Bug Summary

File:build/source/llvm/lib/Target/Mips/MipsCallLowering.cpp
Warning:line 332, column 13
Forming reference to null pointer

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name MipsCallLowering.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -resource-dir /usr/lib/llvm-17/lib/clang/17 -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I lib/Target/Mips -I /build/source/llvm/lib/Target/Mips -I include -I /build/source/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fcoverage-prefix-map=/build/source/= -source-date-epoch 1683717183 -O2 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/build-llvm/tools/clang/stage2-bins=build-llvm/tools/clang/stage2-bins -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility=hidden -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2023-05-10-133810-16478-1 -x c++ /build/source/llvm/lib/Target/Mips/MipsCallLowering.cpp
1//===- MipsCallLowering.cpp -------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9/// \file
10/// This file implements the lowering of LLVM calls to machine code calls for
11/// GlobalISel.
12//
13//===----------------------------------------------------------------------===//
14
15#include "MipsCallLowering.h"
16#include "MipsCCState.h"
17#include "MipsMachineFunction.h"
18#include "MipsTargetMachine.h"
19#include "llvm/CodeGen/Analysis.h"
20#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22
23using namespace llvm;
24
25MipsCallLowering::MipsCallLowering(const MipsTargetLowering &TLI)
26 : CallLowering(&TLI) {}
27
28namespace {
29struct MipsOutgoingValueAssigner : public CallLowering::OutgoingValueAssigner {
30 /// This is the name of the function being called
31 /// FIXME: Relying on this is unsound
32 const char *Func = nullptr;
33
34 /// Is this a return value, or an outgoing call operand.
35 bool IsReturn;
36
37 MipsOutgoingValueAssigner(CCAssignFn *AssignFn_, const char *Func,
38 bool IsReturn)
39 : OutgoingValueAssigner(AssignFn_), Func(Func), IsReturn(IsReturn) {}
40
41 bool assignArg(unsigned ValNo, EVT OrigVT, MVT ValVT, MVT LocVT,
42 CCValAssign::LocInfo LocInfo,
43 const CallLowering::ArgInfo &Info, ISD::ArgFlagsTy Flags,
44 CCState &State_) override {
45 MipsCCState &State = static_cast<MipsCCState &>(State_);
46
47 if (IsReturn)
48 State.PreAnalyzeReturnValue(EVT::getEVT(Info.Ty));
49 else
50 State.PreAnalyzeCallOperand(Info.Ty, Info.IsFixed, Func);
51
52 return CallLowering::OutgoingValueAssigner::assignArg(
53 ValNo, OrigVT, ValVT, LocVT, LocInfo, Info, Flags, State);
54 }
55};
56
57struct MipsIncomingValueAssigner : public CallLowering::IncomingValueAssigner {
58 /// This is the name of the function being called
59 /// FIXME: Relying on this is unsound
60 const char *Func = nullptr;
61
62 /// Is this a call return value, or an incoming function argument.
