119304Speter//===-- 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 17#include "llvm/IR/InstrTypes.h" 18 19namespace llvm { 20class Value; 21class Use; 22 23/// Match one of the patterns up to the select/logic op: 24/// %Op0 = icmp ne i4 %X, 0 25/// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y) 26/// %Op1 = extractvalue { i4, i1 } %Agg, 1 27/// %ret = select i1 %Op0, i1 %Op1, i1 false / %ret = and i1 %Op0, %Op1 28/// 29/// %Op0 = icmp eq i4 %X, 0 30/// %Agg = call { i4, i1 } @llvm.[us]mul.with.overflow.i4(i4 %X, i4 %Y) 31/// %NotOp1 = extractvalue { i4, i1 } %Agg, 1 32/// %Op1 = xor i1 %NotOp1, true 33/// %ret = select i1 %Op0, i1 true, i1 %Op1 / %ret = or i1 %Op0, %Op1 34/// 35/// Callers are expected to align that with the operands of the select/logic. 36/// IsAnd is set to true if the Op0 and Op1 are used as the first pattern. 37/// If Op0 and Op1 match one of the patterns above, return true and fill Y's 38/// use. 39 40bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd, 41 Use *&Y); 42bool isCheckForZeroAndMulWithOverflow(Value *Op0, Value *Op1, bool IsAnd); 43} // end namespace llvm 44 45#endif 46