Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===-- 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