107 lines
3.3 KiB
C++
107 lines
3.3 KiB
C++
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//===-- GuardUtils.cpp - Utils for work with guards -------------*- C++ -*-===//
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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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// Utils that are used to perform analyzes related to guards and their
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// conditions.
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/GuardUtils.h"
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#include "llvm/IR/PatternMatch.h"
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using namespace llvm;
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using namespace llvm::PatternMatch;
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bool llvm::isGuard(const User *U) {
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return match(U, m_Intrinsic<Intrinsic::experimental_guard>());
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}
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bool llvm::isWidenableBranch(const User *U) {
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Value *Condition, *WidenableCondition;
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BasicBlock *GuardedBB, *DeoptBB;
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return parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
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DeoptBB);
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}
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bool llvm::isGuardAsWidenableBranch(const User *U) {
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Value *Condition, *WidenableCondition;
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BasicBlock *GuardedBB, *DeoptBB;
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if (!parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
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DeoptBB))
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return false;
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for (auto &Insn : *DeoptBB) {
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if (match(&Insn, m_Intrinsic<Intrinsic::experimental_deoptimize>()))
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return true;
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if (Insn.mayHaveSideEffects())
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return false;
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}
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return false;
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}
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bool llvm::parseWidenableBranch(const User *U, Value *&Condition,
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Value *&WidenableCondition,
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BasicBlock *&IfTrueBB, BasicBlock *&IfFalseBB) {
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Use *C, *WC;
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if (parseWidenableBranch(const_cast<User*>(U), C, WC, IfTrueBB, IfFalseBB)) {
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if (C)
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Condition = C->get();
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else
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Condition = ConstantInt::getTrue(IfTrueBB->getContext());
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WidenableCondition = WC->get();
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return true;
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}
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return false;
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}
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bool llvm::parseWidenableBranch(User *U, Use *&C,Use *&WC,
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BasicBlock *&IfTrueBB, BasicBlock *&IfFalseBB) {
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auto *BI = dyn_cast<BranchInst>(U);
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if (!BI || !BI->isConditional())
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return false;
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auto *Cond = BI->getCondition();
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if (!Cond->hasOneUse())
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return false;
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IfTrueBB = BI->getSuccessor(0);
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IfFalseBB = BI->getSuccessor(1);
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if (match(Cond, m_Intrinsic<Intrinsic::experimental_widenable_condition>())) {
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WC = &BI->getOperandUse(0);
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C = nullptr;
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return true;
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}
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// Check for two cases:
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// 1) br (i1 (and A, WC())), label %IfTrue, label %IfFalse
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// 2) br (i1 (and WC(), B)), label %IfTrue, label %IfFalse
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// We do not check for more generalized and trees as we should canonicalize
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// to the form above in instcombine. (TODO)
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Value *A, *B;
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if (!match(Cond, m_And(m_Value(A), m_Value(B))))
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return false;
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auto *And = dyn_cast<Instruction>(Cond);
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if (!And)
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// Could be a constexpr
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return false;
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if (match(A, m_Intrinsic<Intrinsic::experimental_widenable_condition>()) &&
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A->hasOneUse()) {
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WC = &And->getOperandUse(0);
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C = &And->getOperandUse(1);
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return true;
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}
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if (match(B, m_Intrinsic<Intrinsic::experimental_widenable_condition>()) &&
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B->hasOneUse()) {
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WC = &And->getOperandUse(1);
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C = &And->getOperandUse(0);
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return true;
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}
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return false;
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}
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