1 //===-- GuardUtils.cpp - Utils for work with guards -------------*- C++ -*-===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 // Utils that are used to perform analyzes related to guards and their
9 // conditions.
10 //===----------------------------------------------------------------------===//
11
12 #include "llvm/Analysis/GuardUtils.h"
13 #include "llvm/IR/PatternMatch.h"
14
15 using namespace llvm;
16
isGuard(const User * U)17 bool llvm::isGuard(const User *U) {
18 using namespace llvm::PatternMatch;
19 return match(U, m_Intrinsic<Intrinsic::experimental_guard>());
20 }
21
isGuardAsWidenableBranch(const User * U)22 bool llvm::isGuardAsWidenableBranch(const User *U) {
23 Value *Condition, *WidenableCondition;
24 BasicBlock *GuardedBB, *DeoptBB;
25 if (!parseWidenableBranch(U, Condition, WidenableCondition, GuardedBB,
26 DeoptBB))
27 return false;
28 using namespace llvm::PatternMatch;
29 for (auto &Insn : *DeoptBB) {
30 if (match(&Insn, m_Intrinsic<Intrinsic::experimental_deoptimize>()))
31 return true;
32 if (Insn.mayHaveSideEffects())
33 return false;
34 }
35 return false;
36 }
37
parseWidenableBranch(const User * U,Value * & Condition,Value * & WidenableCondition,BasicBlock * & IfTrueBB,BasicBlock * & IfFalseBB)38 bool llvm::parseWidenableBranch(const User *U, Value *&Condition,
39 Value *&WidenableCondition,
40 BasicBlock *&IfTrueBB, BasicBlock *&IfFalseBB) {
41 using namespace llvm::PatternMatch;
42 if (!match(U, m_Br(m_And(m_Value(Condition), m_Value(WidenableCondition)),
43 IfTrueBB, IfFalseBB)))
44 return false;
45 // TODO: At the moment, we only recognize the branch if the WC call in this
46 // specific position. We should generalize!
47 return match(WidenableCondition,
48 m_Intrinsic<Intrinsic::experimental_widenable_condition>());
49 }
50