GuardUtils.h revision 360784 
1//===-- GuardUtils.h - 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#ifndef LLVM_ANALYSIS_GUARDUTILS_H
13#define LLVM_ANALYSIS_GUARDUTILS_H
14
15namespace llvm {
16
17class BasicBlock;
18class Use;
19class User;
20class Value;
21
22/// Returns true iff \p U has semantics of a guard expressed in a form of call
23/// of llvm.experimental.guard intrinsic.
24bool isGuard(const User *U);
25
26/// Returns true iff \p U is a widenable branch (that is, parseWidenableBranch
27/// returns true).
28bool isWidenableBranch(const User *U);
29
30/// Returns true iff \p U has semantics of a guard expressed in a form of a
31/// widenable conditional branch to deopt block.
32bool isGuardAsWidenableBranch(const User *U);
33
34/// If U is widenable branch looking like:
35///   %cond = ...
36///   %wc = call i1 @llvm.experimental.widenable.condition()
37///   %branch_cond = and i1 %cond, %wc
38///   br i1 %branch_cond, label %if_true_bb, label %if_false_bb ; <--- U
39/// The function returns true, and the values %cond and %wc and blocks
40/// %if_true_bb, if_false_bb are returned in
41/// the parameters (Condition, WidenableCondition, IfTrueBB and IfFalseFF)
42/// respectively. If \p U does not match this pattern, return false.
43bool parseWidenableBranch(const User *U, Value *&Condition,
44                          Value *&WidenableCondition, BasicBlock *&IfTrueBB,
45                          BasicBlock *&IfFalseBB);
46
47/// Analgous to the above, but return the Uses so that that they can be
48/// modified. Unlike previous version, Condition is optional and may be null.
49bool parseWidenableBranch(User *U, Use *&Cond, Use *&WC, BasicBlock *&IfTrueBB,
50                          BasicBlock *&IfFalseBB);
51
52} // llvm
53
54#endif // LLVM_ANALYSIS_GUARDUTILS_H
55