X86RegisterInfo.td revision 9ed08f4a410a3f0b6d38eb6eec0ddb94349e74dd
1//===- X86RegisterInfo.td - Describe the X86 Register File --*- tablegen -*-==//
2// 
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7// 
8//===----------------------------------------------------------------------===//
9//
10// This file describes the X86 Register file, defining the registers themselves,
11// aliases between the registers, and the register classes built out of the
12// registers.
13//
14//===----------------------------------------------------------------------===//
15
16//===----------------------------------------------------------------------===//
17//  Register definitions...
18//
19let Namespace = "X86" in {
20
21  // In the register alias definitions below, we define which registers alias
22  // which others.  We only specify which registers the small registers alias,
23  // because the register file generator is smart enough to figure out that
24  // AL aliases AX if we tell it that AX aliased AL (for example).
25
26  // Dwarf numbering is different for 32-bit and 64-bit, and there are 
27  // variations by target as well. Currently the first entry is for X86-64, 
28  // second - for EH on X86-32/Darwin and third is 'generic' one (X86-32/Linux
29  // and debug information on X86-32/Darwin)
30
31  // 8-bit registers
32  // Low registers
33  def AL : Register<"al">, DwarfRegNum<[0, 0, 0]>;
34  def DL : Register<"dl">, DwarfRegNum<[1, 2, 2]>;
35  def CL : Register<"cl">, DwarfRegNum<[2, 1, 1]>;
36  def BL : Register<"bl">, DwarfRegNum<[3, 3, 3]>;
37
38  // X86-64 only
39  def SIL : Register<"sil">, DwarfRegNum<[4, 6, 6]>;
40  def DIL : Register<"dil">, DwarfRegNum<[5, 7, 7]>;
41  def BPL : Register<"bpl">, DwarfRegNum<[6, 4, 5]>;
42  def SPL : Register<"spl">, DwarfRegNum<[7, 5, 4]>;
43  def R8B  : Register<"r8b">,  DwarfRegNum<[8, -2, -2]>;
44  def R9B  : Register<"r9b">,  DwarfRegNum<[9, -2, -2]>;
45  def R10B : Register<"r10b">, DwarfRegNum<[10, -2, -2]>;
46  def R11B : Register<"r11b">, DwarfRegNum<[11, -2, -2]>;
47  def R12B : Register<"r12b">, DwarfRegNum<[12, -2, -2]>;
48  def R13B : Register<"r13b">, DwarfRegNum<[13, -2, -2]>;
49  def R14B : Register<"r14b">, DwarfRegNum<[14, -2, -2]>;
50  def R15B : Register<"r15b">, DwarfRegNum<[15, -2, -2]>;
51
52  // High registers X86-32 only
53  def AH : Register<"ah">, DwarfRegNum<[0, 0, 0]>;
54  def DH : Register<"dh">, DwarfRegNum<[1, 2, 2]>;
55  def CH : Register<"ch">, DwarfRegNum<[2, 1, 1]>;
56  def BH : Register<"bh">, DwarfRegNum<[3, 3, 3]>;
57
58  // 16-bit registers
59  def AX : RegisterWithSubRegs<"ax", [AH,AL]>, DwarfRegNum<[0, 0, 0]>;
60  def DX : RegisterWithSubRegs<"dx", [DH,DL]>, DwarfRegNum<[1, 2, 2]>;
61  def CX : RegisterWithSubRegs<"cx", [CH,CL]>, DwarfRegNum<[2, 1, 1]>;
62  def BX : RegisterWithSubRegs<"bx", [BH,BL]>, DwarfRegNum<[3, 3, 3]>;
63  def SI : RegisterWithSubRegs<"si", [SIL]>, DwarfRegNum<[4, 6, 6]>;
