llvm-6502/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
Duncan P. N. Exon Smith 88e419d66e DebugInfo: Remove 'inlinedAt:' field from MDLocalVariable
Remove 'inlinedAt:' from MDLocalVariable.  Besides saving some memory
(variables with it seem to be single largest `Metadata` contributer to
memory usage right now in -g -flto builds), this stops optimization and
backend passes from having to change local variables.

The 'inlinedAt:' field was used by the backend in two ways:

 1. To tell the backend whether and into what a variable was inlined.
 2. To create a unique id for each inlined variable.

Instead, rely on the 'inlinedAt:' field of the intrinsic's `!dbg`
attachment, and change the DWARF backend to use a typedef called
`InlinedVariable` which is `std::pair<MDLocalVariable*, MDLocation*>`.
This `DebugLoc` is already passed reliably through the backend (as
verified by r234021).

This commit removes the check from r234021, but I added a new check
(that will survive) in r235048, and changed the `DIBuilder` API in
r235041 to require a `!dbg` attachment whose 'scope:` is in the same
`MDSubprogram` as the variable's.

If this breaks your out-of-tree testcases, perhaps the script I used
(mdlocalvariable-drop-inlinedat.sh) will help; I'll attach it to PR22778
in a moment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235050 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-15 22:29:27 +00:00

61 lines
2.2 KiB
C++

//===-- llvm/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h ----*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
#define LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallVector.h"
namespace llvm {
class MachineFunction;
class MachineInstr;
class MDLocalVariable;
class MDLocation;
class TargetRegisterInfo;
// For each user variable, keep a list of instruction ranges where this variable
// is accessible. The variables are listed in order of appearance.
class DbgValueHistoryMap {
// Each instruction range starts with a DBG_VALUE instruction, specifying the
// location of a variable, which is assumed to be valid until the end of the
// range. If end is not specified, location is valid until the start
// instruction of the next instruction range, or until the end of the
// function.
public:
typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
typedef SmallVector<InstrRange, 4> InstrRanges;
typedef std::pair<const MDLocalVariable *, const MDLocation *>
InlinedVariable;
typedef MapVector<InlinedVariable, InstrRanges> InstrRangesMap;
private:
InstrRangesMap VarInstrRanges;
public:
void startInstrRange(InlinedVariable Var, const MachineInstr &MI);
void endInstrRange(InlinedVariable Var, const MachineInstr &MI);
// Returns register currently describing @Var. If @Var is currently
// unaccessible or is not described by a register, returns 0.
unsigned getRegisterForVar(InlinedVariable Var) const;
bool empty() const { return VarInstrRanges.empty(); }
void clear() { VarInstrRanges.clear(); }
InstrRangesMap::const_iterator begin() const { return VarInstrRanges.begin(); }
InstrRangesMap::const_iterator end() const { return VarInstrRanges.end(); }
};
void calculateDbgValueHistory(const MachineFunction *MF,
const TargetRegisterInfo *TRI,
DbgValueHistoryMap &Result);
}
#endif