llvm-6502/lib/CodeGen/LiveDebugVariables.h
Jakob Stoklund Olesen bb7b23f5b7 Stub out a new LiveDebugVariables pass.
This analysis is going to run immediately after LiveIntervals. It will stay
alive during register allocation and keep track of user variables mentioned in
DBG_VALUE instructions.

When the register allocator is moving values between registers and the stack, it
is very hard to keep track of DBG_VALUE instructions. We usually get it wrong.
This analysis maintains a data structure that makes it easy to update DBG_VALUE
instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120385 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 02:17:10 +00:00

58 lines
1.9 KiB
C++

//===- LiveDebugVariables.h - Tracking debug info variables ----*- c++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides the interface to the LiveDebugVariables analysis.
//
// The analysis removes DBG_VALUE instructions for virtual registers and tracks
// live user variables in a data structure that can be updated during register
// allocation.
//
// After register allocation new DBG_VALUE instructions are emitted to reflect
// the new locations of user variables.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
#define LLVM_CODEGEN_LIVEDEBUGVARIABLES_H
#include "llvm/CodeGen/MachineFunctionPass.h"
namespace llvm {
class LiveDebugVariables : public MachineFunctionPass {
void *pImpl;
public:
static char ID; // Pass identification, replacement for typeid
LiveDebugVariables();
/// renameRegister - Move any user variables in OldReg to NewReg:SubIdx.
/// @param OldReg Old virtual register that is going away.
/// @param NewReg New register holding the user variables.
/// @param SubIdx If NewReg is a virtual register, SubIdx may indicate a sub-
/// register.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
/// emitDebugValues - Emit new DBG_VALUE instructions reflecting the changes
/// that happened during register allocation.
void emitDebugValues();
private:
/// runOnMachineFunction - Analyze and remove DBG_VALUE instructions.
virtual bool runOnMachineFunction(MachineFunction &);
virtual void getAnalysisUsage(AnalysisUsage &) const;
};
} // namespace llvm
#endif // LLVM_CODEGEN_LIVEDEBUGVARIABLES_H