64  def DI : RegisterWithSubRegs<"di", [DIL]>, DwarfRegNum<[5, 7, 7]>;
65  def BP : RegisterWithSubRegs<"bp", [BPL]>, DwarfRegNum<[6, 4, 5]>;
66  def SP : RegisterWithSubRegs<"sp", [SPL]>, DwarfRegNum<[7, 5, 4]>;
67  def IP : Register<"ip">, DwarfRegNum<[16]>;
68  
69  // X86-64 only
70  def R8W  : RegisterWithSubRegs<"r8w", [R8B]>, DwarfRegNum<[8, -2, -2]>;
71  def R9W  : RegisterWithSubRegs<"r9w", [R9B]>, DwarfRegNum<[9, -2, -2]>;
72  def R10W : RegisterWithSubRegs<"r10w", [R10B]>, DwarfRegNum<[10, -2, -2]>;
73  def R11W : RegisterWithSubRegs<"r11w", [R11B]>, DwarfRegNum<[11, -2, -2]>;
74  def R12W : RegisterWithSubRegs<"r12w", [R12B]>, DwarfRegNum<[12, -2, -2]>;
75  def R13W : RegisterWithSubRegs<"r13w", [R13B]>, DwarfRegNum<[13, -2, -2]>;
76  def R14W : RegisterWithSubRegs<"r14w", [R14B]>, DwarfRegNum<[14, -2, -2]>;
77  def R15W : RegisterWithSubRegs<"r15w", [R15B]>, DwarfRegNum<[15, -2, -2]>;
78
79  // 32-bit registers
80  def EAX : RegisterWithSubRegs<"eax", [AX]>, DwarfRegNum<[0, 0, 0]>;
81  def EDX : RegisterWithSubRegs<"edx", [DX]>, DwarfRegNum<[1, 2, 2]>;
82  def ECX : RegisterWithSubRegs<"ecx", [CX]>, DwarfRegNum<[2, 1, 1]>;
83  def EBX : RegisterWithSubRegs<"ebx", [BX]>, DwarfRegNum<[3, 3, 3]>;
84  def ESI : RegisterWithSubRegs<"esi", [SI]>, DwarfRegNum<[4, 6, 6]>;
85  def EDI : RegisterWithSubRegs<"edi", [DI]>, DwarfRegNum<[5, 7, 7]>;
86  def EBP : RegisterWithSubRegs<"ebp", [BP]>, DwarfRegNum<[6, 4, 5]>;
87  def ESP : RegisterWithSubRegs<"esp", [SP]>, DwarfRegNum<[7, 5, 4]>;
88  def EIP : RegisterWithSubRegs<"eip", [IP]>, DwarfRegNum<[16, 8, 8]>;  
89  
90  // X86-64 only
91  def R8D  : RegisterWithSubRegs<"r8d", [R8W]>, DwarfRegNum<[8, -2, -2]>;
92  def R9D  : RegisterWithSubRegs<"r9d", [R9W]>, DwarfRegNum<[9, -2, -2]>;
93  def R10D : RegisterWithSubRegs<"r10d", [R10W]>, DwarfRegNum<[10, -2, -2]>;
94  def R11D : RegisterWithSubRegs<"r11d", [R11W]>, DwarfRegNum<[11, -2, -2]>;
95  def R12D : RegisterWithSubRegs<"r12d", [R12W]>, DwarfRegNum<[12, -2, -2]>;
96  def R13D : RegisterWithSubRegs<"r13d", [R13W]>, DwarfRegNum<[13, -2, -2]>;
97  def R14D : RegisterWithSubRegs<"r14d", [R14W]>, DwarfRegNum<[14, -2, -2]>;
98  def R15D : RegisterWithSubRegs<"r15d", [R15W]>, DwarfRegNum<[15, -2, -2]>;
99
100  // 64-bit registers, X86-64 only
101  def RAX : RegisterWithSubRegs<"rax", [EAX]>, DwarfRegNum<[0, -2, -2]>;
102  def RDX : RegisterWithSubRegs<"rdx", [EDX]>, DwarfRegNum<[1, -2, -2]>;
103  def RCX : RegisterWithSubRegs<"rcx", [ECX]>, DwarfRegNum<[2, -2, -2]>;
104  def RBX : RegisterWithSubRegs<"rbx", [EBX]>, DwarfRegNum<[3, -2, -2]>;
105  def RSI : RegisterWithSubRegs<"rsi", [ESI]>, DwarfRegNum<[4, -2, -2]>;
106  def RDI : RegisterWithSubRegs<"rdi", [EDI]>, DwarfRegNum<[5, -2, -2]>;
107  def RBP : RegisterWithSubRegs<"rbp", [EBP]>, DwarfRegNum<[6, -2, -2]>;
108  def RSP : RegisterWithSubRegs<"rsp", [ESP]>, DwarfRegNum<[7, -2, -2]>;
