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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 #include "src/globals.h"
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   kMips32r1 = v8::internal::MIPSr1,
21   kMips32r2 = v8::internal::MIPSr2,
22   kMips32r6 = v8::internal::MIPSr6,
23   kLoongson
24 };
25 
26 #ifdef _MIPS_ARCH_MIPS32R2
27   static const ArchVariants kArchVariant = kMips32r2;
28 #elif _MIPS_ARCH_MIPS32R6
29   static const ArchVariants kArchVariant = kMips32r6;
30 #elif _MIPS_ARCH_LOONGSON
31 // The loongson flag refers to the LOONGSON architectures based on MIPS-III,
32 // which predates (and is a subset of) the mips32r2 and r1 architectures.
33   static const ArchVariants kArchVariant = kLoongson;
34 #elif _MIPS_ARCH_MIPS32RX
35 // This flags referred to compatibility mode that creates universal code that
36 // can run on any MIPS32 architecture revision. The dynamically generated code
37 // by v8 is specialized for the MIPS host detected in runtime probing.
38   static const ArchVariants kArchVariant = kMips32r1;
39 #else
40   static const ArchVariants kArchVariant = kMips32r1;
41 #endif
42 
43 enum Endianness {
44   kLittle,
45   kBig
46 };
47 
48 #if defined(V8_TARGET_LITTLE_ENDIAN)
49   static const Endianness kArchEndian = kLittle;
50 #elif defined(V8_TARGET_BIG_ENDIAN)
51   static const Endianness kArchEndian = kBig;
52 #else
53 #error Unknown endianness
54 #endif
55 
56 enum FpuMode {
57   kFP32,
58   kFP64,
59   kFPXX
60 };
61 
62 #if defined(FPU_MODE_FP32)
63   static const FpuMode kFpuMode = kFP32;
64 #elif defined(FPU_MODE_FP64)
65   static const FpuMode kFpuMode = kFP64;
66 #elif defined(FPU_MODE_FPXX)
67 #if defined(_MIPS_ARCH_MIPS32R2) || defined(_MIPS_ARCH_MIPS32R6)
68 static const FpuMode kFpuMode = kFPXX;
69 #else
70 #error "FPXX is supported only on Mips32R2 and Mips32R6"
71 #endif
72 #else
73 static const FpuMode kFpuMode = kFP32;
74 #endif
75 
76 #if(defined(__mips_hard_float) && __mips_hard_float != 0)
77 // Use floating-point coprocessor instructions. This flag is raised when
78 // -mhard-float is passed to the compiler.
79 const bool IsMipsSoftFloatABI = false;
80 #elif(defined(__mips_soft_float) && __mips_soft_float != 0)
81 // This flag is raised when -msoft-float is passed to the compiler.
82 // Although FPU is a base requirement for v8, soft-float ABI is used
83 // on soft-float systems with FPU kernel emulation.
84 const bool IsMipsSoftFloatABI = true;
85 #else
86 const bool IsMipsSoftFloatABI = true;
87 #endif
88 
89 #if defined(V8_TARGET_LITTLE_ENDIAN)
90 const uint32_t kHoleNanUpper32Offset = 4;
91 const uint32_t kHoleNanLower32Offset = 0;
92 #elif defined(V8_TARGET_BIG_ENDIAN)
93 const uint32_t kHoleNanUpper32Offset = 0;
94 const uint32_t kHoleNanLower32Offset = 4;
95 #else
96 #error Unknown endianness
97 #endif
98 
99 #define IsFp64Mode() (kFpuMode == kFP64)
100 #define IsFp32Mode() (kFpuMode == kFP32)
101 #define IsFpxxMode() (kFpuMode == kFPXX)
102 
103 #ifndef _MIPS_ARCH_MIPS32RX
104 #define IsMipsArchVariant(check) \
105   (kArchVariant == check)
106 #else
107 #define IsMipsArchVariant(check) \
108   (CpuFeatures::IsSupported(static_cast<CpuFeature>(check)))
109 #endif
110 
111 #if defined(V8_TARGET_LITTLE_ENDIAN)
112 const uint32_t kMipsLwrOffset = 0;
113 const uint32_t kMipsLwlOffset = 3;
114 const uint32_t kMipsSwrOffset = 0;
115 const uint32_t kMipsSwlOffset = 3;
116 #elif defined(V8_TARGET_BIG_ENDIAN)
117 const uint32_t kMipsLwrOffset = 3;
118 const uint32_t kMipsLwlOffset = 0;
119 const uint32_t kMipsSwrOffset = 3;
120 const uint32_t kMipsSwlOffset = 0;
121 #else
122 #error Unknown endianness
123 #endif
124 
125 #define __STDC_FORMAT_MACROS
126 #include <inttypes.h>
127 
128 // Defines constants and accessor classes to assemble, disassemble and
129 // simulate MIPS32 instructions.
130 //
131 // See: MIPS32 Architecture For Programmers
132 //      Volume II: The MIPS32 Instruction Set
133 // Try www.cs.cornell.edu/courses/cs3410/2008fa/MIPS_Vol2.pdf.
134 
135 namespace v8 {
136 namespace internal {
137 
138 // -----------------------------------------------------------------------------
139 // Registers and FPURegisters.
140 
141 // Number of general purpose registers.
142 const int kNumRegisters = 32;
143 const int kInvalidRegister = -1;
144 
145 // Number of registers with HI, LO, and pc.
146 const int kNumSimuRegisters = 35;
147 
148 // In the simulator, the PC register is simulated as the 34th register.
149 const int kPCRegister = 34;
150 
151 // Number coprocessor registers.
152 const int kNumFPURegisters = 32;
153 const int kInvalidFPURegister = -1;
154 
155 // FPU (coprocessor 1) control registers. Currently only FCSR is implemented.
156 const int kFCSRRegister = 31;
157 const int kInvalidFPUControlRegister = -1;
158 const uint32_t kFPUInvalidResult = static_cast<uint32_t>(1 << 31) - 1;
159 const int32_t kFPUInvalidResultNegative = static_cast<int32_t>(1 << 31);
160 const uint64_t kFPU64InvalidResult =
161     static_cast<uint64_t>(static_cast<uint64_t>(1) << 63) - 1;
162 const int64_t kFPU64InvalidResultNegative =
163     static_cast<int64_t>(static_cast<uint64_t>(1) << 63);
164 
165 // FCSR constants.
