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1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef  V8_MIPS_CONSTANTS_H_
6 #define  V8_MIPS_CONSTANTS_H_
7 
8 // UNIMPLEMENTED_ macro for MIPS.
9 #ifdef DEBUG
10 #define UNIMPLEMENTED_MIPS()                                                  \
11   v8::internal::PrintF("%s, \tline %d: \tfunction %s not implemented. \n",    \
12                        __FILE__, __LINE__, __func__)
13 #else
14 #define UNIMPLEMENTED_MIPS()
15 #endif
16 
17 #define UNSUPPORTED_MIPS() v8::internal::PrintF("Unsupported instruction.\n")
18 
19 enum ArchVariants {
20   kMips64r2,
21   kMips64r6
22 };
23 
24 
25 #ifdef _MIPS_ARCH_MIPS64R2
26   static const ArchVariants kArchVariant = kMips64r2;
27 #elif  _MIPS_ARCH_MIPS64R6
28   static const ArchVariants kArchVariant = kMips64r6;
29 #else
30   static const ArchVariants kArchVariant = kMips64r2;
31 #endif
32 
33 
34 // TODO(plind): consider deriving ABI from compiler flags or build system.
35 
36 // ABI-dependent definitions are made with #define in simulator-mips64.h,
37 // so the ABI choice must be available to the pre-processor. However, in all
38 // other cases, we should use the enum AbiVariants with normal if statements.
39 
40 #define MIPS_ABI_N64 1
41 // #define MIPS_ABI_O32 1
42 
43 // The only supported Abi's are O32, and n64.
44 enum AbiVariants {
45   kO32,
46   kN64  // Use upper case N for 'n64' ABI to conform to style standard.
47 };
48 
49 #ifdef MIPS_ABI_N64
50 static const AbiVariants kMipsAbi = kN64;
51 #else
52 static const AbiVariants kMipsAbi = kO32;
53 #endif
54 
55 
56 // TODO(plind): consider renaming these ...
57 #if(defined(__mips_hard_float) && __mips_hard_float != 0)
58 // Use floating-point coprocessor instructions. This flag is raised when
59 // -mhard-float is passed to the compiler.
60 const bool IsMipsSoftFloatABI = false;
61 #elif(defined(__mips_soft_float) && __mips_soft_float != 0)
62 // This flag is raised when -msoft-float is passed to the compiler.
63 // Although FPU is a base requirement for v8, soft-float ABI is used
64 // on soft-float systems with FPU kernel emulation.
65 const bool IsMipsSoftFloatABI = true;
66 #else
67 const bool IsMipsSoftFloatABI = true;
68 #endif
69 
70 
71 #ifndef __STDC_FORMAT_MACROS
72 #define __STDC_FORMAT_MACROS
73 #endif
74 #include <inttypes.h>
75 
76 
77 // Defines constants and accessor classes to assemble, disassemble and
78 // simulate MIPS32 instructions.
79 //
80 // See: MIPS32 Architecture For Programmers
81 //      Volume II: The MIPS32 Instruction Set
82 // Try www.cs.cornell.edu/courses/cs3410/2008fa/MIPS_Vol2.pdf.
83 
84 namespace v8 {
85 namespace internal {
86 
87 // -----------------------------------------------------------------------------
88 // Registers and FPURegisters.
89 
90 // Number of general purpose registers.
91 const int kNumRegisters = 32;
92 const int kInvalidRegister = -1;
93 
94 // Number of registers with HI, LO, and pc.
95 const int kNumSimuRegisters = 35;
96 
97 // In the simulator, the PC register is simulated as the 34th register.
98 const int kPCRegister = 34;
99 
100 // Number coprocessor registers.
101 const int kNumFPURegisters = 32;
102 const int kInvalidFPURegister = -1;
103 
104 // FPU (coprocessor 1) control registers. Currently only FCSR is implemented.
105 const int kFCSRRegister = 31;
106 const int kInvalidFPUControlRegister = -1;
107 const uint32_t kFPUInvalidResult = static_cast<uint32_t>(1 << 31) - 1;
108 const uint64_t kFPU64InvalidResult =
109     static_cast<uint64_t>(static_cast<uint64_t>(1) << 63) - 1;
110 
111 // FCSR constants.
112 const uint32_t kFCSRInexactFlagBit = 2;
113 const uint32_t kFCSRUnderflowFlagBit = 3;
114 const uint32_t kFCSROverflowFlagBit = 4;
115 const uint32_t kFCSRDivideByZeroFlagBit = 5;
116 const uint32_t kFCSRInvalidOpFlagBit = 6;
117 
118 const uint32_t kFCSRInexactFlagMask = 1 << kFCSRInexactFlagBit;
119 const uint32_t kFCSRUnderflowFlagMask = 1 << kFCSRUnderflowFlagBit;
120 const uint32_t kFCSROverflowFlagMask = 1 << kFCSROverflowFlagBit;
121 const uint32_t kFCSRDivideByZeroFlagMask = 1 << kFCSRDivideByZeroFlagBit;
122 const uint32_t kFCSRInvalidOpFlagMask = 1 << kFCSRInvalidOpFlagBit;
123 
124 const uint32_t kFCSRFlagMask =
125     kFCSRInexactFlagMask |
126     kFCSRUnderflowFlagMask |
127     kFCSROverflowFlagMask |
128     kFCSRDivideByZeroFlagMask |
129     kFCSRInvalidOpFlagMask;
130 
131 const uint32_t kFCSRExceptionFlagMask = kFCSRFlagMask ^ kFCSRInexactFlagMask;
132 
133 // 'pref' instruction hints
134 const int32_t kPrefHintLoad = 0;
135 const int32_t kPrefHintStore = 1;
136 const int32_t kPrefHintLoadStreamed = 4;
137 const int32_t kPrefHintStoreStreamed = 5;
138 const int32_t kPrefHintLoadRetained = 6;
139 const int32_t kPrefHintStoreRetained = 7;
140 const int32_t kPrefHintWritebackInvalidate = 25;
141 const int32_t kPrefHintPrepareForStore = 30;
142 
143 // Helper functions for converting between register numbers and names.
