReg(unsigned Reg) {
2569   assert((Reg == Mips::A0) || (Reg == Mips::A2));
2570   return (Reg == Mips::A0) ? Mips::A1 : Mips::A3;
2571 }
2572 
2573 SDValue MipsTargetLowering::passArgOnStack(SDValue StackPtr, unsigned Offset,
2574                                            SDValue Chain, SDValue Arg,
2575                                            const SDLoc &DL, bool IsTailCall,
2576                                            SelectionDAG &DAG) const {
2577   if (!IsTailCall) {
2578     SDValue PtrOff =
2579         DAG.getNode(ISD::ADD, DL, getPointerTy(DAG.getDataLayout()), StackPtr,
2580                     DAG.getIntPtrConstant(Offset, DL));
2581     return DAG.getStore(Chain, DL, Arg, PtrOff, MachinePointerInfo());
2582   }
2583 
2584   MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
2585   int FI = MFI.CreateFixedObject(Arg.getValueSizeInBits() / 8, Offset, false);
2586   SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
2587   return DAG.getStore(Chain, DL, Arg, FIN, MachinePointerInfo(),
2588                       /* Alignment = */ 0, MachineMemOperand::MOVolatile);
2589 }
2590 
2591 void MipsTargetLowering::
2592 getOpndList(SmallVectorImpl<SDValue> &Ops,
2593             std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
2594             bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
2595             bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
2596             SDValue Chain) const {
2597   // Insert node "GP copy globalreg" before call to function.
2598   //
2599   // R_MIPS_CALL* operators (emitted when non-internal functions are called
2600   // in PIC mode) allow symbols to be resolved via lazy binding.
2601   // The lazy binding stub requires GP to point to the GOT.
2602   // Note that we don't need GP to point to the GOT for indirect calls
2603   // (when R_MIPS_CALL* is not used for the call) because Mips linker generates
2604   // lazy binding stub for a function only when R_MIPS_CALL* are the only relocs
2605   // used for the function (that is, Mips linker doesn't generate lazy binding
2606   // stub for a function whose address is taken in the program).
2607   if (IsPICCall && !InternalLinkage && IsCallReloc) {
2608     unsigned GPReg = ABI.IsN64() ? Mips::GP_64 : Mips::GP;
2609     EVT Ty = ABI.IsN64() ? MVT::i64 : MVT::i32;
2610     RegsToPass.push_back(std::make_pair(GPReg, getGlobalReg(CLI.DAG, Ty)));
2611   }
2612 
2613   // Build a sequence of copy-to-reg nodes chained together with token
2614   // chain and flag operands which copy the outgoing args into registers.
2615   // The InFlag in necessary since all emitted instructions must be
2616   // stuck together.
2617   SDValue InFlag;
2618 
2619   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
2620     Chain = CLI.DAG.getCopyToReg(Chain, CLI.DL, RegsToPass[i].first,
2621                                  RegsToPass[i].second, InFlag);
2622     InFlag = Chain.getValue(1);
2623   }
2624 
2625   // Add argument registers to the end of the list so that they are
2626   // known live into the call.
2627   for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
2628     Ops.push_back(CLI.DAG.getRegister(RegsToPass[i].first,
2629                                       RegsToPass[i].second.getValueType()));
2630 
2631   // Add a register mask operand representing the call-preserved registers.
2632   const TargetRegisterInfo *TRI = Subtarget.getRegisterInfo();
2633   const uint32_t *Mask =
2634       TRI->getCallPreservedMask(CLI.DAG.getMachineFunction(), CLI.CallConv);
2635   assert(Mask && "Missing call preserved mask for calling convention");
2636   if (Subtarget.inMips16HardFloat()) {
2637     if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(CLI.Callee)) {
2638       llvm::StringRef Sym = G->getGlobal()->getName();
2639       Function *F = G->getGlobal()->getParent()->getFunction(Sym);
2640       if (F && F->hasFnAttribute("__Mips16RetHelper")) {
2641         Mask = MipsRegisterInfo::getMips16RetHelperMask();
2642       }
2643     }
2644   }
2645   Ops.push_back(CLI.DAG.getRegisterMask(Mask));
2646 
2647   if (InFlag.getNode())
2648     Ops.push_back(InFlag);
2649 }
2650 
2651 /// LowerCall - functions arguments are copied from virtual regs to
2652 /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
2653 SDValue
2654 MipsTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
2655                               SmallVectorImpl<SDValue> &InVals) const {
2656   SelectionDAG &DAG                     = CLI.DAG;
2657   SDLoc DL                              = CLI.DL;
2658   SmallVectorImpl<ISD::OutputArg> &Outs = CLI.Outs;
2659   SmallVectorImpl<SDValue> &OutVals     = CLI.OutVals;
2660   SmallVectorImpl<ISD::InputArg> &Ins   = CLI.Ins;
2661   SDValue Chain                         = CLI.Chain;
2662   SDValue Callee                        = CLI.Callee;
2663   bool &IsTailCall                      = CLI.IsTailCall;
2664   CallingConv::ID CallConv              = CLI.CallConv;
2665   bool IsVarArg                         = CLI.IsVarArg;
2666 
2667   MachineFunction &MF = DAG.getMachineFunction();
2668   MachineFrameInfo &MFI = MF.getFrameInfo();
2669   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
2670   MipsFunctionInfo *FuncInfo = MF.getInfo<MipsFunctionInfo>();
2671   bool IsPIC = isPositionIndependent();
2672 
2673   // Analyze operands of the call, assigning locations to each operand.
2674   SmallVector<CCValAssign, 16> ArgLocs;
2675   MipsCCState CCInfo(
2676       CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs, *DAG.getContext(),
2677       MipsCCState::getSpecialCallingConvForCallee(Callee.getNode(), Subtarget));
2678 
2679   // Allocate the reserved argument area. It seems strange to do this from the
2680   // caller side but removing it breaks the frame size calculation.
2681   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), 1);
2682 
2683   CCInfo.AnalyzeCallOperands(Outs, CC_Mips, CLI.getArgs(), Callee.getNode());
2684 
2685   // Get a count of how many bytes are to be pushed on the stack.
2686   unsigned NextStackOffset = CCInfo.getNextStackOffset();
2687 
2688   // Check if it's really possible to do a tail call.
2689   if (IsTailCall)
2690     IsTailCall = isEligibleForTailCallOptimization(
2691         CCInfo, NextStackOffset, *MF.getInfo<MipsFunctionInfo>());
2692 
2693   if (!IsTailCall && CLI.CS && CLI.CS->isMustTailCall())
2694     report_fatal_error("failed to perform tail call elimination on a call "
2695                        "site marked musttail");
2696 
2697   if (IsTailCall)
2698     ++NumTailCalls;
2699 
2700   // Chain is the output chain of the last Load/Store or CopyToReg node.
2701   // ByValChain is the output chain of the last Memcpy node created for copying
2702   // byval arguments to the stack.
2703   unsigned StackAlignment = TFL->getStackAlignment();
2704   NextStackOffset = alignTo(NextStackOffset, StackAlignment);
2705   SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, DL, true);
2706 
2707   if (!IsTailCall)
2708     Chain = DAG.getCALLSEQ_START(Chain, NextStackOffsetVal, DL);
2709 
2710   SDValue StackPtr =
2711       DAG.getCopyFromReg(Chain, DL, ABI.IsN64() ? Mips::SP_64 : Mips::SP,
2712                          getPointerTy(DAG.getDataLayout()));
2713 
2714   std::deque< std::pair<unsigned, SDValue> > RegsToPass;
2715   SmallVector<SDValue, 8> MemOpChains;
2716 
2717   CCInfo.rewindByValRegsInfo();
2718 
2719   // Walk the register/memloc assignments, inserting copies/loads.
2720   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
2721     SDValue Arg = OutVals[i];
2722     CCValAssign &VA = ArgLocs[i];
2723     MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
2724     ISD::ArgFlagsTy Flags = Outs[i].Flags;
2725     bool UseUpperBits = false;
2726 
2727     // ByVal Arg.