166 const uint32_t kFCSRInexactFlagBit = 2;
167 const uint32_t kFCSRUnderflowFlagBit = 3;
168 const uint32_t kFCSROverflowFlagBit = 4;
169 const uint32_t kFCSRDivideByZeroFlagBit = 5;
170 const uint32_t kFCSRInvalidOpFlagBit = 6;
171 const uint32_t kFCSRNaN2008FlagBit = 18;
172 
173 const uint32_t kFCSRInexactFlagMask = 1 << kFCSRInexactFlagBit;
174 const uint32_t kFCSRUnderflowFlagMask = 1 << kFCSRUnderflowFlagBit;
175 const uint32_t kFCSROverflowFlagMask = 1 << kFCSROverflowFlagBit;
176 const uint32_t kFCSRDivideByZeroFlagMask = 1 << kFCSRDivideByZeroFlagBit;
177 const uint32_t kFCSRInvalidOpFlagMask = 1 << kFCSRInvalidOpFlagBit;
178 const uint32_t kFCSRNaN2008FlagMask = 1 << kFCSRNaN2008FlagBit;
179 
180 const uint32_t kFCSRFlagMask =
181     kFCSRInexactFlagMask |
182     kFCSRUnderflowFlagMask |
183     kFCSROverflowFlagMask |
184     kFCSRDivideByZeroFlagMask |
185     kFCSRInvalidOpFlagMask;
186 
187 const uint32_t kFCSRExceptionFlagMask = kFCSRFlagMask ^ kFCSRInexactFlagMask;
188 
189 // 'pref' instruction hints
190 const int32_t kPrefHintLoad = 0;
191 const int32_t kPrefHintStore = 1;
192 const int32_t kPrefHintLoadStreamed = 4;
193 const int32_t kPrefHintStoreStreamed = 5;
194 const int32_t kPrefHintLoadRetained = 6;
195 const int32_t kPrefHintStoreRetained = 7;
196 const int32_t kPrefHintWritebackInvalidate = 25;
197 const int32_t kPrefHintPrepareForStore = 30;
198 
199 // Helper functions for converting between register numbers and names.
200 class Registers {
201  public:
202   // Return the name of the register.
203   static const char* Name(int reg);
204 
205   // Lookup the register number for the name provided.
206   static int Number(const char* name);
207 
208   struct RegisterAlias {
209     int reg;
210     const char* name;
211   };
212 
213   static const int32_t kMaxValue = 0x7fffffff;
214   static const int32_t kMinValue = 0x80000000;
215 
216  private:
217   static const char* names_[kNumSimuRegisters];
218   static const RegisterAlias aliases_[];
219 };
220 
221 // Helper functions for converting between register numbers and names.
222 class FPURegisters {
223  public:
224   // Return the name of the register.
225   static const char* Name(int reg);
226 
227   // Lookup the register number for the name provided.
228   static int Number(const char* name);
229 
230   struct RegisterAlias {
231     int creg;
232     const char* name;
233   };
234 
235  private:
236   static const char* names_[kNumFPURegisters];
237   static const RegisterAlias aliases_[];
238 };
239 
240 
241 // -----------------------------------------------------------------------------
242 // Instructions encoding constants.
243 
244 // On MIPS all instructions are 32 bits.
245 typedef int32_t Instr;
246 
247 // Special Software Interrupt codes when used in the presence of the MIPS
248 // simulator.
249 enum SoftwareInterruptCodes {
250   // Transition to C code.
251   call_rt_redirected = 0xfffff
252 };
253 
254 // On MIPS Simulator breakpoints can have different codes:
255 // - Breaks between 0 and kMaxWatchpointCode are treated as simple watchpoints,
256 //   the simulator will run through them and print the registers.
257 // - Breaks between kMaxWatchpointCode and kMaxStopCode are treated as stop()
258 //   instructions (see Assembler::stop()).
259 // - Breaks larger than kMaxStopCode are simple breaks, dropping you into the
260 //   debugger.
261 const uint32_t kMaxWatchpointCode = 31;
262 const uint32_t kMaxStopCode = 127;
263 STATIC_ASSERT(kMaxWatchpointCode < kMaxStopCode);
264 
265 
266 // ----- Fields offset and length.
267 const int kOpcodeShift   = 26;
268 const int kOpcodeBits    = 6;
269 const int kRsShift       = 21;
270 const int kRsBits        = 5;
271 const int kRtShift       = 16;
272 const int kRtBits        = 5;
273 const int kRdShift       = 11;
274 const int kRdBits        = 5;
275 const int kSaShift       = 6;
276 const int kSaBits        = 5;
277 const int kLsaSaBits = 2;
278 const int kFunctionShift = 0;
279 const int kFunctionBits  = 6;
280 const int kLuiShift      = 16;
281 const int kBp2Shift = 6;
282 const int kBp2Bits = 2;
283 
284 const int kImm16Shift = 0;
285 const int kImm16Bits  = 16;
286 const int kImm18Shift = 0;
287 const int kImm18Bits = 18;
288 const int kImm19Shift = 0;
289 const int kImm19Bits = 19;
290 const int kImm21Shift = 0;
291 const int kImm21Bits  = 21;
292 const int kImm26Shift = 0;
293 const int kImm26Bits  = 26;
294 const int kImm28Shift = 0;
295 const int kImm28Bits  = 28;
296 const int kImm32Shift = 0;
297 const int kImm32Bits  = 32;
298 
299 // In branches and jumps immediate fields point to words, not bytes,
300 // and are therefore shifted by 2.
301 const int kImmFieldShift = 2;
302 
303 const int kFrBits        = 5;
304 const int kFrShift       = 21;
305 const int kFsShift       = 11;
306 const int kFsBits        = 5;
307 const int kFtShift       = 16;
308 const int kFtBits        = 5;
309 const int kFdShift       = 6;
310 const int kFdBits        = 5;
311 const int kFCccShift     = 8;
312 const int kFCccBits      = 3;
313 const int kFBccShift     = 18;
314 const int kFBccBits      = 3;
315 const int kFBtrueShift   = 16;
316 const int kFBtrueBits    = 1;
317 
318 // ----- Miscellaneous useful masks.
319 // Instruction bit masks.
320 const int kOpcodeMask = ((1 << kOpcodeBits) - 1) << kOpcodeShift;
321 const int kImm16Mask = ((1 << kImm16Bits) - 1) << kImm16Shift;
322 const int kImm18Mask = ((1 << kImm18Bits) - 1) << kImm18Shift;
323 const int kImm19Mask = ((1 << kImm19Bits) - 1) << kImm19Shift;
324 const int kImm21Mask = ((1 << kImm21Bits) - 1) << kImm21Shift;
325 const int kImm26Mask = ((1 << kImm26Bits) - 1) << kImm26Shift;
326 const int kImm28Mask = ((1 << kImm28Bits) - 1) << kImm28Shift;
327 const int kRsFieldMask = ((1 << kRsBits) - 1) << kRsShift;
328 const int kRtFieldMask = ((1 << kRtBits) - 1) << kRtShift;
329 const int kRdFieldMask = ((1 << kRdBits) - 1) << kRdShift;
330 const int kSaFieldMask = ((1 << kSaBits) - 1) << kSaShift;
331 const int kFunctionFieldMask = ((1 << kFunctionBits) - 1) << kFunctionShift;
332 // Misc masks.
333 const int kHiMask = 0xffff << 16;
334 const int kLoMask = 0xffff;
335 const int kSignMask = 0x80000000;
336 const int kJumpAddrMask = (1 << (kImm26Bits + kImmFieldShift)) - 1;
337 
338 // ----- MIPS Opcodes and Function Fields.
339 // We use this presentation to stay close to the table representation in
340 // MIPS32 Architecture For Programmers, Volume II: The MIPS32 Instruction Set.