144 class Registers {
145  public:
146   // Return the name of the register.
147   static const char* Name(int reg);
148 
149   // Lookup the register number for the name provided.
150   static int Number(const char* name);
151 
152   struct RegisterAlias {
153     int reg;
154     const char* name;
155   };
156 
157   static const int64_t kMaxValue = 0x7fffffffffffffffl;
158   static const int64_t kMinValue = 0x8000000000000000l;
159 
160  private:
161   static const char* names_[kNumSimuRegisters];
162   static const RegisterAlias aliases_[];
163 };
164 
165 // Helper functions for converting between register numbers and names.
166 class FPURegisters {
167  public:
168   // Return the name of the register.
169   static const char* Name(int reg);
170 
171   // Lookup the register number for the name provided.
172   static int Number(const char* name);
173 
174   struct RegisterAlias {
175     int creg;
176     const char* name;
177   };
178 
179  private:
180   static const char* names_[kNumFPURegisters];
181   static const RegisterAlias aliases_[];
182 };
183 
184 
185 // -----------------------------------------------------------------------------
186 // Instructions encoding constants.
187 
188 // On MIPS all instructions are 32 bits.
189 typedef int32_t Instr;
190 
191 // Special Software Interrupt codes when used in the presence of the MIPS
192 // simulator.
193 enum SoftwareInterruptCodes {
194   // Transition to C code.
195   call_rt_redirected = 0xfffff
196 };
197 
198 // On MIPS Simulator breakpoints can have different codes:
199 // - Breaks between 0 and kMaxWatchpointCode are treated as simple watchpoints,
200 //   the simulator will run through them and print the registers.
201 // - Breaks between kMaxWatchpointCode and kMaxStopCode are treated as stop()
202 //   instructions (see Assembler::stop()).
203 // - Breaks larger than kMaxStopCode are simple breaks, dropping you into the
204 //   debugger.
205 const uint32_t kMaxWatchpointCode = 31;
206 const uint32_t kMaxStopCode = 127;
207 STATIC_ASSERT(kMaxWatchpointCode < kMaxStopCode);
208 
209 
210 // ----- Fields offset and length.
211 const int kOpcodeShift   = 26;
212 const int kOpcodeBits    = 6;
213 const int kRsShift       = 21;
214 const int kRsBits        = 5;
215 const int kRtShift       = 16;
216 const int kRtBits        = 5;
217 const int kRdShift       = 11;
218 const int kRdBits        = 5;
219 const int kSaShift       = 6;
220 const int kSaBits        = 5;
221 const int kFunctionShift = 0;
222 const int kFunctionBits  = 6;
223 const int kLuiShift      = 16;
224 
225 const int kImm16Shift = 0;
226 const int kImm16Bits  = 16;
227 const int kImm21Shift = 0;
228 const int kImm21Bits  = 21;
229 const int kImm26Shift = 0;
230 const int kImm26Bits  = 26;
231 const int kImm28Shift = 0;
232 const int kImm28Bits  = 28;
233 const int kImm32Shift = 0;
234 const int kImm32Bits  = 32;
235 
236 // In branches and jumps immediate fields point to words, not bytes,
237 // and are therefore shifted by 2.
238 const int kImmFieldShift = 2;
239 
240 const int kFrBits        = 5;
241 const int kFrShift       = 21;
242 const int kFsShift       = 11;
243 const int kFsBits        = 5;
244 const int kFtShift       = 16;
245 const int kFtBits        = 5;
246 const int kFdShift       = 6;
247 const int kFdBits        = 5;
248 const int kFCccShift     = 8;
249 const int kFCccBits      = 3;
250 const int kFBccShift     = 18;
251 const int kFBccBits      = 3;
252 const int kFBtrueShift   = 16;
253 const int kFBtrueBits    = 1;
254 
255 // ----- Miscellaneous useful masks.
256 // Instruction bit masks.
257 const int  kOpcodeMask   = ((1 << kOpcodeBits) - 1) << kOpcodeShift;
258 const int  kImm16Mask    = ((1 << kImm16Bits) - 1) << kImm16Shift;
259 const int  kImm26Mask    = ((1 << kImm26Bits) - 1) << kImm26Shift;
260 const int  kImm28Mask    = ((1 << kImm28Bits) - 1) << kImm28Shift;
261 const int  kRsFieldMask  = ((1 << kRsBits) - 1) << kRsShift;
262 const int  kRtFieldMask  = ((1 << kRtBits) - 1) << kRtShift;
263 const int  kRdFieldMask  = ((1 << kRdBits) - 1) << kRdShift;
264 const int  kSaFieldMask  = ((1 << kSaBits) - 1) << kSaShift;
265 const int  kFunctionFieldMask = ((1 << kFunctionBits) - 1) << kFunctionShift;
266 // Misc masks.
