1 //===-- PPCRegisterInfo.cpp - PowerPC Register Information ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the PowerPC implementation of the TargetRegisterInfo
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "reginfo"
16 #include "PPCRegisterInfo.h"
18 #include "PPCFrameLowering.h"
19 #include "PPCInstrBuilder.h"
20 #include "PPCMachineFunctionInfo.h"
21 #include "PPCSubtarget.h"
22 #include "llvm/ADT/BitVector.h"
23 #include "llvm/ADT/STLExtras.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/CodeGen/MachineRegisterInfo.h"
29 #include "llvm/CodeGen/RegisterScavenging.h"
30 #include "llvm/IR/CallingConv.h"
31 #include "llvm/IR/Constants.h"
32 #include "llvm/IR/Function.h"
33 #include "llvm/IR/Type.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/ErrorHandling.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/raw_ostream.h"
39 #include "llvm/Target/TargetFrameLowering.h"
40 #include "llvm/Target/TargetInstrInfo.h"
41 #include "llvm/Target/TargetMachine.h"
42 #include "llvm/Target/TargetOptions.h"
45 #define GET_REGINFO_TARGET_DESC
46 #include "PPCGenRegisterInfo.inc"
51 EnableBasePointer("ppc-use-base-pointer", cl::Hidden, cl::init(true),
52 cl::desc("Enable use of a base pointer for complex stack frames"));
55 AlwaysBasePointer("ppc-always-use-base-pointer", cl::Hidden, cl::init(false),
56 cl::desc("Force the use of a base pointer in every function"));
58 PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST)
59 : PPCGenRegisterInfo(ST.isPPC64() ? PPC::LR8 : PPC::LR,
61 ST.isPPC64() ? 0 : 1),
63 ImmToIdxMap[PPC::LD] = PPC::LDX; ImmToIdxMap[PPC::STD] = PPC::STDX;
64 ImmToIdxMap[PPC::LBZ] = PPC::LBZX; ImmToIdxMap[PPC::STB] = PPC::STBX;
65 ImmToIdxMap[PPC::LHZ] = PPC::LHZX; ImmToIdxMap[PPC::LHA] = PPC::LHAX;
66 ImmToIdxMap[PPC::LWZ] = PPC::LWZX; ImmToIdxMap[PPC::LWA] = PPC::LWAX;
67 ImmToIdxMap[PPC::LFS] = PPC::LFSX; ImmToIdxMap[PPC::LFD] = PPC::LFDX;
68 ImmToIdxMap[PPC::STH] = PPC::STHX; ImmToIdxMap[PPC::STW] = PPC::STWX;
69 ImmToIdxMap[PPC::STFS] = PPC::STFSX; ImmToIdxMap[PPC::STFD] = PPC::STFDX;
70 ImmToIdxMap[PPC::ADDI] = PPC::ADD4;
71 ImmToIdxMap[PPC::LWA_32] = PPC::LWAX_32;
74 ImmToIdxMap[PPC::LHA8] = PPC::LHAX8; ImmToIdxMap[PPC::LBZ8] = PPC::LBZX8;
75 ImmToIdxMap[PPC::LHZ8] = PPC::LHZX8; ImmToIdxMap[PPC::LWZ8] = PPC::LWZX8;
76 ImmToIdxMap[PPC::STB8] = PPC::STBX8; ImmToIdxMap[PPC::STH8] = PPC::STHX8;
77 ImmToIdxMap[PPC::STW8] = PPC::STWX8; ImmToIdxMap[PPC::STDU] = PPC::STDUX;
78 ImmToIdxMap[PPC::ADDI8] = PPC::ADD8;
81 /// getPointerRegClass - Return the register class to use to hold pointers.
82 /// This is used for addressing modes.
83 const TargetRegisterClass *
84 PPCRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
86 // Note that PPCInstrInfo::FoldImmediate also directly uses this Kind value
87 // when it checks for ZERO folding.
89 if (Subtarget.isPPC64())
90 return &PPC::G8RC_NOX0RegClass;
91 return &PPC::GPRC_NOR0RegClass;
94 if (Subtarget.isPPC64())
95 return &PPC::G8RCRegClass;
96 return &PPC::GPRCRegClass;
100 PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
101 if (Subtarget.isDarwinABI())
102 return Subtarget.isPPC64() ? (Subtarget.hasAltivec() ?
