llvm-6502/lib/Target/Mips/MipsMachineFunction.h
Dan Gohman 98ca4f2a32 Major calling convention code refactoring.
Instead of awkwardly encoding calling-convention information with ISD::CALL,
ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering
provides three virtual functions for targets to override:
LowerFormalArguments, LowerCall, and LowerRet, which replace the custom
lowering done on the special nodes. They provide the same information, but
in a more immediately usable format.

This also reworks much of the target-independent tail call logic. The
decision of whether or not to perform a tail call is now cleanly split
between target-independent portions, and the target dependent portion
in IsEligibleForTailCallOptimization.

This also synchronizes all in-tree targets, to help enable future
refactoring and feature work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78142 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-05 01:29:28 +00:00

140 lines
5.2 KiB
C++

//===-- MipsMachineFunctionInfo.h - Private data used for Mips ----*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the Mips specific subclass of MachineFunctionInfo.
//
//===----------------------------------------------------------------------===//
#ifndef MIPS_MACHINE_FUNCTION_INFO_H
#define MIPS_MACHINE_FUNCTION_INFO_H
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/VectorExtras.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
namespace llvm {
/// MipsFunctionInfo - This class is derived from MachineFunction private
/// Mips target-specific information for each MachineFunction.
class MipsFunctionInfo : public MachineFunctionInfo {
private:
/// Holds for each function where on the stack the Frame Pointer must be
/// saved. This is used on Prologue and Epilogue to emit FP save/restore
int FPStackOffset;
/// Holds for each function where on the stack the Return Address must be
/// saved. This is used on Prologue and Epilogue to emit RA save/restore
int RAStackOffset;
/// At each function entry, two special bitmask directives must be emitted
/// to help debugging, for CPU and FPU callee saved registers. Both need
/// the negative offset from the final stack size and its higher registers
/// location on the stack.
int CPUTopSavedRegOff;
int FPUTopSavedRegOff;
/// MipsFIHolder - Holds a FrameIndex and it's Stack Pointer Offset
struct MipsFIHolder {
int FI;
int SPOffset;
MipsFIHolder(int FrameIndex, int StackPointerOffset)
: FI(FrameIndex), SPOffset(StackPointerOffset) {}
};
/// When PIC is used the GP must be saved on the stack on the function
/// prologue and must be reloaded from this stack location after every
/// call. A reference to its stack location and frame index must be kept
/// to be used on emitPrologue and processFunctionBeforeFrameFinalized.
MipsFIHolder GPHolder;
/// On LowerFormalArguments the stack size is unknown, so the Stack
/// Pointer Offset calculation of "not in register arguments" must be
/// postponed to emitPrologue.
SmallVector<MipsFIHolder, 16> FnLoadArgs;
bool HasLoadArgs;
// When VarArgs, we must write registers back to caller stack, preserving
// on register arguments. Since the stack size is unknown on
// LowerFormalArguments, the Stack Pointer Offset calculation must be
// postponed to emitPrologue.
SmallVector<MipsFIHolder, 4> FnStoreVarArgs;
bool HasStoreVarArgs;
/// SRetReturnReg - Some subtargets require that sret lowering includes
/// returning the value of the returned struct in a register. This field
/// holds the virtual register into which the sret argument is passed.
unsigned SRetReturnReg;
/// GlobalBaseReg - keeps track of the virtual register initialized for
/// use as the global base register. This is used for PIC in some PIC
/// relocation models.
unsigned GlobalBaseReg;
public:
MipsFunctionInfo(MachineFunction& MF)
: FPStackOffset(0), RAStackOffset(0), CPUTopSavedRegOff(0),
FPUTopSavedRegOff(0), GPHolder(-1,-1), HasLoadArgs(false),
HasStoreVarArgs(false), SRetReturnReg(0), GlobalBaseReg(0)
{}
int getFPStackOffset() const { return FPStackOffset; }
void setFPStackOffset(int Off) { FPStackOffset = Off; }
int getRAStackOffset() const { return RAStackOffset; }
void setRAStackOffset(int Off) { RAStackOffset = Off; }
int getCPUTopSavedRegOff() const { return CPUTopSavedRegOff; }
void setCPUTopSavedRegOff(int Off) { CPUTopSavedRegOff = Off; }
int getFPUTopSavedRegOff() const { return FPUTopSavedRegOff; }
void setFPUTopSavedRegOff(int Off) { FPUTopSavedRegOff = Off; }
int getGPStackOffset() const { return GPHolder.SPOffset; }
int getGPFI() const { return GPHolder.FI; }
void setGPStackOffset(int Off) { GPHolder.SPOffset = Off; }
void setGPFI(int FI) { GPHolder.FI = FI; }
bool hasLoadArgs() const { return HasLoadArgs; }
bool hasStoreVarArgs() const { return HasStoreVarArgs; }
void recordLoadArgsFI(int FI, int SPOffset) {
if (!HasLoadArgs) HasLoadArgs=true;
FnLoadArgs.push_back(MipsFIHolder(FI, SPOffset));
}
void recordStoreVarArgsFI(int FI, int SPOffset) {
if (!HasStoreVarArgs) HasStoreVarArgs=true;
FnStoreVarArgs.push_back(MipsFIHolder(FI, SPOffset));
}
void adjustLoadArgsFI(MachineFrameInfo *MFI) const {
if (!hasLoadArgs()) return;
for (unsigned i = 0, e = FnLoadArgs.size(); i != e; ++i)
MFI->setObjectOffset( FnLoadArgs[i].FI, FnLoadArgs[i].SPOffset );
}
void adjustStoreVarArgsFI(MachineFrameInfo *MFI) const {
if (!hasStoreVarArgs()) return;
for (unsigned i = 0, e = FnStoreVarArgs.size(); i != e; ++i)
MFI->setObjectOffset( FnStoreVarArgs[i].FI, FnStoreVarArgs[i].SPOffset );
}
unsigned getSRetReturnReg() const { return SRetReturnReg; }
void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }
};
} // end of namespace llvm
#endif // MIPS_MACHINE_FUNCTION_INFO_H