267 const int  kHiMask       =   0xffff << 16;
268 const int  kLoMask       =   0xffff;
269 const int  kSignMask     =   0x80000000;
270 const int  kJumpAddrMask = (1 << (kImm26Bits + kImmFieldShift)) - 1;
271 const int64_t  kHi16MaskOf64 =   (int64_t)0xffff << 48;
272 const int64_t  kSe16MaskOf64 =   (int64_t)0xffff << 32;
273 const int64_t  kTh16MaskOf64 =   (int64_t)0xffff << 16;
274 
275 // ----- MIPS Opcodes and Function Fields.
276 // We use this presentation to stay close to the table representation in
277 // MIPS32 Architecture For Programmers, Volume II: The MIPS32 Instruction Set.
278 enum Opcode {
279   SPECIAL   =   0 << kOpcodeShift,
280   REGIMM    =   1 << kOpcodeShift,
281 
282   J         =   ((0 << 3) + 2) << kOpcodeShift,
283   JAL       =   ((0 << 3) + 3) << kOpcodeShift,
284   BEQ       =   ((0 << 3) + 4) << kOpcodeShift,
285   BNE       =   ((0 << 3) + 5) << kOpcodeShift,
286   BLEZ      =   ((0 << 3) + 6) << kOpcodeShift,
287   BGTZ      =   ((0 << 3) + 7) << kOpcodeShift,
288 
289   ADDI      =   ((1 << 3) + 0) << kOpcodeShift,
290   ADDIU     =   ((1 << 3) + 1) << kOpcodeShift,
291   SLTI      =   ((1 << 3) + 2) << kOpcodeShift,
292   SLTIU     =   ((1 << 3) + 3) << kOpcodeShift,
293   ANDI      =   ((1 << 3) + 4) << kOpcodeShift,
294   ORI       =   ((1 << 3) + 5) << kOpcodeShift,
295   XORI      =   ((1 << 3) + 6) << kOpcodeShift,
296   LUI       =   ((1 << 3) + 7) << kOpcodeShift,  // LUI/AUI family.
297   DAUI      =   ((3 << 3) + 5) << kOpcodeShift,
298 
299   BEQC      =   ((2 << 3) + 0) << kOpcodeShift,
300   COP1      =   ((2 << 3) + 1) << kOpcodeShift,  // Coprocessor 1 class.
301   BEQL      =   ((2 << 3) + 4) << kOpcodeShift,
302   BNEL      =   ((2 << 3) + 5) << kOpcodeShift,
303   BLEZL     =   ((2 << 3) + 6) << kOpcodeShift,
304   BGTZL     =   ((2 << 3) + 7) << kOpcodeShift,
305 
306   DADDI     =   ((3 << 3) + 0) << kOpcodeShift,  // This is also BNEC.
307   DADDIU    =   ((3 << 3) + 1) << kOpcodeShift,
308   LDL       =   ((3 << 3) + 2) << kOpcodeShift,
309   LDR       =   ((3 << 3) + 3) << kOpcodeShift,
310   SPECIAL2  =   ((3 << 3) + 4) << kOpcodeShift,
311   SPECIAL3  =   ((3 << 3) + 7) << kOpcodeShift,
312 
313   LB        =   ((4 << 3) + 0) << kOpcodeShift,
314   LH        =   ((4 << 3) + 1) << kOpcodeShift,
315   LWL       =   ((4 << 3) + 2) << kOpcodeShift,
316   LW        =   ((4 << 3) + 3) << kOpcodeShift,
317   LBU       =   ((4 << 3) + 4) << kOpcodeShift,
318   LHU       =   ((4 << 3) + 5) << kOpcodeShift,
319   LWR       =   ((4 << 3) + 6) << kOpcodeShift,
320   LWU       =   ((4 << 3) + 7) << kOpcodeShift,
321 
322   SB        =   ((5 << 3) + 0) << kOpcodeShift,
323   SH        =   ((5 << 3) + 1) << kOpcodeShift,
324   SWL       =   ((5 << 3) + 2) << kOpcodeShift,
325   SW        =   ((5 << 3) + 3) << kOpcodeShift,
326   SDL       =   ((5 << 3) + 4) << kOpcodeShift,
327   SDR       =   ((5 << 3) + 5) << kOpcodeShift,
328   SWR       =   ((5 << 3) + 6) << kOpcodeShift,
329 
330   LWC1      =   ((6 << 3) + 1) << kOpcodeShift,
331   LLD       =   ((6 << 3) + 4) << kOpcodeShift,
332   LDC1      =   ((6 << 3) + 5) << kOpcodeShift,
333   BEQZC     =   ((6 << 3) + 6) << kOpcodeShift,
334   LD        =   ((6 << 3) + 7) << kOpcodeShift,
335 
336   PREF      =   ((6 << 3) + 3) << kOpcodeShift,
337 
338   SWC1      =   ((7 << 3) + 1) << kOpcodeShift,
339   SCD       =   ((7 << 3) + 4) << kOpcodeShift,
340   SDC1      =   ((7 << 3) + 5) << kOpcodeShift,
341   BNEZC     =   ((7 << 3) + 6) << kOpcodeShift,
342   SD        =   ((7 << 3) + 7) << kOpcodeShift,
343 
344   COP1X     =   ((1 << 4) + 3) << kOpcodeShift
345 };
346 
347 enum SecondaryField {
348   // SPECIAL Encoding of Function Field.