341 enum Opcode : uint32_t {
342   SPECIAL = 0U << kOpcodeShift,
343   REGIMM = 1U << kOpcodeShift,
344 
345   J = ((0U << 3) + 2) << kOpcodeShift,
346   JAL = ((0U << 3) + 3) << kOpcodeShift,
347   BEQ = ((0U << 3) + 4) << kOpcodeShift,
348   BNE = ((0U << 3) + 5) << kOpcodeShift,
349   BLEZ = ((0U << 3) + 6) << kOpcodeShift,
350   BGTZ = ((0U << 3) + 7) << kOpcodeShift,
351 
352   ADDI = ((1U << 3) + 0) << kOpcodeShift,
353   ADDIU = ((1U << 3) + 1) << kOpcodeShift,
354   SLTI = ((1U << 3) + 2) << kOpcodeShift,
355   SLTIU = ((1U << 3) + 3) << kOpcodeShift,
356   ANDI = ((1U << 3) + 4) << kOpcodeShift,
357   ORI = ((1U << 3) + 5) << kOpcodeShift,
358   XORI = ((1U << 3) + 6) << kOpcodeShift,
359   LUI = ((1U << 3) + 7) << kOpcodeShift,  // LUI/AUI family.
360 
361   BEQC = ((2U << 3) + 0) << kOpcodeShift,
362   COP1 = ((2U << 3) + 1) << kOpcodeShift,  // Coprocessor 1 class.
363   BEQL = ((2U << 3) + 4) << kOpcodeShift,
364   BNEL = ((2U << 3) + 5) << kOpcodeShift,
365   BLEZL = ((2U << 3) + 6) << kOpcodeShift,
366   BGTZL = ((2U << 3) + 7) << kOpcodeShift,
367 
368   DADDI = ((3U << 3) + 0) << kOpcodeShift,  // This is also BNEC.
369   SPECIAL2 = ((3U << 3) + 4) << kOpcodeShift,
370   SPECIAL3 = ((3U << 3) + 7) << kOpcodeShift,
371 
372   LB = ((4U << 3) + 0) << kOpcodeShift,
373   LH = ((4U << 3) + 1) << kOpcodeShift,
374   LWL = ((4U << 3) + 2) << kOpcodeShift,
375   LW = ((4U << 3) + 3) << kOpcodeShift,
376   LBU = ((4U << 3) + 4) << kOpcodeShift,
377   LHU = ((4U << 3) + 5) << kOpcodeShift,
378   LWR = ((4U << 3) + 6) << kOpcodeShift,
379   SB = ((5U << 3) + 0) << kOpcodeShift,
380   SH = ((5U << 3) + 1) << kOpcodeShift,
381   SWL = ((5U << 3) + 2) << kOpcodeShift,
382   SW = ((5U << 3) + 3) << kOpcodeShift,
383   SWR = ((5U << 3) + 6) << kOpcodeShift,
384 
385   LWC1 = ((6U << 3) + 1) << kOpcodeShift,
386   BC = ((6U << 3) + 2) << kOpcodeShift,
387   LDC1 = ((6U << 3) + 5) << kOpcodeShift,
388   POP66 = ((6U << 3) + 6) << kOpcodeShift,  // beqzc, jic
389 
390   PREF = ((6U << 3) + 3) << kOpcodeShift,
391 
392   SWC1 = ((7U << 3) + 1) << kOpcodeShift,
393   BALC = ((7U << 3) + 2) << kOpcodeShift,
394   PCREL = ((7U << 3) + 3) << kOpcodeShift,
395   SDC1 = ((7U << 3) + 5) << kOpcodeShift,
396   POP76 = ((7U << 3) + 6) << kOpcodeShift,  // bnezc, jialc
397 
398   COP1X = ((1U << 4) + 3) << kOpcodeShift,
399 
400   // New r6 instruction.
401   POP06 = BLEZ,   // bgeuc/bleuc, blezalc, bgezalc
402   POP07 = BGTZ,   // bltuc/bgtuc, bgtzalc, bltzalc
403   POP10 = ADDI,   // beqzalc, bovc, beqc
404   POP26 = BLEZL,  // bgezc, blezc, bgec/blec
405   POP27 = BGTZL,  // bgtzc, bltzc, bltc/bgtc
406   POP30 = DADDI,  // bnezalc, bnvc, bnec
407 };
408 
409 enum SecondaryField : uint32_t {
410   // SPECIAL Encoding of Function Field.
411   SLL = ((0U << 3) + 0),
412   MOVCI = ((0U << 3) + 1),
413   SRL = ((0U << 3) + 2),
414   SRA = ((0U << 3) + 3),
415   SLLV = ((0U << 3) + 4),
416   LSA = ((0U << 3) + 5),
417   SRLV = ((0U << 3) + 6),
418   SRAV = ((0U << 3) + 7),
419 
420   JR = ((1U << 3) + 0),
421   JALR = ((1U << 3) + 1),
422   MOVZ = ((1U << 3) + 2),
423   MOVN = ((1U << 3) + 3),
424   BREAK = ((1U << 3) + 5),
425   SYNC = ((1U << 3) + 7),
426 
427   MFHI = ((2U << 3) + 0),
428   CLZ_R6 = ((2U << 3) + 0),
429   CLO_R6 = ((2U << 3) + 1),
430   MFLO = ((2U << 3) + 2),
431 
432   MULT = ((3U << 3) + 0),
433   MULTU = ((3U << 3) + 1),
434   DIV = ((3U << 3) + 2),
435   DIVU = ((3U << 3) + 3),
436 
437   ADD = ((4U << 3) + 0),
438   ADDU = ((4U << 3) + 1),
439   SUB = ((4U << 3) + 2),
440   SUBU = ((4U << 3) + 3),
441   AND = ((4U << 3) + 4),
442   OR = ((4U << 3) + 5),
443   XOR = ((4U << 3) + 6),
444   NOR = ((4U << 3) + 7),
445 
446   SLT = ((5U << 3) + 2),
447   SLTU = ((5U << 3) + 3),
448 
449   TGE = ((6U << 3) + 0),
450   TGEU = ((6U << 3) + 1),
451   TLT = ((6U << 3) + 2),
452   TLTU = ((6U << 3) + 3),
453   TEQ = ((6U << 3) + 4),
454   SELEQZ_S = ((6U << 3) + 5),
455   TNE = ((6U << 3) + 6),
456   SELNEZ_S = ((6U << 3) + 7),
457 
458   // Multiply integers in r6.
459   MUL_MUH = ((3U << 3) + 0),    // MUL, MUH.
460   MUL_MUH_U = ((3U << 3) + 1),  // MUL_U, MUH_U.
461   RINT = ((3U << 3) + 2),
462 
463   MUL_OP = ((0U << 3) + 2),
464   MUH_OP = ((0U << 3) + 3),
465   DIV_OP = ((0U << 3) + 2),
466   MOD_OP = ((0U << 3) + 3),
467 
468   DIV_MOD = ((3U << 3) + 2),
469   DIV_MOD_U = ((3U << 3) + 3),
470 
471   // SPECIAL2 Encoding of Function Field.
472   MUL = ((0U << 3) + 2),
473   CLZ = ((4U << 3) + 0),
474   CLO = ((4U << 3) + 1),
475 
476   // SPECIAL3 Encoding of Function Field.
477   EXT = ((0U << 3) + 0),
478   INS = ((0U << 3) + 4),
479   BSHFL = ((4U << 3) + 0),
480 
481   // SPECIAL3 Encoding of sa Field.
482   BITSWAP = ((0U << 3) + 0),
483   ALIGN = ((0U << 3) + 2),
484   WSBH = ((0U << 3) + 2),
485   SEB = ((2U << 3) + 0),
486   SEH = ((3U << 3) + 0),
487 
488   // REGIMM  encoding of rt Field.