103 CSR_Darwin64_Altivec_SaveList :
104 CSR_Darwin64_SaveList) :
105 (Subtarget.hasAltivec() ?
106 CSR_Darwin32_Altivec_SaveList :
107 CSR_Darwin32_SaveList);
109 return Subtarget.isPPC64() ? (Subtarget.hasAltivec() ?
110 CSR_SVR464_Altivec_SaveList :
111 CSR_SVR464_SaveList) :
112 (Subtarget.hasAltivec() ?
113 CSR_SVR432_Altivec_SaveList :
114 CSR_SVR432_SaveList);
118 PPCRegisterInfo::getCallPreservedMask(CallingConv::ID CC) const {
119 if (Subtarget.isDarwinABI())
120 return Subtarget.isPPC64() ? (Subtarget.hasAltivec() ?
121 CSR_Darwin64_Altivec_RegMask :
122 CSR_Darwin64_RegMask) :
123 (Subtarget.hasAltivec() ?
124 CSR_Darwin32_Altivec_RegMask :
125 CSR_Darwin32_RegMask);
127 return Subtarget.isPPC64() ? (Subtarget.hasAltivec() ?
128 CSR_SVR464_Altivec_RegMask :
129 CSR_SVR464_RegMask) :
130 (Subtarget.hasAltivec() ?
131 CSR_SVR432_Altivec_RegMask :
136 PPCRegisterInfo::getNoPreservedMask() const {
137 return CSR_NoRegs_RegMask;
140 BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
141 BitVector Reserved(getNumRegs());
142 const PPCFrameLowering *PPCFI =
143 static_cast<const PPCFrameLowering*>(MF.getTarget().getFrameLowering());
145 // The ZERO register is not really a register, but the representation of r0
146 // when used in instructions that treat r0 as the constant 0.
147 Reserved.set(PPC::ZERO);
148 Reserved.set(PPC::ZERO8);
150 // The FP register is also not really a register, but is the representation
151 // of the frame pointer register used by ISD::FRAMEADDR.
152 Reserved.set(PPC::FP);
153 Reserved.set(PPC::FP8);
155 // The BP register is also not really a register, but is the representation
156 // of the base pointer register used by setjmp.
157 Reserved.set(PPC::BP);
158 Reserved.set(PPC::BP8);
160 // The counter registers must be reserved so that counter-based loops can
161 // be correctly formed (and the mtctr instructions are not DCE'd).
162 Reserved.set(PPC::CTR);
163 Reserved.set(PPC::CTR8);
165 Reserved.set(PPC::R1);
166 Reserved.set(PPC::LR);
167 Reserved.set(PPC::LR8);
168 Reserved.set(PPC::RM);
170 if (!Subtarget.isDarwinABI() || !Subtarget.hasAltivec())
171 Reserved.set(PPC::VRSAVE);
173 // The SVR4 ABI reserves r2 and r13
174 if (Subtarget.isSVR4ABI()) {
175 Reserved.set(PPC::R2); // System-reserved register
176 Reserved.set(PPC::R13); // Small Data Area pointer register
179 // On PPC64, r13 is the thread pointer. Never allocate this register.
180 if (Subtarget.isPPC64()) {
181 Reserved.set(PPC::R13);
183 Reserved.set(PPC::X1);
184 Reserved.set(PPC::X13);
186 if (PPCFI->needsFP(MF))
187 Reserved.set(PPC::X31);
189 if (hasBasePointer(MF))
190 Reserved.set(PPC::X30);
192 // The 64-bit SVR4 ABI reserves r2 for the TOC pointer.
193 if (Subtarget.isSVR4ABI()) {
194 Reserved.set(PPC::X2);
198 if (PPCFI->needsFP(MF))
199 Reserved.set(PPC::R31);
201 if (hasBasePointer(MF))
202 Reserved.set(PPC::R30);
204 // Reserve Altivec registers when Altivec is unavailable.