349   SLL       =   ((0 << 3) + 0),
350   MOVCI     =   ((0 << 3) + 1),
351   SRL       =   ((0 << 3) + 2),
352   SRA       =   ((0 << 3) + 3),
353   SLLV      =   ((0 << 3) + 4),
354   SRLV      =   ((0 << 3) + 6),
355   SRAV      =   ((0 << 3) + 7),
356 
357   JR        =   ((1 << 3) + 0),
358   JALR      =   ((1 << 3) + 1),
359   MOVZ      =   ((1 << 3) + 2),
360   MOVN      =   ((1 << 3) + 3),
361   BREAK     =   ((1 << 3) + 5),
362 
363   MFHI      =   ((2 << 3) + 0),
364   CLZ_R6    =   ((2 << 3) + 0),
365   CLO_R6    =   ((2 << 3) + 1),
366   MFLO      =   ((2 << 3) + 2),
367   DSLLV     =   ((2 << 3) + 4),
368   DSRLV     =   ((2 << 3) + 6),
369   DSRAV     =   ((2 << 3) + 7),
370 
371   MULT      =   ((3 << 3) + 0),
372   MULTU     =   ((3 << 3) + 1),
373   DIV       =   ((3 << 3) + 2),
374   DIVU      =   ((3 << 3) + 3),
375   DMULT     =   ((3 << 3) + 4),
376   DMULTU    =   ((3 << 3) + 5),
377   DDIV      =   ((3 << 3) + 6),
378   DDIVU     =   ((3 << 3) + 7),
379 
380   ADD       =   ((4 << 3) + 0),
381   ADDU      =   ((4 << 3) + 1),
382   SUB       =   ((4 << 3) + 2),
383   SUBU      =   ((4 << 3) + 3),
384   AND       =   ((4 << 3) + 4),
385   OR        =   ((4 << 3) + 5),
386   XOR       =   ((4 << 3) + 6),
387   NOR       =   ((4 << 3) + 7),
388 
389   SLT       =   ((5 << 3) + 2),
390   SLTU      =   ((5 << 3) + 3),
391   DADD      =   ((5 << 3) + 4),
392   DADDU     =   ((5 << 3) + 5),
393   DSUB      =   ((5 << 3) + 6),
394   DSUBU     =   ((5 << 3) + 7),
395 
396   TGE       =   ((6 << 3) + 0),
397   TGEU      =   ((6 << 3) + 1),
398   TLT       =   ((6 << 3) + 2),
399   TLTU      =   ((6 << 3) + 3),
400   TEQ       =   ((6 << 3) + 4),
401   SELEQZ_S  =   ((6 << 3) + 5),
402   TNE       =   ((6 << 3) + 6),
403   SELNEZ_S  =   ((6 << 3) + 7),
404 
405   DSLL      =   ((7 << 3) + 0),
406   DSRL      =   ((7 << 3) + 2),
407   DSRA      =   ((7 << 3) + 3),
408   DSLL32    =   ((7 << 3) + 4),
409   DSRL32    =   ((7 << 3) + 6),
410   DSRA32    =   ((7 << 3) + 7),
411 
412   // Multiply integers in r6.
413   MUL_MUH   =   ((3 << 3) + 0),  // MUL, MUH.
414   MUL_MUH_U =   ((3 << 3) + 1),  // MUL_U, MUH_U.
415   D_MUL_MUH =   ((7 << 2) + 0),  // DMUL, DMUH.
416   D_MUL_MUH_U = ((7 << 2) + 1),  // DMUL_U, DMUH_U.
417 
418   MUL_OP    =   ((0 << 3) + 2),
419   MUH_OP    =   ((0 << 3) + 3),
420   DIV_OP    =   ((0 << 3) + 2),
421   MOD_OP    =   ((0 << 3) + 3),
422 
423   DIV_MOD   =   ((3 << 3) + 2),
424   DIV_MOD_U =   ((3 << 3) + 3),
425   D_DIV_MOD =   ((3 << 3) + 6),
426   D_DIV_MOD_U = ((3 << 3) + 7),
427 
428   // drotr in special4?
429 
430   // SPECIAL2 Encoding of Function Field.
431   MUL       =   ((0 << 3) + 2),
432   CLZ       =   ((4 << 3) + 0),
433   CLO       =   ((4 << 3) + 1),
434 
435   // SPECIAL3 Encoding of Function Field.
436   EXT       =   ((0 << 3) + 0),
437   DEXTM     =   ((0 << 3) + 1),
438   DEXTU     =   ((0 << 3) + 2),
439   DEXT      =   ((0 << 3) + 3),
440   INS       =   ((0 << 3) + 4),
441   DINSM     =   ((0 << 3) + 5),
442   DINSU     =   ((0 << 3) + 6),
443   DINS      =   ((0 << 3) + 7),
444 
445   DSBH      =   ((4 << 3) + 4),
446 
447   // REGIMM  encoding of rt Field.