2728     if (Flags.isByVal()) {
2729       unsigned FirstByValReg, LastByValReg;
2730       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
2731       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
2732 
2733       assert(Flags.getByValSize() &&
2734              "ByVal args of size 0 should have been ignored by front-end.");
2735       assert(ByValIdx < CCInfo.getInRegsParamsCount());
2736       assert(!IsTailCall &&
2737              "Do not tail-call optimize if there is a byval argument.");
2738       passByValArg(Chain, DL, RegsToPass, MemOpChains, StackPtr, MFI, DAG, Arg,
2739                    FirstByValReg, LastByValReg, Flags, Subtarget.isLittle(),
2740                    VA);
2741       CCInfo.nextInRegsParam();
2742       continue;
2743     }
2744 
2745     // Promote the value if needed.
2746     switch (VA.getLocInfo()) {
2747     default:
2748       llvm_unreachable("Unknown loc info!");
2749     case CCValAssign::Full:
2750       if (VA.isRegLoc()) {
2751         if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
2752             (ValVT == MVT::f64 && LocVT == MVT::i64) ||
2753             (ValVT == MVT::i64 && LocVT == MVT::f64))
2754           Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
2755         else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
2756           SDValue Lo = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2757                                    Arg, DAG.getConstant(0, DL, MVT::i32));
2758           SDValue Hi = DAG.getNode(MipsISD::ExtractElementF64, DL, MVT::i32,
2759                                    Arg, DAG.getConstant(1, DL, MVT::i32));
2760           if (!Subtarget.isLittle())
2761             std::swap(Lo, Hi);
2762           unsigned LocRegLo = VA.getLocReg();
2763           unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
2764           RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
2765           RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
2766           continue;
2767         }
2768       }
2769       break;
2770     case CCValAssign::BCvt:
2771       Arg = DAG.getNode(ISD::BITCAST, DL, LocVT, Arg);
2772       break;
2773     case CCValAssign::SExtUpper:
2774       UseUpperBits = true;
2775       LLVM_FALLTHROUGH;
2776     case CCValAssign::SExt:
2777       Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, LocVT, Arg);
2778       break;
2779     case CCValAssign::ZExtUpper:
2780       UseUpperBits = true;
2781       LLVM_FALLTHROUGH;
2782     case CCValAssign::ZExt:
2783       Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, LocVT, Arg);
2784       break;
2785     case CCValAssign::AExtUpper:
2786       UseUpperBits = true;
2787       LLVM_FALLTHROUGH;
2788     case CCValAssign::AExt:
2789       Arg = DAG.getNode(ISD::ANY_EXTEND, DL, LocVT, Arg);
2790       break;
2791     }
2792 
2793     if (UseUpperBits) {
2794       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
2795       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2796       Arg = DAG.getNode(
2797           ISD::SHL, DL, VA.getLocVT(), Arg,
2798           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2799     }
2800 
2801     // Arguments that can be passed on register must be kept at
2802     // RegsToPass vector
2803     if (VA.isRegLoc()) {
2804       RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
2805       continue;
2806     }
2807 
2808     // Register can't get to this point...
2809     assert(VA.isMemLoc());
2810 
2811     // emit ISD::STORE whichs stores the
2812     // parameter value to a stack Location
2813     MemOpChains.push_back(passArgOnStack(StackPtr, VA.getLocMemOffset(),
2814                                          Chain, Arg, DL, IsTailCall, DAG));
2815   }
2816 
2817   // Transform all store nodes into one single node because all store
2818   // nodes are independent of each other.
2819   if (!MemOpChains.empty())
2820     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
2821 
2822   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
2823   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
2824   // node so that legalize doesn't hack it.
2825   bool IsPICCall = (ABI.IsN64() || IsPIC); // true if calls are translated to
2826                                            // jalr $25
2827   bool GlobalOrExternal = false, InternalLinkage = false, IsCallReloc = false;
2828   SDValue CalleeLo;
2829   EVT Ty = Callee.getValueType();
2830 
2831   if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
2832     if (IsPICCall) {
2833       const GlobalValue *Val = G->getGlobal();
2834       InternalLinkage = Val->hasInternalLinkage();
2835 
2836       if (InternalLinkage)
2837         Callee = getAddrLocal(G, DL, Ty, DAG, ABI.IsN32() || ABI.IsN64());
2838       else if (LargeGOT) {
2839         Callee = getAddrGlobalLargeGOT(G, DL, Ty, DAG, MipsII::MO_CALL_HI16,
2840                                        MipsII::MO_CALL_LO16, Chain,
2841                                        FuncInfo->callPtrInfo(Val));
2842         IsCallReloc = true;
2843       } else {
2844         Callee = getAddrGlobal(G, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
2845                                FuncInfo->callPtrInfo(Val));
2846         IsCallReloc = true;
2847       }
2848     } else
2849       Callee = DAG.getTargetGlobalAddress(G->getGlobal(), DL,
2850                                           getPointerTy(DAG.getDataLayout()), 0,
2851                                           MipsII::MO_NO_FLAG);
2852     GlobalOrExternal = true;
2853   }
2854   else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
2855     const char *Sym = S->getSymbol();
2856 
2857     if (!ABI.IsN64() && !IsPIC) // !N64 && static
2858       Callee = DAG.getTargetExternalSymbol(
2859           Sym, getPointerTy(DAG.getDataLayout()), MipsII::MO_NO_FLAG);
2860     else if (LargeGOT) {
2861       Callee = getAddrGlobalLargeGOT(S, DL, Ty, DAG, MipsII::MO_CALL_HI16,
2862                                      MipsII::MO_CALL_LO16, Chain,
2863                                      FuncInfo->callPtrInfo(Sym));
2864       IsCallReloc = true;
2865     } else { // N64 || PIC
2866       Callee = getAddrGlobal(S, DL, Ty, DAG, MipsII::MO_GOT_CALL, Chain,
2867                              FuncInfo->callPtrInfo(Sym));
2868       IsCallReloc = true;
2869     }
2870 
2871     GlobalOrExternal = true;
2872   }
2873 
2874   SmallVector<SDValue, 8> Ops(1, Chain);
2875   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
2876 
2877   getOpndList(Ops, RegsToPass, IsPICCall, GlobalOrExternal, InternalLinkage,
2878               IsCallReloc, CLI, Callee, Chain);
2879 
2880   if (IsTailCall) {
2881     MF.getFrameInfo().setHasTailCall();
2882     return DAG.getNode(MipsISD::TailCall, DL, MVT::Other, Ops);
2883   }
2884 
2885   Chain = DAG.getNode(MipsISD::JmpLink, DL, NodeTys, Ops);
2886   SDValue InFlag = Chain.getValue(1);
2887 
2888   // Create the CALLSEQ_END node.
2889   Chain = DAG.getCALLSEQ_END(Chain, NextStackOffsetVal,
2890                              DAG.getIntPtrConstant(0, DL, true), InFlag, DL);
2891   InFlag = Chain.getValue(1);
2892 
2893   // Handle result values, copying them out of physregs into vregs that we
2894   // return.
2895   return LowerCallResult(Chain, InFlag, CallConv, IsVarArg, Ins, DL, DAG,
2896                          InVals, CLI);
2897 }
2898 
2899 /// LowerCallResult - Lower the result values of a call into the
2900 /// appropriate copies out of appropriate physical registers.
2901 SDValue MipsTargetLowering::LowerCallResult(
2902     SDValue Chain, SDValue InFlag, CallingConv::ID CallConv, bool IsVarArg,
2903     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
2904     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
2905     TargetLowering::CallLoweringInfo &CLI) const {
2906   // Assign locations to each value returned by this call.
2907   SmallVector<CCValAssign, 16> RVLocs;
2908   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
2909                      *DAG.getContext());
2910   CCInfo.AnalyzeCallResult(Ins, RetCC_Mips, CLI);
2911 
2912   // Copy all of the result registers out of their specified physreg.
