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revng-revng/lib/RemoveExtractValues/RemoveExtractValuesPass.cpp
T
Giacomo Vercesi ab125b35b0 Fix License headers
Change company name to "rev.ng Labs Srl" in all license headers
to reflect changed company name and legal status
Add missing license headers to files that didn't have one
2022-04-19 12:17:59 +02:00

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2.4 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 "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<llvm::Type *>
OpaqueEVPool(F.getParent(), /* PurgeOnDestruction */ false);
initOpaqueEVPool(OpaqueEVPool);
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(F.getContext(), I);
auto *ExtractValueFunction = OpaqueEVPool.get(EVFunctionType,
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;
}