llvm-6502/lib/Target/CellSPU/SPURegisterInfo.cpp
Jim Grosbach fcb4a8ead3 Simplify eliminateFrameIndex() interface back down now that PEI doesn't need
to try to re-use scavenged frame index reference registers. rdar://8277890

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112241 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-26 23:32:16 +00:00

620 lines
21 KiB
C++

//===- SPURegisterInfo.cpp - Cell SPU Register Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the Cell implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "reginfo"
#include "SPU.h"
#include "SPURegisterInfo.h"
#include "SPURegisterNames.h"
#include "SPUInstrBuilder.h"
#include "SPUSubtarget.h"
#include "SPUMachineFunction.h"
#include "SPUFrameInfo.h"
#include "llvm/Constants.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include <cstdlib>
using namespace llvm;
/// getRegisterNumbering - Given the enum value for some register, e.g.
/// PPC::F14, return the number that it corresponds to (e.g. 14).
unsigned SPURegisterInfo::getRegisterNumbering(unsigned RegEnum) {
using namespace SPU;
switch (RegEnum) {
case SPU::R0: return 0;
case SPU::R1: return 1;
case SPU::R2: return 2;
case SPU::R3: return 3;
case SPU::R4: return 4;
case SPU::R5: return 5;
case SPU::R6: return 6;
case SPU::R7: return 7;
case SPU::R8: return 8;
case SPU::R9: return 9;
case SPU::R10: return 10;
case SPU::R11: return 11;
case SPU::R12: return 12;
case SPU::R13: return 13;
case SPU::R14: return 14;
case SPU::R15: return 15;
case SPU::R16: return 16;
case SPU::R17: return 17;
case SPU::R18: return 18;
case SPU::R19: return 19;
case SPU::R20: return 20;
case SPU::R21: return 21;
case SPU::R22: return 22;
case SPU::R23: return 23;
case SPU::R24: return 24;
case SPU::R25: return 25;
case SPU::R26: return 26;
case SPU::R27: return 27;
case SPU::R28: return 28;
case SPU::R29: return 29;
case SPU::R30: return 30;
case SPU::R31: return 31;
case SPU::R32: return 32;
case SPU::R33: return 33;
case SPU::R34: return 34;
case SPU::R35: return 35;
case SPU::R36: return 36;
case SPU::R37: return 37;
case SPU::R38: return 38;
case SPU::R39: return 39;
case SPU::R40: return 40;
case SPU::R41: return 41;
case SPU::R42: return 42;
case SPU::R43: return 43;
case SPU::R44: return 44;
case SPU::R45: return 45;
case SPU::R46: return 46;
case SPU::R47: return 47;
case SPU::R48: return 48;
case SPU::R49: return 49;
case SPU::R50: return 50;
case SPU::R51: return 51;
case SPU::R52: return 52;
case SPU::R53: return 53;
case SPU::R54: return 54;
case SPU::R55: return 55;
case SPU::R56: return 56;
case SPU::R57: return 57;
case SPU::R58: return 58;
case SPU::R59: return 59;
case SPU::R60: return 60;
case SPU::R61: return 61;
case SPU::R62: return 62;
case SPU::R63: return 63;
case SPU::R64: return 64;
case SPU::R65: return 65;
case SPU::R66: return 66;
case SPU::R67: return 67;
case SPU::R68: return 68;
case SPU::R69: return 69;
case SPU::R70: return 70;
case SPU::R71: return 71;
case SPU::R72: return 72;
case SPU::R73: return 73;
case SPU::R74: return 74;
case SPU::R75: return 75;
case SPU::R76: return 76;
case SPU::R77: return 77;
case SPU::R78: return 78;
case SPU::R79: return 79;
case SPU::R80: return 80;
case SPU::R81: return 81;
case SPU::R82: return 82;
case SPU::R83: return 83;
case SPU::R84: return 84;
case SPU::R85: return 85;
case SPU::R86: return 86;
case SPU::R87: return 87;
case SPU::R88: return 88;
case SPU::R89: return 89;
case SPU::R90: return 90;
case SPU::R91: return 91;
case SPU::R92: return 92;
case SPU::R93: return 93;
case SPU::R94: return 94;
case SPU::R95: return 95;
case SPU::R96: return 96;
case SPU::R97: return 97;
case SPU::R98: return 98;
case SPU::R99: return 99;
case SPU::R100: return 100;
case SPU::R101: return 101;
case SPU::R102: return 102;
case SPU::R103: return 103;
case SPU::R104: return 104;
case SPU::R105: return 105;
case SPU::R106: return 106;
case SPU::R107: return 107;
case SPU::R108: return 108;
case SPU::R109: return 109;
case SPU::R110: return 110;
case SPU::R111: return 111;
case SPU::R112: return 112;
case SPU::R113: return 113;
case SPU::R114: return 114;
case SPU::R115: return 115;
case SPU::R116: return 116;
case SPU::R117: return 117;
case SPU::R118: return 118;
case SPU::R119: return 119;
case SPU::R120: return 120;
case SPU::R121: return 121;
case SPU::R122: return 122;
case SPU::R123: return 123;
case SPU::R124: return 124;
case SPU::R125: return 125;
case SPU::R126: return 126;
case SPU::R127: return 127;
default:
report_fatal_error("Unhandled reg in SPURegisterInfo::getRegisterNumbering");
}
}
SPURegisterInfo::SPURegisterInfo(const SPUSubtarget &subtarget,
const TargetInstrInfo &tii) :
SPUGenRegisterInfo(SPU::ADJCALLSTACKDOWN, SPU::ADJCALLSTACKUP),
Subtarget(subtarget),
TII(tii)
{
}
/// getPointerRegClass - Return the register class to use to hold pointers.
