| //===-- 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 |
| |
| #include "llvm/IR/InstrTypes.h" |
| |
| namespace llvm { |
| class Value; |
| class Use; |
| |
| /// 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 |