| //===--- SimplifyInstruction.h - Fold instructions --------------*- C++ -*-===// |
| // |
| // This source file is part of the Swift.org open source project |
| // |
| // Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors |
| // Licensed under Apache License v2.0 with Runtime Library Exception |
| // |
| // See https://swift.org/LICENSE.txt for license information |
| // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // An analysis that provides utilities for folding instructions. Since it is an |
| // analysis it does not modify the IR in anyway. This is left to actual |
| // SIL Transforms. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "swift/SIL/SILInstruction.h" |
| |
| namespace swift { |
| |
| class SILInstruction; |
| |
| /// \brief Try to simplify the specified instruction, performing local |
| /// analysis of the operands of the instruction, without looking at its uses |
| /// (e.g. constant folding). If a simpler result can be found, it is |
| /// returned, otherwise a null SILValue is returned. |
| SILValue simplifyInstruction(SILInstruction *I); |
| |
| /// Simplify invocations of builtin operations that may overflow. |
| /// All such operations return a tuple (result, overflow_flag). |
| /// This function try to simplify such operations, but returns only a |
| /// simplified first element of a tuple. The overflow flag is not returned |
| /// explicitly, because this simplification is only possible if there is |
| /// no overflow. Therefore the overflow flag is known to have a value of 0 if |
| /// simplification was successful. |
| /// In case when a simplification is not possible, a null SILValue is returned. |
| SILValue simplifyOverflowBuiltinInstruction(BuiltinInst *BI); |
| |
| } // end namespace swift |
