xref: /llvm-project/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp (revision 61f39d186c274a4cca98c25c3570ee425a3a6c79)
1 //===- PPCRegisterInfo.cpp - PowerPC Register Information -------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the PowerPC implementation of the MRegisterInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #define DEBUG_TYPE "reginfo"
15 #include "PPC.h"
16 #include "PPCInstrBuilder.h"
17 #include "PPCMachineFunctionInfo.h"
18 #include "PPCRegisterInfo.h"
19 #include "PPCFrameInfo.h"
20 #include "PPCSubtarget.h"
21 #include "llvm/Constants.h"
22 #include "llvm/Type.h"
23 #include "llvm/CodeGen/ValueTypes.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineModuleInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineLocation.h"
29 #include "llvm/CodeGen/SelectionDAGNodes.h"
30 #include "llvm/Target/TargetFrameInfo.h"
31 #include "llvm/Target/TargetInstrInfo.h"
32 #include "llvm/Target/TargetMachine.h"
33 #include "llvm/Target/TargetOptions.h"
34 #include "llvm/Support/CommandLine.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/ADT/BitVector.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include <cstdlib>
40 using namespace llvm;
41 
42 /// getRegisterNumbering - Given the enum value for some register, e.g.
43 /// PPC::F14, return the number that it corresponds to (e.g. 14).
44 unsigned PPCRegisterInfo::getRegisterNumbering(unsigned RegEnum) {
45   using namespace PPC;
46   switch (RegEnum) {
47   case R0 :  case X0 :  case F0 :  case V0 : case CR0:  return  0;
48   case R1 :  case X1 :  case F1 :  case V1 : case CR1:  return  1;
49   case R2 :  case X2 :  case F2 :  case V2 : case CR2:  return  2;
50   case R3 :  case X3 :  case F3 :  case V3 : case CR3:  return  3;
51   case R4 :  case X4 :  case F4 :  case V4 : case CR4:  return  4;
52   case R5 :  case X5 :  case F5 :  case V5 : case CR5:  return  5;
53   case R6 :  case X6 :  case F6 :  case V6 : case CR6:  return  6;
54   case R7 :  case X7 :  case F7 :  case V7 : case CR7:  return  7;
55   case R8 :  case X8 :  case F8 :  case V8 : return  8;
56   case R9 :  case X9 :  case F9 :  case V9 : return  9;
57   case R10:  case X10:  case F10:  case V10: return 10;
58   case R11:  case X11:  case F11:  case V11: return 11;
59   case R12:  case X12:  case F12:  case V12: return 12;
60   case R13:  case X13:  case F13:  case V13: return 13;
61   case R14:  case X14:  case F14:  case V14: return 14;
62   case R15:  case X15:  case F15:  case V15: return 15;
63   case R16:  case X16:  case F16:  case V16: return 16;
64   case R17:  case X17:  case F17:  case V17: return 17;
65   case R18:  case X18:  case F18:  case V18: return 18;
66   case R19:  case X19:  case F19:  case V19: return 19;
67   case R20:  case X20:  case F20:  case V20: return 20;
68   case R21:  case X21:  case F21:  case V21: return 21;
69   case R22:  case X22:  case F22:  case V22: return 22;
70   case R23:  case X23:  case F23:  case V23: return 23;
71   case R24:  case X24:  case F24:  case V24: return 24;
72   case R25:  case X25:  case F25:  case V25: return 25;
73   case R26:  case X26:  case F26:  case V26: return 26;
74   case R27:  case X27:  case F27:  case V27: return 27;
75   case R28:  case X28:  case F28:  case V28: return 28;
76   case R29:  case X29:  case F29:  case V29: return 29;
77   case R30:  case X30:  case F30:  case V30: return 30;
78   case R31:  case X31:  case F31:  case V31: return 31;
79   default:
80     cerr << "Unhandled reg in PPCRegisterInfo::getRegisterNumbering!\n";
81     abort();
82   }
83 }
84 
85 PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
86                                  const TargetInstrInfo &tii)
87   : PPCGenRegisterInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP),
88     Subtarget(ST), TII(tii) {
89   ImmToIdxMap[PPC::LD]   = PPC::LDX;    ImmToIdxMap[PPC::STD]  = PPC::STDX;
90   ImmToIdxMap[PPC::LBZ]  = PPC::LBZX;   ImmToIdxMap[PPC::STB]  = PPC::STBX;
91   ImmToIdxMap[PPC::LHZ]  = PPC::LHZX;   ImmToIdxMap[PPC::LHA]  = PPC::LHAX;
92   ImmToIdxMap[PPC::LWZ]  = PPC::LWZX;   ImmToIdxMap[PPC::LWA]  = PPC::LWAX;
93   ImmToIdxMap[PPC::LFS]  = PPC::LFSX;   ImmToIdxMap[PPC::LFD]  = PPC::LFDX;
94   ImmToIdxMap[PPC::STH]  = PPC::STHX;   ImmToIdxMap[PPC::STW]  = PPC::STWX;
95   ImmToIdxMap[PPC::STFS] = PPC::STFSX;  ImmToIdxMap[PPC::STFD] = PPC::STFDX;
96   ImmToIdxMap[PPC::ADDI] = PPC::ADD4;
97   ImmToIdxMap[PPC::ADDI8] = PPC::ADD8;
98 }
99 
100 void
101 PPCRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
102                                      MachineBasicBlock::iterator MI,
103                                      unsigned SrcReg, int FrameIdx,
104                                      const TargetRegisterClass *RC) const {
105   if (RC == PPC::GPRCRegisterClass) {
106     if (SrcReg != PPC::LR) {
107       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STW))
108                         .addReg(SrcReg, false, false, true), FrameIdx);
109     } else {
110       // FIXME: this spills LR immediately to memory in one step.  To do this,
111       // we use R11, which we know cannot be used in the prolog/epilog.  This is
112       // a hack.
113       BuildMI(MBB, MI, TII.get(PPC::MFLR), PPC::R11);
114       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STW))
115                         .addReg(PPC::R11, false, false, true), FrameIdx);
116     }
117   } else if (RC == PPC::G8RCRegisterClass) {
118     if (SrcReg != PPC::LR8) {
119       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STD))
120                         .addReg(SrcReg, false, false, true), FrameIdx);
121     } else {
122       // FIXME: this spills LR immediately to memory in one step.  To do this,
123       // we use R11, which we know cannot be used in the prolog/epilog.  This is
124       // a hack.
125       BuildMI(MBB, MI, TII.get(PPC::MFLR8), PPC::X11);
126       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STD))
127                         .addReg(PPC::X11, false, false, true), FrameIdx);
128     }
129   } else if (RC == PPC::F8RCRegisterClass) {
130     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STFD))
131                       .addReg(SrcReg, false, false, true), FrameIdx);
132   } else if (RC == PPC::F4RCRegisterClass) {
133     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STFS))
134                       .addReg(SrcReg, false, false, true), FrameIdx);
135   } else if (RC == PPC::CRRCRegisterClass) {
136     // FIXME: We use R0 here, because it isn't available for RA.