2913   for (unsigned i = 0; i != RVLocs.size(); ++i) {
2914     CCValAssign &VA = RVLocs[i];
2915     assert(VA.isRegLoc() && "Can only return in registers!");
2916 
2917     SDValue Val = DAG.getCopyFromReg(Chain, DL, RVLocs[i].getLocReg(),
2918                                      RVLocs[i].getLocVT(), InFlag);
2919     Chain = Val.getValue(1);
2920     InFlag = Val.getValue(2);
2921 
2922     if (VA.isUpperBitsInLoc()) {
2923       unsigned ValSizeInBits = Ins[i].ArgVT.getSizeInBits();
2924       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2925       unsigned Shift =
2926           VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
2927       Val = DAG.getNode(
2928           Shift, DL, VA.getLocVT(), Val,
2929           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2930     }
2931 
2932     switch (VA.getLocInfo()) {
2933     default:
2934       llvm_unreachable("Unknown loc info!");
2935     case CCValAssign::Full:
2936       break;
2937     case CCValAssign::BCvt:
2938       Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
2939       break;
2940     case CCValAssign::AExt:
2941     case CCValAssign::AExtUpper:
2942       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2943       break;
2944     case CCValAssign::ZExt:
2945     case CCValAssign::ZExtUpper:
2946       Val = DAG.getNode(ISD::AssertZext, DL, VA.getLocVT(), Val,
2947                         DAG.getValueType(VA.getValVT()));
2948       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2949       break;
2950     case CCValAssign::SExt:
2951     case CCValAssign::SExtUpper:
2952       Val = DAG.getNode(ISD::AssertSext, DL, VA.getLocVT(), Val,
2953                         DAG.getValueType(VA.getValVT()));
2954       Val = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Val);
2955       break;
2956     }
2957 
2958     InVals.push_back(Val);
2959   }
2960 
2961   return Chain;
2962 }
2963 
2964 static SDValue UnpackFromArgumentSlot(SDValue Val, const CCValAssign &VA,
2965                                       EVT ArgVT, const SDLoc &DL,
2966                                       SelectionDAG &DAG) {
2967   MVT LocVT = VA.getLocVT();
2968   EVT ValVT = VA.getValVT();
2969 
2970   // Shift into the upper bits if necessary.
2971   switch (VA.getLocInfo()) {
2972   default:
2973     break;
2974   case CCValAssign::AExtUpper:
2975   case CCValAssign::SExtUpper:
2976   case CCValAssign::ZExtUpper: {
2977     unsigned ValSizeInBits = ArgVT.getSizeInBits();
2978     unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
2979     unsigned Opcode =
2980         VA.getLocInfo() == CCValAssign::ZExtUpper ? ISD::SRL : ISD::SRA;
2981     Val = DAG.getNode(
2982         Opcode, DL, VA.getLocVT(), Val,
2983         DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
2984     break;
2985   }
2986   }
2987 
2988   // If this is an value smaller than the argument slot size (32-bit for O32,
2989   // 64-bit for N32/N64), it has been promoted in some way to the argument slot
2990   // size. Extract the value and insert any appropriate assertions regarding
2991   // sign/zero extension.
2992   switch (VA.getLocInfo()) {
2993   default:
2994     llvm_unreachable("Unknown loc info!");
2995   case CCValAssign::Full:
2996     break;
2997   case CCValAssign::AExtUpper:
2998   case CCValAssign::AExt:
2999     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3000     break;
3001   case CCValAssign::SExtUpper:
3002   case CCValAssign::SExt:
3003     Val = DAG.getNode(ISD::AssertSext, DL, LocVT, Val, DAG.getValueType(ValVT));
3004     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3005     break;
3006   case CCValAssign::ZExtUpper:
3007   case CCValAssign::ZExt:
3008     Val = DAG.getNode(ISD::AssertZext, DL, LocVT, Val, DAG.getValueType(ValVT));
3009     Val = DAG.getNode(ISD::TRUNCATE, DL, ValVT, Val);
3010     break;
3011   case CCValAssign::BCvt:
3012     Val = DAG.getNode(ISD::BITCAST, DL, ValVT, Val);
3013     break;
3014   }
3015 
3016   return Val;
3017 }
3018 
3019 //===----------------------------------------------------------------------===//
3020 //             Formal Arguments Calling Convention Implementation
3021 //===----------------------------------------------------------------------===//
3022 /// LowerFormalArguments - transform physical registers into virtual registers
3023 /// and generate load operations for arguments places on the stack.
3024 SDValue MipsTargetLowering::LowerFormalArguments(
3025     SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
3026     const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
3027     SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
3028   MachineFunction &MF = DAG.getMachineFunction();
3029   MachineFrameInfo &MFI = MF.getFrameInfo();
3030   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3031 
3032   MipsFI->setVarArgsFrameIndex(0);
3033 
3034   // Used with vargs to acumulate store chains.
3035   std::vector<SDValue> OutChains;
3036 
3037   // Assign locations to all of the incoming arguments.
3038   SmallVector<CCValAssign, 16> ArgLocs;
3039   MipsCCState CCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), ArgLocs,
3040                      *DAG.getContext());
3041   CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(CallConv), 1);
3042   const Function *Func = DAG.getMachineFunction().getFunction();
3043   Function::const_arg_iterator FuncArg = Func->arg_begin();
3044 
3045   if (Func->hasFnAttribute("interrupt") && !Func->arg_empty())
3046     report_fatal_error(
3047         "Functions with the interrupt attribute cannot have arguments!");
3048 
3049   CCInfo.AnalyzeFormalArguments(Ins, CC_Mips_FixedArg);
3050   MipsFI->setFormalArgInfo(CCInfo.getNextStackOffset(),
3051                            CCInfo.getInRegsParamsCount() > 0);
3052 
3053   unsigned CurArgIdx = 0;
3054   CCInfo.rewindByValRegsInfo();
3055 
3056   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3057     CCValAssign &VA = ArgLocs[i];
3058     if (Ins[i].isOrigArg()) {
3059       std::advance(FuncArg, Ins[i].getOrigArgIndex() - CurArgIdx);
3060       CurArgIdx = Ins[i].getOrigArgIndex();
3061     }
3062     EVT ValVT = VA.getValVT();
3063     ISD::ArgFlagsTy Flags = Ins[i].Flags;
3064     bool IsRegLoc = VA.isRegLoc();
3065 
3066     if (Flags.isByVal()) {
3067       assert(Ins[i].isOrigArg() && "Byval arguments cannot be implicit");
3068       unsigned FirstByValReg, LastByValReg;
3069       unsigned ByValIdx = CCInfo.getInRegsParamsProcessed();
3070       CCInfo.getInRegsParamInfo(ByValIdx, FirstByValReg, LastByValReg);
3071 
3072       assert(Flags.getByValSize() &&
3073              "ByVal args of size 0 should have been ignored by front-end.");
3074       assert(ByValIdx < CCInfo.getInRegsParamsCount());
3075       copyByValRegs(Chain, DL, OutChains, DAG, Flags, InVals, &*FuncArg,
3076                     FirstByValReg, LastByValReg, VA, CCInfo);
3077       CCInfo.nextInRegsParam();
3078       continue;
3079     }
3080 
3081     // Arguments stored on registers
3082     if (IsRegLoc) {
3083       MVT RegVT = VA.getLocVT();
3084       unsigned ArgReg = VA.getLocReg();
3085       const TargetRegisterClass *RC = getRegClassFor(RegVT);
3086 
3087       // Transform the arguments stored on
3088       // physical registers into virtual ones
3089       unsigned Reg = addLiveIn(DAG.getMachineFunction(), ArgReg, RC);
3090       SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
3091 
3092       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3093 
3094       // Handle floating point arguments passed in integer registers and
3095       // long double arguments passed in floating point registers.
3096       if ((RegVT == MVT::i32 && ValVT == MVT::f32) ||
3097           (RegVT == MVT::i64 && ValVT == MVT::f64) ||
3098           (RegVT == MVT::f64 && ValVT == MVT::i64))
3099         ArgValue = DAG.getNode(ISD::BITCAST, DL, ValVT, ArgValue);
3100       else if (ABI.IsO32() && RegVT == MVT::i32 &&
3101                ValVT == MVT::f64) {
3102         unsigned Reg2 = addLiveIn(DAG.getMachineFunction(),
3103                                   getNextIntArgReg(ArgReg), RC);
3104         SDValue ArgValue2 = DAG.getCopyFromReg(Chain, DL, Reg2, RegVT);
3105         if (!Subtarget.isLittle())
3106           std::swap(ArgValue, ArgValue2);
3107         ArgValue = DAG.getNode(MipsISD::BuildPairF64, DL, MVT::f64,
3108                                ArgValue, ArgValue2);
3109       }
3110 
3111       InVals.push_back(ArgValue);
3112     } else { // VA.isRegLoc()
3113       MVT LocVT = VA.getLocVT();
3114 
3115       if (ABI.IsO32()) {
3116         // We ought to be able to use LocVT directly but O32 sets it to i32
3117         // when allocating floating point values to integer registers.
