aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm16/lib/CodeGen/PreISelIntrinsicLowering.cpp
blob: 87e2f9f2002115f6c092c30bbceea60c5622a4b4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
//===- PreISelIntrinsicLowering.cpp - Pre-ISel intrinsic lowering pass ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This pass implements IR lowering for the llvm.load.relative and llvm.objc.*
// intrinsics.
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/PreISelIntrinsicLowering.h"
#include "llvm/Analysis/ObjCARCInstKind.h"
#include "llvm/Analysis/ObjCARCUtil.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"

using namespace llvm;

static bool lowerLoadRelative(Function &F) {
  if (F.use_empty())
    return false;

  bool Changed = false;
  Type *Int32Ty = Type::getInt32Ty(F.getContext());
  Type *Int32PtrTy = Int32Ty->getPointerTo();
  Type *Int8Ty = Type::getInt8Ty(F.getContext());

  for (Use &U : llvm::make_early_inc_range(F.uses())) {
    auto CI = dyn_cast<CallInst>(U.getUser());
    if (!CI || CI->getCalledOperand() != &F)
      continue;

    IRBuilder<> B(CI);
    Value *OffsetPtr =
        B.CreateGEP(Int8Ty, CI->getArgOperand(0), CI->getArgOperand(1));
    Value *OffsetPtrI32 = B.CreateBitCast(OffsetPtr, Int32PtrTy);
    Value *OffsetI32 = B.CreateAlignedLoad(Int32Ty, OffsetPtrI32, Align(4));

    Value *ResultPtr = B.CreateGEP(Int8Ty, CI->getArgOperand(0), OffsetI32);

    CI->replaceAllUsesWith(ResultPtr);
    CI->eraseFromParent();
    Changed = true;
  }

  return Changed;
}

// ObjCARC has knowledge about whether an obj-c runtime function needs to be
// always tail-called or never tail-called.
static CallInst::TailCallKind getOverridingTailCallKind(const Function &F) {
  objcarc::ARCInstKind Kind = objcarc::GetFunctionClass(&F);
  if (objcarc::IsAlwaysTail(Kind))
    return CallInst::TCK_Tail;
  else if (objcarc::IsNeverTail(Kind))
    return CallInst::TCK_NoTail;
  return CallInst::TCK_None;
}

static bool lowerObjCCall(Function &F, const char *NewFn,
                          bool setNonLazyBind = false) {
  assert(IntrinsicInst::mayLowerToFunctionCall(F.getIntrinsicID()) &&
         "Pre-ISel intrinsics do lower into regular function calls");
  if (F.use_empty())
    return false;

  // If we haven't already looked up this function, check to see if the
  // program already contains a function with this name.
  Module *M = F.getParent();
  FunctionCallee FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());

  if (Function *Fn = dyn_cast<Function>(FCache.getCallee())) {
    Fn->setLinkage(F.getLinkage());
    if (setNonLazyBind && !Fn->isWeakForLinker()) {
      // If we have Native ARC, set nonlazybind attribute for these APIs for
      // performance.
      Fn->addFnAttr(Attribute::NonLazyBind);
    }
  }

  CallInst::TailCallKind OverridingTCK = getOverridingTailCallKind(F);

  for (Use &U : llvm::make_early_inc_range(F.uses())) {
    auto *CB = cast<CallBase>(U.getUser());

    if (CB->getCalledFunction() != &F) {
      objcarc::ARCInstKind Kind = objcarc::getAttachedARCFunctionKind(CB);
      (void)Kind;
      assert((Kind == objcarc::ARCInstKind::RetainRV ||
              Kind == objcarc::ARCInstKind::UnsafeClaimRV) &&
             "use expected to be the argument of operand bundle "
             "\"clang.arc.attachedcall\"");
      U.set(FCache.getCallee());
      continue;
    }

    auto *CI = cast<CallInst>(CB);
    assert(CI->getCalledFunction() && "Cannot lower an indirect call!");

    IRBuilder<> Builder(CI->getParent(), CI->getIterator());
    SmallVector<Value *, 8> Args(CI->args());
    SmallVector<llvm::OperandBundleDef, 1> BundleList;
    CI->getOperandBundlesAsDefs(BundleList);
    CallInst *NewCI = Builder.CreateCall(FCache, Args, BundleList);
    NewCI->setName(CI->getName());

