1//===-- OverflowInstAnalysis.h - Utils to fold overflow insts ----*- 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//
9// This file holds routines to help analyse overflow instructions
10// and fold them into constants or other overflow instructions
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
15#define LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H
16
17namespace llvm {
18class Use;
19class Value;
20
21/// Match one of the patterns up to the select/logic op:
22/// %Op0 = icmp ne i4 %X, 0
23/// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
24/// %Op1 = extractvalue { i4, i1 } %Agg, 1
25/// %ret = select i1 %Op0, i1 %Op1, i1 false / %ret = and i1 %Op0, %Op1
26///
27/// %Op0 = icmp eq i4 %X, 0
28/// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y)
29/// %NotOp1 = extractvalue { i4, i1 } %Agg, 1
30/// %Op1 = xor i1 %NotOp1, true
31/// %ret = select i1 %Op0, i1 true, i1 %Op1 / %ret = or i1 %Op0, %Op1
32///
33/// Callers are expected to align that with the operands of the select/logic.
34/// IsAnd is set to true if the Op0 and Op1 are used as the first pattern.
35/// If Op0 and Op1 match one of the patterns above, return true and fill Y's
36/// use.
37
38bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd,
39 Use *&Y);
40bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd);
41} // end namespace llvm
42
43#endif
44

source code of llvm/include/llvm/Analysis/OverflowInstAnalysis.h