448   BLTZ      =   ((0 << 3) + 0) << 16,
449   BGEZ      =   ((0 << 3) + 1) << 16,
450   BLTZAL    =   ((2 << 3) + 0) << 16,
451   BGEZAL    =   ((2 << 3) + 1) << 16,
452   BGEZALL   =   ((2 << 3) + 3) << 16,
453   DAHI      =   ((0 << 3) + 6) << 16,
454   DATI      =   ((3 << 3) + 6) << 16,
455 
456   // COP1 Encoding of rs Field.
457   MFC1      =   ((0 << 3) + 0) << 21,
458   DMFC1     =   ((0 << 3) + 1) << 21,
459   CFC1      =   ((0 << 3) + 2) << 21,
460   MFHC1     =   ((0 << 3) + 3) << 21,
461   MTC1      =   ((0 << 3) + 4) << 21,
462   DMTC1     =   ((0 << 3) + 5) << 21,
463   CTC1      =   ((0 << 3) + 6) << 21,
464   MTHC1     =   ((0 << 3) + 7) << 21,
465   BC1       =   ((1 << 3) + 0) << 21,
466   S         =   ((2 << 3) + 0) << 21,
467   D         =   ((2 << 3) + 1) << 21,
468   W         =   ((2 << 3) + 4) << 21,
469   L         =   ((2 << 3) + 5) << 21,
470   PS        =   ((2 << 3) + 6) << 21,
471   // COP1 Encoding of Function Field When rs=S.
472   ROUND_L_S =   ((1 << 3) + 0),
473   TRUNC_L_S =   ((1 << 3) + 1),
474   CEIL_L_S  =   ((1 << 3) + 2),
475   FLOOR_L_S =   ((1 << 3) + 3),
476   ROUND_W_S =   ((1 << 3) + 4),
477   TRUNC_W_S =   ((1 << 3) + 5),
478   CEIL_W_S  =   ((1 << 3) + 6),
479   FLOOR_W_S =   ((1 << 3) + 7),
480   CVT_D_S   =   ((4 << 3) + 1),
481   CVT_W_S   =   ((4 << 3) + 4),
482   CVT_L_S   =   ((4 << 3) + 5),
483   CVT_PS_S  =   ((4 << 3) + 6),
484   // COP1 Encoding of Function Field When rs=D.
485   ADD_D     =   ((0 << 3) + 0),
486   SUB_D     =   ((0 << 3) + 1),
487   MUL_D     =   ((0 << 3) + 2),
488   DIV_D     =   ((0 << 3) + 3),
489   SQRT_D    =   ((0 << 3) + 4),
490   ABS_D     =   ((0 << 3) + 5),
491   MOV_D     =   ((0 << 3) + 6),
492   NEG_D     =   ((0 << 3) + 7),
493   ROUND_L_D =   ((1 << 3) + 0),
494   TRUNC_L_D =   ((1 << 3) + 1),
495   CEIL_L_D  =   ((1 << 3) + 2),
496   FLOOR_L_D =   ((1 << 3) + 3),
497   ROUND_W_D =   ((1 << 3) + 4),
498   TRUNC_W_D =   ((1 << 3) + 5),
499   CEIL_W_D  =   ((1 << 3) + 6),
500   FLOOR_W_D =   ((1 << 3) + 7),
501   MIN       =   ((3 << 3) + 4),
502   MINA      =   ((3 << 3) + 5),
503   MAX       =   ((3 << 3) + 6),
504   MAXA      =   ((3 << 3) + 7),
505   CVT_S_D   =   ((4 << 3) + 0),
506   CVT_W_D   =   ((4 << 3) + 4),
507   CVT_L_D   =   ((4 << 3) + 5),
508   C_F_D     =   ((6 << 3) + 0),
509   C_UN_D    =   ((6 << 3) + 1),
510   C_EQ_D    =   ((6 << 3) + 2),
511   C_UEQ_D   =   ((6 << 3) + 3),
512   C_OLT_D   =   ((6 << 3) + 4),
513   C_ULT_D   =   ((6 << 3) + 5),
514   C_OLE_D   =   ((6 << 3) + 6),
515   C_ULE_D   =   ((6 << 3) + 7),
516   // COP1 Encoding of Function Field When rs=W or L.
517   CVT_S_W   =   ((4 << 3) + 0),
518   CVT_D_W   =   ((4 << 3) + 1),
519   CVT_S_L   =   ((4 << 3) + 0),
520   CVT_D_L   =   ((4 << 3) + 1),
521   BC1EQZ    =   ((2 << 2) + 1) << 21,
522   BC1NEZ    =   ((3 << 2) + 1) << 21,
523   // COP1 CMP positive predicates Bit 5..4 = 00.
524   CMP_AF    =   ((0 << 3) + 0),
525   CMP_UN    =   ((0 << 3) + 1),
526   CMP_EQ    =   ((0 << 3) + 2),
527   CMP_UEQ   =   ((0 << 3) + 3),
528   CMP_LT    =   ((0 << 3) + 4),
529   CMP_ULT   =   ((0 << 3) + 5),
530   CMP_LE    =   ((0 << 3) + 6),
531   CMP_ULE   =   ((0 << 3) + 7),
532   CMP_SAF   =   ((1 << 3) + 0),
533   CMP_SUN   =   ((1 << 3) + 1),
534   CMP_SEQ   =   ((1 << 3) + 2),
535   CMP_SUEQ  =   ((1 << 3) + 3),
536   CMP_SSLT  =   ((1 << 3) + 4),
537   CMP_SSULT =   ((1 << 3) + 5),
538   CMP_SLE   =   ((1 << 3) + 6),
539   CMP_SULE  =   ((1 << 3) + 7),
540   // COP1 CMP negative predicates Bit 5..4 = 01.
