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 return 32 - DefaultSafety;
233 case PPC::CRRCRegClassID:
234 return 8 - DefaultSafety;
238 //===----------------------------------------------------------------------===//
239 // Stack Frame Processing methods
240 //===----------------------------------------------------------------------===//
242 /// lowerDynamicAlloc - Generate the code for allocating an object in the
243 /// current frame. The sequence of code with be in the general form
245 /// addi R0, SP, \#frameSize ; get the address of the previous frame
246 /// stwxu R0, SP, Rnegsize ; add and update the SP with the negated size
247 /// addi Rnew, SP, \#maxCalFrameSize ; get the top of the allocation
249 void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II) const {
250 // Get the instruction.
251 MachineInstr &MI = *II;
252 // Get the instruction's basic block.
253 MachineBasicBlock &MBB = *MI.getParent();
254 // Get the basic block's function.
255 MachineFunction &MF = *MBB.getParent();
256 // Get the frame info.
257 MachineFrameInfo *MFI = MF.getFrameInfo();
258 // Get the instruction info.
259 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
260 // Determine whether 64-bit pointers are used.
261 bool LP64 = Subtarget.isPPC64();
262 DebugLoc dl = MI.getDebugLoc();
264 // Get the maximum call stack size.
265 unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
266 // Get the total frame size.
267 unsigned FrameSize = MFI->getStackSize();
269 // Get stack alignments.
270 unsigned TargetAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
271 unsigned MaxAlign = MFI->getMaxAlignment();
272 assert((maxCallFrameSize & (MaxAlign-1)) == 0 &&
273 "Maximum call-frame size not sufficiently aligned");
275 // Determine the previous frame's address. If FrameSize can't be
276 // represented as 16 bits or we need special alignment, then we load the
277 // previous frame's address from 0(SP). Why not do an addis of the hi?
278 // Because R0 is our only safe tmp register and addi/addis treat R0 as zero.
279 // Constructing the constant and adding would take 3 instructions.
280 // Fortunately, a frame greater than 32K is rare.
281 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
282 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
283 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
285 if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
286 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg)
290 BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
294 BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg)
299 bool KillNegSizeReg = MI.getOperand(1).isKill();
300 unsigned NegSizeReg = MI.getOperand(1).getReg();
302 // Grow the stack and update the stack pointer link, then determine the
303 // address of new allocated space.
305 if (MaxAlign > TargetAlign) {
306 unsigned UnalNegSizeReg = NegSizeReg;
307 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
309 // Unfortunately, there is no andi, only andi., and we can't insert that
310 // here because we might clobber cr0 while it is live.
311 BuildMI(MBB, II, dl, TII.get(PPC::LI8), NegSizeReg)
312 .addImm(~(MaxAlign-1));
314 unsigned NegSizeReg1 = NegSizeReg;
315 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
316 BuildMI(MBB, II, dl, TII.get(PPC::AND8), NegSizeReg)
317 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
318 .addReg(NegSizeReg1, RegState::Kill);
319 KillNegSizeReg = true;
322 BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
323 .addReg(Reg, RegState::Kill)
325 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
326 BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
328 .addImm(maxCallFrameSize);
330 if (MaxAlign > TargetAlign) {
331 unsigned UnalNegSizeReg = NegSizeReg;
332 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
334 // Unfortunately, there is no andi, only andi., and we can't insert that
335 // here because we might clobber cr0 while it is live.
336 BuildMI(MBB, II, dl, TII.get(PPC::LI), NegSizeReg)
337 .addImm(~(MaxAlign-1));
339 unsigned NegSizeReg1 = NegSizeReg;
340 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
341 BuildMI(MBB, II, dl, TII.get(PPC::AND), NegSizeReg)
342 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
343 .addReg(NegSizeReg1, RegState::Kill);
344 KillNegSizeReg = true;
347 BuildMI(MBB, II, dl, TII.get(PPC::STWUX), PPC::R1)
348 .addReg(Reg, RegState::Kill)
350 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
351 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
353 .addImm(maxCallFrameSize);
356 // Discard the DYNALLOC instruction.