489   BLTZ = ((0U << 3) + 0) << 16,
490   BGEZ = ((0U << 3) + 1) << 16,
491   BLTZAL = ((2U << 3) + 0) << 16,
492   BGEZAL = ((2U << 3) + 1) << 16,
493   BGEZALL = ((2U << 3) + 3) << 16,
494 
495   // COP1 Encoding of rs Field.
496   MFC1 = ((0U << 3) + 0) << 21,
497   CFC1 = ((0U << 3) + 2) << 21,
498   MFHC1 = ((0U << 3) + 3) << 21,
499   MTC1 = ((0U << 3) + 4) << 21,
500   CTC1 = ((0U << 3) + 6) << 21,
501   MTHC1 = ((0U << 3) + 7) << 21,
502   BC1 = ((1U << 3) + 0) << 21,
503   S = ((2U << 3) + 0) << 21,
504   D = ((2U << 3) + 1) << 21,
505   W = ((2U << 3) + 4) << 21,
506   L = ((2U << 3) + 5) << 21,
507   PS = ((2U << 3) + 6) << 21,
508   // COP1 Encoding of Function Field When rs=S.
509 
510   ADD_S = ((0U << 3) + 0),
511   SUB_S = ((0U << 3) + 1),
512   MUL_S = ((0U << 3) + 2),
513   DIV_S = ((0U << 3) + 3),
514   ABS_S = ((0U << 3) + 5),
515   SQRT_S = ((0U << 3) + 4),
516   MOV_S = ((0U << 3) + 6),
517   NEG_S = ((0U << 3) + 7),
518   ROUND_L_S = ((1U << 3) + 0),
519   TRUNC_L_S = ((1U << 3) + 1),
520   CEIL_L_S = ((1U << 3) + 2),
521   FLOOR_L_S = ((1U << 3) + 3),
522   ROUND_W_S = ((1U << 3) + 4),
523   TRUNC_W_S = ((1U << 3) + 5),
524   CEIL_W_S = ((1U << 3) + 6),
525   FLOOR_W_S = ((1U << 3) + 7),
526   RECIP_S = ((2U << 3) + 5),
527   RSQRT_S = ((2U << 3) + 6),
528   MADDF_S = ((3U << 3) + 0),
529   MSUBF_S = ((3U << 3) + 1),
530   CLASS_S = ((3U << 3) + 3),
531   CVT_D_S = ((4U << 3) + 1),
532   CVT_W_S = ((4U << 3) + 4),
533   CVT_L_S = ((4U << 3) + 5),
534   CVT_PS_S = ((4U << 3) + 6),
535 
536   // COP1 Encoding of Function Field When rs=D.
537   ADD_D = ((0U << 3) + 0),
538   SUB_D = ((0U << 3) + 1),
539   MUL_D = ((0U << 3) + 2),
540   DIV_D = ((0U << 3) + 3),
541   SQRT_D = ((0U << 3) + 4),
542   ABS_D = ((0U << 3) + 5),
543   MOV_D = ((0U << 3) + 6),
544   NEG_D = ((0U << 3) + 7),
545   ROUND_L_D = ((1U << 3) + 0),
546   TRUNC_L_D = ((1U << 3) + 1),
547   CEIL_L_D = ((1U << 3) + 2),
548   FLOOR_L_D = ((1U << 3) + 3),
549   ROUND_W_D = ((1U << 3) + 4),
550   TRUNC_W_D = ((1U << 3) + 5),
551   CEIL_W_D = ((1U << 3) + 6),
552   FLOOR_W_D = ((1U << 3) + 7),
553   RECIP_D = ((2U << 3) + 5),
554   RSQRT_D = ((2U << 3) + 6),
555   MADDF_D = ((3U << 3) + 0),
556   MSUBF_D = ((3U << 3) + 1),
557   CLASS_D = ((3U << 3) + 3),
558   MIN = ((3U << 3) + 4),
559   MINA = ((3U << 3) + 5),
560   MAX = ((3U << 3) + 6),
561   MAXA = ((3U << 3) + 7),
562   CVT_S_D = ((4U << 3) + 0),
563   CVT_W_D = ((4U << 3) + 4),
564   CVT_L_D = ((4U << 3) + 5),
565   C_F_D = ((6U << 3) + 0),
566   C_UN_D = ((6U << 3) + 1),
567   C_EQ_D = ((6U << 3) + 2),
568   C_UEQ_D = ((6U << 3) + 3),
569   C_OLT_D = ((6U << 3) + 4),
570   C_ULT_D = ((6U << 3) + 5),
571   C_OLE_D = ((6U << 3) + 6),
572   C_ULE_D = ((6U << 3) + 7),
573 
574   // COP1 Encoding of Function Field When rs=W or L.
575   CVT_S_W = ((4U << 3) + 0),
576   CVT_D_W = ((4U << 3) + 1),
577   CVT_S_L = ((4U << 3) + 0),
578   CVT_D_L = ((4U << 3) + 1),
579   BC1EQZ = ((2U << 2) + 1) << 21,
580   BC1NEZ = ((3U << 2) + 1) << 21,
581   // COP1 CMP positive predicates Bit 5..4 = 00.
582   CMP_AF = ((0U << 3) + 0),
583   CMP_UN = ((0U << 3) + 1),
584   CMP_EQ = ((0U << 3) + 2),
585   CMP_UEQ = ((0U << 3) + 3),
586   CMP_LT = ((0U << 3) + 4),
587   CMP_ULT = ((0U << 3) + 5),
588   CMP_LE = ((0U << 3) + 6),
589   CMP_ULE = ((0U << 3) + 7),
590   CMP_SAF = ((1U << 3) + 0),
591   CMP_SUN = ((1U << 3) + 1),
592   CMP_SEQ = ((1U << 3) + 2),
593   CMP_SUEQ = ((1U << 3) + 3),
594   CMP_SSLT = ((1U << 3) + 4),
595   CMP_SSULT = ((1U << 3) + 5),
596   CMP_SLE = ((1U << 3) + 6),
597   CMP_SULE = ((1U << 3) + 7),
598   // COP1 CMP negative predicates Bit 5..4 = 01.
599   CMP_AT = ((2U << 3) + 0),  // Reserved, not implemented.
600   CMP_OR = ((2U << 3) + 1),
601   CMP_UNE = ((2U << 3) + 2),
602   CMP_NE = ((2U << 3) + 3),
603   CMP_UGE = ((2U << 3) + 4),  // Reserved, not implemented.
604   CMP_OGE = ((2U << 3) + 5),  // Reserved, not implemented.
605   CMP_UGT = ((2U << 3) + 6),  // Reserved, not implemented.
606   CMP_OGT = ((2U << 3) + 7),  // Reserved, not implemented.
607   CMP_SAT = ((3U << 3) + 0),  // Reserved, not implemented.
608   CMP_SOR = ((3U << 3) + 1),
609   CMP_SUNE = ((3U << 3) + 2),
610   CMP_SNE = ((3U << 3) + 3),
611   CMP_SUGE = ((3U << 3) + 4),  // Reserved, not implemented.
612   CMP_SOGE = ((3U << 3) + 5),  // Reserved, not implemented.
613   CMP_SUGT = ((3U << 3) + 6),  // Reserved, not implemented.
614   CMP_SOGT = ((3U << 3) + 7),  // Reserved, not implemented.
615 
616   SEL = ((2U << 3) + 0),
617   MOVZ_C = ((2U << 3) + 2),
618   MOVN_C = ((2U << 3) + 3),
619   SELEQZ_C = ((2U << 3) + 4),  // COP1 on FPR registers.
620   MOVF = ((2U << 3) + 1),      // Function field for MOVT.fmt and MOVF.fmt
621   SELNEZ_C = ((2U << 3) + 7),  // COP1 on FPR registers.
622   // COP1 Encoding of Function Field When rs=PS.