/// This is used for addressing modes.
const TargetRegisterClass *
SPURegisterInfo::getPointerRegClass(unsigned Kind) const {
return &SPU::R32CRegClass;
}
const unsigned *
SPURegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const
{
// Cell ABI calling convention
static const unsigned SPU_CalleeSaveRegs[] = {
SPU::R80, SPU::R81, SPU::R82, SPU::R83,
SPU::R84, SPU::R85, SPU::R86, SPU::R87,
SPU::R88, SPU::R89, SPU::R90, SPU::R91,
SPU::R92, SPU::R93, SPU::R94, SPU::R95,
SPU::R96, SPU::R97, SPU::R98, SPU::R99,
SPU::R100, SPU::R101, SPU::R102, SPU::R103,
SPU::R104, SPU::R105, SPU::R106, SPU::R107,
SPU::R108, SPU::R109, SPU::R110, SPU::R111,
SPU::R112, SPU::R113, SPU::R114, SPU::R115,
SPU::R116, SPU::R117, SPU::R118, SPU::R119,
SPU::R120, SPU::R121, SPU::R122, SPU::R123,
SPU::R124, SPU::R125, SPU::R126, SPU::R127,
SPU::R2, /* environment pointer */
SPU::R1, /* stack pointer */
SPU::R0, /* link register */
0 /* end */
};
return SPU_CalleeSaveRegs;
}
/*!
R0 (link register), R1 (stack pointer) and R2 (environment pointer -- this is
generally unused) are the Cell's reserved registers
*/
BitVector SPURegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(SPU::R0); // LR
Reserved.set(SPU::R1); // SP
Reserved.set(SPU::R2); // environment pointer
return Reserved;
}
//===----------------------------------------------------------------------===//
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
// needsFP - Return true if the specified function should have a dedicated frame
// pointer register. This is true if the function has variable sized allocas or
// if frame pointer elimination is disabled.
//
static bool needsFP(const MachineFunction &MF) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects();
}
//--------------------------------------------------------------------------
// hasFP - Return true if the specified function actually has a dedicated frame
// pointer register. This is true if the function needs a frame pointer and has
// a non-zero stack size.
bool
SPURegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
return MFI->getStackSize() && needsFP(MF);
}
//--------------------------------------------------------------------------
void
SPURegisterInfo::eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator I)
const
{
// Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
MBB.erase(I);
}
void
SPURegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
RegScavenger *RS) const
{
unsigned i = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
DebugLoc dl = II->getDebugLoc();
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
MachineOperand &SPOp = MI.getOperand(i);
int FrameIndex = SPOp.getIndex();
// Now add the frame object offset to the offset from r1.
int Offset = MFI->getObjectOffset(FrameIndex);
// Most instructions, except for generated FrameIndex additions using AIr32
// and ILAr32, have the immediate in operand 1. AIr32 and ILAr32 have the
// immediate in operand 2.
unsigned OpNo = 1;
if (MI.getOpcode() == SPU::AIr32 || MI.getOpcode() == SPU::ILAr32)
OpNo = 2;
MachineOperand &MO = MI.getOperand(OpNo);
// Offset is biased by $lr's slot at the bottom.
