//==-- PPCFrameLowering.h - Define frame lowering for PowerPC ----*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
#ifndef POWERPC_FRAMEINFO_H
#define POWERPC_FRAMEINFO_H
#include "PPC.h"
#include "PPCSubtarget.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/STLExtras.h"
namespace llvm {
class PPCSubtarget;
class PPCFrameLowering: public TargetFrameLowering {
const PPCSubtarget &Subtarget;
public:
PPCFrameLowering(const PPCSubtarget &sti)
: TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 16, 0),
Subtarget(sti) {
}
void determineFrameLayout(MachineFunction &MF) const;
/// emitProlog/emitEpilog - These methods insert prolog and epilog code into
/// the function.
void emitPrologue(MachineFunction &MF) const;
void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;
bool hasFP(const MachineFunction &MF) const;
bool needsFP(const MachineFunction &MF) const;
void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS = NULL) const;
void processFunctionBeforeFrameFinalized(MachineFunction &MF) const;
/// targetHandlesStackFrameRounding - Returns true if the target is
/// responsible for rounding up the stack frame (probably at emitPrologue
/// time).
bool targetHandlesStackFrameRounding() const { return true; }
/// getReturnSaveOffset - Return the previous frame offset to save the
/// return address.
static unsigned getReturnSaveOffset(bool isPPC64, bool isDarwinABI) {
if (isDarwinABI)
return isPPC64 ? 16 : 8;
// SVR4 ABI:
return isPPC64 ? 16 : 4;
}
/// getFramePointerSaveOffset - Return the previous frame offset to save the
/// frame pointer.
static unsigned getFramePointerSaveOffset(bool isPPC64, bool isDarwinABI) {
// For the Darwin ABI:
// We cannot use the TOC save slot (offset +20) in the PowerPC linkage area
// for saving the frame pointer (if needed.) While the published ABI has
// not used this slot since at least MacOSX 10.2, there is older code
// around that does use it, and that needs to continue to work.
if (isDarwinABI)
return isPPC64 ? -8U : -4U;
// SVR4 ABI: First slot in the general register save area.
return isPPC64 ? -8U : -4U;
}
/// getLinkageSize - Return the size of the PowerPC ABI linkage area.
///
static unsigned getLinkageSize(bool isPPC64, bool isDarwinABI) {
if (isDarwinABI || isPPC64)
return 6 * (isPPC64 ? 8 : 4);
// SVR4 ABI:
return 8;
}
/// getMinCallArgumentsSize - Return the size of the minium PowerPC ABI
/// argument area.
static unsigned getMinCallArgumentsSize(bool isPPC64, bool isDarwinABI) {
// For the Darwin ABI / 64-bit SVR4 ABI:
// The prolog code of the callee may store up to 8 GPR argument registers to
// the stack, allowing va_start to index over them in memory if its varargs.
// Because we cannot tell if this is needed on the caller side, we have to
// conservatively assume that it is needed. As such, make sure we have at
// least enough stack space for the caller to store the 8 GPRs.
if (isDarwinABI || isPPC64)
return 8 * (isPPC64 ? 8 : 4);
// 32-bit SVR4 ABI:
// There is no default stack allocated for the 8 first GPR arguments.
return 0;
}
/// getMinCallFrameSize - Return the minimum size a call frame can be using
/// the PowerPC ABI.
static unsigned getMinCallFrameSize(bool isPPC64, bool isDarwinABI) {
// The call frame needs to be at least big enough for linkage and 8 args.
return getLinkageSize(isPPC64, isDarwinABI) +
getMinCallArgumentsSize(isPPC64, isDarwinABI);
}
// With the SVR4 ABI, callee-saved registers have fixed offsets on the stack.
const SpillSlot *
getCalleeSavedSpillSlots(unsigned &NumEntries) const {
if (Subtarget.isDarwinABI()) {
NumEntries = 1;
if (Subtarget.isPPC64()) {
static const SpillSlot darwin64Offsets = {PPC::X31, -8};
return &darwin64Offsets;
} else {
static const SpillSlot darwinOffsets = {PPC::R31, -4};
return &darwinOffsets;
}
}
// Early exit if not using the SVR4 ABI.
if (!Subtarget.isSVR4ABI()) {
NumEntries = 0;
return 0;
}
static const SpillSlot Offsets[] = {
// Floating-point register save area offsets.
{PPC::F31, -8},
{PPC::F30, -16},
{PPC::F29, -24},
{PPC::F28, -32},
{PPC::F27, -40},
{PPC::F26, -48},
{PPC::F25, -56},
{PPC::F24, -64},
{PPC::F23, -72},
{PPC::F22, -80},
{PPC::F21, -88},
{PPC::F20, -96},
{PPC::F19, -104},
{PPC::F18, -112},
{PPC::F17, -120},
{PPC::F16, -128},
{PPC::F15, -136},
{PPC::F14, -144},
// General register save area offsets.