541   CMP_AT    =   ((2 << 3) + 0),  // Reserved, not implemented.
542   CMP_OR    =   ((2 << 3) + 1),
543   CMP_UNE   =   ((2 << 3) + 2),
544   CMP_NE    =   ((2 << 3) + 3),
545   CMP_UGE   =   ((2 << 3) + 4),  // Reserved, not implemented.
546   CMP_OGE   =   ((2 << 3) + 5),  // Reserved, not implemented.
547   CMP_UGT   =   ((2 << 3) + 6),  // Reserved, not implemented.
548   CMP_OGT   =   ((2 << 3) + 7),  // Reserved, not implemented.
549   CMP_SAT   =   ((3 << 3) + 0),  // Reserved, not implemented.
550   CMP_SOR   =   ((3 << 3) + 1),
551   CMP_SUNE  =   ((3 << 3) + 2),
552   CMP_SNE   =   ((3 << 3) + 3),
553   CMP_SUGE  =   ((3 << 3) + 4),  // Reserved, not implemented.
554   CMP_SOGE  =   ((3 << 3) + 5),  // Reserved, not implemented.
555   CMP_SUGT  =   ((3 << 3) + 6),  // Reserved, not implemented.
556   CMP_SOGT  =   ((3 << 3) + 7),  // Reserved, not implemented.
557 
558   SEL       =   ((2 << 3) + 0),
559   SELEQZ_C  =   ((2 << 3) + 4),  // COP1 on FPR registers.
560   SELNEZ_C  =   ((2 << 3) + 7),  // COP1 on FPR registers.
561 
562   // COP1 Encoding of Function Field When rs=PS.
563   // COP1X Encoding of Function Field.
564   MADD_D    =   ((4 << 3) + 1),
565 
566   NULLSF    =   0
567 };
568 
569 
570 // ----- Emulated conditions.
571 // On MIPS we use this enum to abstract from conditional branch instructions.
572 // The 'U' prefix is used to specify unsigned comparisons.
573 // Opposite conditions must be paired as odd/even numbers
574 // because 'NegateCondition' function flips LSB to negate condition.
575 enum Condition {
576   // Any value < 0 is considered no_condition.
577   kNoCondition  = -1,
578 
579   overflow      =  0,
580   no_overflow   =  1,
581   Uless         =  2,
582   Ugreater_equal=  3,
583   equal         =  4,
584   not_equal     =  5,
585   Uless_equal   =  6,
586   Ugreater      =  7,
587   negative      =  8,
588   positive      =  9,
589   parity_even   = 10,
590   parity_odd    = 11,
591   less          = 12,
592   greater_equal = 13,
593   less_equal    = 14,
594   greater       = 15,
595   ueq           = 16,  // Unordered or Equal.
596   nue           = 17,  // Not (Unordered or Equal).
597 
598   cc_always     = 18,
599 
600   // Aliases.
601   carry         = Uless,
602   not_carry     = Ugreater_equal,
603   zero          = equal,
604   eq            = equal,
605   not_zero      = not_equal,
606   ne            = not_equal,
607   nz            = not_equal,
608   sign          = negative,
609   not_sign      = positive,
610   mi            = negative,
611   pl            = positive,
612   hi            = Ugreater,
613   ls            = Uless_equal,
614   ge            = greater_equal,
615   lt            = less,
616   gt            = greater,
617   le            = less_equal,
618   hs            = Ugreater_equal,
619   lo            = Uless,
620   al            = cc_always,
621 
622   cc_default    = kNoCondition
623 };
624 
625 
626 // Returns the equivalent of !cc.
627 // Negation of the default kNoCondition (-1) results in a non-default
628 // no_condition value (-2). As long as tests for no_condition check
629 // for condition < 0, this will work as expected.
NegateCondition(Condition cc)630 inline Condition NegateCondition(Condition cc) {
631   DCHECK(cc != cc_always);
632   return static_cast<Condition>(cc ^ 1);
633 }
634 
635 
636 // Commute a condition such that {a cond b == b cond' a}.
CommuteCondition(Condition cc)637 inline Condition CommuteCondition(Condition cc) {
638   switch (cc) {
639     case Uless:
640       return Ugreater;
641     case Ugreater:
642       return Uless;
643     case Ugreater_equal:
644       return Uless_equal;
645     case Uless_equal:
646       return Ugreater_equal;
647     case less:
648       return greater;
649     case greater:
650       return less;
651     case greater_equal:
652       return less_equal;
653     case less_equal:
654       return greater_equal;
655     default:
656       return cc;
657   }
658 }
659 
660 
661 // ----- Coprocessor conditions.
662 enum FPUCondition {
663   kNoFPUCondition = -1,
664 
665   F     = 0,  // False.
666   UN    = 1,  // Unordered.
667   EQ    = 2,  // Equal.
668   UEQ   = 3,  // Unordered or Equal.
669   OLT   = 4,  // Ordered or Less Than.
670   ULT   = 5,  // Unordered or Less Than.
671   OLE   = 6,  // Ordered or Less Than or Equal.
672   ULE   = 7   // Unordered or Less Than or Equal.
673 };
674 
675 
676 // FPU rounding modes.