Offset += MO.getImm() + MFI->getStackSize() + SPUFrameInfo::minStackSize();
assert((Offset & 0xf) == 0
&& "16-byte alignment violated in eliminateFrameIndex");
// Replace the FrameIndex with base register with $sp (aka $r1)
SPOp.ChangeToRegister(SPU::R1, false);
// if 'Offset' doesn't fit to the D-form instruction's
// immediate, convert the instruction to X-form
// if the instruction is not an AI (which takes a s10 immediate), assume
// it is a load/store that can take a s14 immediate
if ((MI.getOpcode() == SPU::AIr32 && !isInt<10>(Offset))
|| !isInt<14>(Offset)) {
int newOpcode = convertDFormToXForm(MI.getOpcode());
unsigned tmpReg = findScratchRegister(II, RS, &SPU::R32CRegClass, SPAdj);
BuildMI(MBB, II, dl, TII.get(SPU::ILr32), tmpReg )
.addImm(Offset);
BuildMI(MBB, II, dl, TII.get(newOpcode), MI.getOperand(0).getReg())
.addReg(tmpReg, RegState::Kill)
.addReg(SPU::R1);
// remove the replaced D-form instruction
MBB.erase(II);
} else {
MO.ChangeToImmediate(Offset);
}
}
/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
void
SPURegisterInfo::determineFrameLayout(MachineFunction &MF) const
{
MachineFrameInfo *MFI = MF.getFrameInfo();
// Get the number of bytes to allocate from the FrameInfo
unsigned FrameSize = MFI->getStackSize();
// Get the alignments provided by the target, and the maximum alignment
// (if any) of the fixed frame objects.
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned Align = std::max(TargetAlign, MFI->getMaxAlignment());
assert(isPowerOf2_32(Align) && "Alignment is not power of 2");
unsigned AlignMask = Align - 1;
// Get the maximum call frame size of all the calls.
unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
// If we have dynamic alloca then maxCallFrameSize needs to be aligned so
// that allocations will be aligned.
if (MFI->hasVarSizedObjects())
maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
// Update maximum call frame size.
MFI->setMaxCallFrameSize(maxCallFrameSize);
// Include call frame size in total.
FrameSize += maxCallFrameSize;
// Make sure the frame is aligned.
FrameSize = (FrameSize + AlignMask) & ~AlignMask;
// Update frame info.
MFI->setStackSize(FrameSize);
}
void SPURegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS)
const {
// Mark LR and SP unused, since the prolog spills them to stack and
// we don't want anyone else to spill them for us.
//
// Also, unless R2 is really used someday, don't spill it automatically.
MF.getRegInfo().setPhysRegUnused(SPU::R0);
MF.getRegInfo().setPhysRegUnused(SPU::R1);
MF.getRegInfo().setPhysRegUnused(SPU::R2);
MachineFrameInfo *MFI = MF.getFrameInfo();
const TargetRegisterClass *RC = &SPU::R32CRegClass;
RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
RC->getAlignment(),
false));
}
void SPURegisterInfo::emitPrologue(MachineFunction &MF) const
{
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
// Prepare for debug frame info.
bool hasDebugInfo = MMI.hasDebugInfo();
MCSymbol *FrameLabel = 0;
// Move MBBI back to the beginning of the function.
MBBI = MBB.begin();
// Work out frame sizes.
determineFrameLayout(MF);
int FrameSize = MFI->getStackSize();
assert((FrameSize & 0xf) == 0
&& "SPURegisterInfo::emitPrologue: FrameSize not aligned");
// the "empty" frame size is 16 - just the register scavenger spill slot
if (FrameSize > 16 || MFI->adjustsStack()) {
FrameSize = -(FrameSize + SPUFrameInfo::minStackSize());
if (hasDebugInfo) {
// Mark effective beginning of when frame pointer becomes valid.
FrameLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(FrameLabel);
}
// Adjust stack pointer, spilling $lr -> 16($sp) and $sp -> -FrameSize($sp)
// for the ABI
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R0).addImm(16)
.addReg(SPU::R1);
if (isInt<10>(FrameSize)) {
// Spill $sp to adjusted $sp
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R1).addImm(FrameSize)
.addReg(SPU::R1);
// Adjust $sp by required amout
BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1).addReg(SPU::R1)
.addImm(FrameSize);
} else if (isInt<16>(FrameSize)) {
// Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
// $r2 to adjust $sp:
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
.addImm(-16)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
.addImm(FrameSize);
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQXr32), SPU::R1)
.addReg(SPU::R2)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
.addReg(SPU::R1)
.addReg(SPU::R2);
BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2)
.addReg(SPU::R2)
.addImm(16);
BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
.addReg(SPU::R2)
.addReg(SPU::R1);
} else {
report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
}
if (hasDebugInfo) {
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
// Show update of SP.
