Files
revng-revng/lib/RemoveExtractValues/RemoveExtractValuesPass.cpp
T
Alvise de Faveri ad524a4d4d ModelGEP: Return the size of the gepped field
ModelGEP calls in LLVM IR now return an integer that has the same
size of the field being addressed by the ModelGEP.

AddressOf calls, instead, can accept any integer size as argument but
always return a pointer-sized integer.
2022-06-28 10:14:10 +02:00

80 lines
2.5 KiB
C++

//
// Copyright rev.ng Labs Srl. See LICENSE.md for details.
//
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "revng/Support/Assert.h"
#include "revng/Support/FunctionTags.h"
#include "revng/Support/IRHelpers.h"
#include "revng/Support/OpaqueFunctionsPool.h"
#include "revng-c/RemoveExtractValues/RemoveExtractValuesPass.h"
#include "revng-c/Support/FunctionTags.h"
using namespace llvm;
char RemoveExtractValues::ID = 0;
using Reg = RegisterPass<RemoveExtractValues>;
static Reg X("remove-extractvalues",
"Substitute extractvalues with opaque calls so that they don't "
"get optimized",
true,
true);
bool RemoveExtractValues::runOnFunction(llvm::Function &F) {
using namespace llvm;
// Collect all ExtractValues
SmallVector<ExtractValueInst *, 16> ToReplace;
for (auto &BB : F)
for (auto &I : BB)
if (auto *ExtractVal = llvm::dyn_cast<llvm::ExtractValueInst>(&I))
ToReplace.push_back(ExtractVal);
if (ToReplace.empty())
return false;
// Create a pool of functions with the same behavior: we will need a different
// function for each different struct
OpaqueFunctionsPool<TypePair> OpaqueEVPool(F.getParent(),
/* PurgeOnDestruction */ false);
initOpaqueEVPool(OpaqueEVPool, F.getParent());
llvm::LLVMContext &LLVMCtx = F.getContext();
IRBuilder<> Builder(LLVMCtx);
for (ExtractValueInst *I : ToReplace) {
Builder.SetInsertPoint(I);
// Collect arguments of the ExtractValue
SmallVector<Value *, 8> ArgValues = { I->getAggregateOperand() };
for (auto Idx : I->indices()) {
auto *IndexVal = ConstantInt::get(IntegerType::getInt64Ty(LLVMCtx), Idx);
ArgValues.push_back(IndexVal);
}
// Get or generate the function
auto *EVFunctionType = getOpaqueEVFunctionType(I);
const TypePair &Key = { I->getType(), I->getAggregateOperand()->getType() };
auto *ExtractValueFunction = OpaqueEVPool.get(Key,
EVFunctionType,
"OpaqueExtractvalue");
// Emit a call to the new function
CallInst *InjectedCall = Builder.CreateCall(ExtractValueFunction,
ArgValues);
I->replaceAllUsesWith(InjectedCall);
InjectedCall->copyMetadata(*I);
I->eraseFromParent();
}
return true;
}