360 /// lowerCRSpilling - Generate the code for spilling a CR register. Instead of
361 /// reserving a whole register (R0), we scrounge for one here. This generates
364 /// mfcr rA ; Move the conditional register into GPR rA.
365 /// rlwinm rA, rA, SB, 0, 31 ; Shift the bits left so they are in CR0's slot.
366 /// stw rA, FI ; Store rA to the frame.
368 void PPCRegisterInfo::lowerCRSpilling(MachineBasicBlock::iterator II,
369 unsigned FrameIndex) const {
370 // Get the instruction.
371 MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset>
372 // Get the instruction's basic block.
373 MachineBasicBlock &MBB = *MI.getParent();
374 MachineFunction &MF = *MBB.getParent();
375 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
376 DebugLoc dl = MI.getDebugLoc();
378 bool LP64 = Subtarget.isPPC64();
379 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
380 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
382 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
383 unsigned SrcReg = MI.getOperand(0).getReg();
385 // We need to store the CR in the low 4-bits of the saved value. First, issue
386 // an MFOCRF to save all of the CRBits and, if needed, kill the SrcReg.
387 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
388 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
390 // If the saved register wasn't CR0, shift the bits left so that they are in
392 if (SrcReg != PPC::CR0) {
394 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
396 // rlwinm rA, rA, ShiftBits, 0, 31.
397 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
398 .addReg(Reg1, RegState::Kill)
399 .addImm(getEncodingValue(SrcReg) * 4)
404 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
405 .addReg(Reg, RegState::Kill),
408 // Discard the pseudo instruction.
412 void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II,
413 unsigned FrameIndex) const {
414 // Get the instruction.
415 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CR <offset>
416 // Get the instruction's basic block.
417 MachineBasicBlock &MBB = *MI.getParent();
418 MachineFunction &MF = *MBB.getParent();
419 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
420 DebugLoc dl = MI.getDebugLoc();
422 bool LP64 = Subtarget.isPPC64();
423 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
424 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
426 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
427 unsigned DestReg = MI.getOperand(0).getReg();
428 assert(MI.definesRegister(DestReg) &&
429 "RESTORE_CR does not define its destination");
431 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
434 // If the reloaded register isn't CR0, shift the bits right so that they are
435 // in the right CR's slot.
436 if (DestReg != PPC::CR0) {
438 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
440 unsigned ShiftBits = getEncodingValue(DestReg)*4;
441 // rlwinm r11, r11, 32-ShiftBits, 0, 31.
442 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
443 .addReg(Reg1, RegState::Kill).addImm(32-ShiftBits).addImm(0)
447 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF), DestReg)
448 .addReg(Reg, RegState::Kill);
450 // Discard the pseudo instruction.
454 static unsigned getCRFromCRBit(unsigned SrcReg) {
456 if (SrcReg == PPC::CR0LT || SrcReg == PPC::CR0GT ||
457 SrcReg == PPC::CR0EQ || SrcReg == PPC::CR0UN)
459 else if (SrcReg == PPC::CR1LT || SrcReg == PPC::CR1GT ||
460 SrcReg == PPC::CR1EQ || SrcReg == PPC::CR1UN)
462 else if (SrcReg == PPC::CR2LT || SrcReg == PPC::CR2GT ||
463 SrcReg == PPC::CR2EQ || SrcReg == PPC::CR2UN)
465 else if (SrcReg == PPC::CR3LT || SrcReg == PPC::CR3GT ||
466 SrcReg == PPC::CR3EQ || SrcReg == PPC::CR3UN)
468 else if (SrcReg == PPC::CR4LT || SrcReg == PPC::CR4GT ||
469 SrcReg == PPC::CR4EQ || SrcReg == PPC::CR4UN)
471 else if (SrcReg == PPC::CR5LT || SrcReg == PPC::CR5GT ||
472 SrcReg == PPC::CR5EQ || SrcReg == PPC::CR5UN)
474 else if (SrcReg == PPC::CR6LT || SrcReg == PPC::CR6GT ||
475 SrcReg == PPC::CR6EQ || SrcReg == PPC::CR6UN)
477 else if (SrcReg == PPC::CR7LT || SrcReg == PPC::CR7GT ||
478 SrcReg == PPC::CR7EQ || SrcReg == PPC::CR7UN)
481 assert(Reg != 0 && "Invalid CR bit register");
485 void PPCRegisterInfo::lowerCRBitSpilling(MachineBasicBlock::iterator II,
486 unsigned FrameIndex) const {
487 // Get the instruction.