63 bool IsReturn;
64
65 MipsIncomingValueAssigner(CCAssignFn *AssignFn_, const char *Func,
66 bool IsReturn)
67 : IncomingValueAssigner(AssignFn_), Func(Func), IsReturn(IsReturn) {}
68
69 bool assignArg(unsigned ValNo, EVT OrigVT, MVT ValVT, MVT LocVT,
70 CCValAssign::LocInfo LocInfo,
71 const CallLowering::ArgInfo &Info, ISD::ArgFlagsTy Flags,
72 CCState &State_) override {
73 MipsCCState &State = static_cast<MipsCCState &>(State_);
74
75 if (IsReturn)
76 State.PreAnalyzeCallResult(Info.Ty, Func);
77 else
78 State.PreAnalyzeFormalArgument(Info.Ty, Flags);
79
80 return CallLowering::IncomingValueAssigner::assignArg(
81 ValNo, OrigVT, ValVT, LocVT, LocInfo, Info, Flags, State);
82 }
83};
84
85class MipsIncomingValueHandler : public CallLowering::IncomingValueHandler {
86 const MipsSubtarget &STI;
87
88public:
89 MipsIncomingValueHandler(MachineIRBuilder &MIRBuilder,
90 MachineRegisterInfo &MRI)
91 : IncomingValueHandler(MIRBuilder, MRI),
92 STI(MIRBuilder.getMF().getSubtarget<MipsSubtarget>()) {}
93
94private:
95 void assignValueToReg(Register ValVReg, Register PhysReg,
96 CCValAssign VA) override;
97
98 Register getStackAddress(uint64_t Size, int64_t Offset,
99 MachinePointerInfo &MPO,
100 ISD::ArgFlagsTy Flags) override;
101 void assignValueToAddress(Register ValVReg, Register Addr, LLT MemTy,
102 MachinePointerInfo &MPO, CCValAssign &VA) override;
103
104 unsigned assignCustomValue(CallLowering::ArgInfo &Arg,
105 ArrayRef<CCValAssign> VAs,
106 std::function<void()> *Thunk = nullptr) override;
107
108 virtual void markPhysRegUsed(unsigned PhysReg) {
109 MIRBuilder.getMRI()->addLiveIn(PhysReg);
110 MIRBuilder.getMBB().addLiveIn(PhysReg);
111 }
112};
113
114class CallReturnHandler : public MipsIncomingValueHandler {
115public:
116 CallReturnHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
117 MachineInstrBuilder &MIB)
118 : MipsIncomingValueHandler(MIRBuilder, MRI), MIB(MIB) {}
119
120private:
121 void markPhysRegUsed(unsigned PhysReg) override {
122 MIB.addDef(PhysReg, RegState::Implicit);
123 }
124
125 MachineInstrBuilder &MIB;
126};
127
128} // end anonymous namespace
129
130void MipsIncomingValueHandler::assignValueToReg(Register ValVReg,
131 Register PhysReg,
132 CCValAssign VA) {
133 markPhysRegUsed(PhysReg);
134 IncomingValueHandler::assignValueToReg(ValVReg, PhysReg, VA);
135}
136
137Register MipsIncomingValueHandler::getStackAddress(uint64_t Size,
138 int64_t Offset,
139 MachinePointerInfo &MPO,
140 ISD::ArgFlagsTy Flags) {
141
142 MachineFunction &MF = MIRBuilder.getMF();
143 MachineFrameInfo &MFI = MF.getFrameInfo();
144
145 // FIXME: This should only be immutable for non-byval memory arguments.
146 int FI = MFI.CreateFixedObject(Size, Offset, true);
147 MPO = MachinePointerInfo::getFixedStack(MIRBuilder.getMF(), FI);
148
149 return MIRBuilder.buildFrameIndex(LLT::pointer(0, 32), FI).getReg(0);
150}
151
152void MipsIncomingValueHandler::assignValueToAddress(Register ValVReg,
153 Register Addr, LLT MemTy,
154 MachinePointerInfo &MPO,
155 CCValAssign &VA) {
156 MachineFunction &MF = MIRBuilder.getMF();
157 auto MMO = MF.getMachineMemOperand(MPO, MachineMemOperand::MOLoad, MemTy,
158 inferAlignFromPtrInfo(MF, MPO));
159 MIRBuilder.buildLoad(ValVReg, Addr, *MMO);
160}
161
162/// Handle cases when f64 is split into 2 32-bit GPRs. This is a custom
163/// assignment because generic code assumes getNumRegistersForCallingConv is
164/// accurate. In this case it is not because the type/number are context
165/// dependent on other arguments.