677 enum FPURoundingMode {
678   RN = 0 << 0,  // Round to Nearest.
679   RZ = 1 << 0,  // Round towards zero.
680   RP = 2 << 0,  // Round towards Plus Infinity.
681   RM = 3 << 0,  // Round towards Minus Infinity.
682 
683   // Aliases.
684   kRoundToNearest = RN,
685   kRoundToZero = RZ,
686   kRoundToPlusInf = RP,
687   kRoundToMinusInf = RM
688 };
689 
690 const uint32_t kFPURoundingModeMask = 3 << 0;
691 
692 enum CheckForInexactConversion {
693   kCheckForInexactConversion,
694   kDontCheckForInexactConversion
695 };
696 
697 
698 // -----------------------------------------------------------------------------
699 // Hints.
700 
701 // Branch hints are not used on the MIPS.  They are defined so that they can
702 // appear in shared function signatures, but will be ignored in MIPS
703 // implementations.
704 enum Hint {
705   no_hint = 0
706 };
707 
708 
NegateHint(Hint hint)709 inline Hint NegateHint(Hint hint) {
710   return no_hint;
711 }
712 
713 
714 // -----------------------------------------------------------------------------
715 // Specific instructions, constants, and masks.
716 // These constants are declared in assembler-mips.cc, as they use named
717 // registers and other constants.
718 
719 // addiu(sp, sp, 4) aka Pop() operation or part of Pop(r)
720 // operations as post-increment of sp.
721 extern const Instr kPopInstruction;
722 // addiu(sp, sp, -4) part of Push(r) operation as pre-decrement of sp.
723 extern const Instr kPushInstruction;
724 // sw(r, MemOperand(sp, 0))
725 extern const Instr kPushRegPattern;
726 // lw(r, MemOperand(sp, 0))
727 extern const Instr kPopRegPattern;
728 extern const Instr kLwRegFpOffsetPattern;
729 extern const Instr kSwRegFpOffsetPattern;
730 extern const Instr kLwRegFpNegOffsetPattern;
731 extern const Instr kSwRegFpNegOffsetPattern;
732 // A mask for the Rt register for push, pop, lw, sw instructions.
733 extern const Instr kRtMask;
734 extern const Instr kLwSwInstrTypeMask;
735 extern const Instr kLwSwInstrArgumentMask;
736 extern const Instr kLwSwOffsetMask;
737 
738 // Break 0xfffff, reserved for redirected real time call.
739 const Instr rtCallRedirInstr = SPECIAL | BREAK | call_rt_redirected << 6;
740 // A nop instruction. (Encoding of sll 0 0 0).
741 const Instr nopInstr = 0;
742 
743 class Instruction {
744  public:
745   enum {
746     kInstrSize = 4,
747     kInstrSizeLog2 = 2,
748     // On MIPS PC cannot actually be directly accessed. We behave as if PC was
749     // always the value of the current instruction being executed.
750     kPCReadOffset = 0
751   };
752 
753   // Get the raw instruction bits.
InstructionBits()754   inline Instr InstructionBits() const {
755     return *reinterpret_cast<const Instr*>(this);
756   }
757 
758   // Set the raw instruction bits to value.
SetInstructionBits(Instr value)759   inline void SetInstructionBits(Instr value) {
760     *reinterpret_cast<Instr*>(this) = value;
761   }
762 
763   // Read one particular bit out of the instruction bits.
Bit(int nr)764   inline int Bit(int nr) const {
765     return (InstructionBits() >> nr) & 1;
766   }
767 
768   // Read a bit field out of the instruction bits.
Bits(int hi,int lo)769   inline int Bits(int hi, int lo) const {
770     return (InstructionBits() >> lo) & ((2 << (hi - lo)) - 1);
771   }
772 
773   // Instruction type.
774   enum Type {
775     kRegisterType,
776     kImmediateType,
777     kJumpType,
778     kUnsupported = -1
779   };
780 
781   // Get the encoding type of the instruction.
782   Type InstructionType() const;
783 
784 
785   // Accessors for the different named fields used in the MIPS encoding.
OpcodeValue()786   inline Opcode OpcodeValue() const {
787     return static_cast<Opcode>(
788         Bits(kOpcodeShift + kOpcodeBits - 1, kOpcodeShift));
789   }
790 
RsValue()791   inline int RsValue() const {
792     DCHECK(InstructionType() == kRegisterType ||
793            InstructionType() == kImmediateType);
794     return Bits(kRsShift + kRsBits - 1, kRsShift);
795   }
796 
RtValue()797   inline int RtValue() const {
798     DCHECK(InstructionType() == kRegisterType ||
799            InstructionType() == kImmediateType);
800     return Bits(kRtShift + kRtBits - 1, kRtShift);
801   }
802 
RdValue()803   inline int RdValue() const {
804     DCHECK(InstructionType() == kRegisterType);
805     return Bits(kRdShift + kRdBits - 1, kRdShift);
806   }
807 
SaValue()808   inline int SaValue() const {
809     DCHECK(InstructionType() == kRegisterType);
810     return Bits(kSaShift + kSaBits - 1, kSaShift);
811   }
812 
FunctionValue()813   inline int FunctionValue() const {
814     DCHECK(InstructionType() == kRegisterType ||
815            InstructionType() == kImmediateType);
816     return Bits(kFunctionShift + kFunctionBits - 1, kFunctionShift);
817   }
818 
FdValue()819   inline int FdValue() const {
820     return Bits(kFdShift + kFdBits - 1, kFdShift);
821   }
822 
FsValue()823   inline int FsValue() const {
824     return Bits(kFsShift + kFsBits - 1, kFsShift);
825   }
826 
FtValue()827   inline int FtValue() const {
828     return Bits(kFtShift + kFtBits - 1, kFtShift);
829   }
830 
FrValue()831   inline int FrValue() const {
832     return Bits(kFrShift + kFrBits -1, kFrShift);
833   }
834 
835   // Float Compare condition code instruction bits.