488 MachineInstr &MI = *II; // ; SPILL_CRBIT <SrcReg>, <offset>
489 // Get the instruction's basic block.
490 MachineBasicBlock &MBB = *MI.getParent();
491 MachineFunction &MF = *MBB.getParent();
492 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
493 DebugLoc dl = MI.getDebugLoc();
495 bool LP64 = Subtarget.isPPC64();
496 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
497 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
499 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
500 unsigned SrcReg = MI.getOperand(0).getReg();
502 BuildMI(MBB, II, dl, TII.get(TargetOpcode::KILL),
503 getCRFromCRBit(SrcReg))
504 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
506 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
507 .addReg(getCRFromCRBit(SrcReg));
509 // If the saved register wasn't CR0LT, shift the bits left so that the bit to
510 // store is the first one. Mask all but that bit.
512 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
514 // rlwinm rA, rA, ShiftBits, 0, 0.
515 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
516 .addReg(Reg1, RegState::Kill)
517 .addImm(getEncodingValue(SrcReg))
518 .addImm(0).addImm(0);
520 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
521 .addReg(Reg, RegState::Kill),
524 // Discard the pseudo instruction.
528 void PPCRegisterInfo::lowerCRBitRestore(MachineBasicBlock::iterator II,
529 unsigned FrameIndex) const {
530 // Get the instruction.
531 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CRBIT <offset>
532 // Get the instruction's basic block.
533 MachineBasicBlock &MBB = *MI.getParent();
534 MachineFunction &MF = *MBB.getParent();
535 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
536 DebugLoc dl = MI.getDebugLoc();
538 bool LP64 = Subtarget.isPPC64();
539 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
540 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
542 unsigned Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
543 unsigned DestReg = MI.getOperand(0).getReg();
544 assert(MI.definesRegister(DestReg) &&
545 "RESTORE_CRBIT does not define its destination");
547 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
550 BuildMI(MBB, II, dl, TII.get(TargetOpcode::IMPLICIT_DEF), DestReg);
552 unsigned RegO = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
553 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), RegO)
554 .addReg(getCRFromCRBit(DestReg));
556 unsigned ShiftBits = getEncodingValue(DestReg);
557 // rlwimi r11, r10, 32-ShiftBits, ..., ...
558 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWIMI8 : PPC::RLWIMI), RegO)
559 .addReg(RegO, RegState::Kill).addReg(Reg, RegState::Kill)
560 .addImm(ShiftBits ? 32-ShiftBits : 0)
561 .addImm(ShiftBits).addImm(ShiftBits);
563 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF),
564 getCRFromCRBit(DestReg))
565 .addReg(RegO, RegState::Kill)
566 // Make sure we have a use dependency all the way through this
567 // sequence of instructions. We can't have the other bits in the CR
568 // modified in between the mfocrf and the mtocrf.
569 .addReg(getCRFromCRBit(DestReg), RegState::Implicit);
571 // Discard the pseudo instruction.
575 void PPCRegisterInfo::lowerVRSAVESpilling(MachineBasicBlock::iterator II,
576 unsigned FrameIndex) const {
577 // Get the instruction.
578 MachineInstr &MI = *II; // ; SPILL_VRSAVE <SrcReg>, <offset>
579 // Get the instruction's basic block.
580 MachineBasicBlock &MBB = *MI.getParent();
581 MachineFunction &MF = *MBB.getParent();
582 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
583 DebugLoc dl = MI.getDebugLoc();
585 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
586 unsigned Reg = MF.getRegInfo().createVirtualRegister(GPRC);
587 unsigned SrcReg = MI.getOperand(0).getReg();
589 BuildMI(MBB, II, dl, TII.get(PPC::MFVRSAVEv), Reg)
590 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
592 addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::STW))
593 .addReg(Reg, RegState::Kill),
596 // Discard the pseudo instruction.