109
110  def R8  : RegisterWithSubRegs<"r8", [R8D]>, DwarfRegNum<[8, -2, -2]>;
111  def R9  : RegisterWithSubRegs<"r9", [R9D]>, DwarfRegNum<[9, -2, -2]>;
112  def R10 : RegisterWithSubRegs<"r10", [R10D]>, DwarfRegNum<[10, -2, -2]>;
113  def R11 : RegisterWithSubRegs<"r11", [R11D]>, DwarfRegNum<[11, -2, -2]>;
114  def R12 : RegisterWithSubRegs<"r12", [R12D]>, DwarfRegNum<[12, -2, -2]>;
115  def R13 : RegisterWithSubRegs<"r13", [R13D]>, DwarfRegNum<[13, -2, -2]>;
116  def R14 : RegisterWithSubRegs<"r14", [R14D]>, DwarfRegNum<[14, -2, -2]>;
117  def R15 : RegisterWithSubRegs<"r15", [R15D]>, DwarfRegNum<[15, -2, -2]>;
118  def RIP : RegisterWithSubRegs<"rip", [EIP]>,  DwarfRegNum<[16, -2, -2]>;
119
120  // MMX Registers. These are actually aliased to ST0 .. ST7
121  def MM0 : Register<"mm0">, DwarfRegNum<[41, 29, 29]>;
122  def MM1 : Register<"mm1">, DwarfRegNum<[42, 30, 30]>;
123  def MM2 : Register<"mm2">, DwarfRegNum<[43, 31, 31]>;
124  def MM3 : Register<"mm3">, DwarfRegNum<[44, 32, 32]>;
125  def MM4 : Register<"mm4">, DwarfRegNum<[45, 33, 33]>;
126  def MM5 : Register<"mm5">, DwarfRegNum<[46, 34, 34]>;
127  def MM6 : Register<"mm6">, DwarfRegNum<[47, 35, 35]>;
128  def MM7 : Register<"mm7">, DwarfRegNum<[48, 36, 36]>;
129  
130  // Pseudo Floating Point registers
131  def FP0 : Register<"fp0">;
132  def FP1 : Register<"fp1">;
133  def FP2 : Register<"fp2">;
134  def FP3 : Register<"fp3">;
135  def FP4 : Register<"fp4">;
136  def FP5 : Register<"fp5">;
137  def FP6 : Register<"fp6">; 
138
139  // XMM Registers, used by the various SSE instruction set extensions
140  def XMM0: Register<"xmm0">, DwarfRegNum<[17, 21, 21]>;
141  def XMM1: Register<"xmm1">, DwarfRegNum<[18, 22, 22]>;
142  def XMM2: Register<"xmm2">, DwarfRegNum<[19, 23, 23]>;
143  def XMM3: Register<"xmm3">, DwarfRegNum<[20, 24, 24]>;
144  def XMM4: Register<"xmm4">, DwarfRegNum<[21, 25, 25]>;
145  def XMM5: Register<"xmm5">, DwarfRegNum<[22, 26, 26]>;
146  def XMM6: Register<"xmm6">, DwarfRegNum<[23, 27, 27]>;
147  def XMM7: Register<"xmm7">, DwarfRegNum<[24, 28, 28]>;
148
149  // X86-64 only
150  def XMM8:  Register<"xmm8">,  DwarfRegNum<[25, -2, -2]>;
151  def XMM9:  Register<"xmm9">,  DwarfRegNum<[26, -2, -2]>;
152  def XMM10: Register<"xmm10">, DwarfRegNum<[27, -2, -2]>;
153  def XMM11: Register<"xmm11">, DwarfRegNum<[28, -2, -2]>;
154  def XMM12: Register<"xmm12">, DwarfRegNum<[29, -2, -2]>;
155  def XMM13: Register<"xmm13">, DwarfRegNum<[30, -2, -2]>;
156  def XMM14: Register<"xmm14">, DwarfRegNum<[31, -2, -2]>;
157  def XMM15: Register<"xmm15">, DwarfRegNum<[32, -2, -2]>;
158
159  // Floating point stack registers
160  def ST0 : Register<"st(0)">, DwarfRegNum<[33, 12, 11]>;
161  def ST1 : Register<"st(1)">, DwarfRegNum<[34, 13, 12]>;
162  def ST2 : Register<"st(2)">, DwarfRegNum<[35, 14, 13]>;
163  def ST3 : Register<"st(3)">, DwarfRegNum<[36, 15, 14]>;