3118         // This shouldn't influence how we load the value into registers unless
3119         // we are targeting softfloat.
3120         if (VA.getValVT().isFloatingPoint() && !Subtarget.useSoftFloat())
3121           LocVT = VA.getValVT();
3122       }
3123 
3124       // sanity check
3125       assert(VA.isMemLoc());
3126 
3127       // The stack pointer offset is relative to the caller stack frame.
3128       int FI = MFI.CreateFixedObject(LocVT.getSizeInBits() / 8,
3129                                      VA.getLocMemOffset(), true);
3130 
3131       // Create load nodes to retrieve arguments from the stack
3132       SDValue FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3133       SDValue ArgValue = DAG.getLoad(
3134           LocVT, DL, Chain, FIN,
3135           MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI));
3136       OutChains.push_back(ArgValue.getValue(1));
3137 
3138       ArgValue = UnpackFromArgumentSlot(ArgValue, VA, Ins[i].ArgVT, DL, DAG);
3139 
3140       InVals.push_back(ArgValue);
3141     }
3142   }
3143 
3144   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
3145     // The mips ABIs for returning structs by value requires that we copy
3146     // the sret argument into $v0 for the return. Save the argument into
3147     // a virtual register so that we can access it from the return points.
3148     if (Ins[i].Flags.isSRet()) {
3149       unsigned Reg = MipsFI->getSRetReturnReg();
3150       if (!Reg) {
3151         Reg = MF.getRegInfo().createVirtualRegister(
3152             getRegClassFor(ABI.IsN64() ? MVT::i64 : MVT::i32));
3153         MipsFI->setSRetReturnReg(Reg);
3154       }
3155       SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[i]);
3156       Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
3157       break;
3158     }
3159   }
3160 
3161   if (IsVarArg)
3162     writeVarArgRegs(OutChains, Chain, DL, DAG, CCInfo);
3163 
3164   // All stores are grouped in one node to allow the matching between
3165   // the size of Ins and InVals. This only happens when on varg functions
3166   if (!OutChains.empty()) {
3167     OutChains.push_back(Chain);
3168     Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
3169   }
3170 
3171   return Chain;
3172 }
3173 
3174 //===----------------------------------------------------------------------===//
3175 //               Return Value Calling Convention Implementation
3176 //===----------------------------------------------------------------------===//
3177 
3178 bool
3179 MipsTargetLowering::CanLowerReturn(CallingConv::ID CallConv,
3180                                    MachineFunction &MF, bool IsVarArg,
3181                                    const SmallVectorImpl<ISD::OutputArg> &Outs,
3182                                    LLVMContext &Context) const {
3183   SmallVector<CCValAssign, 16> RVLocs;
3184   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, Context);
3185   return CCInfo.CheckReturn(Outs, RetCC_Mips);
3186 }
3187 
3188 bool
3189 MipsTargetLowering::shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const {
3190   if (Subtarget.hasMips3() && Subtarget.useSoftFloat()) {
3191     if (Type == MVT::i32)
3192       return true;
3193   }
3194   return IsSigned;
3195 }
3196 
3197 SDValue
3198 MipsTargetLowering::LowerInterruptReturn(SmallVectorImpl<SDValue> &RetOps,
3199                                          const SDLoc &DL,
3200                                          SelectionDAG &DAG) const {
3201 
3202   MachineFunction &MF = DAG.getMachineFunction();
3203   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3204 
3205   MipsFI->setISR();
3206 
3207   return DAG.getNode(MipsISD::ERet, DL, MVT::Other, RetOps);
3208 }
3209 
3210 SDValue
3211 MipsTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
3212                                 bool IsVarArg,
3213                                 const SmallVectorImpl<ISD::OutputArg> &Outs,
3214                                 const SmallVectorImpl<SDValue> &OutVals,
3215                                 const SDLoc &DL, SelectionDAG &DAG) const {
3216   // CCValAssign - represent the assignment of
3217   // the return value to a location
3218   SmallVector<CCValAssign, 16> RVLocs;
3219   MachineFunction &MF = DAG.getMachineFunction();
3220 
3221   // CCState - Info about the registers and stack slot.
3222   MipsCCState CCInfo(CallConv, IsVarArg, MF, RVLocs, *DAG.getContext());
3223 
3224   // Analyze return values.
3225   CCInfo.AnalyzeReturn(Outs, RetCC_Mips);
3226 
3227   SDValue Flag;
3228   SmallVector<SDValue, 4> RetOps(1, Chain);
3229 
3230   // Copy the result values into the output registers.
3231   for (unsigned i = 0; i != RVLocs.size(); ++i) {
3232     SDValue Val = OutVals[i];
3233     CCValAssign &VA = RVLocs[i];
3234     assert(VA.isRegLoc() && "Can only return in registers!");
3235     bool UseUpperBits = false;
3236 
3237     switch (VA.getLocInfo()) {
3238     default:
3239       llvm_unreachable("Unknown loc info!");
3240     case CCValAssign::Full:
3241       break;
3242     case CCValAssign::BCvt:
3243       Val = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Val);
3244       break;
3245     case CCValAssign::AExtUpper:
3246       UseUpperBits = true;
3247       LLVM_FALLTHROUGH;
3248     case CCValAssign::AExt:
3249       Val = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Val);
3250       break;
3251     case CCValAssign::ZExtUpper:
3252       UseUpperBits = true;
3253       LLVM_FALLTHROUGH;
3254     case CCValAssign::ZExt:
3255       Val = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Val);
3256       break;
3257     case CCValAssign::SExtUpper:
3258       UseUpperBits = true;
3259       LLVM_FALLTHROUGH;
3260     case CCValAssign::SExt:
3261       Val = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Val);
3262       break;
3263     }
3264 
3265     if (UseUpperBits) {
3266       unsigned ValSizeInBits = Outs[i].ArgVT.getSizeInBits();
3267       unsigned LocSizeInBits = VA.getLocVT().getSizeInBits();
3268       Val = DAG.getNode(
3269           ISD::SHL, DL, VA.getLocVT(), Val,
3270           DAG.getConstant(LocSizeInBits - ValSizeInBits, DL, VA.getLocVT()));
3271     }
3272 
3273     Chain = DAG.getCopyToReg(Chain, DL, VA.getLocReg(), Val, Flag);
3274 
3275     // Guarantee that all emitted copies are stuck together with flags.
3276     Flag = Chain.getValue(1);
3277     RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
3278   }
3279 
3280   // The mips ABIs for returning structs by value requires that we copy
3281   // the sret argument into $v0 for the return. We saved the argument into
3282   // a virtual register in the entry block, so now we copy the value out
3283   // and into $v0.
3284   if (MF.getFunction()->hasStructRetAttr()) {
3285     MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3286     unsigned Reg = MipsFI->getSRetReturnReg();
3287 
3288     if (!Reg)
3289       llvm_unreachable("sret virtual register not created in the entry block");
3290     SDValue Val =
3291         DAG.getCopyFromReg(Chain, DL, Reg, getPointerTy(DAG.getDataLayout()));
3292     unsigned V0 = ABI.IsN64() ? Mips::V0_64 : Mips::V0;
3293 
3294     Chain = DAG.getCopyToReg(Chain, DL, V0, Val, Flag);
3295     Flag = Chain.getValue(1);
3296     RetOps.push_back(DAG.getRegister(V0, getPointerTy(DAG.getDataLayout())));
3297   }
3298 
3299   RetOps[0] = Chain;  // Update chain.
3300 
3301   // Add the flag if we have it.
3302   if (Flag.getNode())
3303     RetOps.push_back(Flag);
3304 
3305   // ISRs must use "eret".
3306   if (DAG.getMachineFunction().getFunction()->hasFnAttribute("interrupt"))
3307     return LowerInterruptReturn(RetOps, DL, DAG);
3308 
3309   // Standard return on Mips is a "jr $ra"
3310   return DAG.getNode(MipsISD::Ret, DL, MVT::Other, RetOps);
3311 }
3312 
3313 //===----------------------------------------------------------------------===//
3314 //                           Mips Inline Assembly Support
3315 //===----------------------------------------------------------------------===//
3316 
3317 /// getConstraintType - Given a constraint letter, return the type of
3318 /// constraint it is for this target.