FCccValue()836   inline int FCccValue() const {
837     return Bits(kFCccShift + kFCccBits - 1, kFCccShift);
838   }
839 
840   // Float Branch condition code instruction bits.
FBccValue()841   inline int FBccValue() const {
842     return Bits(kFBccShift + kFBccBits - 1, kFBccShift);
843   }
844 
845   // Float Branch true/false instruction bit.
FBtrueValue()846   inline int FBtrueValue() const {
847     return Bits(kFBtrueShift + kFBtrueBits - 1, kFBtrueShift);
848   }
849 
850   // Return the fields at their original place in the instruction encoding.
OpcodeFieldRaw()851   inline Opcode OpcodeFieldRaw() const {
852     return static_cast<Opcode>(InstructionBits() & kOpcodeMask);
853   }
854 
RsFieldRaw()855   inline int RsFieldRaw() const {
856     DCHECK(InstructionType() == kRegisterType ||
857            InstructionType() == kImmediateType);
858     return InstructionBits() & kRsFieldMask;
859   }
860 
861   // Same as above function, but safe to call within InstructionType().
RsFieldRawNoAssert()862   inline int RsFieldRawNoAssert() const {
863     return InstructionBits() & kRsFieldMask;
864   }
865 
RtFieldRaw()866   inline int RtFieldRaw() const {
867     DCHECK(InstructionType() == kRegisterType ||
868            InstructionType() == kImmediateType);
869     return InstructionBits() & kRtFieldMask;
870   }
871 
RdFieldRaw()872   inline int RdFieldRaw() const {
873     DCHECK(InstructionType() == kRegisterType);
874     return InstructionBits() & kRdFieldMask;
875   }
876 
SaFieldRaw()877   inline int SaFieldRaw() const {
878     DCHECK(InstructionType() == kRegisterType);
879     return InstructionBits() & kSaFieldMask;
880   }
881 
FunctionFieldRaw()882   inline int FunctionFieldRaw() const {
883     return InstructionBits() & kFunctionFieldMask;
884   }
885 
886   // Get the secondary field according to the opcode.
SecondaryValue()887   inline int SecondaryValue() const {
888     Opcode op = OpcodeFieldRaw();
889     switch (op) {
890       case SPECIAL:
891       case SPECIAL2:
892         return FunctionValue();
893       case COP1:
894         return RsValue();
895       case REGIMM:
896         return RtValue();
897       default:
898         return NULLSF;
899     }
900   }
901 
Imm16Value()902   inline int32_t Imm16Value() const {
903     DCHECK(InstructionType() == kImmediateType);
904     return Bits(kImm16Shift + kImm16Bits - 1, kImm16Shift);
905   }
906 
Imm21Value()907   inline int32_t Imm21Value() const {
908     DCHECK(InstructionType() == kImmediateType);
909     return Bits(kImm21Shift + kImm21Bits - 1, kImm21Shift);
910   }
911 
Imm26Value()912   inline int32_t Imm26Value() const {
913     DCHECK(InstructionType() == kJumpType);
914     return Bits(kImm26Shift + kImm26Bits - 1, kImm26Shift);
915   }
916 
917   // Say if the instruction should not be used in a branch delay slot.
918   bool IsForbiddenInBranchDelay() const;
919   // Say if the instruction 'links'. e.g. jal, bal.
920   bool IsLinkingInstruction() const;
921   // Say if the instruction is a break or a trap.
922   bool IsTrap() const;
923 
924   // Instructions are read of out a code stream. The only way to get a
925   // reference to an instruction is to convert a pointer. There is no way
926   // to allocate or create instances of class Instruction.
927   // Use the At(pc) function to create references to Instruction.
At(byte * pc)928   static Instruction* At(byte* pc) {
929     return reinterpret_cast<Instruction*>(pc);
930   }
931 
932  private:
933   // We need to prevent the creation of instances of class Instruction.
934   DISALLOW_IMPLICIT_CONSTRUCTORS(Instruction);
935 };
936 
937 
938 // -----------------------------------------------------------------------------
939 // MIPS assembly various constants.
940 
941 // C/C++ argument slots size.
942 const int kCArgSlotCount = (kMipsAbi == kN64) ? 0 : 4;
943 
944 // TODO(plind): below should be based on kPointerSize
945 // TODO(plind): find all usages and remove the needless instructions for n64.
946 const int kCArgsSlotsSize = kCArgSlotCount * Instruction::kInstrSize * 2;
947 
948 const int kBranchReturnOffset = 2 * Instruction::kInstrSize;
949 
950 } }   // namespace v8::internal
951 
952 #endif    // #ifndef V8_MIPS_CONSTANTS_H_
953