205 if (!Subtarget.hasAltivec())
206 for (TargetRegisterClass::iterator I = PPC::VRRCRegClass.begin(),
207 IE = PPC::VRRCRegClass.end(); I != IE; ++I)
214 PPCRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
215 MachineFunction &MF) const {
216 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
217 const unsigned DefaultSafety = 1;
219 switch (RC->getID()) {
222 case PPC::G8RC_NOX0RegClassID:
223 case PPC::GPRC_NOR0RegClassID:
224 case PPC::G8RCRegClassID:
225 case PPC::GPRCRegClassID: {
226 unsigned FP = TFI->hasFP(MF) ? 1 : 0;
227 return 32 - FP - DefaultSafety;
229 case PPC::F8RCRegClassID:
230 case PPC::F4RCRegClassID:
231 case PPC::VRRCRegClassID:
232 case PPC::VSLRCRegClassID:
233 case PPC::VSHRCRegClassID:
234 return 32 - DefaultSafety;
235 case PPC::VSRCRegClassID:
236 return 64 - DefaultSafety;
237 case PPC::CRRCRegClassID:
238 return 8 - DefaultSafety;
242 //===----------------------------------------------------------------------===//
243 // Stack Frame Processing methods
244 //===----------------------------------------------------------------------===//
246 /// lowerDynamicAlloc - Generate the code for allocating an object in the
247 /// current frame. The sequence of code with be in the general form
249 /// addi R0, SP, \#frameSize ; get the address of the previous frame
250 /// stwxu R0, SP, Rnegsize ; add and update the SP with the negated size
251 /// addi Rnew, SP, \#maxCalFrameSize ; get the top of the allocation
253 void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II) const {
254 // Get the instruction.
255 MachineInstr &MI = *II;
256 // Get the instruction's basic block.
257 MachineBasicBlock &MBB = *MI.getParent();
258 // Get the basic block's function.
259 MachineFunction &MF = *MBB.getParent();
260 // Get the frame info.
261 MachineFrameInfo *MFI = MF.getFrameInfo();
262 // Get the instruction info.
263 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
264 // Determine whether 64-bit pointers are used.
265 bool LP64 = Subtarget.isPPC64();
266 DebugLoc dl = MI.getDebugLoc();
268 // Get the maximum call stack size.
269 unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
270 // Get the total frame size.
271 unsigned FrameSize = MFI->getStackSize();
273 // Get stack alignments.
274 unsigned TargetAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
275 unsigned MaxAlign = MFI->getMaxAlignment();
276 assert((maxCallFrameSize & (MaxAlign-1)) == 0 &&
277 "Maximum call-frame size not sufficiently aligned");
279 // Determine the previous frame's address. If FrameSize can't be
280 // represented as 16 bits or we need special alignment, then we load the
281 // previous frame's address from 0(SP). Why not do an addis of the hi?
282 // Because R0 is our only safe tmp register and addi/addis treat R0 as zero.
283 // Constructing the constant and adding would take 3 instructions.
284 // Fortunately, a frame greater than 32K is rare.
285 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
286 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
287 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
289 if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
290 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg)
294 BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
298 BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg)
303 bool KillNegSizeReg = MI.getOperand(1).isKill();
304 unsigned NegSizeReg = MI.getOperand(1).getReg();
306 // Grow the stack and update the stack pointer link, then determine the
307 // address of new allocated space.
309 if (MaxAlign > TargetAlign) {
310 unsigned UnalNegSizeReg = NegSizeReg;
311 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
313 // Unfortunately, there is no andi, only andi., and we can't insert that
314 // here because we might clobber cr0 while it is live.
315 BuildMI(MBB, II, dl, TII.get(PPC::LI8), NegSizeReg)
316 .addImm(~(MaxAlign-1));
318 unsigned NegSizeReg1 = NegSizeReg;
319 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
320 BuildMI(MBB, II, dl, TII.get(PPC::AND8), NegSizeReg)
321 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
322 .addReg(NegSizeReg1, RegState::Kill);
323 KillNegSizeReg = true;
326 BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
327 .addReg(Reg, RegState::Kill)
329 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
330 BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
332 .addImm(maxCallFrameSize);
334 if (MaxAlign > TargetAlign) {
335 unsigned UnalNegSizeReg = NegSizeReg;
336 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
338 // Unfortunately, there is no andi, only andi., and we can't insert that
339 // here because we might clobber cr0 while it is live.