    // Try to set the most appropriate TailCallKind based on both the current
    // attributes and the ones that we could get from ObjCARC's special
    // knowledge of the runtime functions.
    //
    // std::max respects both requirements of notail and tail here:
    // * notail on either the call or from ObjCARC becomes notail
    // * tail on either side is stronger than none, but not notail
    CallInst::TailCallKind TCK = CI->getTailCallKind();
    NewCI->setTailCallKind(std::max(TCK, OverridingTCK));

    if (!CI->use_empty())
      CI->replaceAllUsesWith(NewCI);
    CI->eraseFromParent();
  }

  return true;
}

static bool lowerIntrinsics(Module &M) {
  bool Changed = false;
  for (Function &F : M) {
    if (F.getName().startswith("llvm.load.relative.")) {
      Changed |= lowerLoadRelative(F);
      continue;
    }
    switch (F.getIntrinsicID()) {
    default:
      break;
    case Intrinsic::objc_autorelease:
      Changed |= lowerObjCCall(F, "objc_autorelease");
      break;
    case Intrinsic::objc_autoreleasePoolPop:
      Changed |= lowerObjCCall(F, "objc_autoreleasePoolPop");
      break;
    case Intrinsic::objc_autoreleasePoolPush:
      Changed |= lowerObjCCall(F, "objc_autoreleasePoolPush");
      break;
    case Intrinsic::objc_autoreleaseReturnValue:
      Changed |= lowerObjCCall(F, "objc_autoreleaseReturnValue");
      break;
    case Intrinsic::objc_copyWeak:
      Changed |= lowerObjCCall(F, "objc_copyWeak");
      break;
    case Intrinsic::objc_destroyWeak:
      Changed |= lowerObjCCall(F, "objc_destroyWeak");
      break;
    case Intrinsic::objc_initWeak:
      Changed |= lowerObjCCall(F, "objc_initWeak");
      break;
    case Intrinsic::objc_loadWeak:
      Changed |= lowerObjCCall(F, "objc_loadWeak");
      break;
    case Intrinsic::objc_loadWeakRetained:
      Changed |= lowerObjCCall(F, "objc_loadWeakRetained");
      break;
    case Intrinsic::objc_moveWeak:
      Changed |= lowerObjCCall(F, "objc_moveWeak");
      break;
    case Intrinsic::objc_release:
      Changed |= lowerObjCCall(F, "objc_release", true);
      break;
    case Intrinsic::objc_retain:
      Changed |= lowerObjCCall(F, "objc_retain", true);
      break;
    case Intrinsic::objc_retainAutorelease:
      Changed |= lowerObjCCall(F, "objc_retainAutorelease");
      break;
    case Intrinsic::objc_retainAutoreleaseReturnValue:
      Changed |= lowerObjCCall(F, "objc_retainAutoreleaseReturnValue");
      break;
    case Intrinsic::objc_retainAutoreleasedReturnValue:
      Changed |= lowerObjCCall(F, "objc_retainAutoreleasedReturnValue");
      break;
    case Intrinsic::objc_retainBlock:
      Changed |= lowerObjCCall(F, "objc_retainBlock");
      break;
    case Intrinsic::objc_storeStrong:
      Changed |= lowerObjCCall(F, "objc_storeStrong");
      break;
    case Intrinsic::objc_storeWeak:
      Changed |= lowerObjCCall(F, "objc_storeWeak");
      break;
    case Intrinsic::objc_unsafeClaimAutoreleasedReturnValue:
      Changed |= lowerObjCCall(F, "objc_unsafeClaimAutoreleasedReturnValue");
      break;
    case Intrinsic::objc_retainedObject:
      Changed |= lowerObjCCall(F, "objc_retainedObject");
      break;
    case Intrinsic::objc_unretainedObject:
      Changed |= lowerObjCCall(F, "objc_unretainedObject");
      break;
    case Intrinsic::objc_unretainedPointer:
      Changed |= lowerObjCCall(F, "objc_unretainedPointer");
      break;
    case Intrinsic::objc_retain_autorelease:
      Changed |= lowerObjCCall(F, "objc_retain_autorelease");
      break;
    case Intrinsic::objc_sync_enter:
      Changed |= lowerObjCCall(F, "objc_sync_enter");
      break;
    case Intrinsic::objc_sync_exit:
      Changed |= lowerObjCCall(F, "objc_sync_exit");
      break;
    }
  }
  return Changed;
}

namespace {

class PreISelIntrinsicLoweringLegacyPass : public ModulePass {
public:
  static char ID;

  PreISelIntrinsicLoweringLegacyPass() : ModulePass(ID) {}

  bool runOnModule(Module &M) override { return lowerIntrinsics(M); }
};

} // end anonymous namespace

char PreISelIntrinsicLoweringLegacyPass::ID;

INITIALIZE_PASS(PreISelIntrinsicLoweringLegacyPass,
                "pre-isel-intrinsic-lowering", "Pre-ISel Intrinsic Lowering",
                false, false)

ModulePass *llvm::createPreISelIntrinsicLoweringPass() {
  return new PreISelIntrinsicLoweringLegacyPass;
}

PreservedAnalyses PreISelIntrinsicLoweringPass::run(Module &M,
                                                    ModuleAnalysisManager &AM) {
  if (!lowerIntrinsics(M))
    return PreservedAnalyses::all();
  else
    return PreservedAnalyses::none();
}