137     // We need to store the CR in the low 4-bits of the saved value.  First,
138     // issue a MFCR to save all of the CRBits.
139     BuildMI(MBB, MI, TII.get(PPC::MFCR), PPC::R0);
140 
141     // If the saved register wasn't CR0, shift the bits left so that they are in
142     // CR0's slot.
143     if (SrcReg != PPC::CR0) {
144       unsigned ShiftBits = PPCRegisterInfo::getRegisterNumbering(SrcReg)*4;
145       // rlwinm r0, r0, ShiftBits, 0, 31.
146       BuildMI(MBB, MI, TII.get(PPC::RLWINM), PPC::R0)
147         .addReg(PPC::R0).addImm(ShiftBits).addImm(0).addImm(31);
148     }
149 
150     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::STW))
151                       .addReg(PPC::R0, false, false, true), FrameIdx);
152   } else if (RC == PPC::VRRCRegisterClass) {
153     // We don't have indexed addressing for vector loads.  Emit:
154     // R11 = ADDI FI#
155     // Dest = LVX R0, R11
156     //
157     // FIXME: We use R0 here, because it isn't available for RA.
158     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::ADDI), PPC::R0),
159                       FrameIdx, 0, 0);
160     BuildMI(MBB, MI, TII.get(PPC::STVX))
161       .addReg(SrcReg, false, false, true).addReg(PPC::R0).addReg(PPC::R0);
162   } else {
163     assert(0 && "Unknown regclass!");
164     abort();
165   }
166 }
167 
168 void
169 PPCRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
170                                       MachineBasicBlock::iterator MI,
171                                       unsigned DestReg, int FrameIdx,
172                                       const TargetRegisterClass *RC) const {
173   if (RC == PPC::GPRCRegisterClass) {
174     if (DestReg != PPC::LR) {
175       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LWZ), DestReg), FrameIdx);
176     } else {
177       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LWZ), PPC::R11),FrameIdx);
178       BuildMI(MBB, MI, TII.get(PPC::MTLR)).addReg(PPC::R11);
179     }
180   } else if (RC == PPC::G8RCRegisterClass) {
181     if (DestReg != PPC::LR8) {
182       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LD), DestReg), FrameIdx);
183     } else {
184       addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LD), PPC::R11), FrameIdx);
185       BuildMI(MBB, MI, TII.get(PPC::MTLR8)).addReg(PPC::R11);
186     }
187   } else if (RC == PPC::F8RCRegisterClass) {
188     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LFD), DestReg), FrameIdx);
189   } else if (RC == PPC::F4RCRegisterClass) {
190     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LFS), DestReg), FrameIdx);
191   } else if (RC == PPC::CRRCRegisterClass) {
192     // FIXME: We use R0 here, because it isn't available for RA.
193     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::LWZ), PPC::R0), FrameIdx);
194 
195     // If the reloaded register isn't CR0, shift the bits right so that they are
196     // in the right CR's slot.
197     if (DestReg != PPC::CR0) {
198       unsigned ShiftBits = PPCRegisterInfo::getRegisterNumbering(DestReg)*4;
199       // rlwinm r11, r11, 32-ShiftBits, 0, 31.
200       BuildMI(MBB, MI, TII.get(PPC::RLWINM), PPC::R0)
201         .addReg(PPC::R0).addImm(32-ShiftBits).addImm(0).addImm(31);
202     }
203 
204     BuildMI(MBB, MI, TII.get(PPC::MTCRF), DestReg).addReg(PPC::R0);
205   } else if (RC == PPC::VRRCRegisterClass) {
206     // We don't have indexed addressing for vector loads.  Emit:
207     // R11 = ADDI FI#
208     // Dest = LVX R0, R11
209     //
210     // FIXME: We use R0 here, because it isn't available for RA.
211     addFrameReference(BuildMI(MBB, MI, TII.get(PPC::ADDI), PPC::R0),
212                       FrameIdx, 0, 0);
213     BuildMI(MBB, MI, TII.get(PPC::LVX),DestReg).addReg(PPC::R0).addReg(PPC::R0);
214   } else {
215     assert(0 && "Unknown regclass!");
216     abort();
217   }
218 }
219 
220 void PPCRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
221                                    MachineBasicBlock::iterator MI,
222                                    unsigned DestReg, unsigned SrcReg,
223                                    const TargetRegisterClass *RC) const {
224   if (RC == PPC::GPRCRegisterClass) {
225     BuildMI(MBB, MI, TII.get(PPC::OR), DestReg).addReg(SrcReg).addReg(SrcReg);
226   } else if (RC == PPC::G8RCRegisterClass) {
227     BuildMI(MBB, MI, TII.get(PPC::OR8), DestReg).addReg(SrcReg).addReg(SrcReg);
228   } else if (RC == PPC::F4RCRegisterClass) {
229     BuildMI(MBB, MI, TII.get(PPC::FMRS), DestReg).addReg(SrcReg);
230   } else if (RC == PPC::F8RCRegisterClass) {
231     BuildMI(MBB, MI, TII.get(PPC::FMRD), DestReg).addReg(SrcReg);
232   } else if (RC == PPC::CRRCRegisterClass) {
233     BuildMI(MBB, MI, TII.get(PPC::MCRF), DestReg).addReg(SrcReg);
234   } else if (RC == PPC::VRRCRegisterClass) {
235     BuildMI(MBB, MI, TII.get(PPC::VOR), DestReg).addReg(SrcReg).addReg(SrcReg);
236   } else {
237     cerr << "Attempt to copy register that is not GPR or FPR";
238     abort();
239   }
240 }
241 
242 void PPCRegisterInfo::reMaterialize(MachineBasicBlock &MBB,
243                                     MachineBasicBlock::iterator I,
244                                     unsigned DestReg,
245                                     const MachineInstr *Orig) const {
246   MachineInstr *MI = Orig->clone();
247   MI->getOperand(0).setReg(DestReg);
248   MBB.insert(I, MI);
249 }
250 
251 const unsigned* PPCRegisterInfo::getCalleeSavedRegs() const {
252   // 32-bit Darwin calling convention.