600 void PPCRegisterInfo::lowerVRSAVERestore(MachineBasicBlock::iterator II,
601 unsigned FrameIndex) const {
602 // Get the instruction.
603 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_VRSAVE <offset>
604 // Get the instruction's basic block.
605 MachineBasicBlock &MBB = *MI.getParent();
606 MachineFunction &MF = *MBB.getParent();
607 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
608 DebugLoc dl = MI.getDebugLoc();
610 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
611 unsigned Reg = MF.getRegInfo().createVirtualRegister(GPRC);
612 unsigned DestReg = MI.getOperand(0).getReg();
613 assert(MI.definesRegister(DestReg) &&
614 "RESTORE_VRSAVE does not define its destination");
616 addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::LWZ),
619 BuildMI(MBB, II, dl, TII.get(PPC::MTVRSAVEv), DestReg)
620 .addReg(Reg, RegState::Kill);
622 // Discard the pseudo instruction.
627 PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
628 unsigned Reg, int &FrameIdx) const {
630 // For the nonvolatile condition registers (CR2, CR3, CR4) in an SVR4
631 // ABI, return true to prevent allocating an additional frame slot.
632 // For 64-bit, the CR save area is at SP+8; the value of FrameIdx = 0
633 // is arbitrary and will be subsequently ignored. For 32-bit, we have
634 // previously created the stack slot if needed, so return its FrameIdx.
635 if (Subtarget.isSVR4ABI() && PPC::CR2 <= Reg && Reg <= PPC::CR4) {
636 if (Subtarget.isPPC64())
639 const PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
640 FrameIdx = FI->getCRSpillFrameIndex();
647 // Figure out if the offset in the instruction must be a multiple of 4.
648 // This is true for instructions like "STD".
649 static bool usesIXAddr(const MachineInstr &MI) {
650 unsigned OpC = MI.getOpcode();
663 // Return the OffsetOperandNo given the FIOperandNum (and the instruction).
664 static unsigned getOffsetONFromFION(const MachineInstr &MI,
665 unsigned FIOperandNum) {
666 // Take into account whether it's an add or mem instruction
667 unsigned OffsetOperandNo = (FIOperandNum == 2) ? 1 : 2;
668 if (MI.isInlineAsm())
669 OffsetOperandNo = FIOperandNum-1;
671 return OffsetOperandNo;
675 PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
676 int SPAdj, unsigned FIOperandNum,
677 RegScavenger *RS) const {
678 assert(SPAdj == 0 && "Unexpected");
680 // Get the instruction.
681 MachineInstr &MI = *II;
682 // Get the instruction's basic block.
683 MachineBasicBlock &MBB = *MI.getParent();
684 // Get the basic block's function.
685 MachineFunction &MF = *MBB.getParent();
686 // Get the instruction info.
687 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
688 // Get the frame info.
689 MachineFrameInfo *MFI = MF.getFrameInfo();
690 DebugLoc dl = MI.getDebugLoc();
692 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
694 // Get the frame index.
695 int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
697 // Get the frame pointer save index. Users of this index are primarily
698 // DYNALLOC instructions.
699 PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
700 int FPSI = FI->getFramePointerSaveIndex();
701 // Get the instruction opcode.
702 unsigned OpC = MI.getOpcode();
704 // Special case for dynamic alloca.
705 if (FPSI && FrameIndex == FPSI &&
706 (OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
707 lowerDynamicAlloc(II);
711 // Special case for pseudo-ops SPILL_CR and RESTORE_CR, etc.
712 if (OpC == PPC::SPILL_CR) {
713 lowerCRSpilling(II, FrameIndex);
715 } else if (OpC == PPC::RESTORE_CR) {
716 lowerCRRestore(II, FrameIndex);
718 } else if (OpC == PPC::SPILL_CRBIT) {
719 lowerCRBitSpilling(II, FrameIndex);
721 } else if (OpC == PPC::RESTORE_CRBIT) {
722 lowerCRBitRestore(II, FrameIndex);
724 } else if (OpC == PPC::SPILL_VRSAVE) {
725 lowerVRSAVESpilling(II, FrameIndex);
727 } else if (OpC == PPC::RESTORE_VRSAVE) {
728 lowerVRSAVERestore(II, FrameIndex);
732 // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
733 MI.getOperand(FIOperandNum).ChangeToRegister(
734 FrameIndex < 0 ? getBaseRegister(MF) : getFrameRegister(MF), false);
736 // Figure out if the offset in the instruction is shifted right two bits.