164  def ST4 : Register<"st(4)">, DwarfRegNum<[37, 16, 15]>;
165  def ST5 : Register<"st(5)">, DwarfRegNum<[38, 17, 16]>;
166  def ST6 : Register<"st(6)">, DwarfRegNum<[39, 18, 17]>;
167  def ST7 : Register<"st(7)">, DwarfRegNum<[40, 19, 18]>; 
168
169  // Status flags register
170  def EFLAGS : Register<"eflags">;
171}
172
173
174//===----------------------------------------------------------------------===//
175// Subregister Set Definitions... now that we have all of the pieces, define the
176// sub registers for each register.
177//
178
179def x86_subreg_8bit    : PatLeaf<(i32 1)>;
180def x86_subreg_16bit   : PatLeaf<(i32 2)>;
181def x86_subreg_32bit   : PatLeaf<(i32 3)>;
182
183def : SubRegSet<1, [AX, CX, DX, BX, SP,  BP,  SI,  DI,  
184                    R8W, R9W, R10W, R11W, R12W, R13W, R14W, R15W],
185                   [AL, CL, DL, BL, SPL, BPL, SIL, DIL, 
186                    R8B, R9B, R10B, R11B, R12B, R13B, R14B, R15B]>;
187
188// It's unclear if this subreg set is safe, given that not all registers
189// in the class have an 'H' subreg.
190// def : SubRegSet<2, [AX, CX, DX, BX],
191//                    [AH, CH, DH, BH]>;
192
193def : SubRegSet<1, [EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,  
194                    R8D, R9D, R10D, R11D, R12D, R13D, R14D, R15D],
195                   [AL, CL, DL, BL, SPL, BPL, SIL, DIL, 
196                    R8B, R9B, R10B, R11B, R12B, R13B, R14B, R15B]>;
197
198def : SubRegSet<2, [EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI,  
199                    R8D, R9D, R10D, R11D, R12D, R13D, R14D, R15D],
200                   [AX,  CX,  DX,  BX,  SP,  BP,  SI,  DI, 
201                    R8W, R9W, R10W, R11W, R12W, R13W, R14W, R15W]>;
202
203
204def : SubRegSet<1, [RAX, RCX, RDX, RBX, RSP, RBP, RSI, RDI,  
205                    R8,  R9,  R10, R11, R12, R13, R14, R15],
206                   [AL, CL, DL, BL, SPL, BPL, SIL, DIL, 
207                    R8B, R9B, R10B, R11B, R12B, R13B, R14B, R15B]>;
208
209def : SubRegSet<2, [RAX, RCX, RDX, RBX, RSP, RBP, RSI, RDI,  
210                    R8,  R9,  R10, R11, R12, R13, R14, R15],
211                   [AX,  CX,  DX,  BX,  SP,  BP,  SI,  DI, 
212                    R8W, R9W, R10W, R11W, R12W, R13W, R14W, R15W]>;
213                    
214def : SubRegSet<3, [RAX, RCX, RDX, RBX, RSP, RBP, RSI, RDI,  
215                    R8,  R9,  R10, R11, R12, R13, R14, R15],
216                   [EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI, 
217                    R8D, R9D, R10D, R11D, R12D, R13D, R14D, R15D]>;
218
219//===----------------------------------------------------------------------===//
220// Register Class Definitions... now that we have all of the pieces, define the
221// top-level register classes.  The order specified in the register list is
222// implicitly defined to be the register allocation order.
