1 //===-- GuardUtils.cpp - Utils for work with guards -------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
8 // Utils that are used to perform analyzes related to guards and their
10 //===----------------------------------------------------------------------===//
12 #include "llvm/Analysis/GuardUtils.h"
13 #include "llvm/IR/PatternMatch.h"
16 using namespace llvm::PatternMatch;
18 bool llvm::isGuard(const User *U) {
19 return match(U, m_Intrinsic<Intrinsic::experimental_guard>());
22 bool llvm::isWidenableBranch(const User *U) {
23 Value *Condition, *WidenableCondition;
24 BasicBlock *GuardedBB, *DeoptBB;
25 return parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
29 bool llvm::isGuardAsWidenableBranch(const User *U) {
30 Value *Condition, *WidenableCondition;
31 BasicBlock *GuardedBB, *DeoptBB;
32 if (!parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
35 for (auto &Insn : *DeoptBB) {
36 if (match(&Insn, m_Intrinsic<Intrinsic::experimental_deoptimize>()))
38 if (Insn.mayHaveSideEffects())
44 bool llvm::parseWidenableBranch(const User *U, Value *&Condition,
45 Value *&WidenableCondition,
46 BasicBlock *&IfTrueBB, BasicBlock *&IfFalseBB) {
49 if (parseWidenableBranch(const_cast<User*>(U), C, WC, IfTrueBB, IfFalseBB)) {
53 Condition = ConstantInt::getTrue(IfTrueBB->getContext());
54 WidenableCondition = WC->get();
60 bool llvm::parseWidenableBranch(User *U, Use *&C,Use *&WC,
61 BasicBlock *&IfTrueBB, BasicBlock *&IfFalseBB) {
63 auto *BI = dyn_cast<BranchInst>(U);
64 if (!BI || !BI->isConditional())
66 auto *Cond = BI->getCondition();
67 if (!Cond->hasOneUse())
70 IfTrueBB = BI->getSuccessor(0);
71 IfFalseBB = BI->getSuccessor(1);
73 if (match(Cond, m_Intrinsic<Intrinsic::experimental_widenable_condition>())) {
74 WC = &BI->getOperandUse(0);
79 // Check for two cases:
80 // 1) br (i1 (and A, WC())), label %IfTrue, label %IfFalse
81 // 2) br (i1 (and WC(), B)), label %IfTrue, label %IfFalse
82 // We do not check for more generalized and trees as we should canonicalize
83 // to the form above in instcombine. (TODO)
85 if (!match(Cond, m_And(m_Value(A), m_Value(B))))
87 auto *And = dyn_cast<Instruction>(Cond);
89 // Could be a constexpr
92 if (match(A, m_Intrinsic<Intrinsic::experimental_widenable_condition>()) &&
94 WC = &And->getOperandUse(0);
95 C = &And->getOperandUse(1);
99 if (match(B, m_Intrinsic<Intrinsic::experimental_widenable_condition>()) &&
101 WC = &And->getOperandUse(1);
102 C = &And->getOperandUse(0);