51 lines
2.1 KiB
C++
51 lines
2.1 KiB
C++
//===-- OrderedInstructions.cpp - Instruction dominance function ---------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines utility to check dominance relation of 2 instructions.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/OrderedInstructions.h"
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using namespace llvm;
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bool OrderedInstructions::localDominates(const Instruction *InstA,
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const Instruction *InstB) const {
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assert(InstA->getParent() == InstB->getParent() &&
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"Instructions must be in the same basic block");
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const BasicBlock *IBB = InstA->getParent();
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auto OBB = OBBMap.find(IBB);
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if (OBB == OBBMap.end())
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OBB = OBBMap.insert({IBB, make_unique<OrderedBasicBlock>(IBB)}).first;
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return OBB->second->dominates(InstA, InstB);
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}
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/// Given 2 instructions, use OrderedBasicBlock to check for dominance relation
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/// if the instructions are in the same basic block, Otherwise, use dominator
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/// tree.
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bool OrderedInstructions::dominates(const Instruction *InstA,
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const Instruction *InstB) const {
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// Use ordered basic block to do dominance check in case the 2 instructions
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// are in the same basic block.
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if (InstA->getParent() == InstB->getParent())
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return localDominates(InstA, InstB);
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return DT->dominates(InstA->getParent(), InstB->getParent());
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}
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bool OrderedInstructions::dfsBefore(const Instruction *InstA,
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const Instruction *InstB) const {
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// Use ordered basic block in case the 2 instructions are in the same basic
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// block.
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if (InstA->getParent() == InstB->getParent())
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return localDominates(InstA, InstB);
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DomTreeNode *DA = DT->getNode(InstA->getParent());
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DomTreeNode *DB = DT->getNode(InstB->getParent());
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return DA->getDFSNumIn() < DB->getDFSNumIn();
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}
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