3319 MipsTargetLowering::ConstraintType
3320 MipsTargetLowering::getConstraintType(StringRef Constraint) const {
3321   // Mips specific constraints
3322   // GCC config/mips/constraints.md
3323   //
3324   // 'd' : An address register. Equivalent to r
3325   //       unless generating MIPS16 code.
3326   // 'y' : Equivalent to r; retained for
3327   //       backwards compatibility.
3328   // 'c' : A register suitable for use in an indirect
3329   //       jump. This will always be $25 for -mabicalls.
3330   // 'l' : The lo register. 1 word storage.
3331   // 'x' : The hilo register pair. Double word storage.
3332   if (Constraint.size() == 1) {
3333     switch (Constraint[0]) {
3334       default : break;
3335       case 'd':
3336       case 'y':
3337       case 'f':
3338       case 'c':
3339       case 'l':
3340       case 'x':
3341         return C_RegisterClass;
3342       case 'R':
3343         return C_Memory;
3344     }
3345   }
3346 
3347   if (Constraint == "ZC")
3348     return C_Memory;
3349 
3350   return TargetLowering::getConstraintType(Constraint);
3351 }
3352 
3353 /// Examine constraint type and operand type and determine a weight value.
3354 /// This object must already have been set up with the operand type
3355 /// and the current alternative constraint selected.
3356 TargetLowering::ConstraintWeight
3357 MipsTargetLowering::getSingleConstraintMatchWeight(
3358     AsmOperandInfo &info, const char *constraint) const {
3359   ConstraintWeight weight = CW_Invalid;
3360   Value *CallOperandVal = info.CallOperandVal;
3361     // If we don't have a value, we can't do a match,
3362     // but allow it at the lowest weight.
3363   if (!CallOperandVal)
3364     return CW_Default;
3365   Type *type = CallOperandVal->getType();
3366   // Look at the constraint type.
3367   switch (*constraint) {
3368   default:
3369     weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
3370     break;
3371   case 'd':
3372   case 'y':
3373     if (type->isIntegerTy())
3374       weight = CW_Register;
3375     break;
3376   case 'f': // FPU or MSA register
3377     if (Subtarget.hasMSA() && type->isVectorTy() &&
3378         cast<VectorType>(type)->getBitWidth() == 128)
3379       weight = CW_Register;
3380     else if (type->isFloatTy())
3381       weight = CW_Register;
3382     break;
3383   case 'c': // $25 for indirect jumps
3384   case 'l': // lo register
3385   case 'x': // hilo register pair
3386     if (type->isIntegerTy())
3387       weight = CW_SpecificReg;
3388     break;
3389   case 'I': // signed 16 bit immediate
3390   case 'J': // integer zero
3391   case 'K': // unsigned 16 bit immediate
3392   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3393   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3394   case 'O': // signed 15 bit immediate (+- 16383)
3395   case 'P': // immediate in the range of 65535 to 1 (inclusive)
3396     if (isa<ConstantInt>(CallOperandVal))
3397       weight = CW_Constant;
3398     break;
3399   case 'R':
3400     weight = CW_Memory;
3401     break;
3402   }
3403   return weight;
3404 }
3405 
3406 /// This is a helper function to parse a physical register string and split it
3407 /// into non-numeric and numeric parts (Prefix and Reg). The first boolean flag
3408 /// that is returned indicates whether parsing was successful. The second flag
3409 /// is true if the numeric part exists.
3410 static std::pair<bool, bool> parsePhysicalReg(StringRef C, StringRef &Prefix,
3411                                               unsigned long long &Reg) {
3412   if (C.front() != '{' || C.back() != '}')
3413     return std::make_pair(false, false);
3414 
3415   // Search for the first numeric character.
3416   StringRef::const_iterator I, B = C.begin() + 1, E = C.end() - 1;
3417   I = std::find_if(B, E, isdigit);
3418 
3419   Prefix = StringRef(B, I - B);
3420 
3421   // The second flag is set to false if no numeric characters were found.
3422   if (I == E)
3423     return std::make_pair(true, false);
3424 
3425   // Parse the numeric characters.
3426   return std::make_pair(!getAsUnsignedInteger(StringRef(I, E - I), 10, Reg),
3427                         true);
3428 }
3429 
3430 std::pair<unsigned, const TargetRegisterClass *> MipsTargetLowering::
3431 parseRegForInlineAsmConstraint(StringRef C, MVT VT) const {
3432   const TargetRegisterInfo *TRI =
3433       Subtarget.getRegisterInfo();
3434   const TargetRegisterClass *RC;
3435   StringRef Prefix;
3436   unsigned long long Reg;
3437 
3438   std::pair<bool, bool> R = parsePhysicalReg(C, Prefix, Reg);
3439 
3440   if (!R.first)
3441     return std::make_pair(0U, nullptr);
3442 
3443   if ((Prefix == "hi" || Prefix == "lo")) { // Parse hi/lo.
3444     // No numeric characters follow "hi" or "lo".
3445     if (R.second)
3446       return std::make_pair(0U, nullptr);
3447 
3448     RC = TRI->getRegClass(Prefix == "hi" ?
3449                           Mips::HI32RegClassID : Mips::LO32RegClassID);
3450     return std::make_pair(*(RC->begin()), RC);
3451   } else if (Prefix.startswith("$msa")) {
3452     // Parse $msa(ir|csr|access|save|modify|request|map|unmap)
3453 
3454     // No numeric characters follow the name.
3455     if (R.second)
3456       return std::make_pair(0U, nullptr);
3457 
3458     Reg = StringSwitch<unsigned long long>(Prefix)
3459               .Case("$msair", Mips::MSAIR)
3460               .Case("$msacsr", Mips::MSACSR)
3461               .Case("$msaaccess", Mips::MSAAccess)
3462               .Case("$msasave", Mips::MSASave)
3463               .Case("$msamodify", Mips::MSAModify)
3464               .Case("$msarequest", Mips::MSARequest)
3465               .Case("$msamap", Mips::MSAMap)
3466               .Case("$msaunmap", Mips::MSAUnmap)
3467               .Default(0);
3468 
3469     if (!Reg)
3470       return std::make_pair(0U, nullptr);
3471 
3472     RC = TRI->getRegClass(Mips::MSACtrlRegClassID);
3473     return std::make_pair(Reg, RC);
3474   }
3475 
3476   if (!R.second)
3477     return std::make_pair(0U, nullptr);
3478 
3479   if (Prefix == "$f") { // Parse $f0-$f31.
3480     // If the size of FP registers is 64-bit or Reg is an even number, select
3481     // the 64-bit register class. Otherwise, select the 32-bit register class.
3482     if (VT == MVT::Other)
3483       VT = (Subtarget.isFP64bit() || !(Reg % 2)) ? MVT::f64 : MVT::f32;
3484 
3485     RC = getRegClassFor(VT);
3486 
3487     if (RC == &Mips::AFGR64RegClass) {
3488       assert(Reg % 2 == 0);
3489       Reg >>= 1;
3490     }
3491   } else if (Prefix == "$fcc") // Parse $fcc0-$fcc7.
3492     RC = TRI->getRegClass(Mips::FCCRegClassID);
3493   else if (Prefix == "$w") { // Parse $w0-$w31.
3494     RC = getRegClassFor((VT == MVT::Other) ? MVT::v16i8 : VT);
3495   } else { // Parse $0-$31.
3496     assert(Prefix == "$");
3497     RC = getRegClassFor((VT == MVT::Other) ? MVT::i32 : VT);
3498   }
3499 
3500   assert(Reg < RC->getNumRegs());
3501   return std::make_pair(*(RC->begin() + Reg), RC);
3502 }
3503 
3504 /// Given a register class constraint, like 'r', if this corresponds directly
3505 /// to an LLVM register class, return a register of 0 and the register class
3506 /// pointer.
3507 std::pair<unsigned, const TargetRegisterClass *>
3508 MipsTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
3509                                                  StringRef Constraint,
3510                                                  MVT VT) const {
3511   if (Constraint.size() == 1) {
3512     switch (Constraint[0]) {
3513     case 'd': // Address register. Same as 'r' unless generating MIPS16 code.