223//
224
225// List call-clobbered registers before callee-save registers. RBX, RBP, (and 
226// R12, R13, R14, and R15 for X86-64) are callee-save registers.
227// In 64-mode, there are 12 additional i8 registers, SIL, DIL, BPL, SPL, and
228// R8B, ... R15B. 
229// FIXME: Allow AH, CH, DH, BH in 64-mode for non-REX instructions,
230def GR8 : RegisterClass<"X86", [i8],  8,
231                        [AL, CL, DL, BL, AH, CH, DH, BH, SIL, DIL, BPL, SPL,
232                         R8B, R9B, R10B, R11B, R12B, R13B, R14B, R15B]> {
233  let MethodProtos = [{
234    iterator allocation_order_begin(const MachineFunction &MF) const;
235    iterator allocation_order_end(const MachineFunction &MF) const;
236  }];
237  let MethodBodies = [{
238      // Does the function dedicate RBP / EBP to being a frame ptr?
239      // If so, don't allocate SPL or BPL.
240      static const unsigned X86_GR8_AO_64_fp[] =
241      {X86::AL,   X86::CL,   X86::DL,   X86::SIL, X86::DIL,
242       X86::R8B,  X86::R9B,  X86::R10B, X86::R11B,
243       X86::BL,   X86::R12B, X86::R13B, X86::R14B, X86::R15B};
244      // If not, just don't allocate SPL.
245      static const unsigned X86_GR8_AO_64[] =
246      {X86::AL,   X86::CL,   X86::DL,   X86::SIL, X86::DIL,
247       X86::R8B,  X86::R9B,  X86::R10B, X86::R11B,
248       X86::BL,   X86::R12B, X86::R13B, X86::R14B, X86::R15B, X86::BPL};
249      // In 32-mode, none of the 8-bit registers aliases EBP or ESP.
250      static const unsigned X86_GR8_AO_32[] =
251      {X86::AL, X86::CL, X86::DL, X86::AH, X86::CH, X86::DH, X86::BL, X86::BH};
252
253    GR8Class::iterator
254    GR8Class::allocation_order_begin(const MachineFunction &MF) const {
255      const TargetMachine &TM = MF.getTarget();
256      const TargetRegisterInfo *RI = TM.getRegisterInfo();
257      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
258      if (!Subtarget.is64Bit())
259        return X86_GR8_AO_32;
260      else if (RI->hasFP(MF))
261        return X86_GR8_AO_64_fp;
262      else
263        return X86_GR8_AO_64;
264    }
265
266    GR8Class::iterator
267    GR8Class::allocation_order_end(const MachineFunction &MF) const {
268      const TargetMachine &TM = MF.getTarget();
269      const TargetRegisterInfo *RI = TM.getRegisterInfo();
270      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
271      if (!Subtarget.is64Bit())
272        return X86_GR8_AO_32 + (sizeof(X86_GR8_AO_32) / sizeof(unsigned));
273      else if (RI->hasFP(MF))
274        return X86_GR8_AO_64_fp + (sizeof(X86_GR8_AO_64_fp) / sizeof(unsigned));
275      else
276        return X86_GR8_AO_64 + (sizeof(X86_GR8_AO_64) / sizeof(unsigned));
277    }
278  }];
279}
280
281
282def GR16 : RegisterClass<"X86", [i16], 16,
283                         [AX, CX, DX, SI, DI, BX, BP, SP,
284                          R8W, R9W, R10W, R11W, R12W, R13W, R14W, R15W]> {
285  let SubRegClassList = [GR8];
286  let MethodProtos = [{
287    iterator allocation_order_begin(const MachineFunction &MF) const;
288    iterator allocation_order_end(const MachineFunction &MF) const;
289  }];
290  let MethodBodies = [{
291      // Does the function dedicate RBP / EBP to being a frame ptr?