166unsigned
167MipsIncomingValueHandler::assignCustomValue(CallLowering::ArgInfo &Arg,
168 ArrayRef<CCValAssign> VAs,
169 std::function<void()> *Thunk) {
170 const CCValAssign &VALo = VAs[0];
171 const CCValAssign &VAHi = VAs[1];
172
173 assert(VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 &&(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 175, __extension__
__PRETTY_FUNCTION__))
174 VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 &&(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 175, __extension__
__PRETTY_FUNCTION__))
175 "unexpected custom value")(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 175, __extension__
__PRETTY_FUNCTION__));
176
177 auto CopyLo = MIRBuilder.buildCopy(LLT::scalar(32), VALo.getLocReg());
178 auto CopyHi = MIRBuilder.buildCopy(LLT::scalar(32), VAHi.getLocReg());
179 if (!STI.isLittle())
180 std::swap(CopyLo, CopyHi);
181
182 Arg.OrigRegs.assign(Arg.Regs.begin(), Arg.Regs.end());
183 Arg.Regs = { CopyLo.getReg(0), CopyHi.getReg(0) };
184 MIRBuilder.buildMergeLikeInstr(Arg.OrigRegs[0], {CopyLo, CopyHi});
185
186 markPhysRegUsed(VALo.getLocReg());
187 markPhysRegUsed(VAHi.getLocReg());
188 return 2;
189}
190
191namespace {
192class MipsOutgoingValueHandler : public CallLowering::OutgoingValueHandler {
193 const MipsSubtarget &STI;
194
195public:
196 MipsOutgoingValueHandler(MachineIRBuilder &MIRBuilder,
197 MachineRegisterInfo &MRI, MachineInstrBuilder &MIB)
198 : OutgoingValueHandler(MIRBuilder, MRI),
199 STI(MIRBuilder.getMF().getSubtarget<MipsSubtarget>()), MIB(MIB) {}
200
201private:
202 void assignValueToReg(Register ValVReg, Register PhysReg,
203 CCValAssign VA) override;
204
205 Register getStackAddress(uint64_t Size, int64_t Offset,
206 MachinePointerInfo &MPO,
207 ISD::ArgFlagsTy Flags) override;
208
209 void assignValueToAddress(Register ValVReg, Register Addr, LLT MemTy,
210 MachinePointerInfo &MPO, CCValAssign &VA) override;
211 unsigned assignCustomValue(CallLowering::ArgInfo &Arg,
212 ArrayRef<CCValAssign> VAs,
213 std::function<void()> *Thunk) override;
214
215 MachineInstrBuilder &MIB;
216};
217} // end anonymous namespace
218
219void MipsOutgoingValueHandler::assignValueToReg(Register ValVReg,
220 Register PhysReg,
221 CCValAssign VA) {
222 Register ExtReg = extendRegister(ValVReg, VA);
223 MIRBuilder.buildCopy(PhysReg, ExtReg);
224 MIB.addUse(PhysReg, RegState::Implicit);
225}
226
227Register MipsOutgoingValueHandler::getStackAddress(uint64_t Size,
228 int64_t Offset,
229 MachinePointerInfo &MPO,
230 ISD::ArgFlagsTy Flags) {
231 MachineFunction &MF = MIRBuilder.getMF();
232 MPO = MachinePointerInfo::getStack(MF, Offset);
233
234 LLT p0 = LLT::pointer(0, 32);
235 LLT s32 = LLT::scalar(32);
236 auto SPReg = MIRBuilder.buildCopy(p0, Register(Mips::SP));
237
238 auto OffsetReg = MIRBuilder.buildConstant(s32, Offset);
239 auto AddrReg = MIRBuilder.buildPtrAdd(p0, SPReg, OffsetReg);
240 return AddrReg.getReg(0);
241}
242
243void MipsOutgoingValueHandler::assignValueToAddress(Register ValVReg,
244 Register Addr, LLT MemTy,
245 MachinePointerInfo &MPO,
246 CCValAssign &VA) {
247 MachineFunction &MF = MIRBuilder.getMF();
