llvm-project/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp

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//===- 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/CodeGen/Passes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/User.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 (auto I = F.use_begin(), E = F.use_end(); I != E;) {
auto CI = dyn_cast<CallInst>(I->getUser());
++I;
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) {
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();
[opaque pointer types] Add a FunctionCallee wrapper type, and use it. Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc doesn't choke on it, hopefully. Original Message: The FunctionCallee type is effectively a {FunctionType*,Value*} pair, and is a useful convenience to enable code to continue passing the result of getOrInsertFunction() through to EmitCall, even once pointer types lose their pointee-type. Then: - update the CallInst/InvokeInst instruction creation functions to take a Callee, - modify getOrInsertFunction to return FunctionCallee, and - update all callers appropriately. One area of particular note is the change to the sanitizer code. Previously, they had been casting the result of `getOrInsertFunction` to a `Function*` via `checkSanitizerInterfaceFunction`, and storing that. That would report an error if someone had already inserted a function declaraction with a mismatching signature. However, in general, LLVM allows for such mismatches, as `getOrInsertFunction` will automatically insert a bitcast if needed. As part of this cleanup, cause the sanitizer code to do the same. (It will call its functions using the expected signature, however they may have been declared.) Finally, in a small number of locations, callers of `getOrInsertFunction` actually were expecting/requiring that a brand new function was being created. In such cases, I've switched them to Function::Create instead. Differential Revision: https://reviews.llvm.org/D57315 llvm-svn: 352827
2019-02-01 10:28:03 +08:00
FunctionCallee FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());
[opaque pointer types] Add a FunctionCallee wrapper type, and use it. Recommit r352791 after tweaking DerivedTypes.h slightly, so that gcc doesn't choke on it, hopefully. Original Message: The FunctionCallee type is effectively a {FunctionType*,Value*} pair, and is a useful convenience to enable code to continue passing the result of getOrInsertFunction() through to EmitCall, even once pointer types lose their pointee-type. Then: - update the CallInst/InvokeInst instruction creation functions to take a Callee, - modify getOrInsertFunction to return FunctionCallee, and - update all callers appropriately. One area of particular note is the change to the sanitizer code. Previously, they had been casting the result of `getOrInsertFunction` to a `Function*` via `checkSanitizerInterfaceFunction`, and storing that. That would report an error if someone had already inserted a function declaraction with a mismatching signature. However, in general, LLVM allows for such mismatches, as `getOrInsertFunction` will automatically insert a bitcast if needed. As part of this cleanup, cause the sanitizer code to do the same. (It will call its functions using the expected signature, however they may have been declared.) Finally, in a small number of locations, callers of `getOrInsertFunction` actually were expecting/requiring that a brand new function was being created. In such cases, I've switched them to Function::Create instead. Differential Revision: https://reviews.llvm.org/D57315 llvm-svn: 352827
2019-02-01 10:28:03 +08:00
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 (auto I = F.use_begin(), E = F.use_end(); I != E;) {
auto *CI = cast<CallInst>(I->getUser());
assert(CI->getCalledFunction() && "Cannot lower an indirect call!");
++I;
IRBuilder<> Builder(CI->getParent(), CI->getIterator());
SmallVector<Value *, 8> Args(CI->args());
CallInst *NewCI = Builder.CreateCall(FCache, Args);
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();
}