292      // If so, don't allocate SP or BP.
293      static const unsigned X86_GR16_AO_64_fp[] =
294      {X86::AX,  X86::CX,   X86::DX,   X86::SI,   X86::DI,
295       X86::R8W, X86::R9W,  X86::R10W, X86::R11W,
296       X86::BX,  X86::R12W, X86::R13W, X86::R14W, X86::R15W};
297      static const unsigned X86_GR16_AO_32_fp[] =
298      {X86::AX, X86::CX, X86::DX, X86::SI, X86::DI, X86::BX};
299      // If not, just don't allocate SPL.
300      static const unsigned X86_GR16_AO_64[] =
301      {X86::AX,  X86::CX,   X86::DX,   X86::SI,   X86::DI,
302       X86::R8W, X86::R9W,  X86::R10W, X86::R11W,
303       X86::BX,  X86::R12W, X86::R13W, X86::R14W, X86::R15W, X86::BP};
304      static const unsigned X86_GR16_AO_32[] =
305      {X86::AX, X86::CX, X86::DX, X86::SI, X86::DI, X86::BX, X86::BP};
306
307    GR16Class::iterator
308    GR16Class::allocation_order_begin(const MachineFunction &MF) const {
309      const TargetMachine &TM = MF.getTarget();
310      const TargetRegisterInfo *RI = TM.getRegisterInfo();
311      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
312      if (Subtarget.is64Bit()) {
313        if (RI->hasFP(MF))
314          return X86_GR16_AO_64_fp;
315        else
316          return X86_GR16_AO_64;
317      } else {
318        if (RI->hasFP(MF))
319          return X86_GR16_AO_32_fp;
320        else
321          return X86_GR16_AO_32;
322      }
323    }
324
325    GR16Class::iterator
326    GR16Class::allocation_order_end(const MachineFunction &MF) const {
327      const TargetMachine &TM = MF.getTarget();
328      const TargetRegisterInfo *RI = TM.getRegisterInfo();
329      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
330      if (Subtarget.is64Bit()) {
331        if (RI->hasFP(MF))
332          return X86_GR16_AO_64_fp+(sizeof(X86_GR16_AO_64_fp)/sizeof(unsigned));
333        else
334          return X86_GR16_AO_64 + (sizeof(X86_GR16_AO_64) / sizeof(unsigned));
335      } else {
336        if (RI->hasFP(MF))
337          return X86_GR16_AO_32_fp+(sizeof(X86_GR16_AO_32_fp)/sizeof(unsigned));
338        else
339          return X86_GR16_AO_32 + (sizeof(X86_GR16_AO_32) / sizeof(unsigned));
340      }
341    }
342  }];
343}
344
345
346def GR32 : RegisterClass<"X86", [i32], 32, 
347                         [EAX, ECX, EDX, ESI, EDI, EBX, EBP, ESP,
348                          R8D, R9D, R10D, R11D, R12D, R13D, R14D, R15D]> {
349  let SubRegClassList = [GR8, GR16];
350  let MethodProtos = [{
351    iterator allocation_order_begin(const MachineFunction &MF) const;
352    iterator allocation_order_end(const MachineFunction &MF) const;
353  }];
354  let MethodBodies = [{
355      // Does the function dedicate RBP / EBP to being a frame ptr?
356      // If so, don't allocate ESP or EBP.
357      static const unsigned X86_GR32_AO_64_fp[] =
358      {X86::EAX, X86::ECX,  X86::EDX,  X86::ESI,  X86::EDI,
359       X86::R8D, X86::R9D,  X86::R10D, X86::R11D,
360       X86::EBX, X86::R12D, X86::R13D, X86::R14D, X86::R15D};
361      static const unsigned X86_GR32_AO_32_fp[] =
362      {X86::EAX, X86::ECX, X86::EDX, X86::ESI, X86::EDI, X86::EBX};
363      // If not, just don't allocate SPL.