737 bool isIXAddr = usesIXAddr(MI);
739 // If the instruction is not present in ImmToIdxMap, then it has no immediate
740 // form (and must be r+r).
741 bool noImmForm = !MI.isInlineAsm() && !ImmToIdxMap.count(OpC);
743 // Now add the frame object offset to the offset from r1.
744 int Offset = MFI->getObjectOffset(FrameIndex);
745 Offset += MI.getOperand(OffsetOperandNo).getImm();
747 // If we're not using a Frame Pointer that has been set to the value of the
748 // SP before having the stack size subtracted from it, then add the stack size
749 // to Offset to get the correct offset.
750 // Naked functions have stack size 0, although getStackSize may not reflect that
751 // because we didn't call all the pieces that compute it for naked functions.
752 if (!MF.getFunction()->getAttributes().
753 hasAttribute(AttributeSet::FunctionIndex, Attribute::Naked)) {
754 if (!(hasBasePointer(MF) && FrameIndex < 0))
755 Offset += MFI->getStackSize();
758 // If we can, encode the offset directly into the instruction. If this is a
759 // normal PPC "ri" instruction, any 16-bit value can be safely encoded. If
760 // this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits
761 // clear can be encoded. This is extremely uncommon, because normally you
762 // only "std" to a stack slot that is at least 4-byte aligned, but it can
763 // happen in invalid code.
764 assert(OpC != PPC::DBG_VALUE &&
765 "This should be handle in a target independent way");
766 if (!noImmForm && isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0)) {
767 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
771 // The offset doesn't fit into a single register, scavenge one to build the
774 bool is64Bit = Subtarget.isPPC64();
775 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
776 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
777 const TargetRegisterClass *RC = is64Bit ? G8RC : GPRC;
778 unsigned SRegHi = MF.getRegInfo().createVirtualRegister(RC),
779 SReg = MF.getRegInfo().createVirtualRegister(RC);
781 // Insert a set of rA with the full offset value before the ld, st, or add
782 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SRegHi)
783 .addImm(Offset >> 16);
784 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::ORI8 : PPC::ORI), SReg)
785 .addReg(SRegHi, RegState::Kill)
788 // Convert into indexed form of the instruction:
790 // sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
791 // addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
792 unsigned OperandBase;
796 else if (OpC != TargetOpcode::INLINEASM) {
797 assert(ImmToIdxMap.count(OpC) &&
798 "No indexed form of load or store available!");
799 unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
800 MI.setDesc(TII.get(NewOpcode));
803 OperandBase = OffsetOperandNo;
806 unsigned StackReg = MI.getOperand(FIOperandNum).getReg();
807 MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
808 MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false, false, true);
811 unsigned PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
812 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
814 if (!Subtarget.isPPC64())
815 return TFI->hasFP(MF) ? PPC::R31 : PPC::R1;
817 return TFI->hasFP(MF) ? PPC::X31 : PPC::X1;
820 unsigned PPCRegisterInfo::getBaseRegister(const MachineFunction &MF) const {
821 if (!hasBasePointer(MF))
822 return getFrameRegister(MF);
824 return Subtarget.isPPC64() ? PPC::X30 : PPC::R30;
827 bool PPCRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
828 if (!EnableBasePointer)
830 if (AlwaysBasePointer)
833 // If we need to realign the stack, then the stack pointer can no longer
834 // serve as an offset into the caller's stack space. As a result, we need a
836 return needsStackRealignment(MF);
839 bool PPCRegisterInfo::canRealignStack(const MachineFunction &MF) const {
840 if (MF.getFunction()->hasFnAttribute("no-realign-stack"))
846 bool PPCRegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
847 const MachineFrameInfo *MFI = MF.getFrameInfo();
848 const Function *F = MF.getFunction();
849 unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
850 bool requiresRealignment =
851 ((MFI->getMaxAlignment() > StackAlign) ||
852 F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
853 Attribute::StackAlignment));
855 return requiresRealignment && canRealignStack(MF);
858 /// Returns true if the instruction's frame index
859 /// reference would be better served by a base register other than FP
860 /// or SP. Used by LocalStackFrameAllocation to determine which frame index
861 /// references it should create new base registers for.