248 uint64_t LocMemOffset = VA.getLocMemOffset();
249
250 auto MMO = MF.getMachineMemOperand(
251 MPO, MachineMemOperand::MOStore, MemTy,
252 commonAlignment(STI.getStackAlignment(), LocMemOffset));
253
254 Register ExtReg = extendRegister(ValVReg, VA);
255 MIRBuilder.buildStore(ExtReg, Addr, *MMO);
256}
257
258unsigned
259MipsOutgoingValueHandler::assignCustomValue(CallLowering::ArgInfo &Arg,
260 ArrayRef<CCValAssign> VAs,
261 std::function<void()> *Thunk) {
262 const CCValAssign &VALo = VAs[0];
263 const CCValAssign &VAHi = VAs[1];
264
265 assert(VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 &&(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 267, __extension__
__PRETTY_FUNCTION__))
266 VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 &&(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 267, __extension__
__PRETTY_FUNCTION__))
267 "unexpected custom value")(static_cast <bool> (VALo.getLocVT() == MVT::i32 &&
VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT
::f64 && VAHi.getValVT() == MVT::f64 && "unexpected custom value"
) ? void (0) : __assert_fail ("VALo.getLocVT() == MVT::i32 && VAHi.getLocVT() == MVT::i32 && VALo.getValVT() == MVT::f64 && VAHi.getValVT() == MVT::f64 && \"unexpected custom value\""
, "llvm/lib/Target/Mips/MipsCallLowering.cpp", 267, __extension__
__PRETTY_FUNCTION__));
268
269 auto Unmerge =
270 MIRBuilder.buildUnmerge({LLT::scalar(32), LLT::scalar(32)}, Arg.Regs[0]);
271 Register Lo = Unmerge.getReg(0);
272 Register Hi = Unmerge.getReg(1);
273
274 Arg.OrigRegs.assign(Arg.Regs.begin(), Arg.Regs.end());
275 Arg.Regs = { Lo, Hi };
276 if (!STI.isLittle())
277 std::swap(Lo, Hi);
278
279 // If we can return a thunk, just include the register copies. The unmerge can
280 // be emitted earlier.
281 if (Thunk) {
282 *Thunk = [=]() {
283 MIRBuilder.buildCopy(VALo.getLocReg(), Lo);
284 MIRBuilder.buildCopy(VAHi.getLocReg(), Hi);
285 };
286 return 2;
287 }
288 MIRBuilder.buildCopy(VALo.getLocReg(), Lo);
289 MIRBuilder.buildCopy(VAHi.getLocReg(), Hi);
290 return 2;
291}
292
293static bool isSupportedArgumentType(Type *T) {
294 if (T->isIntegerTy())
295 return true;
296 if (T->isPointerTy())
297 return true;
298 if (T->isFloatingPointTy())
299 return true;
300 return false;
301}
302
303static bool isSupportedReturnType(Type *T) {
304 if (T->isIntegerTy())
305 return true;
306 if (T->isPointerTy())
307 return true;
308 if (T->isFloatingPointTy())
309 return true;
310 if (T->isAggregateType())
311 return true;
312 return false;
313}
314
315bool MipsCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
316 const Value *Val, ArrayRef<Register> VRegs,
317 FunctionLoweringInfo &FLI) const {
318
319 MachineInstrBuilder Ret = MIRBuilder.buildInstrNoInsert(Mips::RetRA);
320
321 if (Val != nullptr && !isSupportedReturnType(Val->getType()))
1
Assuming pointer value is null
→
322 return false;
323
324 if (!VRegs.empty()) {
2
←
Assuming the condition is true
→
3
←
Taking true branch
→
325 MachineFunction &MF = MIRBuilder.getMF();
326 const Function &F = MF.getFunction();
327 const DataLayout &DL = MF.getDataLayout();
328 const MipsTargetLowering &TLI = *getTLI<MipsTargetLowering>();