623 
624   // COP1X Encoding of Function Field.
625   MADD_S = ((4U << 3) + 0),
626   MADD_D = ((4U << 3) + 1),
627   MSUB_S = ((5U << 3) + 0),
628   MSUB_D = ((5U << 3) + 1),
629 
630   // PCREL Encoding of rt Field.
631   ADDIUPC = ((0U << 2) + 0),
632   LWPC = ((0U << 2) + 1),
633   AUIPC = ((3U << 3) + 6),
634   ALUIPC = ((3U << 3) + 7),
635 
636   // POP66 Encoding of rs Field.
637   JIC = ((0U << 5) + 0),
638 
639   // POP76 Encoding of rs Field.
640   JIALC = ((0U << 5) + 0),
641 
642   NULLSF = 0U
643 };
644 
645 // ----- Emulated conditions.
646 // On MIPS we use this enum to abstract from conditional branch instructions.
647 // The 'U' prefix is used to specify unsigned comparisons.
648 // Opposite conditions must be paired as odd/even numbers
649 // because 'NegateCondition' function flips LSB to negate condition.
650 enum Condition {
651   // Any value < 0 is considered no_condition.
652   kNoCondition = -1,
653   overflow = 0,
654   no_overflow = 1,
655   Uless = 2,
656   Ugreater_equal = 3,
657   Uless_equal = 4,
658   Ugreater = 5,
659   equal = 6,
660   not_equal = 7,  // Unordered or Not Equal.
661   negative = 8,
662   positive = 9,
663   parity_even = 10,
664   parity_odd = 11,
665   less = 12,
666   greater_equal = 13,
667   less_equal = 14,
668   greater = 15,
669   ueq = 16,  // Unordered or Equal.
670   ogl = 17,  // Ordered and Not Equal.
671   cc_always = 18,
672 
673   // Aliases.
674   carry = Uless,
675   not_carry = Ugreater_equal,
676   zero = equal,
677   eq = equal,
678   not_zero = not_equal,
679   ne = not_equal,
680   nz = not_equal,
681   sign = negative,
682   not_sign = positive,
683   mi = negative,
684   pl = positive,
685   hi = Ugreater,
686   ls = Uless_equal,
687   ge = greater_equal,
688   lt = less,
689   gt = greater,
690   le = less_equal,
691   hs = Ugreater_equal,
692   lo = Uless,
693   al = cc_always,
694   ult = Uless,
695   uge = Ugreater_equal,
696   ule = Uless_equal,
697   ugt = Ugreater,
698   cc_default = kNoCondition
699 };
700 
701 
702 // Returns the equivalent of !cc.
703 // Negation of the default kNoCondition (-1) results in a non-default
704 // no_condition value (-2). As long as tests for no_condition check
705 // for condition < 0, this will work as expected.
NegateCondition(Condition cc)706 inline Condition NegateCondition(Condition cc) {
707   DCHECK(cc != cc_always);
708   return static_cast<Condition>(cc ^ 1);
709 }
710 
711 
NegateFpuCondition(Condition cc)712 inline Condition NegateFpuCondition(Condition cc) {
713   DCHECK(cc != cc_always);
714   switch (cc) {
715     case ult:
716       return ge;
717     case ugt:
718       return le;
719     case uge:
720       return lt;
721     case ule:
722       return gt;
723     case lt:
724       return uge;
725     case gt:
726       return ule;
727     case ge:
728       return ult;
729     case le:
730       return ugt;
731     case eq:
732       return ne;
733     case ne:
734       return eq;
735     case ueq:
736       return ogl;
737     case ogl:
738       return ueq;
739     default:
740       return cc;
741   }
742 }
743 
744 
745 // Commute a condition such that {a cond b == b cond' a}.
CommuteCondition(Condition cc)746 inline Condition CommuteCondition(Condition cc) {
747   switch (cc) {
748     case Uless:
749       return Ugreater;
750     case Ugreater:
751       return Uless;
752     case Ugreater_equal:
753       return Uless_equal;
754     case Uless_equal:
755       return Ugreater_equal;
756     case less:
757       return greater;
758     case greater:
759       return less;
760     case greater_equal:
761       return less_equal;
762     case less_equal:
763       return greater_equal;
764     default:
765       return cc;
766   }
767 }
768 
769 
770 // ----- Coprocessor conditions.
771 enum FPUCondition {
772   kNoFPUCondition = -1,
773 
774   F = 0x00,    // False.
775   UN = 0x01,   // Unordered.
776   EQ = 0x02,   // Equal.
777   UEQ = 0x03,  // Unordered or Equal.
778   OLT = 0x04,  // Ordered or Less Than, on Mips release < 6.
779   LT = 0x04,   // Ordered or Less Than, on Mips release >= 6.
780   ULT = 0x05,  // Unordered or Less Than.
781   OLE = 0x06,  // Ordered or Less Than or Equal, on Mips release < 6.
782   LE = 0x06,   // Ordered or Less Than or Equal, on Mips release >= 6.
783   ULE = 0x07,  // Unordered or Less Than or Equal.
784 
785   // Following constants are available on Mips release >= 6 only.
786   ORD = 0x11,  // Ordered, on Mips release >= 6.
787   UNE = 0x12,  // Not equal, on Mips release >= 6.
788   NE = 0x13,   // Ordered Greater Than or Less Than. on Mips >= 6 only.
789 };
790 
791 
792 // FPU rounding modes.
793 enum FPURoundingMode {
794   RN = 0 << 0,  // Round to Nearest.
795   RZ = 1 << 0,  // Round towards zero.
796   RP = 2 << 0,  // Round towards Plus Infinity.
797   RM = 3 << 0,  // Round towards Minus Infinity.
798 
799   // Aliases.
800   kRoundToNearest = RN,
801   kRoundToZero = RZ,
802   kRoundToPlusInf = RP,
803   kRoundToMinusInf = RM,
804 
805   mode_round = RN,
806   mode_ceil = RP,
807   mode_floor = RM,
808   mode_trunc = RZ
809 };
810 
811 const uint32_t kFPURoundingModeMask = 3 << 0;
812 
813 enum CheckForInexactConversion {
814   kCheckForInexactConversion,
815   kDontCheckForInexactConversion
816 };
817 
818 enum class MaxMinKind : int { kMin = 0, kMax = 1 };
819 
820 // -----------------------------------------------------------------------------
821 // Hints.
822 
823 // Branch hints are not used on the MIPS.  They are defined so that they can
824 // appear in shared function signatures, but will be ignored in MIPS
825 // implementations.
826 enum Hint {
827   no_hint = 0
828 };
829 
830 
NegateHint(Hint hint)831 inline Hint NegateHint(Hint hint) {
832   return no_hint;
833 }
834 
835 
836 // -----------------------------------------------------------------------------
837 // Specific instructions, constants, and masks.
838 // These constants are declared in assembler-mips.cc, as they use named
839 // registers and other constants.
840 
841 // addiu(sp, sp, 4) aka Pop() operation or part of Pop(r)
842 // operations as post-increment of sp.