364      static const unsigned X86_GR32_AO_64[] =
365      {X86::EAX, X86::ECX,  X86::EDX,  X86::ESI,  X86::EDI,
366       X86::R8D, X86::R9D,  X86::R10D, X86::R11D,
367       X86::EBX, X86::R12D, X86::R13D, X86::R14D, X86::R15D, X86::EBP};
368      static const unsigned X86_GR32_AO_32[] =
369      {X86::EAX, X86::ECX, X86::EDX, X86::ESI, X86::EDI, X86::EBX, X86::EBP};
370
371    GR32Class::iterator
372    GR32Class::allocation_order_begin(const MachineFunction &MF) const {
373      const TargetMachine &TM = MF.getTarget();
374      const TargetRegisterInfo *RI = TM.getRegisterInfo();
375      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
376      if (Subtarget.is64Bit()) {
377        if (RI->hasFP(MF))
378          return X86_GR32_AO_64_fp;
379        else
380          return X86_GR32_AO_64;
381      } else {
382        if (RI->hasFP(MF))
383          return X86_GR32_AO_32_fp;
384        else
385          return X86_GR32_AO_32;
386      }
387    }
388
389    GR32Class::iterator
390    GR32Class::allocation_order_end(const MachineFunction &MF) const {
391      const TargetMachine &TM = MF.getTarget();
392      const TargetRegisterInfo *RI = TM.getRegisterInfo();
393      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
394      if (Subtarget.is64Bit()) {
395        if (RI->hasFP(MF))
396          return X86_GR32_AO_64_fp+(sizeof(X86_GR32_AO_64_fp)/sizeof(unsigned));
397        else
398          return X86_GR32_AO_64 + (sizeof(X86_GR32_AO_64) / sizeof(unsigned));
399      } else {
400        if (RI->hasFP(MF))
401          return X86_GR32_AO_32_fp+(sizeof(X86_GR32_AO_32_fp)/sizeof(unsigned));
402        else
403          return X86_GR32_AO_32 + (sizeof(X86_GR32_AO_32) / sizeof(unsigned));
404      }
405    }
406  }];
407}
408
409
410def GR64 : RegisterClass<"X86", [i64], 64, 
411                         [RAX, RCX, RDX, RSI, RDI, R8, R9, R10, R11,
412                          RBX, R12, R13, R14, R15, RBP, RSP]> {
413  let SubRegClassList = [GR8, GR16, GR32];
414  let MethodProtos = [{
415    iterator allocation_order_end(const MachineFunction &MF) const;
416  }];
417  let MethodBodies = [{
418    GR64Class::iterator
419    GR64Class::allocation_order_end(const MachineFunction &MF) const {
420      const TargetMachine &TM = MF.getTarget();
421      const TargetRegisterInfo *RI = TM.getRegisterInfo();
422      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
423      if (!Subtarget.is64Bit())
424        return begin();  // None of these are allocatable in 32-bit.
425      if (RI->hasFP(MF)) // Does the function dedicate RBP to being a frame ptr?
426        return end()-2;  // If so, don't allocate RSP or RBP
427      else
428        return end()-1;  // If not, just don't allocate RSP
429    }
430  }];
431}
432
433
434// GR16, GR32 subclasses which contain registers that have GR8 sub-registers.
435// These should only be used for 32-bit mode.
436def GR16_ : RegisterClass<"X86", [i16], 16, [AX, CX, DX, BX]> {
437  let SubRegClassList = [GR8];
438}
439def GR32_ : RegisterClass<"X86", [i32], 32, [EAX, ECX, EDX, EBX]> {
440  let SubRegClassList = [GR8, GR16];
441}
442
443// Scalar SSE2 floating point registers.
