1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 12:43:36 +01:00
llvm-mirror/include/llvm/IR/ReplaceConstant.h
hsmahesha b3154f6617 [IR] Add utility to convert constant expression operands (of an instruction) to instructions.
In the situation where we need to replace a constant operand C from a constant expression CE
by an instruction NI, it not possible without converting CE itself into an instruction. This
utility helps to convert the given set of constant expression operands from an instruction I
into a corresponding set of instructions.

The current use-case for this utility is from the patches - https://reviews.llvm.org/D103225
and https://reviews.llvm.org/D103655.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D103661
2021-06-08 03:22:32 +05:30

61 lines
2.6 KiB
C++

//===- ReplaceConstant.h - Replacing LLVM constant expressions --*- 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 declares the utility function for replacing LLVM constant
// expressions by instructions.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_REPLACECONSTANT_H
#define LLVM_IR_REPLACECONSTANT_H
#include "llvm/IR/Constants.h"
#include "llvm/IR/Instruction.h"
#include <map>
#include <vector>
namespace llvm {
/// Create a replacement instruction for constant expression \p CE and insert
/// it before \p Instr.
Instruction *createReplacementInstr(ConstantExpr *CE, Instruction *Instr);
/// The given instruction \p I contains given constant expression \p CE as one
/// of its operands, possibly nested within constant expression trees. Convert
/// all reachable paths from contant expression operands of \p I to \p CE into
/// corresponding instructions, insert them before \p I, update operands of \p I
/// accordingly, and if required, return all such converted instructions at
/// \p Insts.
void convertConstantExprsToInstructions(
Instruction *I, ConstantExpr *CE,
SmallPtrSetImpl<Instruction *> *Insts = nullptr);
/// The given instruction \p I contains constant expression CE within the
/// constant expression trees of it`s constant expression operands, and
/// \p CEPaths holds all the reachable paths (to CE) from such constant
/// expression trees of \p I. Convert constant expressions within these paths
/// into corresponding instructions, insert them before \p I, update operands of
/// \p I accordingly, and if required, return all such converted instructions at
/// \p Insts.
void convertConstantExprsToInstructions(
Instruction *I,
std::map<Use *, std::vector<std::vector<ConstantExpr *>>> &CEPaths,
SmallPtrSetImpl<Instruction *> *Insts = nullptr);
/// Given an instruction \p I which uses given constant expression \p CE as
/// operand, either directly or nested within other constant expressions, return
/// all reachable paths from the constant expression operands of \p I to \p CE,
/// and return collected paths at \p CEPaths.
void collectConstantExprPaths(
Instruction *I, ConstantExpr *CE,
std::map<Use *, std::vector<std::vector<ConstantExpr *>>> &CEPaths);
} // end namespace llvm
#endif // LLVM_IR_REPLACECONSTANT_H