843 extern const Instr kPopInstruction;
844 // addiu(sp, sp, -4) part of Push(r) operation as pre-decrement of sp.
845 extern const Instr kPushInstruction;
846 // sw(r, MemOperand(sp, 0))
847 extern const Instr kPushRegPattern;
848 // lw(r, MemOperand(sp, 0))
849 extern const Instr kPopRegPattern;
850 extern const Instr kLwRegFpOffsetPattern;
851 extern const Instr kSwRegFpOffsetPattern;
852 extern const Instr kLwRegFpNegOffsetPattern;
853 extern const Instr kSwRegFpNegOffsetPattern;
854 // A mask for the Rt register for push, pop, lw, sw instructions.
855 extern const Instr kRtMask;
856 extern const Instr kLwSwInstrTypeMask;
857 extern const Instr kLwSwInstrArgumentMask;
858 extern const Instr kLwSwOffsetMask;
859 
860 // Break 0xfffff, reserved for redirected real time call.
861 const Instr rtCallRedirInstr = SPECIAL | BREAK | call_rt_redirected << 6;
862 // A nop instruction. (Encoding of sll 0 0 0).
863 const Instr nopInstr = 0;
864 
OpcodeToBitNumber(Opcode opcode)865 static constexpr uint64_t OpcodeToBitNumber(Opcode opcode) {
866   return 1ULL << (static_cast<uint32_t>(opcode) >> kOpcodeShift);
867 }
868 
869 class InstructionBase {
870  public:
871   enum {
872     kInstrSize = 4,
873     kInstrSizeLog2 = 2,
874     // On MIPS PC cannot actually be directly accessed. We behave as if PC was
875     // always the value of the current instruction being executed.
876     kPCReadOffset = 0
877   };
878 
879   // Instruction type.
880   enum Type { kRegisterType, kImmediateType, kJumpType, kUnsupported = -1 };
881 
882   // Get the raw instruction bits.
InstructionBits()883   inline Instr InstructionBits() const {
884     return *reinterpret_cast<const Instr*>(this);
885   }
886 
887   // Set the raw instruction bits to value.
SetInstructionBits(Instr value)888   inline void SetInstructionBits(Instr value) {
889     *reinterpret_cast<Instr*>(this) = value;
890   }
891 
892   // Read one particular bit out of the instruction bits.
Bit(int nr)893   inline int Bit(int nr) const {
894     return (InstructionBits() >> nr) & 1;
895   }
896 
897   // Read a bit field out of the instruction bits.
Bits(int hi,int lo)898   inline int Bits(int hi, int lo) const {
899     return (InstructionBits() >> lo) & ((2U << (hi - lo)) - 1);
900   }
901 
902 
903   static constexpr uint64_t kOpcodeImmediateTypeMask =
904       OpcodeToBitNumber(REGIMM) | OpcodeToBitNumber(BEQ) |
905       OpcodeToBitNumber(BNE) | OpcodeToBitNumber(BLEZ) |
906       OpcodeToBitNumber(BGTZ) | OpcodeToBitNumber(ADDI) |
907       OpcodeToBitNumber(DADDI) | OpcodeToBitNumber(ADDIU) |
908       OpcodeToBitNumber(SLTI) | OpcodeToBitNumber(SLTIU) |
909       OpcodeToBitNumber(ANDI) | OpcodeToBitNumber(ORI) |
910       OpcodeToBitNumber(XORI) | OpcodeToBitNumber(LUI) |
911       OpcodeToBitNumber(BEQL) | OpcodeToBitNumber(BNEL) |
912       OpcodeToBitNumber(BLEZL) | OpcodeToBitNumber(BGTZL) |
913       OpcodeToBitNumber(POP66) | OpcodeToBitNumber(POP76) |
914       OpcodeToBitNumber(LB) | OpcodeToBitNumber(LH) | OpcodeToBitNumber(LWL) |
915       OpcodeToBitNumber(LW) | OpcodeToBitNumber(LBU) | OpcodeToBitNumber(LHU) |
916       OpcodeToBitNumber(LWR) | OpcodeToBitNumber(SB) | OpcodeToBitNumber(SH) |
917       OpcodeToBitNumber(SWL) | OpcodeToBitNumber(SW) | OpcodeToBitNumber(SWR) |
918       OpcodeToBitNumber(LWC1) | OpcodeToBitNumber(LDC1) |
919       OpcodeToBitNumber(SWC1) | OpcodeToBitNumber(SDC1) |
920       OpcodeToBitNumber(PCREL) | OpcodeToBitNumber(BC) |
921       OpcodeToBitNumber(BALC);
922 
923 #define FunctionFieldToBitNumber(function) (1ULL << function)
924 
925   static const uint64_t kFunctionFieldRegisterTypeMask =
926       FunctionFieldToBitNumber(JR) | FunctionFieldToBitNumber(JALR) |
927       FunctionFieldToBitNumber(BREAK) | FunctionFieldToBitNumber(SLL) |
928       FunctionFieldToBitNumber(SRL) | FunctionFieldToBitNumber(SRA) |
929       FunctionFieldToBitNumber(SLLV) | FunctionFieldToBitNumber(SRLV) |
930       FunctionFieldToBitNumber(SRAV) | FunctionFieldToBitNumber(LSA) |
931       FunctionFieldToBitNumber(MFHI) | FunctionFieldToBitNumber(MFLO) |
932       FunctionFieldToBitNumber(MULT) | FunctionFieldToBitNumber(MULTU) |
933       FunctionFieldToBitNumber(DIV) | FunctionFieldToBitNumber(DIVU) |
934       FunctionFieldToBitNumber(ADD) | FunctionFieldToBitNumber(ADDU) |
935       FunctionFieldToBitNumber(SUB) | FunctionFieldToBitNumber(SUBU) |
936       FunctionFieldToBitNumber(AND) | FunctionFieldToBitNumber(OR) |
937       FunctionFieldToBitNumber(XOR) | FunctionFieldToBitNumber(NOR) |
938       FunctionFieldToBitNumber(SLT) | FunctionFieldToBitNumber(SLTU) |
939       FunctionFieldToBitNumber(TGE) | FunctionFieldToBitNumber(TGEU) |
940       FunctionFieldToBitNumber(TLT) | FunctionFieldToBitNumber(TLTU) |
941       FunctionFieldToBitNumber(TEQ) | FunctionFieldToBitNumber(TNE) |
942       FunctionFieldToBitNumber(MOVZ) | FunctionFieldToBitNumber(MOVN) |
943       FunctionFieldToBitNumber(MOVCI) | FunctionFieldToBitNumber(SELEQZ_S) |
944       FunctionFieldToBitNumber(SELNEZ_S) | FunctionFieldToBitNumber(SYNC);
945 
946   // Accessors for the different named fields used in the MIPS encoding.
OpcodeValue()947   inline Opcode OpcodeValue() const {
948     return static_cast<Opcode>(
949         Bits(kOpcodeShift + kOpcodeBits - 1, kOpcodeShift));
950   }
951 
FunctionFieldRaw()952   inline int FunctionFieldRaw() const {
953     return InstructionBits() & kFunctionFieldMask;
954   }
955 
956   // Return the fields at their original place in the instruction encoding.
OpcodeFieldRaw()957   inline Opcode OpcodeFieldRaw() const {
958     return static_cast<Opcode>(InstructionBits() & kOpcodeMask);
959   }
960 
961   // Safe to call within InstructionType().