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize);
Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
unsigned Reg = CSI[I].getReg();
if (Reg == SPU::R0) continue;
MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
MachineLocation CSSrc(Reg);
Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
}
// Mark effective beginning of when frame pointer is ready.
MCSymbol *ReadyLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(ReadyLabel);
MachineLocation FPDst(SPU::R1);
MachineLocation FPSrc(MachineLocation::VirtualFP);
Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
}
} else {
// This is a leaf function -- insert a branch hint iff there are
// sufficient number instructions in the basic block. Note that
// this is just a best guess based on the basic block's size.
if (MBB.size() >= (unsigned) SPUFrameInfo::branchHintPenalty()) {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
dl = MBBI->getDebugLoc();
// Insert terminator label
BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL))
.addSym(MMI.getContext().CreateTempSymbol());
}
}
}
void
SPURegisterInfo::emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const
{
MachineBasicBlock::iterator MBBI = prior(MBB.end());
const MachineFrameInfo *MFI = MF.getFrameInfo();
int FrameSize = MFI->getStackSize();
int LinkSlotOffset = SPUFrameInfo::stackSlotSize();
DebugLoc dl = MBBI->getDebugLoc();
assert(MBBI->getOpcode() == SPU::RET &&
"Can only insert epilog into returning blocks");
assert((FrameSize & 0xf) == 0
&& "SPURegisterInfo::emitEpilogue: FrameSize not aligned");
// the "empty" frame size is 16 - just the register scavenger spill slot
if (FrameSize > 16 || MFI->adjustsStack()) {
FrameSize = FrameSize + SPUFrameInfo::minStackSize();
if (isInt<10>(FrameSize + LinkSlotOffset)) {
// Reload $lr, adjust $sp by required amount
// Note: We do this to slightly improve dual issue -- not by much, but it
// is an opportunity for dual issue.
BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0)
.addImm(FrameSize + LinkSlotOffset)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1)
.addReg(SPU::R1)
.addImm(FrameSize);
} else if (FrameSize <= (1 << 16) - 1 && FrameSize >= -(1 << 16)) {
// Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
// $r2 to adjust $sp:
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
.addImm(16)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
.addImm(FrameSize);
BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
.addReg(SPU::R1)
.addReg(SPU::R2);
BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0)
.addImm(16)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2).
addReg(SPU::R2)
.addImm(16);
BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
.addReg(SPU::R2)
.addReg(SPU::R1);
} else {
report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
}
}
}
unsigned
SPURegisterInfo::getRARegister() const
{
return SPU::R0;
}
unsigned
SPURegisterInfo::getFrameRegister(const MachineFunction &MF) const
{
return SPU::R1;
}
void
SPURegisterInfo::getInitialFrameState(std::vector<MachineMove> &Moves) const
{
// Initial state of the frame pointer is R1.
MachineLocation Dst(MachineLocation::VirtualFP);
MachineLocation Src(SPU::R1, 0);
Moves.push_back(MachineMove(0, Dst, Src));
}
int
SPURegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
// FIXME: Most probably dwarf numbers differs for Linux and Darwin
return SPUGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
}
int
SPURegisterInfo::convertDFormToXForm(int dFormOpcode) const
{
switch(dFormOpcode)
{
case SPU::AIr32: return SPU::Ar32;
case SPU::LQDr32: return SPU::LQXr32;
case SPU::LQDr128: return SPU::LQXr128;
case SPU::LQDv16i8: return SPU::LQXv16i8;
case SPU::LQDv4i32: return SPU::LQXv4i32;
case SPU::LQDv4f32: return SPU::LQXv4f32;
case SPU::STQDr32: return SPU::STQXr32;
case SPU::STQDr128: return SPU::STQXr128;
case SPU::STQDv16i8: return SPU::STQXv16i8;
case SPU::STQDv4i32: return SPU::STQXv4i32;
case SPU::STQDv4f32: return SPU::STQXv4f32;
default: assert( false && "Unhandled D to X-form conversion");
}
// default will assert, but need to return something to keep the
// compiler happy.
return dFormOpcode;
}
// TODO this is already copied from PPC. Could this convenience function
// be moved to the RegScavenger class?
unsigned
SPURegisterInfo::findScratchRegister(MachineBasicBlock::iterator II,
RegScavenger *RS,
const TargetRegisterClass *RC,
int SPAdj) const
{
assert(RS && "Register scavenging must be on");
unsigned Reg = RS->FindUnusedReg(RC);
if (Reg == 0)
Reg = RS->scavengeRegister(RC, II, SPAdj);
assert( Reg && "Register scavenger failed");
return Reg;
}
#include "SPUGenRegisterInfo.inc"