3514     case 'y': // Same as 'r'. Exists for compatibility.
3515     case 'r':
3516       if (VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) {
3517         if (Subtarget.inMips16Mode())
3518           return std::make_pair(0U, &Mips::CPU16RegsRegClass);
3519         return std::make_pair(0U, &Mips::GPR32RegClass);
3520       }
3521       if (VT == MVT::i64 && !Subtarget.isGP64bit())
3522         return std::make_pair(0U, &Mips::GPR32RegClass);
3523       if (VT == MVT::i64 && Subtarget.isGP64bit())
3524         return std::make_pair(0U, &Mips::GPR64RegClass);
3525       // This will generate an error message
3526       return std::make_pair(0U, nullptr);
3527     case 'f': // FPU or MSA register
3528       if (VT == MVT::v16i8)
3529         return std::make_pair(0U, &Mips::MSA128BRegClass);
3530       else if (VT == MVT::v8i16 || VT == MVT::v8f16)
3531         return std::make_pair(0U, &Mips::MSA128HRegClass);
3532       else if (VT == MVT::v4i32 || VT == MVT::v4f32)
3533         return std::make_pair(0U, &Mips::MSA128WRegClass);
3534       else if (VT == MVT::v2i64 || VT == MVT::v2f64)
3535         return std::make_pair(0U, &Mips::MSA128DRegClass);
3536       else if (VT == MVT::f32)
3537         return std::make_pair(0U, &Mips::FGR32RegClass);
3538       else if ((VT == MVT::f64) && (!Subtarget.isSingleFloat())) {
3539         if (Subtarget.isFP64bit())
3540           return std::make_pair(0U, &Mips::FGR64RegClass);
3541         return std::make_pair(0U, &Mips::AFGR64RegClass);
3542       }
3543       break;
3544     case 'c': // register suitable for indirect jump
3545       if (VT == MVT::i32)
3546         return std::make_pair((unsigned)Mips::T9, &Mips::GPR32RegClass);
3547       assert(VT == MVT::i64 && "Unexpected type.");
3548       return std::make_pair((unsigned)Mips::T9_64, &Mips::GPR64RegClass);
3549     case 'l': // register suitable for indirect jump
3550       if (VT == MVT::i32)
3551         return std::make_pair((unsigned)Mips::LO0, &Mips::LO32RegClass);
3552       return std::make_pair((unsigned)Mips::LO0_64, &Mips::LO64RegClass);
3553     case 'x': // register suitable for indirect jump
3554       // Fixme: Not triggering the use of both hi and low
3555       // This will generate an error message
3556       return std::make_pair(0U, nullptr);
3557     }
3558   }
3559 
3560   std::pair<unsigned, const TargetRegisterClass *> R;
3561   R = parseRegForInlineAsmConstraint(Constraint, VT);
3562 
3563   if (R.second)
3564     return R;
3565 
3566   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
3567 }
3568 
3569 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
3570 /// vector.  If it is invalid, don't add anything to Ops.
3571 void MipsTargetLowering::LowerAsmOperandForConstraint(SDValue Op,
3572                                                      std::string &Constraint,
3573                                                      std::vector<SDValue>&Ops,
3574                                                      SelectionDAG &DAG) const {
3575   SDLoc DL(Op);
3576   SDValue Result;
3577 
3578   // Only support length 1 constraints for now.
3579   if (Constraint.length() > 1) return;
3580 
3581   char ConstraintLetter = Constraint[0];
3582   switch (ConstraintLetter) {
3583   default: break; // This will fall through to the generic implementation
3584   case 'I': // Signed 16 bit constant
3585     // If this fails, the parent routine will give an error
3586     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3587       EVT Type = Op.getValueType();
3588       int64_t Val = C->getSExtValue();
3589       if (isInt<16>(Val)) {
3590         Result = DAG.getTargetConstant(Val, DL, Type);
3591         break;
3592       }
3593     }
3594     return;
3595   case 'J': // integer zero
3596     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3597       EVT Type = Op.getValueType();
3598       int64_t Val = C->getZExtValue();
3599       if (Val == 0) {
3600         Result = DAG.getTargetConstant(0, DL, Type);
3601         break;
3602       }
3603     }
3604     return;
3605   case 'K': // unsigned 16 bit immediate
3606     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3607       EVT Type = Op.getValueType();
3608       uint64_t Val = (uint64_t)C->getZExtValue();
3609       if (isUInt<16>(Val)) {
3610         Result = DAG.getTargetConstant(Val, DL, Type);
3611         break;
3612       }
3613     }
3614     return;
3615   case 'L': // signed 32 bit immediate where lower 16 bits are 0
3616     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3617       EVT Type = Op.getValueType();
3618       int64_t Val = C->getSExtValue();
3619       if ((isInt<32>(Val)) && ((Val & 0xffff) == 0)){
3620         Result = DAG.getTargetConstant(Val, DL, Type);
3621         break;
3622       }
3623     }
3624     return;
3625   case 'N': // immediate in the range of -65535 to -1 (inclusive)
3626     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3627       EVT Type = Op.getValueType();
3628       int64_t Val = C->getSExtValue();
3629       if ((Val >= -65535) && (Val <= -1)) {
3630         Result = DAG.getTargetConstant(Val, DL, Type);
3631         break;
3632       }
3633     }
3634     return;
3635   case 'O': // signed 15 bit immediate
3636     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3637       EVT Type = Op.getValueType();
3638       int64_t Val = C->getSExtValue();
3639       if ((isInt<15>(Val))) {
3640         Result = DAG.getTargetConstant(Val, DL, Type);
3641         break;
3642       }
3643     }
3644     return;
3645   case 'P': // immediate in the range of 1 to 65535 (inclusive)
3646     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
3647       EVT Type = Op.getValueType();
3648       int64_t Val = C->getSExtValue();
3649       if ((Val <= 65535) && (Val >= 1)) {
3650         Result = DAG.getTargetConstant(Val, DL, Type);
3651         break;
3652       }
3653     }
3654     return;
3655   }
3656 
3657   if (Result.getNode()) {
3658     Ops.push_back(Result);
3659     return;
3660   }
3661 
3662   TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
3663 }
3664 
3665 bool MipsTargetLowering::isLegalAddressingMode(const DataLayout &DL,
3666                                                const AddrMode &AM, Type *Ty,
3667                                                unsigned AS) const {
3668   // No global is ever allowed as a base.
3669   if (AM.BaseGV)
3670     return false;
3671 
3672   switch (AM.Scale) {
3673   case 0: // "r+i" or just "i", depending on HasBaseReg.
3674     break;
3675   case 1:
3676     if (!AM.HasBaseReg) // allow "r+i".
3677       break;
3678     return false; // disallow "r+r" or "r+r+i".
3679   default:
3680     return false;
3681   }
3682 
3683   return true;
3684 }
3685 
3686 bool
3687 MipsTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
3688   // The Mips target isn't yet aware of offsets.
3689   return false;
3690 }
3691 
3692 EVT MipsTargetLowering::getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
3693                                             unsigned SrcAlign,
3694                                             bool IsMemset, bool ZeroMemset,
3695                                             bool MemcpyStrSrc,
3696                                             MachineFunction &MF) const {
3697   if (Subtarget.hasMips64())
3698     return MVT::i64;
3699 
3700   return MVT::i32;
3701 }
3702 
3703 bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT) const {
3704   if (VT != MVT::f32 && VT != MVT::f64)
3705     return false;
3706   if (Imm.isNegZero())
3707     return false;
3708   return Imm.isZero();
3709 }
3710 
3711 unsigned MipsTargetLowering::getJumpTableEncoding() const {
3712   if (ABI.IsN64())
3713     return MachineJumpTableInfo::EK_GPRel64BlockAddress;
3714 
3715   return TargetLowering::getJumpTableEncoding();
3716 }
3717 
3718 bool MipsTargetLowering::useSoftFloat() const {
3719   return Subtarget.useSoftFloat();
3720 }
3721 
3722 void MipsTargetLowering::copyByValRegs(
3723     SDValue Chain, const SDLoc &DL, std::vector<SDValue> &OutChains,
3724     SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
3725     SmallVectorImpl<SDValue> &InVals, const Argument *FuncArg,
3726     unsigned FirstReg, unsigned LastReg, const CCValAssign &VA,
3727     MipsCCState &State) const {
3728   MachineFunction &MF = DAG.getMachineFunction();
3729   MachineFrameInfo &MFI = MF.getFrameInfo();
3730   unsigned GPRSizeInBytes = Subtarget.getGPRSizeInBytes();
3731   unsigned NumRegs = LastReg - FirstReg;
3732   unsigned RegAreaSize = NumRegs * GPRSizeInBytes;
3733   unsigned FrameObjSize = std::max(Flags.getByValSize(), RegAreaSize);
3734   int FrameObjOffset;
3735   ArrayRef<MCPhysReg> ByValArgRegs = ABI.GetByValArgRegs();
3736 
3737   if (RegAreaSize)
3738     FrameObjOffset =
3739         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
3740         (int)((ByValArgRegs.size() - FirstReg) * GPRSizeInBytes);
3741   else
3742     FrameObjOffset = VA.getLocMemOffset();
3743 
3744   // Create frame object.