329
330 SmallVector<ArgInfo, 8> RetInfos;
331
332 ArgInfo ArgRetInfo(VRegs, *Val, 0);
4
←
Forming reference to null pointer
333 setArgFlags(ArgRetInfo, AttributeList::ReturnIndex, DL, F);
334 splitToValueTypes(ArgRetInfo, RetInfos, DL, F.getCallingConv());
335
336 SmallVector<CCValAssign, 16> ArgLocs;
337 SmallVector<ISD::OutputArg, 8> Outs;
338
339 MipsCCState CCInfo(F.getCallingConv(), F.isVarArg(), MF, ArgLocs,
340 F.getContext());
341
342 MipsOutgoingValueHandler RetHandler(MIRBuilder, MF.getRegInfo(), Ret);
343 std::string FuncName = F.getName().str();
344 MipsOutgoingValueAssigner Assigner(TLI.CCAssignFnForReturn(),
345 FuncName.c_str(), /*IsReturn*/ true);
346
347 if (!determineAssignments(Assigner, RetInfos, CCInfo))
348 return false;
349
350 if (!handleAssignments(RetHandler, RetInfos, CCInfo, ArgLocs, MIRBuilder))
351 return false;
352 }
353
354 MIRBuilder.insertInstr(Ret);
355 return true;
356}
357
358bool MipsCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
359 const Function &F,
360 ArrayRef<ArrayRef<Register>> VRegs,
361 FunctionLoweringInfo &FLI) const {
362
363 // Quick exit if there aren't any args.
364 if (F.arg_empty())
365 return true;
366
367 for (auto &Arg : F.args()) {
368 if (!isSupportedArgumentType(Arg.getType()))
369 return false;
370 }
371
372 MachineFunction &MF = MIRBuilder.getMF();
373 const DataLayout &DL = MF.getDataLayout();
374 const MipsTargetLowering &TLI = *getTLI<MipsTargetLowering>();
375
376 SmallVector<ArgInfo, 8> ArgInfos;
377 unsigned i = 0;
378 for (auto &Arg : F.args()) {
379 ArgInfo AInfo(VRegs[i], Arg, i);
380 setArgFlags(AInfo, i + AttributeList::FirstArgIndex, DL, F);
381
382 splitToValueTypes(AInfo, ArgInfos, DL, F.getCallingConv());
383 ++i;
384 }
385
386 SmallVector<ISD::InputArg, 8> Ins;
387
388 SmallVector<CCValAssign, 16> ArgLocs;
389 MipsCCState CCInfo(F.getCallingConv(), F.isVarArg(), MF, ArgLocs,
390 F.getContext());
391
392 const MipsTargetMachine &TM =
393 static_cast<const MipsTargetMachine &>(MF.getTarget());
394 const MipsABIInfo &ABI = TM.getABI();
395 CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(F.getCallingConv()),
396 Align(1));
397
398 const std::string FuncName = F.getName().str();
399 MipsIncomingValueAssigner Assigner(TLI.CCAssignFnForCall(), FuncName.c_str(),
400 /*IsReturn*/ false);
401 if (!determineAssignments(Assigner, ArgInfos, CCInfo))
402 return false;
403
404 MipsIncomingValueHandler Handler(MIRBuilder, MF.getRegInfo());
405 if (!handleAssignments(Handler, ArgInfos, CCInfo, ArgLocs, MIRBuilder))
406 return false;
407
408 if (F.isVarArg()) {
409 ArrayRef<MCPhysReg> ArgRegs = ABI.GetVarArgRegs();
410 unsigned Idx = CCInfo.getFirstUnallocated(ArgRegs);
411
412 int VaArgOffset;
413 unsigned RegSize = 4;
414 if (ArgRegs.size() == Idx)
415 VaArgOffset = alignTo(CCInfo.getNextStackOffset(), RegSize);
416 else {
417 VaArgOffset =
418 (int)ABI.GetCalleeAllocdArgSizeInBytes(CCInfo.getCallingConv()) -
419 (int)(RegSize * (ArgRegs.size() - Idx));
420 }
421
422 MachineFrameInfo &MFI = MF.getFrameInfo();
423 int FI = MFI.CreateFixedObject(RegSize, VaArgOffset, true);