253   static const unsigned Darwin32_CalleeSavedRegs[] = {
254               PPC::R13, PPC::R14, PPC::R15,
255     PPC::R16, PPC::R17, PPC::R18, PPC::R19,
256     PPC::R20, PPC::R21, PPC::R22, PPC::R23,
257     PPC::R24, PPC::R25, PPC::R26, PPC::R27,
258     PPC::R28, PPC::R29, PPC::R30, PPC::R31,
259 
260     PPC::F14, PPC::F15, PPC::F16, PPC::F17,
261     PPC::F18, PPC::F19, PPC::F20, PPC::F21,
262     PPC::F22, PPC::F23, PPC::F24, PPC::F25,
263     PPC::F26, PPC::F27, PPC::F28, PPC::F29,
264     PPC::F30, PPC::F31,
265 
266     PPC::CR2, PPC::CR3, PPC::CR4,
267     PPC::V20, PPC::V21, PPC::V22, PPC::V23,
268     PPC::V24, PPC::V25, PPC::V26, PPC::V27,
269     PPC::V28, PPC::V29, PPC::V30, PPC::V31,
270 
271     PPC::LR,  0
272   };
273 
274   static const unsigned ELF32_CalleeSavedRegs[] = {
275               PPC::R13, PPC::R14, PPC::R15,
276     PPC::R16, PPC::R17, PPC::R18, PPC::R19,
277     PPC::R20, PPC::R21, PPC::R22, PPC::R23,
278     PPC::R24, PPC::R25, PPC::R26, PPC::R27,
279     PPC::R28, PPC::R29, PPC::R30, PPC::R31,
280 
281               PPC::F11, PPC::F12, PPC::F13,
282     PPC::F14, PPC::F15, PPC::F16, PPC::F17,
283     PPC::F18, PPC::F19, PPC::F20, PPC::F21,
284     PPC::F22, PPC::F23, PPC::F24, PPC::F25,
285     PPC::F26, PPC::F27, PPC::F28, PPC::F29,
286     PPC::F30, PPC::F31,
287 
288     PPC::CR2, PPC::CR3, PPC::CR4,
289     PPC::V20, PPC::V21, PPC::V22, PPC::V23,
290     PPC::V24, PPC::V25, PPC::V26, PPC::V27,
291     PPC::V28, PPC::V29, PPC::V30, PPC::V31,
292 
293     PPC::LR,  0
294   };
295   // 64-bit Darwin calling convention.
296   static const unsigned Darwin64_CalleeSavedRegs[] = {
297     PPC::X14, PPC::X15,
298     PPC::X16, PPC::X17, PPC::X18, PPC::X19,
299     PPC::X20, PPC::X21, PPC::X22, PPC::X23,
300     PPC::X24, PPC::X25, PPC::X26, PPC::X27,
301     PPC::X28, PPC::X29, PPC::X30, PPC::X31,
302 
303     PPC::F14, PPC::F15, PPC::F16, PPC::F17,
304     PPC::F18, PPC::F19, PPC::F20, PPC::F21,
305     PPC::F22, PPC::F23, PPC::F24, PPC::F25,
306     PPC::F26, PPC::F27, PPC::F28, PPC::F29,
307     PPC::F30, PPC::F31,
308 
309     PPC::CR2, PPC::CR3, PPC::CR4,
310     PPC::V20, PPC::V21, PPC::V22, PPC::V23,
311     PPC::V24, PPC::V25, PPC::V26, PPC::V27,
312     PPC::V28, PPC::V29, PPC::V30, PPC::V31,
313 
314     PPC::LR8,  0
315   };
316 
317   static const unsigned ELF64_CalleeSavedRegs[] = {
318     PPC::X14, PPC::X15,
319     PPC::X16, PPC::X17, PPC::X18, PPC::X19,
320     PPC::X20, PPC::X21, PPC::X22, PPC::X23,
321     PPC::X24, PPC::X25, PPC::X26, PPC::X27,
322     PPC::X28, PPC::X29, PPC::X30, PPC::X31,
323 
324               PPC::F11, PPC::F12, PPC::F13,
325     PPC::F14, PPC::F15, PPC::F16, PPC::F17,
326     PPC::F18, PPC::F19, PPC::F20, PPC::F21,
327     PPC::F22, PPC::F23, PPC::F24, PPC::F25,
328     PPC::F26, PPC::F27, PPC::F28, PPC::F29,
329     PPC::F30, PPC::F31,
330 
331     PPC::CR2, PPC::CR3, PPC::CR4,
332     PPC::V20, PPC::V21, PPC::V22, PPC::V23,
333     PPC::V24, PPC::V25, PPC::V26, PPC::V27,
334     PPC::V28, PPC::V29, PPC::V30, PPC::V31,
335 
336     PPC::LR8,  0
337   };
338 
339   if (Subtarget.isMachoABI())
340     return Subtarget.isPPC64() ? Darwin64_CalleeSavedRegs :
341                                  Darwin32_CalleeSavedRegs;
342 
343   // ELF.
344   return Subtarget.isPPC64() ? ELF64_CalleeSavedRegs : ELF32_CalleeSavedRegs;
345 }
346 
347 const TargetRegisterClass* const*
348 PPCRegisterInfo::getCalleeSavedRegClasses() const {
349   // 32-bit Darwin calling convention.
350   static const TargetRegisterClass * const Darwin32_CalleeSavedRegClasses[] = {
351                        &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
352     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
353     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
354     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
355     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
356 
357     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
358     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
359     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
360     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
361     &PPC::F8RCRegClass,&PPC::F8RCRegClass,
362 
363     &PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
364 
365     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
366     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
367     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
368 
369     &PPC::GPRCRegClass, 0
370   };
371 
372   static const TargetRegisterClass * const ELF32_CalleeSavedRegClasses[] = {
373                        &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
374     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
375     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
376     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
377     &PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
378 
379                        &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
380     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
381     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
382     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
383     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
384     &PPC::F8RCRegClass,&PPC::F8RCRegClass,
385 
386     &PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
387 
388     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
389     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
390     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
391 
392     &PPC::GPRCRegClass, 0
393   };
394 
395   // 64-bit Darwin calling convention.
396   static const TargetRegisterClass * const Darwin64_CalleeSavedRegClasses[] = {
397     &PPC::G8RCRegClass,&PPC::G8RCRegClass,
398     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
399     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
400     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
401     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
402 
403     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
404     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
405     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
406     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
407     &PPC::F8RCRegClass,&PPC::F8RCRegClass,
408 
409     &PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
410 
411     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
412     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
413     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
414 
415     &PPC::G8RCRegClass, 0
416   };
417 
418   static const TargetRegisterClass * const ELF64_CalleeSavedRegClasses[] = {
419     &PPC::G8RCRegClass,&PPC::G8RCRegClass,
420     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
421     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
422     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
423     &PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
424 
425                        &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
426     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
427     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
428     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
429     &PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
430     &PPC::F8RCRegClass,&PPC::F8RCRegClass,
431 
432     &PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
433 
434     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
435     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
436     &PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
437 
438     &PPC::G8RCRegClass, 0
439   };
440 
441   if (Subtarget.isMachoABI())
442     return Subtarget.isPPC64() ? Darwin64_CalleeSavedRegClasses :
443                                  Darwin32_CalleeSavedRegClasses;
444 
445   // ELF.