340 BuildMI(MBB, II, dl, TII.get(PPC::LI), NegSizeReg)
341 .addImm(~(MaxAlign-1));
343 unsigned NegSizeReg1 = NegSizeReg;
344 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
345 BuildMI(MBB, II, dl, TII.get(PPC::AND), NegSizeReg)
346 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
347 .addReg(NegSizeReg1, RegState::Kill);
348 KillNegSizeReg = true;
351 BuildMI(MBB, II, dl, TII.get(PPC::STWUX), PPC::R1)
352 .addReg(Reg, RegState::Kill)
354 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
355 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
357 .addImm(maxCallFrameSize);
360 // Discard the DYNALLOC instruction.
364 /// lowerCRSpilling - Generate the code for spilling a CR register. Instead of
365 /// reserving a whole register (R0), we scrounge for one here. This generates
368 /// mfcr rA ; Move the conditional register into GPR rA.
369 /// rlwinm rA, rA, SB, 0, 31 ; Shift the bits left so they are in CR0's slot.
370 /// stw rA, FI ; Store rA to the frame.
372 void PPCRegisterInfo::lowerCRSpilling(MachineBasicBlock::iterator II,
373 unsigned FrameIndex) const {
374 // Get the instruction.
375 MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset>
376 // Get the instruction's basic block.
377 MachineBasicBlock &MBB = *MI.getParent();
378 MachineFunction &MF = *MBB.getParent();
379 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
380 DebugLoc dl = MI.getDebugLoc();
382 bool LP64 = Subtarget.isPPC64();
383 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
384 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
386 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
387 unsigned SrcReg = MI.getOperand(0).getReg();
389 // We need to store the CR in the low 4-bits of the saved value. First, issue
390 // an MFOCRF to save all of the CRBits and, if needed, kill the SrcReg.
391 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
392 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
394 // If the saved register wasn't CR0, shift the bits left so that they are in
396 if (SrcReg != PPC::CR0) {
398 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
400 // rlwinm rA, rA, ShiftBits, 0, 31.
401 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
402 .addReg(Reg1, RegState::Kill)
403 .addImm(getEncodingValue(SrcReg) * 4)
408 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
409 .addReg(Reg, RegState::Kill),
412 // Discard the pseudo instruction.
416 void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II,
417 unsigned FrameIndex) const {
418 // Get the instruction.
419 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CR <offset>
420 // Get the instruction's basic block.
421 MachineBasicBlock &MBB = *MI.getParent();
422 MachineFunction &MF = *MBB.getParent();
423 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
424 DebugLoc dl = MI.getDebugLoc();
426 bool LP64 = Subtarget.isPPC64();
427 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
428 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
430 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
431 unsigned DestReg = MI.getOperand(0).getReg();
432 assert(MI.definesRegister(DestReg) &&
433 "RESTORE_CR does not define its destination");
435 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
438 // If the reloaded register isn't CR0, shift the bits right so that they are
439 // in the right CR's slot.
440 if (DestReg != PPC::CR0) {
442 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
444 unsigned ShiftBits = getEncodingValue(DestReg)*4;
445 // rlwinm r11, r11, 32-ShiftBits, 0, 31.
446 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
447 .addReg(Reg1, RegState::Kill).addImm(32-ShiftBits).addImm(0)
451 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF), DestReg)
452 .addReg(Reg, RegState::Kill);
454 // Discard the pseudo instruction.
458 static unsigned getCRFromCRBit(unsigned SrcReg) {
460 if (SrcReg == PPC::CR0LT || SrcReg == PPC::CR0GT ||
461 SrcReg == PPC::CR0EQ || SrcReg == PPC::CR0UN)
463 else if (SrcReg == PPC::CR1LT || SrcReg == PPC::CR1GT ||
464 SrcReg == PPC::CR1EQ || SrcReg == PPC::CR1UN)
466 else if (SrcReg == PPC::CR2LT || SrcReg == PPC::CR2GT ||
467 SrcReg == PPC::CR2EQ || SrcReg == PPC::CR2UN)
469 else if (SrcReg == PPC::CR3LT || SrcReg == PPC::CR3GT ||
470 SrcReg == PPC::CR3EQ || SrcReg == PPC::CR3UN)
472 else if (SrcReg == PPC::CR4LT || SrcReg == PPC::CR4GT ||
473 SrcReg == PPC::CR4EQ || SrcReg == PPC::CR4UN)
475 else if (SrcReg == PPC::CR5LT || SrcReg == PPC::CR5GT ||
476 SrcReg == PPC::CR5EQ || SrcReg == PPC::CR5UN)
478 else if (SrcReg == PPC::CR6LT || SrcReg == PPC::CR6GT ||
479 SrcReg == PPC::CR6EQ || SrcReg == PPC::CR6UN)
481 else if (SrcReg == PPC::CR7LT || SrcReg == PPC::CR7GT ||
482 SrcReg == PPC::CR7EQ || SrcReg == PPC::CR7UN)
485 assert(Reg != 0 && "Invalid CR bit register");
489 void PPCRegisterInfo::lowerCRBitSpilling(MachineBasicBlock::iterator II,
490 unsigned FrameIndex) const {
491 // Get the instruction.