3745   EVT PtrTy = getPointerTy(DAG.getDataLayout());
3746   int FI = MFI.CreateFixedObject(FrameObjSize, FrameObjOffset, true);
3747   SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
3748   InVals.push_back(FIN);
3749 
3750   if (!NumRegs)
3751     return;
3752 
3753   // Copy arg registers.
3754   MVT RegTy = MVT::getIntegerVT(GPRSizeInBytes * 8);
3755   const TargetRegisterClass *RC = getRegClassFor(RegTy);
3756 
3757   for (unsigned I = 0; I < NumRegs; ++I) {
3758     unsigned ArgReg = ByValArgRegs[FirstReg + I];
3759     unsigned VReg = addLiveIn(MF, ArgReg, RC);
3760     unsigned Offset = I * GPRSizeInBytes;
3761     SDValue StorePtr = DAG.getNode(ISD::ADD, DL, PtrTy, FIN,
3762                                    DAG.getConstant(Offset, DL, PtrTy));
3763     SDValue Store = DAG.getStore(Chain, DL, DAG.getRegister(VReg, RegTy),
3764                                  StorePtr, MachinePointerInfo(FuncArg, Offset));
3765     OutChains.push_back(Store);
3766   }
3767 }
3768 
3769 // Copy byVal arg to registers and stack.
3770 void MipsTargetLowering::passByValArg(
3771     SDValue Chain, const SDLoc &DL,
3772     std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
3773     SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
3774     MachineFrameInfo &MFI, SelectionDAG &DAG, SDValue Arg, unsigned FirstReg,
3775     unsigned LastReg, const ISD::ArgFlagsTy &Flags, bool isLittle,
3776     const CCValAssign &VA) const {
3777   unsigned ByValSizeInBytes = Flags.getByValSize();
3778   unsigned OffsetInBytes = 0; // From beginning of struct
3779   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3780   unsigned Alignment = std::min(Flags.getByValAlign(), RegSizeInBytes);
3781   EVT PtrTy = getPointerTy(DAG.getDataLayout()),
3782       RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
3783   unsigned NumRegs = LastReg - FirstReg;
3784 
3785   if (NumRegs) {
3786     ArrayRef<MCPhysReg> ArgRegs = ABI.GetByValArgRegs();
3787     bool LeftoverBytes = (NumRegs * RegSizeInBytes > ByValSizeInBytes);
3788     unsigned I = 0;
3789 
3790     // Copy words to registers.
3791     for (; I < NumRegs - LeftoverBytes; ++I, OffsetInBytes += RegSizeInBytes) {
3792       SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3793                                     DAG.getConstant(OffsetInBytes, DL, PtrTy));
3794       SDValue LoadVal = DAG.getLoad(RegTy, DL, Chain, LoadPtr,
3795                                     MachinePointerInfo(), Alignment);
3796       MemOpChains.push_back(LoadVal.getValue(1));
3797       unsigned ArgReg = ArgRegs[FirstReg + I];
3798       RegsToPass.push_back(std::make_pair(ArgReg, LoadVal));
3799     }
3800 
3801     // Return if the struct has been fully copied.
3802     if (ByValSizeInBytes == OffsetInBytes)
3803       return;
3804 
3805     // Copy the remainder of the byval argument with sub-word loads and shifts.
3806     if (LeftoverBytes) {
3807       SDValue Val;
3808 
3809       for (unsigned LoadSizeInBytes = RegSizeInBytes / 2, TotalBytesLoaded = 0;
3810            OffsetInBytes < ByValSizeInBytes; LoadSizeInBytes /= 2) {
3811         unsigned RemainingSizeInBytes = ByValSizeInBytes - OffsetInBytes;
3812 
3813         if (RemainingSizeInBytes < LoadSizeInBytes)
3814           continue;
3815 
3816         // Load subword.
3817         SDValue LoadPtr = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3818                                       DAG.getConstant(OffsetInBytes, DL,
3819                                                       PtrTy));
3820         SDValue LoadVal = DAG.getExtLoad(
3821             ISD::ZEXTLOAD, DL, RegTy, Chain, LoadPtr, MachinePointerInfo(),
3822             MVT::getIntegerVT(LoadSizeInBytes * 8), Alignment);
3823         MemOpChains.push_back(LoadVal.getValue(1));
3824 
3825         // Shift the loaded value.
3826         unsigned Shamt;
3827 
3828         if (isLittle)
3829           Shamt = TotalBytesLoaded * 8;
3830         else
3831           Shamt = (RegSizeInBytes - (TotalBytesLoaded + LoadSizeInBytes)) * 8;
3832 
3833         SDValue Shift = DAG.getNode(ISD::SHL, DL, RegTy, LoadVal,
3834                                     DAG.getConstant(Shamt, DL, MVT::i32));
3835 
3836         if (Val.getNode())
3837           Val = DAG.getNode(ISD::OR, DL, RegTy, Val, Shift);
3838         else
3839           Val = Shift;
3840 
3841         OffsetInBytes += LoadSizeInBytes;
3842         TotalBytesLoaded += LoadSizeInBytes;
3843         Alignment = std::min(Alignment, LoadSizeInBytes);
3844       }
3845 
3846       unsigned ArgReg = ArgRegs[FirstReg + I];
3847       RegsToPass.push_back(std::make_pair(ArgReg, Val));
3848       return;
3849     }
3850   }
3851 
3852   // Copy remainder of byval arg to it with memcpy.
3853   unsigned MemCpySize = ByValSizeInBytes - OffsetInBytes;
3854   SDValue Src = DAG.getNode(ISD::ADD, DL, PtrTy, Arg,
3855                             DAG.getConstant(OffsetInBytes, DL, PtrTy));
3856   SDValue Dst = DAG.getNode(ISD::ADD, DL, PtrTy, StackPtr,
3857                             DAG.getIntPtrConstant(VA.getLocMemOffset(), DL));
3858   Chain = DAG.getMemcpy(Chain, DL, Dst, Src,
3859                         DAG.getConstant(MemCpySize, DL, PtrTy),
3860                         Alignment, /*isVolatile=*/false, /*AlwaysInline=*/false,
3861                         /*isTailCall=*/false,
3862                         MachinePointerInfo(), MachinePointerInfo());
3863   MemOpChains.push_back(Chain);
3864 }
3865 
3866 void MipsTargetLowering::writeVarArgRegs(std::vector<SDValue> &OutChains,
3867                                          SDValue Chain, const SDLoc &DL,
3868                                          SelectionDAG &DAG,
3869                                          CCState &State) const {
3870   ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
3871   unsigned Idx = State.getFirstUnallocated(ArgRegs);
3872   unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3873   MVT RegTy = MVT::getIntegerVT(RegSizeInBytes * 8);
3874   const TargetRegisterClass *RC = getRegClassFor(RegTy);
3875   MachineFunction &MF = DAG.getMachineFunction();
3876   MachineFrameInfo &MFI = MF.getFrameInfo();
3877   MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
3878 
3879   // Offset of the first variable argument from stack pointer.