446   return Subtarget.isPPC64() ? ELF64_CalleeSavedRegClasses :
447                                ELF32_CalleeSavedRegClasses;
448 }
449 
450 // needsFP - Return true if the specified function should have a dedicated frame
451 // pointer register.  This is true if the function has variable sized allocas or
452 // if frame pointer elimination is disabled.
453 //
454 static bool needsFP(const MachineFunction &MF) {
455   const MachineFrameInfo *MFI = MF.getFrameInfo();
456   return NoFramePointerElim || MFI->hasVarSizedObjects();
457 }
458 
459 BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
460   BitVector Reserved(getNumRegs());
461   Reserved.set(PPC::R0);
462   Reserved.set(PPC::R1);
463   Reserved.set(PPC::LR);
464   // In Linux, r2 is reserved for the OS.
465   if (!Subtarget.isDarwin())
466     Reserved.set(PPC::R2);
467   // On PPC64, r13 is the thread pointer.  Never allocate this register.
468   // Note that this is overconservative, as it also prevents allocation of
469   // R31 when the FP is not needed.
470   if (Subtarget.isPPC64()) {
471     Reserved.set(PPC::R13);
472     Reserved.set(PPC::R31);
473   }
474   if (needsFP(MF))
475     Reserved.set(PPC::R31);
476   return Reserved;
477 }
478 
479 /// foldMemoryOperand - PowerPC (like most RISC's) can only fold spills into
480 /// copy instructions, turning them into load/store instructions.
481 MachineInstr *PPCRegisterInfo::foldMemoryOperand(MachineInstr *MI,
482                                                  unsigned OpNum,
483                                                  int FrameIndex) const {
484   // Make sure this is a reg-reg copy.  Note that we can't handle MCRF, because
485   // it takes more than one instruction to store it.
486   unsigned Opc = MI->getOpcode();
487 
488   MachineInstr *NewMI = NULL;
489   if ((Opc == PPC::OR &&
490        MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) {
491     if (OpNum == 0) {  // move -> store
492       unsigned InReg = MI->getOperand(1).getReg();
493       NewMI = addFrameReference(BuildMI(TII.get(PPC::STW)).addReg(InReg),
494                                 FrameIndex);
495     } else {           // move -> load
496       unsigned OutReg = MI->getOperand(0).getReg();
497       NewMI = addFrameReference(BuildMI(TII.get(PPC::LWZ), OutReg),
498                                 FrameIndex);
499     }
500   } else if ((Opc == PPC::OR8 &&
501               MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) {
502     if (OpNum == 0) {  // move -> store
503       unsigned InReg = MI->getOperand(1).getReg();
504       NewMI = addFrameReference(BuildMI(TII.get(PPC::STD)).addReg(InReg),
505                                 FrameIndex);
506     } else {           // move -> load
507       unsigned OutReg = MI->getOperand(0).getReg();
508       NewMI = addFrameReference(BuildMI(TII.get(PPC::LD), OutReg), FrameIndex);
509     }
510   } else if (Opc == PPC::FMRD) {
511     if (OpNum == 0) {  // move -> store
512       unsigned InReg = MI->getOperand(1).getReg();
513       NewMI = addFrameReference(BuildMI(TII.get(PPC::STFD)).addReg(InReg),
514                                 FrameIndex);
515     } else {           // move -> load
516       unsigned OutReg = MI->getOperand(0).getReg();
517       NewMI = addFrameReference(BuildMI(TII.get(PPC::LFD), OutReg), FrameIndex);
518     }
519   } else if (Opc == PPC::FMRS) {
520     if (OpNum == 0) {  // move -> store
521       unsigned InReg = MI->getOperand(1).getReg();
522       NewMI = addFrameReference(BuildMI(TII.get(PPC::STFS)).addReg(InReg),
523                                 FrameIndex);
524     } else {           // move -> load
525       unsigned OutReg = MI->getOperand(0).getReg();
526       NewMI = addFrameReference(BuildMI(TII.get(PPC::LFS), OutReg), FrameIndex);
527     }
528   }
529 
530   if (NewMI)
531     NewMI->copyKillDeadInfo(MI);
532   return NewMI;
533 }
534 
535 //===----------------------------------------------------------------------===//
536 // Stack Frame Processing methods
537 //===----------------------------------------------------------------------===//
538 
539 // hasFP - Return true if the specified function actually has a dedicated frame
540 // pointer register.  This is true if the function needs a frame pointer and has
541 // a non-zero stack size.
542 bool PPCRegisterInfo::hasFP(const MachineFunction &MF) const {
543   const MachineFrameInfo *MFI = MF.getFrameInfo();
544   return MFI->getStackSize() && needsFP(MF);
545 }
546 
547 /// usesLR - Returns if the link registers (LR) has been used in the function.
548 ///
549 bool PPCRegisterInfo::usesLR(MachineFunction &MF) const {
550   PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
551   return FI->usesLR();
552 }
553 
554 void PPCRegisterInfo::
555 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
556                               MachineBasicBlock::iterator I) const {
557   // Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
558   MBB.erase(I);
559 }
560 
561 /// LowerDynamicAlloc - Generate the code for allocating an object in the
562 /// current frame.  The sequence of code with be in the general form
563 ///
564 ///   addi   R0, SP, #frameSize ; get the address of the previous frame
565 ///   stwxu  R0, SP, Rnegsize   ; add and update the SP with the negated size
566 ///   addi   Rnew, SP, #maxCalFrameSize ; get the top of the allocation
567 ///
568 void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II) const {
569   // Get the instruction.
570   MachineInstr &MI = *II;
571   // Get the instruction's basic block.
572   MachineBasicBlock &MBB = *MI.getParent();
573   // Get the basic block's function.
574   MachineFunction &MF = *MBB.getParent();
575   // Get the frame info.
576   MachineFrameInfo *MFI = MF.getFrameInfo();
577   // Determine whether 64-bit pointers are used.
578   bool LP64 = Subtarget.isPPC64();
579 
580   // Get the maximum call stack size.
581   unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
582   // Get the total frame size.
583   unsigned FrameSize = MFI->getStackSize();
584 
585   // Get stack alignments.
586   unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
587   unsigned MaxAlign = MFI->getMaxAlignment();
588   assert(MaxAlign <= TargetAlign &&
589          "Dynamic alloca with large aligns not supported");
590 
591   // Determine the previous frame's address.  If FrameSize can't be
592   // represented as 16 bits or we need special alignment, then we load the
593   // previous frame's address from 0(SP).  Why not do an addis of the hi?
594   // Because R0 is our only safe tmp register and addi/addis treat R0 as zero.
595   // Constructing the constant and adding would take 3 instructions.
596   // Fortunately, a frame greater than 32K is rare.
