Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

96 lines
3.2 KiB
C++

//===- LowerInvoke.cpp - Eliminate Invoke instructions --------------------===//
//
// 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 transformation is designed for use by code generators which do not yet
// support stack unwinding. This pass converts 'invoke' instructions to 'call'
// instructions, so that any exception-handling 'landingpad' blocks become dead
// code (which can be removed by running the '-simplifycfg' pass afterwards).
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/LowerInvoke.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/Utils.h"
using namespace llvm;
#define DEBUG_TYPE "lowerinvoke"
STATISTIC(NumInvokes, "Number of invokes replaced");
namespace {
class LowerInvokeLegacyPass : public FunctionPass {
public:
static char ID; // Pass identification, replacement for typeid
explicit LowerInvokeLegacyPass() : FunctionPass(ID) {
initializeLowerInvokeLegacyPassPass(*PassRegistry::getPassRegistry());
}
bool runOnFunction(Function &F) override;
};
}
char LowerInvokeLegacyPass::ID = 0;
INITIALIZE_PASS(LowerInvokeLegacyPass, "lowerinvoke",
"Lower invoke and unwind, for unwindless code generators",
false, false)
static bool runImpl(Function &F) {
bool Changed = false;
for (BasicBlock &BB : F)
if (InvokeInst *II = dyn_cast<InvokeInst>(BB.getTerminator())) {
SmallVector<Value *, 16> CallArgs(II->arg_begin(), II->arg_end());
SmallVector<OperandBundleDef, 1> OpBundles;
II->getOperandBundlesAsDefs(OpBundles);
// Insert a normal call instruction...
CallInst *NewCall =
CallInst::Create(II->getCalledValue(), CallArgs, OpBundles, "", II);
NewCall->takeName(II);
NewCall->setCallingConv(II->getCallingConv());
NewCall->setAttributes(II->getAttributes());
NewCall->setDebugLoc(II->getDebugLoc());
II->replaceAllUsesWith(NewCall);
// Insert an unconditional branch to the normal destination.
BranchInst::Create(II->getNormalDest(), II);
// Remove any PHI node entries from the exception destination.
II->getUnwindDest()->removePredecessor(&BB);
// Remove the invoke instruction now.
BB.getInstList().erase(II);
++NumInvokes;
Changed = true;
}
return Changed;
}
bool LowerInvokeLegacyPass::runOnFunction(Function &F) {
return runImpl(F);
}
namespace llvm {
char &LowerInvokePassID = LowerInvokeLegacyPass::ID;
// Public Interface To the LowerInvoke pass.
FunctionPass *createLowerInvokePass() { return new LowerInvokeLegacyPass(); }
PreservedAnalyses LowerInvokePass::run(Function &F,
FunctionAnalysisManager &AM) {
bool Changed = runImpl(F);
if (!Changed)
return PreservedAnalyses::all();
return PreservedAnalyses::none();
}
}