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/*========================== begin_copyright_notice ============================
Copyright (C) 2024 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ===========================*/
#include "Compiler/IGCPassSupport.h"
#include "Probe/Assertion.h"
#include "common/LLVMWarningsPush.hpp"
#include <llvm/IR/Function.h>
#include <llvm/IR/IRBuilder.h>
#include <llvm/Transforms/Utils/Local.h>
#include "common/LLVMWarningsPop.hpp"
using namespace llvm;
namespace IGC {
class ForceFunctionsToNop : public FunctionPass {
public:
static char ID;
ForceFunctionsToNop();
~ForceFunctionsToNop() {}
bool runOnFunction(Function &F) override;
virtual StringRef getPassName() const override { return "Force Functions to NOP"; }
};
#define PASS_FLAG "ForceFunctionsToNop"
#define PASS_DESC "Force Immediate Zero Return of Functions"
#define PASS_CFG_ONLY false
#define PASS_ANALYSIS false
IGC_INITIALIZE_PASS_BEGIN(ForceFunctionsToNop, PASS_FLAG, PASS_DESC, PASS_CFG_ONLY, PASS_ANALYSIS)
IGC_INITIALIZE_PASS_END(ForceFunctionsToNop, PASS_FLAG, PASS_DESC, PASS_CFG_ONLY, PASS_ANALYSIS)
char ForceFunctionsToNop::ID = 0;
ForceFunctionsToNop::ForceFunctionsToNop() : FunctionPass(ID) {
initializeForceFunctionsToNopPass(*PassRegistry::getPassRegistry());
}
// This pass will rewrite all functions to return a zero initializer of the
// function's type. It was created to help in shader isolations. The user
// must use Options.txt to narrow the set of hashes to apply this pass.
bool ForceFunctionsToNop::runOnFunction(Function &F) {
IRBuilder<> IRB(F.getContext());
BasicBlock &oldEntryBB = F.getEntryBlock();
BasicBlock *pNewEntryBB = BasicBlock::Create(F.getContext(), "", &F, &oldEntryBB);
IRB.SetInsertPoint(pNewEntryBB);
if (auto *pFnTy = F.getReturnType(); pFnTy->isFirstClassType()) {
auto *pVal = Constant::getNullValue(pFnTy);
IRB.CreateRet(pVal);
} else {
IGC_ASSERT_MESSAGE(pFnTy->isVoidTy(), "Expected void type");
IRB.CreateRetVoid();
}
removeUnreachableBlocks(F);
return true;
}
FunctionPass *createForceFunctionsToNop() { return new ForceFunctionsToNop(); }
} // namespace IGC
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