492 MachineInstr &MI = *II; // ; SPILL_CRBIT <SrcReg>, <offset>
493 // Get the instruction's basic block.
494 MachineBasicBlock &MBB = *MI.getParent();
495 MachineFunction &MF = *MBB.getParent();
496 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
497 DebugLoc dl = MI.getDebugLoc();
499 bool LP64 = Subtarget.isPPC64();
500 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
501 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
503 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
504 unsigned SrcReg = MI.getOperand(0).getReg();
506 BuildMI(MBB, II, dl, TII.get(TargetOpcode::KILL),
507 getCRFromCRBit(SrcReg))
508 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
510 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
511 .addReg(getCRFromCRBit(SrcReg));
513 // If the saved register wasn't CR0LT, shift the bits left so that the bit to
514 // store is the first one. Mask all but that bit.
516 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
518 // rlwinm rA, rA, ShiftBits, 0, 0.
519 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
520 .addReg(Reg1, RegState::Kill)
521 .addImm(getEncodingValue(SrcReg))
522 .addImm(0).addImm(0);
524 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
525 .addReg(Reg, RegState::Kill),
528 // Discard the pseudo instruction.
532 void PPCRegisterInfo::lowerCRBitRestore(MachineBasicBlock::iterator II,
533 unsigned FrameIndex) const {
534 // Get the instruction.
535 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CRBIT <offset>
536 // Get the instruction's basic block.
537 MachineBasicBlock &MBB = *MI.getParent();
538 MachineFunction &MF = *MBB.getParent();
539 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
540 DebugLoc dl = MI.getDebugLoc();
542 bool LP64 = Subtarget.isPPC64();
543 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
544 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
546 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
547 unsigned DestReg = MI.getOperand(0).getReg();
548 assert(MI.definesRegister(DestReg) &&
549 "RESTORE_CRBIT does not define its destination");
551 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
554 BuildMI(MBB, II, dl, TII.get(TargetOpcode::IMPLICIT_DEF), DestReg);
556 unsigned RegO = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
557 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), RegO)
558 .addReg(getCRFromCRBit(DestReg));
560 unsigned ShiftBits = getEncodingValue(DestReg);
561 // rlwimi r11, r10, 32-ShiftBits, ..., ...
562 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWIMI8 : PPC::RLWIMI), RegO)
563 .addReg(RegO, RegState::Kill).addReg(Reg, RegState::Kill)
564 .addImm(ShiftBits ? 32-ShiftBits : 0)
565 .addImm(ShiftBits).addImm(ShiftBits);
567 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF),
568 getCRFromCRBit(DestReg))
569 .addReg(RegO, RegState::Kill)
570 // Make sure we have a use dependency all the way through this
571 // sequence of instructions. We can't have the other bits in the CR
572 // modified in between the mfocrf and the mtocrf.
573 .addReg(getCRFromCRBit(DestReg), RegState::Implicit);
575 // Discard the pseudo instruction.
579 void PPCRegisterInfo::lowerVRSAVESpilling(MachineBasicBlock::iterator II,
580 unsigned FrameIndex) const {
581 // Get the instruction.
582 MachineInstr &MI = *II; // ; SPILL_VRSAVE <SrcReg>, <offset>
583 // Get the instruction's basic block.
