lib/Analysis/GuardUtils.cpp

   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
  17 bool llvm::isGuard(const User *U) {
  18   using namespace llvm::PatternMatch;
  19   return match(U, m_Intrinsic<Intrinsic::experimental_guard>());
  20 }
  21
  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
  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 }