424 MF.getInfo<MipsFunctionInfo>()->setVarArgsFrameIndex(FI);
425
426 for (unsigned I = Idx; I < ArgRegs.size(); ++I, VaArgOffset += RegSize) {
427 MIRBuilder.getMBB().addLiveIn(ArgRegs[I]);
428 LLT RegTy = LLT::scalar(RegSize * 8);
429 MachineInstrBuilder Copy =
430 MIRBuilder.buildCopy(RegTy, Register(ArgRegs[I]));
431 FI = MFI.CreateFixedObject(RegSize, VaArgOffset, true);
432 MachinePointerInfo MPO = MachinePointerInfo::getFixedStack(MF, FI);
433
434 const LLT PtrTy = LLT::pointer(MPO.getAddrSpace(), 32);
435 auto FrameIndex = MIRBuilder.buildFrameIndex(PtrTy, FI);
436 MachineMemOperand *MMO = MF.getMachineMemOperand(
437 MPO, MachineMemOperand::MOStore, RegTy, Align(RegSize));
438 MIRBuilder.buildStore(Copy, FrameIndex, *MMO);
439 }
440 }
441
442 return true;
443}
444
445bool MipsCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
446 CallLoweringInfo &Info) const {
447
448 if (Info.CallConv != CallingConv::C)
449 return false;
450
451 for (auto &Arg : Info.OrigArgs) {
452 if (!isSupportedArgumentType(Arg.Ty))
453 return false;
454 if (Arg.Flags[0].isByVal())
455 return false;
456 if (Arg.Flags[0].isSRet() && !Arg.Ty->isPointerTy())
457 return false;
458 }
459
460 if (!Info.OrigRet.Ty->isVoidTy() && !isSupportedReturnType(Info.OrigRet.Ty))
461 return false;
462
463 MachineFunction &MF = MIRBuilder.getMF();
464 const Function &F = MF.getFunction();
465 const DataLayout &DL = MF.getDataLayout();
466 const MipsTargetLowering &TLI = *getTLI<MipsTargetLowering>();
467 const MipsTargetMachine &TM =
468 static_cast<const MipsTargetMachine &>(MF.getTarget());
469 const MipsABIInfo &ABI = TM.getABI();
470
471 MachineInstrBuilder CallSeqStart =
472 MIRBuilder.buildInstr(Mips::ADJCALLSTACKDOWN);
473
474 const bool IsCalleeGlobalPIC =
475 Info.Callee.isGlobal() && TM.isPositionIndependent();
476
477 MachineInstrBuilder MIB = MIRBuilder.buildInstrNoInsert(
478 Info.Callee.isReg() || IsCalleeGlobalPIC ? Mips::JALRPseudo : Mips::JAL);
479 MIB.addDef(Mips::SP, RegState::Implicit);
480 if (IsCalleeGlobalPIC) {
481 Register CalleeReg =
482 MF.getRegInfo().createGenericVirtualRegister(LLT::pointer(0, 32));
483 MachineInstr *CalleeGlobalValue =
484 MIRBuilder.buildGlobalValue(CalleeReg, Info.Callee.getGlobal());
485 if (!Info.Callee.getGlobal()->hasLocalLinkage())
486 CalleeGlobalValue->getOperand(1).setTargetFlags(MipsII::MO_GOT_CALL);
487 MIB.addUse(CalleeReg);
488 } else
489 MIB.add(Info.Callee);
490 const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
491 MIB.addRegMask(TRI->getCallPreservedMask(MF, Info.CallConv));
492
493 TargetLowering::ArgListTy FuncOrigArgs;
494 FuncOrigArgs.reserve(Info.OrigArgs.size());
495
496 SmallVector<ArgInfo, 8> ArgInfos;
497 for (auto &Arg : Info.OrigArgs)
498 splitToValueTypes(Arg, ArgInfos, DL, Info.CallConv);
499
500 SmallVector<CCValAssign, 8> ArgLocs;
501 bool IsCalleeVarArg = false;
502 if (Info.Callee.isGlobal()) {
503 const Function *CF = static_cast<const Function *>(Info.Callee.getGlobal());
504 IsCalleeVarArg = CF->isVarArg();
505 }
506
507 // FIXME: Should use MipsCCState::getSpecialCallingConvForCallee, but it
508 // depends on looking directly at the call target.
