- //===-- OverflowInstAnalysis.h - Utils to fold overflow insts ----*- C++ -*-==// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file holds routines to help analyse overflow instructions 
- // and fold them into constants or other overflow instructions 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H 
- #define LLVM_ANALYSIS_OVERFLOWINSTANALYSIS_H 
-   
- namespace llvm { 
- class Use; 
- class Value; 
-   
- /// Match one of the patterns up to the select/logic op: 
- ///   %Op0 = icmp ne i4 %X, 0 
- ///   %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y) 
- ///   %Op1 = extractvalue { i4, i1 } %Agg, 1 
- ///   %ret = select i1 %Op0, i1 %Op1, i1 false / %ret = and i1 %Op0, %Op1 
- /// 
- ///   %Op0 = icmp eq i4 %X, 0 
- ///   %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y) 
- ///   %NotOp1 = extractvalue { i4, i1 } %Agg, 1 
- ///   %Op1 = xor i1 %NotOp1, true 
- ///   %ret = select i1 %Op0, i1 true, i1 %Op1 / %ret = or i1 %Op0, %Op1 
- /// 
- /// Callers are expected to align that with the operands of the select/logic. 
- /// IsAnd is set to true if the Op0 and Op1 are used as the first pattern. 
- /// If Op0 and Op1 match one of the patterns above, return true and fill Y's 
- /// use. 
-   
- bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd, 
-                                       Use *&Y); 
- bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd); 
- } // end namespace llvm 
-   
- #endif 
-