597   if (MaxAlign < TargetAlign && isInt16(FrameSize)) {
598     BuildMI(MBB, II, TII.get(PPC::ADDI), PPC::R0)
599       .addReg(PPC::R31)
600       .addImm(FrameSize);
601   } else if (LP64) {
602     BuildMI(MBB, II, TII.get(PPC::LD), PPC::X0)
603       .addImm(0)
604       .addReg(PPC::X1);
605   } else {
606     BuildMI(MBB, II, TII.get(PPC::LWZ), PPC::R0)
607       .addImm(0)
608       .addReg(PPC::R1);
609   }
610 
611   // Grow the stack and update the stack pointer link, then
612   // determine the address of new allocated space.
613   if (LP64) {
614     BuildMI(MBB, II, TII.get(PPC::STDUX))
615       .addReg(PPC::X0)
616       .addReg(PPC::X1)
617       .addReg(MI.getOperand(1).getReg());
618     BuildMI(MBB, II, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
619       .addReg(PPC::X1)
620       .addImm(maxCallFrameSize);
621   } else {
622     BuildMI(MBB, II, TII.get(PPC::STWUX))
623       .addReg(PPC::R0)
624       .addReg(PPC::R1)
625       .addReg(MI.getOperand(1).getReg());
626     BuildMI(MBB, II, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
627       .addReg(PPC::R1)
628       .addImm(maxCallFrameSize);
629   }
630 
631   // Discard the DYNALLOC instruction.
632   MBB.erase(II);
633 }
634 
635 void PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
636                                           RegScavenger *RS) const {
637   // Get the instruction.
638   MachineInstr &MI = *II;
639   // Get the instruction's basic block.
640   MachineBasicBlock &MBB = *MI.getParent();
641   // Get the basic block's function.
642   MachineFunction &MF = *MBB.getParent();
643   // Get the frame info.
644   MachineFrameInfo *MFI = MF.getFrameInfo();
645 
646   // Find out which operand is the frame index.
647   unsigned i = 0;
648   while (!MI.getOperand(i).isFrameIndex()) {
649     ++i;
650     assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
651   }
652   // Take into account whether it's an add or mem instruction
653   unsigned OffIdx = (i == 2) ? 1 : 2;
654   if (MI.getOpcode() == TargetInstrInfo::INLINEASM)
655     OffIdx = i-1;
656 
657   // Get the frame index.
658   int FrameIndex = MI.getOperand(i).getFrameIndex();
659 
660   // Get the frame pointer save index.  Users of this index are primarily
661   // DYNALLOC instructions.
662   PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
663   int FPSI = FI->getFramePointerSaveIndex();
664   // Get the instruction opcode.
665   unsigned OpC = MI.getOpcode();
666 
667   // Special case for dynamic alloca.
668   if (FPSI && FrameIndex == FPSI &&
669       (OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
670     lowerDynamicAlloc(II);
671     return;
672   }
673 
674   // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
675   MI.getOperand(i).ChangeToRegister(hasFP(MF) ? PPC::R31 : PPC::R1, false);
676 
677   // Figure out if the offset in the instruction is shifted right two bits. This
678   // is true for instructions like "STD", which the machine implicitly adds two
679   // low zeros to.
680   bool isIXAddr = false;
681   switch (OpC) {
682   case PPC::LWA:
683   case PPC::LD:
684   case PPC::STD:
685   case PPC::STD_32:
686     isIXAddr = true;
687     break;
688   }
689 
690   // Now add the frame object offset to the offset from r1.
691   int Offset = MFI->getObjectOffset(FrameIndex);
692 
693   if (!isIXAddr)
694     Offset += MI.getOperand(OffIdx).getImmedValue();
695   else
696     Offset += MI.getOperand(OffIdx).getImmedValue() << 2;
697 
698   // If we're not using a Frame Pointer that has been set to the value of the
699   // SP before having the stack size subtracted from it, then add the stack size
700   // to Offset to get the correct offset.
701   Offset += MFI->getStackSize();
702 
703   if (!isInt16(Offset)) {
704     // Insert a set of r0 with the full offset value before the ld, st, or add
705     BuildMI(MBB, II, TII.get(PPC::LIS), PPC::R0).addImm(Offset >> 16);
706     BuildMI(MBB, II, TII.get(PPC::ORI), PPC::R0).addReg(PPC::R0).addImm(Offset);
707 
708     // convert into indexed form of the instruction
709     // sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
710     // addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
711     assert(ImmToIdxMap.count(OpC) &&
712            "No indexed form of load or store available!");
713     unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
714     MI.setInstrDescriptor(TII.get(NewOpcode));
715     MI.getOperand(1).ChangeToRegister(MI.getOperand(i).getReg(), false);
716     MI.getOperand(2).ChangeToRegister(PPC::R0, false);
717   } else {
718     if (isIXAddr) {
719       assert((Offset & 3) == 0 && "Invalid frame offset!");
720       Offset >>= 2;    // The actual encoded value has the low two bits zero.
721     }
722     MI.getOperand(OffIdx).ChangeToImmediate(Offset);
723   }
724 }
725 
726 /// VRRegNo - Map from a numbered VR register to its enum value.
727 ///
728 static const unsigned short VRRegNo[] = {
729  PPC::V0 , PPC::V1 , PPC::V2 , PPC::V3 , PPC::V4 , PPC::V5 , PPC::V6 , PPC::V7 ,
730  PPC::V8 , PPC::V9 , PPC::V10, PPC::V11, PPC::V12, PPC::V13, PPC::V14, PPC::V15,
731  PPC::V16, PPC::V17, PPC::V18, PPC::V19, PPC::V20, PPC::V21, PPC::V22, PPC::V23,
732  PPC::V24, PPC::V25, PPC::V26, PPC::V27, PPC::V28, PPC::V29, PPC::V30, PPC::V31
733 };
734 
735 /// RemoveVRSaveCode - We have found that this function does not need any code
736 /// to manipulate the VRSAVE register, even though it uses vector registers.
737 /// This can happen when the only registers used are known to be live in or out
738 /// of the function.  Remove all of the VRSAVE related code from the function.
739 static void RemoveVRSaveCode(MachineInstr *MI) {
740   MachineBasicBlock *Entry = MI->getParent();
741   MachineFunction *MF = Entry->getParent();
742 
743   // We know that the MTVRSAVE instruction immediately follows MI.  Remove it.
744   MachineBasicBlock::iterator MBBI = MI;
745   ++MBBI;
746   assert(MBBI != Entry->end() && MBBI->getOpcode() == PPC::MTVRSAVE);
747   MBBI->eraseFromParent();
748 
749   bool RemovedAllMTVRSAVEs = true;
750   // See if we can find and remove the MTVRSAVE instruction from all of the
751   // epilog blocks.