509 MipsCCState CCInfo(Info.CallConv, IsCalleeVarArg, MF, ArgLocs,
510 F.getContext());
511
512 CCInfo.AllocateStack(ABI.GetCalleeAllocdArgSizeInBytes(Info.CallConv),
513 Align(1));
514
515 const char *Call =
516 Info.Callee.isSymbol() ? Info.Callee.getSymbolName() : nullptr;
517
518 MipsOutgoingValueAssigner Assigner(TLI.CCAssignFnForCall(), Call,
519 /*IsReturn*/ false);
520 if (!determineAssignments(Assigner, ArgInfos, CCInfo))
521 return false;
522
523 MipsOutgoingValueHandler ArgHandler(MIRBuilder, MF.getRegInfo(), MIB);
524 if (!handleAssignments(ArgHandler, ArgInfos, CCInfo, ArgLocs, MIRBuilder))
525 return false;
526
527 unsigned NextStackOffset = CCInfo.getNextStackOffset();
528 unsigned StackAlignment = F.getParent()->getOverrideStackAlignment();
529 if (!StackAlignment) {
530 const TargetFrameLowering *TFL = MF.getSubtarget().getFrameLowering();
531 StackAlignment = TFL->getStackAlignment();
532 }
533 NextStackOffset = alignTo(NextStackOffset, StackAlignment);
534 CallSeqStart.addImm(NextStackOffset).addImm(0);
535
536 if (IsCalleeGlobalPIC) {
537 MIRBuilder.buildCopy(
538 Register(Mips::GP),
539 MF.getInfo<MipsFunctionInfo>()->getGlobalBaseRegForGlobalISel(MF));
540 MIB.addDef(Mips::GP, RegState::Implicit);
541 }
542 MIRBuilder.insertInstr(MIB);
543 if (MIB->getOpcode() == Mips::JALRPseudo) {
544 const MipsSubtarget &STI = MIRBuilder.getMF().getSubtarget<MipsSubtarget>();
545 MIB.constrainAllUses(MIRBuilder.getTII(), *STI.getRegisterInfo(),
546 *STI.getRegBankInfo());
547 }
548
549 if (!Info.OrigRet.Ty->isVoidTy()) {
550 ArgInfos.clear();
551
552 CallLowering::splitToValueTypes(Info.OrigRet, ArgInfos, DL,
553 F.getCallingConv());
554
555 const std::string FuncName = F.getName().str();
556 SmallVector<ISD::InputArg, 8> Ins;
557 SmallVector<CCValAssign, 8> ArgLocs;
558 MipsIncomingValueAssigner Assigner(TLI.CCAssignFnForReturn(),
559 FuncName.c_str(),
560 /*IsReturn*/ true);
561 CallReturnHandler RetHandler(MIRBuilder, MF.getRegInfo(), MIB);
562
563 MipsCCState CCInfo(F.getCallingConv(), F.isVarArg(), MF, ArgLocs,
564 F.getContext());
565
566 if (!determineAssignments(Assigner, ArgInfos, CCInfo))
567 return false;
568
569 if (!handleAssignments(RetHandler, ArgInfos, CCInfo, ArgLocs, MIRBuilder))
570 return false;
571 }
572
573 MIRBuilder.buildInstr(Mips::ADJCALLSTACKUP).addImm(NextStackOffset).addImm(0);
574
575 return true;
576}