584 MachineBasicBlock &MBB = *MI.getParent();
585 MachineFunction &MF = *MBB.getParent();
586 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
587 DebugLoc dl = MI.getDebugLoc();
589 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
590 unsigned Reg = MF.getRegInfo().createVirtualRegister(GPRC);
591 unsigned SrcReg = MI.getOperand(0).getReg();
593 BuildMI(MBB, II, dl, TII.get(PPC::MFVRSAVEv), Reg)
594 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
596 addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::STW))
597 .addReg(Reg, RegState::Kill),
600 // Discard the pseudo instruction.
604 void PPCRegisterInfo::lowerVRSAVERestore(MachineBasicBlock::iterator II,
605 unsigned FrameIndex) const {
606 // Get the instruction.
607 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_VRSAVE <offset>
608 // Get the instruction's basic block.
609 MachineBasicBlock &MBB = *MI.getParent();
610 MachineFunction &MF = *MBB.getParent();
611 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
612 DebugLoc dl = MI.getDebugLoc();
614 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
615 unsigned Reg = MF.getRegInfo().createVirtualRegister(GPRC);
616 unsigned DestReg = MI.getOperand(0).getReg();
617 assert(MI.definesRegister(DestReg) &&
618 "RESTORE_VRSAVE does not define its destination");
620 addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::LWZ),
623 BuildMI(MBB, II, dl, TII.get(PPC::MTVRSAVEv), DestReg)
624 .addReg(Reg, RegState::Kill);
626 // Discard the pseudo instruction.
631 PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
632 unsigned Reg, int &FrameIdx) const {
634 // For the nonvolatile condition registers (CR2, CR3, CR4) in an SVR4
635 // ABI, return true to prevent allocating an additional frame slot.
636 // For 64-bit, the CR save area is at SP+8; the value of FrameIdx = 0
637 // is arbitrary and will be subsequently ignored. For 32-bit, we have
638 // previously created the stack slot if needed, so return its FrameIdx.
639 if (Subtarget.isSVR4ABI() && PPC::CR2 <= Reg && Reg <= PPC::CR4) {
640 if (Subtarget.isPPC64())
643 const PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
644 FrameIdx = FI->getCRSpillFrameIndex();
651 // Figure out if the offset in the instruction must be a multiple of 4.
652 // This is true for instructions like "STD".
653 static bool usesIXAddr(const MachineInstr &MI) {
654 unsigned OpC = MI.getOpcode();
667 // Return the OffsetOperandNo given the FIOperandNum (and the instruction).
668 static unsigned getOffsetONFromFION(const MachineInstr &MI,
669 unsigned FIOperandNum) {
670 // Take into account whether it's an add or mem instruction
671 unsigned OffsetOperandNo = (FIOperandNum == 2) ? 1 : 2;
672 if (MI.isInlineAsm())
673 OffsetOperandNo = FIOperandNum-1;
675 return OffsetOperandNo;
679 PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
680 int SPAdj, unsigned FIOperandNum,
681 RegScavenger *RS) const {
682 assert(SPAdj == 0 && "Unexpected");
684 // Get the instruction.
685 MachineInstr &MI = *II;
686 // Get the instruction's basic block.
687 MachineBasicBlock &MBB = *MI.getParent();
688 // Get the basic block's function.
689 MachineFunction &MF = *MBB.getParent();
690 // Get the instruction info.
691 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
692 // Get the frame info.
693 MachineFrameInfo *MFI = MF.getFrameInfo();
694 DebugLoc dl = MI.getDebugLoc();
696 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
698 // Get the frame index.
699 int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
701 // Get the frame pointer save index. Users of this index are primarily
702 // DYNALLOC instructions.
703 PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
704 int FPSI = FI->getFramePointerSaveIndex();
705 // Get the instruction opcode.
706 unsigned OpC = MI.getOpcode();
708 // Special case for dynamic alloca.
709 if (FPSI && FrameIndex == FPSI &&
710 (OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
711 lowerDynamicAlloc(II);
715 // Special case for pseudo-ops SPILL_CR and RESTORE_CR, etc.