862 bool PPCRegisterInfo::
863 needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
864 assert(Offset < 0 && "Local offset must be negative");
866 unsigned FIOperandNum = 0;
867 while (!MI->getOperand(FIOperandNum).isFI()) {
869 assert(FIOperandNum < MI->getNumOperands() &&
870 "Instr doesn't have FrameIndex operand!");
873 unsigned OffsetOperandNo = getOffsetONFromFION(*MI, FIOperandNum);
874 Offset += MI->getOperand(OffsetOperandNo).getImm();
876 // It's the load/store FI references that cause issues, as it can be difficult
877 // to materialize the offset if it won't fit in the literal field. Estimate
878 // based on the size of the local frame and some conservative assumptions
879 // about the rest of the stack frame (note, this is pre-regalloc, so
880 // we don't know everything for certain yet) whether this offset is likely
881 // to be out of range of the immediate. Return true if so.
883 // We only generate virtual base registers for loads and stores that have
884 // an r+i form. Return false for everything else.
885 unsigned OpC = MI->getOpcode();
886 if (!ImmToIdxMap.count(OpC))
889 // Don't generate a new virtual base register just to add zero to it.
890 if ((OpC == PPC::ADDI || OpC == PPC::ADDI8) &&
891 MI->getOperand(2).getImm() == 0)
894 MachineBasicBlock &MBB = *MI->getParent();
895 MachineFunction &MF = *MBB.getParent();
897 const PPCFrameLowering *PPCFI =
898 static_cast<const PPCFrameLowering*>(MF.getTarget().getFrameLowering());
900 PPCFI->determineFrameLayout(MF, false, true);
902 // If we likely don't need a stack frame, then we probably don't need a
903 // virtual base register either.
907 // Estimate an offset from the stack pointer.
908 // The incoming offset is relating to the SP at the start of the function,
909 // but when we access the local it'll be relative to the SP after local
910 // allocation, so adjust our SP-relative offset by that allocation size.
913 // The frame pointer will point to the end of the stack, so estimate the
914 // offset as the difference between the object offset and the FP location.
915 return !isFrameOffsetLegal(MI, Offset);
918 /// Insert defining instruction(s) for BaseReg to
919 /// be a pointer to FrameIdx at the beginning of the basic block.
920 void PPCRegisterInfo::
921 materializeFrameBaseRegister(MachineBasicBlock *MBB,
922 unsigned BaseReg, int FrameIdx,
923 int64_t Offset) const {
924 unsigned ADDriOpc = Subtarget.isPPC64() ? PPC::ADDI8 : PPC::ADDI;
926 MachineBasicBlock::iterator Ins = MBB->begin();
927 DebugLoc DL; // Defaults to "unknown"
928 if (Ins != MBB->end())
929 DL = Ins->getDebugLoc();
931 const MachineFunction &MF = *MBB->getParent();
932 const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
933 const MCInstrDesc &MCID = TII.get(ADDriOpc);
934 MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
935 MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
937 BuildMI(*MBB, Ins, DL, MCID, BaseReg)
938 .addFrameIndex(FrameIdx).addImm(Offset);
942 PPCRegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
943 unsigned BaseReg, int64_t Offset) const {
944 MachineInstr &MI = *I;
946 unsigned FIOperandNum = 0;
947 while (!MI.getOperand(FIOperandNum).isFI()) {
949 assert(FIOperandNum < MI.getNumOperands() &&
950 "Instr doesn't have FrameIndex operand!");
953 MI.getOperand(FIOperandNum).ChangeToRegister(BaseReg, false);
954 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
955 Offset += MI.getOperand(OffsetOperandNo).getImm();
956 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
959 bool PPCRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
960 int64_t Offset) const {
961 return MI->getOpcode() == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm
962 (isInt<16>(Offset) && (!usesIXAddr(*MI) || (Offset & 3) == 0));