RsFieldRawNoAssert()962   inline int RsFieldRawNoAssert() const {
963     return InstructionBits() & kRsFieldMask;
964   }
965 
SaFieldRaw()966   inline int SaFieldRaw() const { return InstructionBits() & kSaFieldMask; }
967 
968   // Get the encoding type of the instruction.
969   inline Type InstructionType() const;
970 
971  protected:
InstructionBase()972   InstructionBase() {}
973 };
974 
975 template <class T>
976 class InstructionGetters : public T {
977  public:
RsValue()978   inline int RsValue() const {
979     DCHECK(this->InstructionType() == InstructionBase::kRegisterType ||
980            this->InstructionType() == InstructionBase::kImmediateType);
981     return InstructionBase::Bits(kRsShift + kRsBits - 1, kRsShift);
982   }
983 
RtValue()984   inline int RtValue() const {
985     DCHECK(this->InstructionType() == InstructionBase::kRegisterType ||
986            this->InstructionType() == InstructionBase::kImmediateType);
987     return this->Bits(kRtShift + kRtBits - 1, kRtShift);
988   }
989 
RdValue()990   inline int RdValue() const {
991     DCHECK(this->InstructionType() == InstructionBase::kRegisterType);
992     return this->Bits(kRdShift + kRdBits - 1, kRdShift);
993   }
994 
SaValue()995   inline int SaValue() const {
996     DCHECK(this->InstructionType() == InstructionBase::kRegisterType);
997     return this->Bits(kSaShift + kSaBits - 1, kSaShift);
998   }
999 
LsaSaValue()1000   inline int LsaSaValue() const {
1001     DCHECK(this->InstructionType() == InstructionBase::kRegisterType);
1002     return this->Bits(kSaShift + kLsaSaBits - 1, kSaShift);
1003   }
1004 
FunctionValue()1005   inline int FunctionValue() const {
1006     DCHECK(this->InstructionType() == InstructionBase::kRegisterType ||
1007            this->InstructionType() == InstructionBase::kImmediateType);
1008     return this->Bits(kFunctionShift + kFunctionBits - 1, kFunctionShift);
1009   }
1010 
FdValue()1011   inline int FdValue() const {
1012     return this->Bits(kFdShift + kFdBits - 1, kFdShift);
1013   }
1014 
FsValue()1015   inline int FsValue() const {
1016     return this->Bits(kFsShift + kFsBits - 1, kFsShift);
1017   }
1018 
FtValue()1019   inline int FtValue() const {
1020     return this->Bits(kFtShift + kFtBits - 1, kFtShift);
1021   }
1022 
FrValue()1023   inline int FrValue() const {
1024     return this->Bits(kFrShift + kFrBits - 1, kFrShift);
1025   }
1026 
Bp2Value()1027   inline int Bp2Value() const {
1028     DCHECK(this->InstructionType() == InstructionBase::kRegisterType);
1029     return this->Bits(kBp2Shift + kBp2Bits - 1, kBp2Shift);
1030   }
1031 
1032   // Float Compare condition code instruction bits.
FCccValue()1033   inline int FCccValue() const {
1034     return this->Bits(kFCccShift + kFCccBits - 1, kFCccShift);
1035   }
1036 
1037   // Float Branch condition code instruction bits.
FBccValue()1038   inline int FBccValue() const {
1039     return this->Bits(kFBccShift + kFBccBits - 1, kFBccShift);
1040   }
1041 
1042   // Float Branch true/false instruction bit.
FBtrueValue()1043   inline int FBtrueValue() const {
1044     return this->Bits(kFBtrueShift + kFBtrueBits - 1, kFBtrueShift);
1045   }
1046 
1047   // Return the fields at their original place in the instruction encoding.
OpcodeFieldRaw()1048   inline Opcode OpcodeFieldRaw() const {
1049     return static_cast<Opcode>(this->InstructionBits() & kOpcodeMask);
1050   }
1051 
RsFieldRaw()1052   inline int RsFieldRaw() const {
1053     DCHECK(this->InstructionType() == InstructionBase::kRegisterType ||
1054            this->InstructionType() == InstructionBase::kImmediateType);
1055     return this->InstructionBits() & kRsFieldMask;
1056   }
1057 
RtFieldRaw()1058   inline int RtFieldRaw() const {
1059     DCHECK(this->InstructionType() == InstructionBase::kRegisterType ||
1060            this->InstructionType() == InstructionBase::kImmediateType);
1061     return this->InstructionBits() & kRtFieldMask;
1062   }
1063 
RdFieldRaw()1064   inline int RdFieldRaw() const {
1065     DCHECK(this->InstructionType() == InstructionBase::kRegisterType);
1066     return this->InstructionBits() & kRdFieldMask;
1067   }
1068 
SaFieldRaw()1069   inline int SaFieldRaw() const {
1070     return this->InstructionBits() & kSaFieldMask;
1071   }
1072 
FunctionFieldRaw()1073   inline int FunctionFieldRaw() const {
1074     return this->InstructionBits() & kFunctionFieldMask;
1075   }
1076 
1077   // Get the secondary field according to the opcode.
SecondaryValue()1078   inline int SecondaryValue() const {
1079     Opcode op = this->OpcodeFieldRaw();
1080     switch (op) {
1081       case SPECIAL:
1082       case SPECIAL2:
1083         return FunctionValue();
1084       case COP1:
1085         return RsValue();
1086       case REGIMM:
1087         return RtValue();
1088       default:
1089         return NULLSF;
1090     }
1091   }
1092 
ImmValue(int bits)1093   inline int32_t ImmValue(int bits) const {
1094     DCHECK(this->InstructionType() == InstructionBase::kImmediateType);
1095     return this->Bits(bits - 1, 0);
1096   }
1097 
Imm16Value()1098   inline int32_t Imm16Value() const {
1099     DCHECK(this->InstructionType() == InstructionBase::kImmediateType);
1100     return this->Bits(kImm16Shift + kImm16Bits - 1, kImm16Shift);
1101   }
1102 
Imm18Value()1103   inline int32_t Imm18Value() const {
1104     DCHECK(this->InstructionType() == InstructionBase::kImmediateType);
1105     return this->Bits(kImm18Shift + kImm18Bits - 1, kImm18Shift);
1106   }
1107 
Imm19Value()1108   inline int32_t Imm19Value() const {
1109     DCHECK(this->InstructionType() == InstructionBase::kImmediateType);
1110     return this->Bits(kImm19Shift + kImm19Bits - 1, kImm19Shift);
1111   }
1112 
Imm21Value()1113   inline int32_t Imm21Value() const {
1114     DCHECK(this->InstructionType() == InstructionBase::kImmediateType);
1115     return this->Bits(kImm21Shift + kImm21Bits - 1, kImm21Shift);
1116   }
1117 
Imm26Value()1118   inline int32_t Imm26Value() const {
1119     DCHECK((this->InstructionType() == InstructionBase::kJumpType) ||
1120            (this->InstructionType() == InstructionBase::kImmediateType));
1121     return this->Bits(kImm26Shift + kImm26Bits - 1, kImm26Shift);
1122   }
1123 
1124   static bool IsForbiddenAfterBranchInstr(Instr instr);
1125 
1126   // Say if the instruction should not be used in a branch delay slot or
1127   // immediately after a compact branch.