716 if (OpC == PPC::SPILL_CR) {
717 lowerCRSpilling(II, FrameIndex);
719 } else if (OpC == PPC::RESTORE_CR) {
720 lowerCRRestore(II, FrameIndex);
722 } else if (OpC == PPC::SPILL_CRBIT) {
723 lowerCRBitSpilling(II, FrameIndex);
725 } else if (OpC == PPC::RESTORE_CRBIT) {
726 lowerCRBitRestore(II, FrameIndex);
728 } else if (OpC == PPC::SPILL_VRSAVE) {
729 lowerVRSAVESpilling(II, FrameIndex);
731 } else if (OpC == PPC::RESTORE_VRSAVE) {
732 lowerVRSAVERestore(II, FrameIndex);
736 // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
737 MI.getOperand(FIOperandNum).ChangeToRegister(
738 FrameIndex < 0 ? getBaseRegister(MF) : getFrameRegister(MF), false);
740 // Figure out if the offset in the instruction is shifted right two bits.
741 bool isIXAddr = usesIXAddr(MI);
743 // If the instruction is not present in ImmToIdxMap, then it has no immediate
744 // form (and must be r+r).
745 bool noImmForm = !MI.isInlineAsm() && !ImmToIdxMap.count(OpC);
747 // Now add the frame object offset to the offset from r1.
748 int Offset = MFI->getObjectOffset(FrameIndex);
749 Offset += MI.getOperand(OffsetOperandNo).getImm();
751 // If we're not using a Frame Pointer that has been set to the value of the
752 // SP before having the stack size subtracted from it, then add the stack size
753 // to Offset to get the correct offset.
754 // Naked functions have stack size 0, although getStackSize may not reflect that
755 // because we didn't call all the pieces that compute it for naked functions.
756 if (!MF.getFunction()->getAttributes().
757 hasAttribute(AttributeSet::FunctionIndex, Attribute::Naked)) {
758 if (!(hasBasePointer(MF) && FrameIndex < 0))
759 Offset += MFI->getStackSize();
762 // If we can, encode the offset directly into the instruction. If this is a
763 // normal PPC "ri" instruction, any 16-bit value can be safely encoded. If
764 // this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits
765 // clear can be encoded. This is extremely uncommon, because normally you
766 // only "std" to a stack slot that is at least 4-byte aligned, but it can
767 // happen in invalid code.
768 assert(OpC != PPC::DBG_VALUE &&
769 "This should be handle in a target independent way");
770 if (!noImmForm && isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0)) {
771 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
775 // The offset doesn't fit into a single register, scavenge one to build the
778 bool is64Bit = Subtarget.isPPC64();
779 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
780 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
781 const TargetRegisterClass *RC = is64Bit ? G8RC : GPRC;
782 unsigned SRegHi = MF.getRegInfo().createVirtualRegister(RC),
783 SReg = MF.getRegInfo().createVirtualRegister(RC);
785 // Insert a set of rA with the full offset value before the ld, st, or add
786 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SRegHi)
787 .addImm(Offset >> 16);
788 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::ORI8 : PPC::ORI), SReg)
789 .addReg(SRegHi, RegState::Kill)
792 // Convert into indexed form of the instruction:
794 // sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
795 // addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
796 unsigned OperandBase;
800 else if (OpC != TargetOpcode::INLINEASM) {
801 assert(ImmToIdxMap.count(OpC) &&
802 "No indexed form of load or store available!");
803 unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
804 MI.setDesc(TII.get(NewOpcode));
807 OperandBase = OffsetOperandNo;
810 unsigned StackReg = MI.getOperand(FIOperandNum).getReg();
811 MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
812 MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false, false, true);
815 unsigned PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
816 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
818 if (!Subtarget.isPPC64())
819 return TFI->hasFP(MF) ? PPC::R31 : PPC::R1;
821 return TFI->hasFP(MF) ? PPC::X31 : PPC::X1;
824 unsigned PPCRegisterInfo::getBaseRegister(const MachineFunction &MF) const {
825 if (!hasBasePointer(MF))
826 return getFrameRegister(MF);
828 return Subtarget.isPPC64() ? PPC::X30 : PPC::R30;
831 bool PPCRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
832 if (!EnableBasePointer)
834 if (AlwaysBasePointer)
837 // If we need to realign the stack, then the stack pointer can no longer
838 // serve as an offset into the caller's stack space. As a result, we need a
840 return needsStackRealignment(MF);
843 bool PPCRegisterInfo::canRealignStack(const MachineFunction &MF) const {
844 if (MF.getFunction()->hasFnAttribute("no-realign-stack"))
850 bool PPCRegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
851 const MachineFrameInfo *MFI = MF.getFrameInfo();
852 const Function *F = MF.getFunction();
853 unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
854 bool requiresRealignment =
855 ((MFI->getMaxAlignment() > StackAlign) ||
856 F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
857 Attribute::StackAlignment));
859 return requiresRealignment && canRealignStack(MF);
862 /// Returns true if the instruction's frame index
863 /// reference would be better served by a base register other than FP
864 /// or SP. Used by LocalStackFrameAllocation to determine which frame index
865 /// references it should create new base registers for.
