llvm-project/llvm/lib/Transforms/Utils/OrderedInstructions.cpp

34 lines
1.3 KiB
C++

//===-- OrderedInstructions.cpp - Instruction dominance function ---------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines utility to check dominance relation of 2 instructions.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/OrderedInstructions.h"
using namespace llvm;
/// Given 2 instructions, use OrderedBasicBlock to check for dominance relation
/// if the instructions are in the same basic block, Otherwise, use dominator
/// tree.
bool OrderedInstructions::dominates(const Instruction *InstA,
const Instruction *InstB) const {
const BasicBlock *IBB = InstA->getParent();
// Use ordered basic block to do dominance check in case the 2 instructions
// are in the same basic block.
if (IBB == InstB->getParent()) {
auto OBB = OBBMap.find(IBB);
if (OBB == OBBMap.end())
OBB = OBBMap.insert({IBB, make_unique<OrderedBasicBlock>(IBB)}).first;
return OBB->second->dominates(InstA, InstB);
} else {
return DT->dominates(InstA->getParent(), InstB->getParent());
}
}