llvm-mirror/lib/IR/ConstantFold.h
Peter Collingbourne fbb7ea5270 IR: Introduce inrange attribute on getelementptr indices.
If the inrange keyword is present before any index, loading from or
storing to any pointer derived from the getelementptr has undefined
behavior if the load or store would access memory outside of the bounds of
the element selected by the index marked as inrange.

This can be used, e.g. for alias analysis or to split globals at element
boundaries where beneficial.

As previously proposed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-July/102472.html

Differential Revision: https://reviews.llvm.org/D22793

llvm-svn: 286514
2016-11-10 22:34:55 +00:00

57 lines
2.4 KiB
C++

//===-- ConstantFolding.h - Internal Constant Folding Interface -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the (internal) constant folding interfaces for LLVM. 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_LIB_IR_CONSTANTFOLD_H
#define LLVM_LIB_IR_CONSTANTFOLD_H
#include "llvm/ADT/Optional.h"
namespace llvm {
template <typename T> class ArrayRef;
class Value;
class Constant;
class Type;
// Constant fold various types of instruction...
Constant *ConstantFoldCastInstruction(
unsigned opcode, ///< The opcode of the cast
Constant *V, ///< The source constant
Type *DestTy ///< The destination type
);
Constant *ConstantFoldSelectInstruction(Constant *Cond,
Constant *V1, Constant *V2);
Constant *ConstantFoldExtractElementInstruction(Constant *Val, Constant *Idx);
Constant *ConstantFoldInsertElementInstruction(Constant *Val, Constant *Elt,
Constant *Idx);
Constant *ConstantFoldShuffleVectorInstruction(Constant *V1, Constant *V2,
Constant *Mask);
Constant *ConstantFoldExtractValueInstruction(Constant *Agg,
ArrayRef<unsigned> Idxs);
Constant *ConstantFoldInsertValueInstruction(Constant *Agg, Constant *Val,
ArrayRef<unsigned> Idxs);
Constant *ConstantFoldBinaryInstruction(unsigned Opcode, Constant *V1,
Constant *V2);
Constant *ConstantFoldCompareInstruction(unsigned short predicate,
Constant *C1, Constant *C2);
Constant *ConstantFoldGetElementPtr(Type *Ty, Constant *C, bool InBounds,
Optional<unsigned> InRangeIndex,
ArrayRef<Value *> Idxs);
} // End llvm namespace
#endif