{PPC::R31, -4},
{PPC::R30, -8},
{PPC::R29, -12},
{PPC::R28, -16},
{PPC::R27, -20},
{PPC::R26, -24},
{PPC::R25, -28},
{PPC::R24, -32},
{PPC::R23, -36},
{PPC::R22, -40},
{PPC::R21, -44},
{PPC::R20, -48},
{PPC::R19, -52},
{PPC::R18, -56},
{PPC::R17, -60},
{PPC::R16, -64},
{PPC::R15, -68},
{PPC::R14, -72},
// CR save area offset.
// FIXME SVR4: Disable CR save area for now.
// {PPC::CR2, -4},
// {PPC::CR3, -4},
// {PPC::CR4, -4},
// {PPC::CR2LT, -4},
// {PPC::CR2GT, -4},
// {PPC::CR2EQ, -4},
// {PPC::CR2UN, -4},
// {PPC::CR3LT, -4},
// {PPC::CR3GT, -4},
// {PPC::CR3EQ, -4},
// {PPC::CR3UN, -4},
// {PPC::CR4LT, -4},
// {PPC::CR4GT, -4},
// {PPC::CR4EQ, -4},
// {PPC::CR4UN, -4},
// VRSAVE save area offset.
{PPC::VRSAVE, -4},
// Vector register save area
{PPC::V31, -16},
{PPC::V30, -32},
{PPC::V29, -48},
{PPC::V28, -64},
{PPC::V27, -80},
{PPC::V26, -96},
{PPC::V25, -112},
{PPC::V24, -128},
{PPC::V23, -144},
{PPC::V22, -160},
{PPC::V21, -176},
{PPC::V20, -192}
};
static const SpillSlot Offsets64[] = {
// Floating-point register save area offsets.
{PPC::F31, -8},
{PPC::F30, -16},
{PPC::F29, -24},
{PPC::F28, -32},
{PPC::F27, -40},
{PPC::F26, -48},
{PPC::F25, -56},
{PPC::F24, -64},
{PPC::F23, -72},
{PPC::F22, -80},
{PPC::F21, -88},
{PPC::F20, -96},
{PPC::F19, -104},
{PPC::F18, -112},
{PPC::F17, -120},
{PPC::F16, -128},
{PPC::F15, -136},
{PPC::F14, -144},
// General register save area offsets.
// FIXME 64-bit SVR4: Are 32-bit registers actually allocated in 64-bit
// mode?
{PPC::R31, -4},
{PPC::R30, -12},
{PPC::R29, -20},
{PPC::R28, -28},
{PPC::R27, -36},
{PPC::R26, -44},
{PPC::R25, -52},
{PPC::R24, -60},
{PPC::R23, -68},
{PPC::R22, -76},
{PPC::R21, -84},
{PPC::R20, -92},
{PPC::R19, -100},
{PPC::R18, -108},
{PPC::R17, -116},
{PPC::R16, -124},
{PPC::R15, -132},
{PPC::R14, -140},
{PPC::X31, -8},
{PPC::X30, -16},
{PPC::X29, -24},
{PPC::X28, -32},
{PPC::X27, -40},
{PPC::X26, -48},
{PPC::X25, -56},
{PPC::X24, -64},
{PPC::X23, -72},
{PPC::X22, -80},
{PPC::X21, -88},
{PPC::X20, -96},
{PPC::X19, -104},
{PPC::X18, -112},
{PPC::X17, -120},
{PPC::X16, -128},
{PPC::X15, -136},
{PPC::X14, -144},
// CR save area offset.
// FIXME SVR4: Disable CR save area for now.
// {PPC::CR2, -4},
// {PPC::CR3, -4},
// {PPC::CR4, -4},
// {PPC::CR2LT, -4},
// {PPC::CR2GT, -4},
// {PPC::CR2EQ, -4},
// {PPC::CR2UN, -4},
// {PPC::CR3LT, -4},
// {PPC::CR3GT, -4},
// {PPC::CR3EQ, -4},
// {PPC::CR3UN, -4},
// {PPC::CR4LT, -4},
// {PPC::CR4GT, -4},
// {PPC::CR4EQ, -4},
// {PPC::CR4UN, -4},
// VRSAVE save area offset.
{PPC::VRSAVE, -4},
// Vector register save area
{PPC::V31, -16},
{PPC::V30, -32},
{PPC::V29, -48},
{PPC::V28, -64},
{PPC::V27, -80},
{PPC::V26, -96},
{PPC::V25, -112},
{PPC::V24, -128},
{PPC::V23, -144},
{PPC::V22, -160},
{PPC::V21, -176},
{PPC::V20, -192}
};
if (Subtarget.isPPC64()) {
NumEntries = array_lengthof(Offsets64);
return Offsets64;
} else {
NumEntries = array_lengthof(Offsets);
return Offsets;
}
}
};
} // End llvm namespace
#endif