ConstantFold.h

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//==-- ConstantFold.h - DL-independent Constant Folding Interface -*- 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 defines the DataLayout-independent constant folding interface.
// When possible, the DataLayout-aware constant folding interface in
// Analysis/ConstantFolding.h should be preferred.
//
// These interfaces are used by the ConstantExpr::get* methods to automatically
// fold constants when possible.
//
// These operators may return a null object if they don't know how to perform
// the specified operation on the specified constant types.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_IR_CONSTANTFOLD_H
#define LLVM_IR_CONSTANTFOLD_H
 
#include "llvm/IR/InstrTypes.h"
#include "llvm/Support/Compiler.h"
#include <optional>
 
namespace llvm {
template <typename T> class ArrayRef;
class Value;
class Constant;
class Type;
 
// Constant fold various types of instruction...
LLVM_ABI Constant *
ConstantFoldCastInstruction(unsigned opcode, ///< The opcode of the cast
                            Constant *V,     ///< The source constant
                            Type *DestTy     ///< The destination type
);
 
/// Attempt to constant fold a select instruction with the specified
/// operands. The constant result is returned if successful; if not, null is
/// returned.
LLVM_ABI Constant *ConstantFoldSelectInstruction(Constant *Cond, Constant *V1,
                                                 Constant *V2);
 
/// Attempt to constant fold an extractelement instruction with the
/// specified operands and indices.  The constant result is returned if
/// successful; if not, null is returned.
LLVM_ABI Constant *ConstantFoldExtractElementInstruction(Constant *Val,
                                                         Constant *Idx);
 
/// Attempt to constant fold an insertelement instruction with the
/// specified operands and indices.  The constant result is returned if
/// successful; if not, null is returned.
LLVM_ABI Constant *ConstantFoldInsertElementInstruction(Constant *Val,
                                                        Constant *Elt,
                                                        Constant *Idx);
 
/// Attempt to constant fold a shufflevector instruction with the
/// specified operands and mask.  See class ShuffleVectorInst for a description
/// of the mask representation. The constant result is returned if successful;
/// if not, null is returned.
LLVM_ABI Constant *ConstantFoldShuffleVectorInstruction(Constant *V1,
                                                        Constant *V2,
                                                        ArrayRef<int> Mask);
 
/// Attempt to constant fold an extractvalue instruction with the
/// specified operands and indices.  The constant result is returned if
/// successful; if not, null is returned.
LLVM_ABI Constant *ConstantFoldExtractValueInstruction(Constant *Agg,
                                                       ArrayRef<unsigned> Idxs);
 
/// Attempt to constant fold an insertvalue instruction with the specified
/// operands and indices.  The constant result is returned if successful; if
/// not, null is returned.
LLVM_ABI Constant *ConstantFoldInsertValueInstruction(Constant *Agg,
                                                      Constant *Val,
                                                      ArrayRef<unsigned> Idxs);
LLVM_ABI Constant *ConstantFoldUnaryInstruction(unsigned Opcode, Constant *V);
LLVM_ABI Constant *ConstantFoldBinaryInstruction(unsigned Opcode, Constant *V1,
                                                 Constant *V2);
LLVM_ABI Constant *ConstantFoldCompareInstruction(CmpInst::Predicate Predicate,
                                                  Constant *C1, Constant *C2);
LLVM_ABI Constant *
ConstantFoldGetElementPtr(Type *Ty, Constant *C,
                          std::optional<ConstantRange> InRange,
                          ArrayRef<Value *> Idxs);
} // namespace llvm
 
#endif