IsForbiddenAfterBranch()1128   inline bool IsForbiddenAfterBranch() const {
1129     return IsForbiddenAfterBranchInstr(this->InstructionBits());
1130   }
1131 
IsForbiddenInBranchDelay()1132   inline bool IsForbiddenInBranchDelay() const {
1133     return IsForbiddenAfterBranch();
1134   }
1135 
1136   // Say if the instruction 'links'. e.g. jal, bal.
1137   bool IsLinkingInstruction() const;
1138   // Say if the instruction is a break or a trap.
1139   bool IsTrap() const;
1140 };
1141 
1142 class Instruction : public InstructionGetters<InstructionBase> {
1143  public:
1144   // Instructions are read of out a code stream. The only way to get a
1145   // reference to an instruction is to convert a pointer. There is no way
1146   // to allocate or create instances of class Instruction.
1147   // Use the At(pc) function to create references to Instruction.
At(byte * pc)1148   static Instruction* At(byte* pc) {
1149     return reinterpret_cast<Instruction*>(pc);
1150   }
1151 
1152  private:
1153   // We need to prevent the creation of instances of class Instruction.
1154   DISALLOW_IMPLICIT_CONSTRUCTORS(Instruction);
1155 };
1156 
1157 
1158 // -----------------------------------------------------------------------------
1159 // MIPS assembly various constants.
1160 
1161 // C/C++ argument slots size.
1162 const int kCArgSlotCount = 4;
1163 const int kCArgsSlotsSize = kCArgSlotCount * Instruction::kInstrSize;
1164 const int kInvalidStackOffset = -1;
1165 // JS argument slots size.
1166 const int kJSArgsSlotsSize = 0 * Instruction::kInstrSize;
1167 // Assembly builtins argument slots size.
1168 const int kBArgsSlotsSize = 0 * Instruction::kInstrSize;
1169 
1170 const int kBranchReturnOffset = 2 * Instruction::kInstrSize;
1171 
InstructionType()1172 InstructionBase::Type InstructionBase::InstructionType() const {
1173   switch (OpcodeFieldRaw()) {
1174     case SPECIAL:
1175       if (FunctionFieldToBitNumber(FunctionFieldRaw()) &
1176           kFunctionFieldRegisterTypeMask) {
1177         return kRegisterType;
1178       }
1179       return kUnsupported;
1180     case SPECIAL2:
1181       switch (FunctionFieldRaw()) {
1182         case MUL:
1183         case CLZ:
1184           return kRegisterType;
1185         default:
1186           return kUnsupported;
1187       }
1188       break;
1189     case SPECIAL3:
1190       switch (FunctionFieldRaw()) {
1191         case INS:
1192         case EXT:
1193           return kRegisterType;
1194         case BSHFL: {
1195           int sa = SaFieldRaw() >> kSaShift;
1196           switch (sa) {
1197             case BITSWAP:
1198             case WSBH:
1199             case SEB:
1200             case SEH:
1201               return kRegisterType;
1202           }
1203           sa >>= kBp2Bits;
1204           switch (sa) {
1205             case ALIGN:
1206               return kRegisterType;
1207             default:
1208               return kUnsupported;
1209           }
1210         }
1211         default:
1212           return kUnsupported;
1213       }
1214       break;
1215     case COP1:  // Coprocessor instructions.
1216       switch (RsFieldRawNoAssert()) {
1217         case BC1:  // Branch on coprocessor condition.
1218         case BC1EQZ:
1219         case BC1NEZ:
1220           return kImmediateType;
1221         default:
1222           return kRegisterType;
1223       }
1224       break;
1225     case COP1X:
1226       return kRegisterType;
1227 
1228     // 26 bits immediate type instructions. e.g.: j imm26.
1229     case J:
1230     case JAL:
1231       return kJumpType;
1232 
1233     default:
1234         return kImmediateType;
1235   }
1236 }
1237 
1238 #undef OpcodeToBitNumber
1239 #undef FunctionFieldToBitNumber
1240 
1241 // -----------------------------------------------------------------------------
1242 // Instructions.
1243 
1244 template <class P>
IsLinkingInstruction()1245 bool InstructionGetters<P>::IsLinkingInstruction() const {
1246   uint32_t op = this->OpcodeFieldRaw();
1247   switch (op) {
1248     case JAL:
1249       return true;
1250     case POP76:
1251       if (this->RsFieldRawNoAssert() == JIALC)
1252         return true;  // JIALC
1253       else
1254         return false;  // BNEZC
1255     case REGIMM:
1256       switch (this->RtFieldRaw()) {
1257         case BGEZAL:
1258         case BLTZAL:
1259           return true;
1260         default:
1261           return false;
1262       }
1263     case SPECIAL:
1264       switch (this->FunctionFieldRaw()) {
1265         case JALR:
1266           return true;
1267         default:
1268           return false;
1269       }
1270     default:
1271       return false;
1272   }
1273 }
1274 
1275 template <class P>
IsTrap()1276 bool InstructionGetters<P>::IsTrap() const {
1277   if (this->OpcodeFieldRaw() != SPECIAL) {
1278     return false;
1279   } else {
1280     switch (this->FunctionFieldRaw()) {
1281       case BREAK:
1282       case TGE:
1283       case TGEU:
1284       case TLT:
1285       case TLTU:
1286       case TEQ:
1287       case TNE:
1288         return true;
1289       default:
1290         return false;
1291     }
1292   }
1293 }
1294 
1295 // static
1296 template <class T>
IsForbiddenAfterBranchInstr(Instr instr)1297 bool InstructionGetters<T>::IsForbiddenAfterBranchInstr(Instr instr) {
1298   Opcode opcode = static_cast<Opcode>(instr & kOpcodeMask);
1299   switch (opcode) {
1300     case J:
1301     case JAL:
1302     case BEQ:
1303     case BNE:
1304     case BLEZ:  // POP06 bgeuc/bleuc, blezalc, bgezalc
1305     case BGTZ:  // POP07 bltuc/bgtuc, bgtzalc, bltzalc
1306     case BEQL:
1307     case BNEL:
1308     case BLEZL:  // POP26 bgezc, blezc, bgec/blec
1309     case BGTZL:  // POP27 bgtzc, bltzc, bltc/bgtc
1310     case BC:
1311     case BALC:
1312     case POP10:  // beqzalc, bovc, beqc
1313     case POP30:  // bnezalc, bnvc, bnec
1314     case POP66:  // beqzc, jic
1315     case POP76:  // bnezc, jialc
1316       return true;
1317     case REGIMM:
1318       switch (instr & kRtFieldMask) {
1319         case BLTZ:
1320         case BGEZ:
1321         case BLTZAL:
1322         case BGEZAL:
1323           return true;
1324         default:
1325           return false;
1326       }
1327       break;
1328     case SPECIAL:
1329       switch (instr & kFunctionFieldMask) {
1330         case JR:
1331         case JALR:
1332           return true;
1333         default:
1334           return false;
1335       }
1336       break;
1337     case COP1:
1338       switch (instr & kRsFieldMask) {
1339         case BC1:
1340         case BC1EQZ:
1341         case BC1NEZ:
1342           return true;
1343           break;
1344         default:
1345           return false;
1346       }
1347       break;
1348     default:
1349       return false;
1350   }
1351 }
1352 }  // namespace internal
1353 }  // namespace v8
1354 
1355 #endif    // #ifndef V8_MIPS_CONSTANTS_H_
1356