752   const TargetInstrInfo &TII = *MF->getTarget().getInstrInfo();
753   for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I) {
754     // If last instruction is a return instruction, add an epilogue
755     if (!I->empty() && TII.isReturn(I->back().getOpcode())) {
756       bool FoundIt = false;
757       for (MBBI = I->end(); MBBI != I->begin(); ) {
758         --MBBI;
759         if (MBBI->getOpcode() == PPC::MTVRSAVE) {
760           MBBI->eraseFromParent();  // remove it.
761           FoundIt = true;
762           break;
763         }
764       }
765       RemovedAllMTVRSAVEs &= FoundIt;
766     }
767   }
768 
769   // If we found and removed all MTVRSAVE instructions, remove the read of
770   // VRSAVE as well.
771   if (RemovedAllMTVRSAVEs) {
772     MBBI = MI;
773     assert(MBBI != Entry->begin() && "UPDATE_VRSAVE is first instr in block?");
774     --MBBI;
775     assert(MBBI->getOpcode() == PPC::MFVRSAVE && "VRSAVE instrs wandered?");
776     MBBI->eraseFromParent();
777   }
778 
779   // Finally, nuke the UPDATE_VRSAVE.
780   MI->eraseFromParent();
781 }
782 
783 // HandleVRSaveUpdate - MI is the UPDATE_VRSAVE instruction introduced by the
784 // instruction selector.  Based on the vector registers that have been used,
785 // transform this into the appropriate ORI instruction.
786 static void HandleVRSaveUpdate(MachineInstr *MI, const bool *UsedRegs,
787                                const TargetInstrInfo &TII) {
788   unsigned UsedRegMask = 0;
789   for (unsigned i = 0; i != 32; ++i)
790     if (UsedRegs[VRRegNo[i]])
791       UsedRegMask |= 1 << (31-i);
792 
793   // Live in and live out values already must be in the mask, so don't bother
794   // marking them.
795   MachineFunction *MF = MI->getParent()->getParent();
796   for (MachineFunction::livein_iterator I =
797        MF->livein_begin(), E = MF->livein_end(); I != E; ++I) {
798     unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(I->first);
799     if (VRRegNo[RegNo] == I->first)        // If this really is a vector reg.
800       UsedRegMask &= ~(1 << (31-RegNo));   // Doesn't need to be marked.
801   }
802   for (MachineFunction::liveout_iterator I =
803        MF->liveout_begin(), E = MF->liveout_end(); I != E; ++I) {
804     unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(*I);
805     if (VRRegNo[RegNo] == *I)              // If this really is a vector reg.
806       UsedRegMask &= ~(1 << (31-RegNo));   // Doesn't need to be marked.
807   }
808 
809   unsigned SrcReg = MI->getOperand(1).getReg();
810   unsigned DstReg = MI->getOperand(0).getReg();
811   // If no registers are used, turn this into a copy.
812   if (UsedRegMask == 0) {
813     // Remove all VRSAVE code.
814     RemoveVRSaveCode(MI);
815     return;
816   } else if ((UsedRegMask & 0xFFFF) == UsedRegMask) {
817     BuildMI(*MI->getParent(), MI, TII.get(PPC::ORI), DstReg)
818         .addReg(SrcReg).addImm(UsedRegMask);
819   } else if ((UsedRegMask & 0xFFFF0000) == UsedRegMask) {
820     BuildMI(*MI->getParent(), MI, TII.get(PPC::ORIS), DstReg)
821         .addReg(SrcReg).addImm(UsedRegMask >> 16);
822   } else {
823     BuildMI(*MI->getParent(), MI, TII.get(PPC::ORIS), DstReg)
824        .addReg(SrcReg).addImm(UsedRegMask >> 16);
825     BuildMI(*MI->getParent(), MI, TII.get(PPC::ORI), DstReg)
826       .addReg(DstReg).addImm(UsedRegMask & 0xFFFF);
827   }
828 
829   // Remove the old UPDATE_VRSAVE instruction.
830   MI->eraseFromParent();
831 }
832 
833 /// determineFrameLayout - Determine the size of the frame and maximum call
834 /// frame size.
835 void PPCRegisterInfo::determineFrameLayout(MachineFunction &MF) const {
836   MachineFrameInfo *MFI = MF.getFrameInfo();
837 
838   // Get the number of bytes to allocate from the FrameInfo
839   unsigned FrameSize = MFI->getStackSize();
840 
841   // Get the alignments provided by the target, and the maximum alignment
842   // (if any) of the fixed frame objects.
843   unsigned MaxAlign = MFI->getMaxAlignment();
844   unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
845   unsigned AlignMask = TargetAlign - 1;  //
846 
847   // If we are a leaf function, and use up to 224 bytes of stack space,
848   // don't have a frame pointer, calls, or dynamic alloca then we do not need
849   // to adjust the stack pointer (we fit in the Red Zone).
850   if (FrameSize <= 224 &&             // Fits in red zone.
851       !MFI->hasVarSizedObjects() &&   // No dynamic alloca.
852       !MFI->hasCalls() &&             // No calls.
853       MaxAlign <= TargetAlign) {      // No special alignment.
854     // No need for frame
855     MFI->setStackSize(0);
856     return;
857   }
858 
859   // Get the maximum call frame size of all the calls.
860   unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
861 
862   // Maximum call frame needs to be at least big enough for linkage and 8 args.
863   unsigned minCallFrameSize =
864     PPCFrameInfo::getMinCallFrameSize(Subtarget.isPPC64(),
865                                       Subtarget.isMachoABI());
866   maxCallFrameSize = std::max(maxCallFrameSize, minCallFrameSize);
867 
868   // If we have dynamic alloca then maxCallFrameSize needs to be aligned so
869   // that allocations will be aligned.
870   if (MFI->hasVarSizedObjects())
871     maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
872 
873   // Update maximum call frame size.
874   MFI->setMaxCallFrameSize(maxCallFrameSize);
875 
876   // Include call frame size in total.
877   FrameSize += maxCallFrameSize;
878 
879   // Make sure the frame is aligned.
880   FrameSize = (FrameSize + AlignMask) & ~AlignMask;
881 
882   // Update frame info.
883   MFI->setStackSize(FrameSize);
884 }
885 
886 void PPCRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
887                                                            RegScavenger *RS)
888   const {
889   //  Save and clear the LR state.
890   PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
891   unsigned LR = getRARegister();
892   FI->setUsesLR(MF.isPhysRegUsed(LR));
893   MF.changePhyRegUsed(LR, false);
894 }
895 
896 void PPCRegisterInfo::emitPrologue(MachineFunction &MF) const {
897   MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
898   MachineBasicBlock::iterator MBBI = MBB.begin();
899   MachineFrameInfo *MFI = MF.getFrameInfo();
900   MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
901 
902   // Prepare for frame info.
903   unsigned FrameLabelId = 0;
904 
905   // Scan the prolog, looking for an UPDATE_VRSAVE instruction.  If we find it,
906   // process it.
907   for (unsigned i = 0; MBBI != MBB.end(); ++i, ++MBBI) {
908     if (MBBI->getOpcode() == PPC::UPDATE_VRSAVE) {
909       HandleVRSaveUpdate(MBBI, MF.getUsedPhysregs(), TII);
910       break;
911     }
912   }
913 
914   // Move MBBI back to the beginning of the function.
