llvm-6502/lib/Target/Mips/MipsFrameLowering.h
Vasileios Kalintiris 330e5f16d1 [mips] Add support for dynamic stack realignment.
Summary:
With this change we are able to realign the stack dynamically, whenever it
contains objects with alignment requirements that are larger than the
alignment specified from the given ABI.

We have to use the $fp register as the frame pointer when we perform
dynamic stack realignment. In complex stack frames, with variably-sized
objects, we reserve additionally the callee-saved register $s7 as the
base pointer in order to reference locals.

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8633

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238829 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-02 13:14:46 +00:00

55 lines
1.6 KiB
C++

//===-- MipsFrameLowering.h - Define frame lowering for Mips ----*- 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_TARGET_MIPS_MIPSFRAMELOWERING_H
#define LLVM_LIB_TARGET_MIPS_MIPSFRAMELOWERING_H
#include "Mips.h"
#include "llvm/Target/TargetFrameLowering.h"
namespace llvm {
class MipsSubtarget;
class MipsFrameLowering : public TargetFrameLowering {
protected:
const MipsSubtarget &STI;
public:
explicit MipsFrameLowering(const MipsSubtarget &sti, unsigned Alignment)
: TargetFrameLowering(StackGrowsDown, Alignment, 0, Alignment), STI(sti) {}
static const MipsFrameLowering *create(const MipsSubtarget &ST);
bool hasFP(const MachineFunction &MF) const override;
bool hasBP(const MachineFunction &MF) const;
bool isFPCloseToIncomingSP() const override { return false; }
void
eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const override;
protected:
uint64_t estimateStackSize(const MachineFunction &MF) const;
};
/// Create MipsFrameLowering objects.
const MipsFrameLowering *createMips16FrameLowering(const MipsSubtarget &ST);
const MipsFrameLowering *createMipsSEFrameLowering(const MipsSubtarget &ST);
} // End llvm namespace
#endif