866 bool PPCRegisterInfo::
867 needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
868 assert(Offset < 0 && "Local offset must be negative");
870 unsigned FIOperandNum = 0;
871 while (!MI->getOperand(FIOperandNum).isFI()) {
873 assert(FIOperandNum < MI->getNumOperands() &&
874 "Instr doesn't have FrameIndex operand!");
877 unsigned OffsetOperandNo = getOffsetONFromFION(*MI, FIOperandNum);
878 Offset += MI->getOperand(OffsetOperandNo).getImm();
880 // It's the load/store FI references that cause issues, as it can be difficult
881 // to materialize the offset if it won't fit in the literal field. Estimate
882 // based on the size of the local frame and some conservative assumptions
883 // about the rest of the stack frame (note, this is pre-regalloc, so
884 // we don't know everything for certain yet) whether this offset is likely
885 // to be out of range of the immediate. Return true if so.
887 // We only generate virtual base registers for loads and stores that have
888 // an r+i form. Return false for everything else.
889 unsigned OpC = MI->getOpcode();
890 if (!ImmToIdxMap.count(OpC))
893 // Don't generate a new virtual base register just to add zero to it.
894 if ((OpC == PPC::ADDI || OpC == PPC::ADDI8) &&
895 MI->getOperand(2).getImm() == 0)
898 MachineBasicBlock &MBB = *MI->getParent();
899 MachineFunction &MF = *MBB.getParent();
901 const PPCFrameLowering *PPCFI =
902 static_cast<const PPCFrameLowering*>(MF.getTarget().getFrameLowering());
904 PPCFI->determineFrameLayout(MF, false, true);
906 // If we likely don't need a stack frame, then we probably don't need a
907 // virtual base register either.
911 // Estimate an offset from the stack pointer.
912 // The incoming offset is relating to the SP at the start of the function,
913 // but when we access the local it'll be relative to the SP after local
914 // allocation, so adjust our SP-relative offset by that allocation size.
917 // The frame pointer will point to the end of the stack, so estimate the
918 // offset as the difference between the object offset and the FP location.
919 return !isFrameOffsetLegal(MI, Offset);
922 /// Insert defining instruction(s) for BaseReg to
923 /// be a pointer to FrameIdx at the beginning of the basic block.
924 void PPCRegisterInfo::
925 materializeFrameBaseRegister(MachineBasicBlock *MBB,
926 unsigned BaseReg, int FrameIdx,
927 int64_t Offset) const {
928 unsigned ADDriOpc = Subtarget.isPPC64() ? PPC::ADDI8 : PPC::ADDI;
930 MachineBasicBlock::iterator Ins = MBB->begin();
931 DebugLoc DL; // Defaults to "unknown"
932 if (Ins != MBB->end())
933 DL = Ins->getDebugLoc();
935 const MachineFunction &MF = *MBB->getParent();
936 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
937 const MCInstrDesc &MCID = TII.get(ADDriOpc);
938 MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
939 MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
941 BuildMI(*MBB, Ins, DL, MCID, BaseReg)
942 .addFrameIndex(FrameIdx).addImm(Offset);
946 PPCRegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
947 unsigned BaseReg, int64_t Offset) const {
948 MachineInstr &MI = *I;
950 unsigned FIOperandNum = 0;
951 while (!MI.getOperand(FIOperandNum).isFI()) {
953 assert(FIOperandNum < MI.getNumOperands() &&
954 "Instr doesn't have FrameIndex operand!");
957 MI.getOperand(FIOperandNum).ChangeToRegister(BaseReg, false);
958 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
959 Offset += MI.getOperand(OffsetOperandNo).getImm();
960 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
963 bool PPCRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
964 int64_t Offset) const {
965 return MI->getOpcode() == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm
966 (isInt<16>(Offset) && (!usesIXAddr(*MI) || (Offset & 3) == 0));