444def FR32 : RegisterClass<"X86", [f32], 32,
445                         [XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7,
446                          XMM8, XMM9, XMM10, XMM11,
447                          XMM12, XMM13, XMM14, XMM15]> {
448  let MethodProtos = [{
449    iterator allocation_order_end(const MachineFunction &MF) const;
450  }];
451  let MethodBodies = [{
452    FR32Class::iterator
453    FR32Class::allocation_order_end(const MachineFunction &MF) const {
454      const TargetMachine &TM = MF.getTarget();
455      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
456      if (!Subtarget.is64Bit())
457        return end()-8; // Only XMM0 to XMM7 are available in 32-bit mode.
458      else
459        return end();
460    }
461  }];
462}
463
464def FR64 : RegisterClass<"X86", [f64], 64,
465                         [XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7,
466                          XMM8, XMM9, XMM10, XMM11,
467                          XMM12, XMM13, XMM14, XMM15]> {
468  let MethodProtos = [{
469    iterator allocation_order_end(const MachineFunction &MF) const;
470  }];
471  let MethodBodies = [{
472    FR64Class::iterator
473    FR64Class::allocation_order_end(const MachineFunction &MF) const {
474      const TargetMachine &TM = MF.getTarget();
475      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
476      if (!Subtarget.is64Bit())
477        return end()-8; // Only XMM0 to XMM7 are available in 32-bit mode.
478      else
479        return end();
480    }
481  }];
482}
483
484
485// FIXME: This sets up the floating point register files as though they are f64
486// values, though they really are f80 values.  This will cause us to spill
487// values as 64-bit quantities instead of 80-bit quantities, which is much much
488// faster on common hardware.  In reality, this should be controlled by a
489// command line option or something.
490
491def RFP32 : RegisterClass<"X86",[f32], 32, [FP0, FP1, FP2, FP3, FP4, FP5, FP6]>;
492def RFP64 : RegisterClass<"X86",[f64], 32, [FP0, FP1, FP2, FP3, FP4, FP5, FP6]>;
493def RFP80 : RegisterClass<"X86",[f80], 32, [FP0, FP1, FP2, FP3, FP4, FP5, FP6]>;
494
495// Floating point stack registers (these are not allocatable by the
496// register allocator - the floating point stackifier is responsible
497// for transforming FPn allocations to STn registers)
498def RST : RegisterClass<"X86", [f80, f64, f32], 32,
499                        [ST0, ST1, ST2, ST3, ST4, ST5, ST6, ST7]> {
500    let MethodProtos = [{
501    iterator allocation_order_end(const MachineFunction &MF) const;
502  }];
503  let MethodBodies = [{
504    RSTClass::iterator
505    RSTClass::allocation_order_end(const MachineFunction &MF) const {
506      return begin();
507    }
508  }];
509}
510
511// Generic vector registers: VR64 and VR128.
512def VR64  : RegisterClass<"X86", [v8i8, v4i16, v2i32, v1i64, v2f32], 64,
513                          [MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7]>;
514def VR128 : RegisterClass<"X86", [v16i8, v8i16, v4i32, v2i64, v4f32, v2f64],128,
515                          [XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7,
516                           XMM8, XMM9, XMM10, XMM11,
517                           XMM12, XMM13, XMM14, XMM15]> {
518  let MethodProtos = [{
519    iterator allocation_order_end(const MachineFunction &MF) const;
520  }];
521  let MethodBodies = [{
522    VR128Class::iterator
523    VR128Class::allocation_order_end(const MachineFunction &MF) const {
524      const TargetMachine &TM = MF.getTarget();
525      const X86Subtarget &Subtarget = TM.getSubtarget<X86Subtarget>();
526      if (!Subtarget.is64Bit())
527        return end()-8; // Only XMM0 to XMM7 are available in 32-bit mode.
528      else
529        return end();
530    }
531  }];
532}
533
534// Status flags registers.
535def CCR : RegisterClass<"X86", [i32], 32, [EFLAGS]> {
536  let CopyCost = -1;  // Don't allow copying of status registers.
537}
538