blob: e2de322933bc1ba0db1945e9c5df146779f346be [file] [log] [blame]
//===- LowerWidenableCondition.cpp - Lower the guard intrinsic ---------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This pass lowers the llvm.widenable.condition intrinsic to default value
// which is i1 true.
#include "llvm/Transforms/Scalar/LowerWidenableCondition.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Transforms/Scalar.h"
using namespace llvm;
namespace {
struct LowerWidenableConditionLegacyPass : public FunctionPass {
static char ID;
LowerWidenableConditionLegacyPass() : FunctionPass(ID) {
bool runOnFunction(Function &F) override;
static bool lowerWidenableCondition(Function &F) {
// Check if we can cheaply rule out the possibility of not having any work to
// do.
auto *WCDecl = F.getParent()->getFunction(
if (!WCDecl || WCDecl->use_empty())
return false;
using namespace llvm::PatternMatch;
SmallVector<CallInst *, 8> ToLower;
// Traverse through the users of WCDecl.
// This is presumably cheaper than traversing all instructions in the
// function.
for (auto *U : WCDecl->users())
if (auto *CI = dyn_cast<CallInst>(U))
if (CI->getFunction() == &F)
if (ToLower.empty())
return false;
for (auto *CI : ToLower) {
return true;
bool LowerWidenableConditionLegacyPass::runOnFunction(Function &F) {
return lowerWidenableCondition(F);
char LowerWidenableConditionLegacyPass::ID = 0;
INITIALIZE_PASS(LowerWidenableConditionLegacyPass, "lower-widenable-condition",
"Lower the widenable condition to default true value", false,
Pass *llvm::createLowerWidenableConditionPass() {
return new LowerWidenableConditionLegacyPass();
PreservedAnalyses LowerWidenableConditionPass::run(Function &F,
FunctionAnalysisManager &AM) {
if (lowerWidenableCondition(F))
return PreservedAnalyses::none();
return PreservedAnalyses::all();