3880   int VaArgOffset;
3881 
3882   if (ArgRegs.size() == Idx)
3883     VaArgOffset = alignTo(State.getNextStackOffset(), RegSizeInBytes);
3884   else {
3885     VaArgOffset =
3886         (int)ABI.GetCalleeAllocdArgSizeInBytes(State.getCallingConv()) -
3887         (int)(RegSizeInBytes * (ArgRegs.size() - Idx));
3888   }
3889 
3890   // Record the frame index of the first variable argument
3891   // which is a value necessary to VASTART.
3892   int FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
3893   MipsFI->setVarArgsFrameIndex(FI);
3894 
3895   // Copy the integer registers that have not been used for argument passing
3896   // to the argument register save area. For O32, the save area is allocated
3897   // in the caller's stack frame, while for N32/64, it is allocated in the
3898   // callee's stack frame.
3899   for (unsigned I = Idx; I < ArgRegs.size();
3900        ++I, VaArgOffset += RegSizeInBytes) {
3901     unsigned Reg = addLiveIn(MF, ArgRegs[I], RC);
3902     SDValue ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegTy);
3903     FI = MFI.CreateFixedObject(RegSizeInBytes, VaArgOffset, true);
3904     SDValue PtrOff = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
3905     SDValue Store =
3906         DAG.getStore(Chain, DL, ArgValue, PtrOff, MachinePointerInfo());
3907     cast<StoreSDNode>(Store.getNode())->getMemOperand()->setValue(
3908         (Value *)nullptr);
3909     OutChains.push_back(Store);
3910   }
3911 }
3912 
3913 void MipsTargetLowering::HandleByVal(CCState *State, unsigned &Size,
3914                                      unsigned Align) const {
3915   const TargetFrameLowering *TFL = Subtarget.getFrameLowering();
3916 
3917   assert(Size && "Byval argument's size shouldn't be 0.");
3918 
3919   Align = std::min(Align, TFL->getStackAlignment());
3920 
3921   unsigned FirstReg = 0;
3922   unsigned NumRegs = 0;
3923 
3924   if (State->getCallingConv() != CallingConv::Fast) {
3925     unsigned RegSizeInBytes = Subtarget.getGPRSizeInBytes();
3926     ArrayRef<MCPhysReg> IntArgRegs = ABI.GetByValArgRegs();
3927     // FIXME: The O32 case actually describes no shadow registers.
3928     const MCPhysReg *ShadowRegs =
3929         ABI.IsO32() ? IntArgRegs.data() : Mips64DPRegs;
3930 
3931     // We used to check the size as well but we can't do that anymore since
3932     // CCState::HandleByVal() rounds up the size after calling this function.
3933     assert(!(Align % RegSizeInBytes) &&
3934            "Byval argument's alignment should be a multiple of"
3935            "RegSizeInBytes.");
3936 
3937     FirstReg = State->getFirstUnallocated(IntArgRegs);
3938 
3939     // If Align > RegSizeInBytes, the first arg register must be even.
3940     // FIXME: This condition happens to do the right thing but it's not the
3941     //        right way to test it. We want to check that the stack frame offset
3942     //        of the register is aligned.
3943     if ((Align > RegSizeInBytes) && (FirstReg % 2)) {
3944       State->AllocateReg(IntArgRegs[FirstReg], ShadowRegs[FirstReg]);
3945       ++FirstReg;
3946     }
3947 
3948     // Mark the registers allocated.
3949     Size = alignTo(Size, RegSizeInBytes);
3950     for (unsigned I = FirstReg; Size > 0 && (I < IntArgRegs.size());
3951          Size -= RegSizeInBytes, ++I, ++NumRegs)
3952       State->AllocateReg(IntArgRegs[I], ShadowRegs[I]);
3953   }
3954 
3955   State->addInRegsParamInfo(FirstReg, FirstReg + NumRegs);
3956 }
3957 
3958 MachineBasicBlock *MipsTargetLowering::emitPseudoSELECT(MachineInstr &MI,
3959                                                         MachineBasicBlock *BB,
3960                                                         bool isFPCmp,
3961                                                         unsigned Opc) const {
3962   assert(!(Subtarget.hasMips4() || Subtarget.hasMips32()) &&
3963          "Subtarget already supports SELECT nodes with the use of"
3964          "conditional-move instructions.");
3965 
3966   const TargetInstrInfo *TII =
3967       Subtarget.getInstrInfo();
3968   DebugLoc DL = MI.getDebugLoc();
3969 
3970   // To "insert" a SELECT instruction, we actually have to insert the
3971   // diamond control-flow pattern.  The incoming instruction knows the
3972   // destination vreg to set, the condition code register to branch on, the
3973   // true/false values to select between, and a branch opcode to use.
3974   const BasicBlock *LLVM_BB = BB->getBasicBlock();
3975   MachineFunction::iterator It = ++BB->getIterator();
3976 
3977   //  thisMBB:
3978   //  ...
3979   //   TrueVal = ...
3980   //   setcc r1, r2, r3
3981   //   bNE   r1, r0, copy1MBB
3982   //   fallthrough --> copy0MBB
3983   MachineBasicBlock *thisMBB  = BB;
3984   MachineFunction *F = BB->getParent();
3985   MachineBasicBlock *copy0MBB = F->CreateMachineBasicBlock(LLVM_BB);
3986   MachineBasicBlock *sinkMBB  = F->CreateMachineBasicBlock(LLVM_BB);
3987   F->insert(It, copy0MBB);
3988   F->insert(It, sinkMBB);
3989 
3990   // Transfer the remainder of BB and its successor edges to sinkMBB.
3991   sinkMBB->splice(sinkMBB->begin(), BB,
3992                   std::next(MachineBasicBlock::iterator(MI)), BB->end());
3993   sinkMBB->transferSuccessorsAndUpdatePHIs(BB);
3994 
3995   // Next, add the true and fallthrough blocks as its successors.
3996   BB->addSuccessor(copy0MBB);
3997   BB->addSuccessor(sinkMBB);
3998 
3999   if (isFPCmp) {
4000     // bc1[tf] cc, sinkMBB
4001     BuildMI(BB, DL, TII->get(Opc))
4002         .addReg(MI.getOperand(1).getReg())
4003         .addMBB(sinkMBB);
4004   } else {
4005     // bne rs, $0, sinkMBB
4006     BuildMI(BB, DL, TII->get(Opc))
4007         .addReg(MI.getOperand(1).getReg())
4008         .addReg(Mips::ZERO)
4009         .addMBB(sinkMBB);
4010   }
4011 
4012   //  copy0MBB:
4013   //   %FalseValue = ...
4014   //   # fallthrough to sinkMBB
4015   BB = copy0MBB;
4016 
4017   // Update machine-CFG edges
4018   BB->addSuccessor(sinkMBB);
4019 
4020   //  sinkMBB:
4021   //   %Result = phi [ %TrueValue, thisMBB ], [ %FalseValue, copy0MBB ]
4022   //  ...
4023   BB = sinkMBB;
4024 
4025   BuildMI(*BB, BB->begin(), DL, TII->get(Mips::PHI), MI.getOperand(0).getReg())
4026       .addReg(MI.getOperand(2).getReg())
4027       .addMBB(thisMBB)
4028       .addReg(MI.getOperand(3).getReg())
4029       .addMBB(copy0MBB);
4030 
4031   MI.eraseFromParent(); // The pseudo instruction is gone now.
4032 
4033   return BB;
4034 }
4035 
4036 // FIXME? Maybe this could be a TableGen attribute on some registers and
4037 // this table could be generated automatically from RegInfo.
4038 unsigned MipsTargetLowering::getRegisterByName(const char* RegName, EVT VT,
4039                                                SelectionDAG &DAG) const {
4040   // Named registers is expected to be fairly rare. For now, just support $28
4041   // since the linux kernel uses it.
4042   if (Subtarget.isGP64bit()) {
4043     unsigned Reg = StringSwitch<unsigned>(RegName)
4044                          .Case("$28", Mips::GP_64)
4045                          .Default(0);
4046     if (Reg)
4047       return Reg;
4048   } else {
4049     unsigned Reg = StringSwitch<unsigned>(RegName)
4050                          .Case("$28", Mips::GP)
4051                          .Default(0);
4052     if (Reg)
4053       return Reg;
4054   }
4055   report_fatal_error("Invalid register name global variable");
4056 }
4057