915   MBBI = MBB.begin();
916 
917   // Work out frame sizes.
918   determineFrameLayout(MF);
919   unsigned FrameSize = MFI->getStackSize();
920 
921   int NegFrameSize = -FrameSize;
922 
923   // Get processor type.
924   bool IsPPC64 = Subtarget.isPPC64();
925   // Get operating system
926   bool IsMachoABI = Subtarget.isMachoABI();
927   // Check if the link register (LR) has been used.
928   bool UsesLR = MFI->hasCalls() || usesLR(MF);
929   // Do we have a frame pointer for this function?
930   bool HasFP = hasFP(MF) && FrameSize;
931 
932   int LROffset = PPCFrameInfo::getReturnSaveOffset(IsPPC64, IsMachoABI);
933   int FPOffset = PPCFrameInfo::getFramePointerSaveOffset(IsPPC64, IsMachoABI);
934 
935   if (IsPPC64) {
936     if (UsesLR)
937       BuildMI(MBB, MBBI, TII.get(PPC::MFLR8), PPC::X0);
938 
939     if (HasFP)
940       BuildMI(MBB, MBBI, TII.get(PPC::STD))
941          .addReg(PPC::X31).addImm(FPOffset/4).addReg(PPC::X1);
942 
943     if (UsesLR)
944       BuildMI(MBB, MBBI, TII.get(PPC::STD))
945          .addReg(PPC::X0).addImm(LROffset/4).addReg(PPC::X1);
946   } else {
947     if (UsesLR)
948       BuildMI(MBB, MBBI, TII.get(PPC::MFLR), PPC::R0);
949 
950     if (HasFP)
951       BuildMI(MBB, MBBI, TII.get(PPC::STW))
952         .addReg(PPC::R31).addImm(FPOffset).addReg(PPC::R1);
953 
954     if (UsesLR)
955       BuildMI(MBB, MBBI, TII.get(PPC::STW))
956         .addReg(PPC::R0).addImm(LROffset).addReg(PPC::R1);
957   }
958 
959   // Skip if a leaf routine.
960   if (!FrameSize) return;
961 
962   // Get stack alignments.
963   unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
964   unsigned MaxAlign = MFI->getMaxAlignment();
965 
966   if (MMI && MMI->needsFrameInfo()) {
967     // Mark effective beginning of when frame pointer becomes valid.
968     FrameLabelId = MMI->NextLabelID();
969     BuildMI(MBB, MBBI, TII.get(PPC::LABEL)).addImm(FrameLabelId);
970   }
971 
972   // Adjust stack pointer: r1 += NegFrameSize.
973   // If there is a preferred stack alignment, align R1 now
974   if (!IsPPC64) {
975     // PPC32.
976     if (MaxAlign > TargetAlign) {
977       assert(isPowerOf2_32(MaxAlign)&&isInt16(MaxAlign)&&"Invalid alignment!");
978       assert(isInt16(NegFrameSize) && "Unhandled stack size and alignment!");
979       BuildMI(MBB, MBBI, TII.get(PPC::RLWINM), PPC::R0)
980         .addReg(PPC::R1).addImm(0).addImm(32-Log2_32(MaxAlign)).addImm(31);
981       BuildMI(MBB, MBBI, TII.get(PPC::SUBFIC) ,PPC::R0).addReg(PPC::R0)
982         .addImm(NegFrameSize);
983       BuildMI(MBB, MBBI, TII.get(PPC::STWUX))
984         .addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0);
985     } else if (isInt16(NegFrameSize)) {
986       BuildMI(MBB, MBBI, TII.get(PPC::STWU),
987               PPC::R1).addReg(PPC::R1).addImm(NegFrameSize).addReg(PPC::R1);
988     } else {
989       BuildMI(MBB, MBBI, TII.get(PPC::LIS), PPC::R0).addImm(NegFrameSize >> 16);
990       BuildMI(MBB, MBBI, TII.get(PPC::ORI), PPC::R0).addReg(PPC::R0)
991         .addImm(NegFrameSize & 0xFFFF);
992       BuildMI(MBB, MBBI, TII.get(PPC::STWUX)).addReg(PPC::R1).addReg(PPC::R1)
993         .addReg(PPC::R0);
994     }
995   } else {    // PPC64.
996     if (MaxAlign > TargetAlign) {
997       assert(isPowerOf2_32(MaxAlign)&&isInt16(MaxAlign)&&"Invalid alignment!");
998       assert(isInt16(NegFrameSize) && "Unhandled stack size and alignment!");
999       BuildMI(MBB, MBBI, TII.get(PPC::RLDICL), PPC::X0)
1000         .addReg(PPC::X1).addImm(0).addImm(64-Log2_32(MaxAlign));
1001       BuildMI(MBB, MBBI, TII.get(PPC::SUBFIC8), PPC::X0).addReg(PPC::X0)
1002         .addImm(NegFrameSize);
1003       BuildMI(MBB, MBBI, TII.get(PPC::STDUX))
1004         .addReg(PPC::X1).addReg(PPC::X1).addReg(PPC::X0);
1005     } else if (isInt16(NegFrameSize)) {
1006       BuildMI(MBB, MBBI, TII.get(PPC::STDU), PPC::X1)
1007              .addReg(PPC::X1).addImm(NegFrameSize/4).addReg(PPC::X1);
1008     } else {
1009       BuildMI(MBB, MBBI, TII.get(PPC::LIS8), PPC::X0).addImm(NegFrameSize >>16);
1010       BuildMI(MBB, MBBI, TII.get(PPC::ORI8), PPC::X0).addReg(PPC::X0)
1011         .addImm(NegFrameSize & 0xFFFF);
1012       BuildMI(MBB, MBBI, TII.get(PPC::STDUX)).addReg(PPC::X1).addReg(PPC::X1)
1013         .addReg(PPC::X0);
1014     }
1015   }
1016 
1017   if (MMI && MMI->needsFrameInfo()) {
1018     std::vector<MachineMove> &Moves = MMI->getFrameMoves();
1019 
1020     if (NegFrameSize) {
1021       // Show update of SP.
1022       MachineLocation SPDst(MachineLocation::VirtualFP);
1023       MachineLocation SPSrc(MachineLocation::VirtualFP, NegFrameSize);
1024       Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
1025     } else {
1026       MachineLocation SP(IsPPC64 ? PPC::X31 : PPC::R31);
1027       Moves.push_back(MachineMove(FrameLabelId, SP, SP));
1028     }
1029 
1030     if (HasFP) {
1031       MachineLocation FPDst(MachineLocation::VirtualFP, FPOffset);
1032       MachineLocation FPSrc(IsPPC64 ? PPC::X31 : PPC::R31);
1033       Moves.push_back(MachineMove(FrameLabelId, FPDst, FPSrc));
1034     }
1035 
1036     // Add callee saved registers to move list.
1037     const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
1038     for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
1039       int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
1040       unsigned Reg = CSI[I].getReg();
1041       if (Reg == PPC::LR || Reg == PPC::LR8) continue;
1042       MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
1043       MachineLocation CSSrc(Reg);
1044       Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
1045     }
1046 
1047     MachineLocation LRDst(MachineLocation::VirtualFP, LROffset);
1048     MachineLocation LRSrc(IsPPC64 ? PPC::LR8 : PPC::LR);
1049     Moves.push_back(MachineMove(FrameLabelId, LRDst, LRSrc));
1050 
1051     // Mark effective beginning of when frame pointer is ready.
1052     unsigned ReadyLabelId = MMI->NextLabelID();
1053     BuildMI(MBB, MBBI, TII.get(PPC::LABEL)).addImm(ReadyLabelId);
1054 
1055     MachineLocation FPDst(HasFP ? (IsPPC64 ? PPC::X31 : PPC::R31) :
1056                                   (IsPPC64 ? PPC::X1 : PPC::R1));
1057     MachineLocation FPSrc(MachineLocation::VirtualFP);
1058     Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
1059   }
1060 
1061   // If there is a frame pointer, copy R1 into R31
1062   if (HasFP) {
1063     if (!IsPPC64) {
1064       BuildMI(MBB, MBBI, TII.get(PPC::OR), PPC::R31).addReg(PPC::R1)
1065         .addReg(PPC::R1);
1066     } else {
1067       BuildMI(MBB, MBBI, TII.get(PPC::OR8), PPC::X31).addReg(PPC::X1)
1068         .addReg(PPC::X1);
1069     }
1070   }
1071 }
1072 
1073 void PPCRegisterInfo::emitEpilogue(MachineFunction &MF,
1074                                    MachineBasicBlock &MBB) const {
1075   MachineBasicBlock::iterator MBBI = prior(MBB.end());
1076   assert(MBBI->getOpcode() == PPC::BLR &&
1077          "Can only insert epilog into returning blocks");
1078 
1079   // Get alignment info so we know how to restore r1
1080   const MachineFrameInfo *MFI = MF.getFrameInfo();
1081   unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
1082   unsigned MaxAlign = MFI->getMaxAlignment();
1083 
1084   // Get the number of bytes allocated from the FrameInfo.
1085   unsigned FrameSize = MFI->getStackSize();
1086 
1087   // Get processor type.
1088   bool IsPPC64 = Subtarget.isPPC64();
1089   // Get operating system
1090   bool IsMachoABI = Subtarget.isMachoABI();
1091   // Check if the link register (LR) has been used.
1092   bool UsesLR = MFI->hasCalls() || usesLR(MF);
1093   // Do we have a frame pointer for this function?
1094   bool HasFP = hasFP(MF) && FrameSize;
1095 
1096   int LROffset = PPCFrameInfo::getReturnSaveOffset(IsPPC64, IsMachoABI);
1097   int FPOffset = PPCFrameInfo::getFramePointerSaveOffset(IsPPC64, IsMachoABI);
1098 
1099   if (FrameSize) {
1100     // The loaded (or persistent) stack pointer value is offset by the 'stwu'
1101     // on entry to the function.  Add this offset back now.
1102     if (!Subtarget.isPPC64()) {
1103       if (isInt16(FrameSize) && TargetAlign >= MaxAlign &&
1104             !MFI->hasVarSizedObjects()) {
1105           BuildMI(MBB, MBBI, TII.get(PPC::ADDI), PPC::R1)
1106               .addReg(PPC::R1).addImm(FrameSize);
1107       } else {
1108         BuildMI(MBB, MBBI, TII.get(PPC::LWZ),PPC::R1).addImm(0).addReg(PPC::R1);
1109       }
1110     } else {
1111       if (isInt16(FrameSize) && TargetAlign >= MaxAlign &&
1112             !MFI->hasVarSizedObjects()) {
1113         BuildMI(MBB, MBBI, TII.get(PPC::ADDI8), PPC::X1)
1114            .addReg(PPC::X1).addImm(FrameSize);
1115       } else {
1116         BuildMI(MBB, MBBI, TII.get(PPC::LD), PPC::X1).addImm(0).addReg(PPC::X1);
1117       }
1118     }
1119   }
1120 
1121   if (IsPPC64) {
1122     if (UsesLR)
1123       BuildMI(MBB, MBBI, TII.get(PPC::LD), PPC::X0)
1124         .addImm(LROffset/4).addReg(PPC::X1);
1125 
1126     if (HasFP)
1127       BuildMI(MBB, MBBI, TII.get(PPC::LD), PPC::X31)
1128         .addImm(FPOffset/4).addReg(PPC::X1);
1129 
1130     if (UsesLR)
1131       BuildMI(MBB, MBBI, TII.get(PPC::MTLR8)).addReg(PPC::X0);
1132   } else {
1133     if (UsesLR)
1134       BuildMI(MBB, MBBI, TII.get(PPC::LWZ), PPC::R0)
1135           .addImm(LROffset).addReg(PPC::R1);
1136 
1137     if (HasFP)
1138       BuildMI(MBB, MBBI, TII.get(PPC::LWZ), PPC::R31)
1139           .addImm(FPOffset).addReg(PPC::R1);
1140 
1141     if (UsesLR)
1142       BuildMI(MBB, MBBI, TII.get(PPC::MTLR)).addReg(PPC::R0);
1143   }
1144 }
1145 
1146 unsigned PPCRegisterInfo::getRARegister() const {
1147   return !Subtarget.isPPC64() ? PPC::LR : PPC::LR8;
1148 }
1149 
1150 unsigned PPCRegisterInfo::getFrameRegister(MachineFunction &MF) const {
1151   if (!Subtarget.isPPC64())
1152     return hasFP(MF) ? PPC::R31 : PPC::R1;
1153   else
1154     return hasFP(MF) ? PPC::X31 : PPC::X1;
1155 }
1156 
1157 void PPCRegisterInfo::getInitialFrameState(std::vector<MachineMove> &Moves)
1158                                                                          const {
1159   // Initial state of the frame pointer is R1.
1160   MachineLocation Dst(MachineLocation::VirtualFP);
1161   MachineLocation Src(PPC::R1, 0);
1162   Moves.push_back(MachineMove(0, Dst, Src));
1163 }
1164 
1165 unsigned PPCRegisterInfo::getEHExceptionRegister() const {
1166   return !Subtarget.isPPC64() ? PPC::R3 : PPC::X3;
1167 }
1168 
1169 unsigned PPCRegisterInfo::getEHHandlerRegister() const {
1170   return !Subtarget.isPPC64() ? PPC::R4 : PPC::X4;
1171 }
1172 
1173 #include "PPCGenRegisterInfo.inc"
1174 
1175