1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_ARM_CONSTANTS_ARM_H_ 29 #define V8_ARM_CONSTANTS_ARM_H_ 30 31 // ARM EABI is required. 32 #if defined(__arm__) && !defined(__ARM_EABI__) 33 #error ARM EABI support is required. 34 #endif 35 36 // This means that interwork-compatible jump instructions are generated. We 37 // want to generate them on the simulator too so it makes snapshots that can 38 // be used on real hardware. 39 #if defined(__THUMB_INTERWORK__) || !defined(__arm__) 40 # define USE_THUMB_INTERWORK 1 41 #endif 42 43 #if defined(__ARM_ARCH_7A__) || \ 44 defined(__ARM_ARCH_7R__) || \ 45 defined(__ARM_ARCH_7__) 46 # define CAN_USE_ARMV7_INSTRUCTIONS 1 47 #endif 48 49 #if defined(__ARM_ARCH_6__) || \ 50 defined(__ARM_ARCH_6J__) || \ 51 defined(__ARM_ARCH_6K__) || \ 52 defined(__ARM_ARCH_6Z__) || \ 53 defined(__ARM_ARCH_6ZK__) || \ 54 defined(__ARM_ARCH_6T2__) || \ 55 defined(CAN_USE_ARMV7_INSTRUCTIONS) 56 # define CAN_USE_ARMV6_INSTRUCTIONS 1 57 #endif 58 59 #if defined(__ARM_ARCH_5T__) || \ 60 defined(__ARM_ARCH_5TE__) || \ 61 defined(CAN_USE_ARMV6_INSTRUCTIONS) 62 # define CAN_USE_ARMV5_INSTRUCTIONS 1 63 # define CAN_USE_THUMB_INSTRUCTIONS 1 64 #endif 65 66 // Simulator should support ARM5 instructions and unaligned access by default. 67 #if !defined(__arm__) 68 # define CAN_USE_ARMV5_INSTRUCTIONS 1 69 # define CAN_USE_THUMB_INSTRUCTIONS 1 70 71 # ifndef CAN_USE_UNALIGNED_ACCESSES 72 # define CAN_USE_UNALIGNED_ACCESSES 1 73 # endif 74 75 #endif 76 77 #if CAN_USE_UNALIGNED_ACCESSES 78 #define V8_TARGET_CAN_READ_UNALIGNED 1 79 #endif 80 81 // Using blx may yield better code, so use it when required or when available 82 #if defined(USE_THUMB_INTERWORK) || defined(CAN_USE_ARMV5_INSTRUCTIONS) 83 #define USE_BLX 1 84 #endif 85 86 namespace v8 { 87 namespace internal { 88 89 // Constant pool marker. 90 const int kConstantPoolMarkerMask = 0xffe00000; 91 const int kConstantPoolMarker = 0x0c000000; 92 const int kConstantPoolLengthMask = 0x001ffff; 93 94 // Number of registers in normal ARM mode. 95 const int kNumRegisters = 16; 96 97 // VFP support. 98 const int kNumVFPSingleRegisters = 32; 99 const int kNumVFPDoubleRegisters = 16; 100 const int kNumVFPRegisters = kNumVFPSingleRegisters + kNumVFPDoubleRegisters; 101 102 // PC is register 15. 103 const int kPCRegister = 15; 104 const int kNoRegister = -1; 105 106 // ----------------------------------------------------------------------------- 107 // Conditions. 108 109 // Defines constants and accessor classes to assemble, disassemble and 110 // simulate ARM instructions. 111 // 112 // Section references in the code refer to the "ARM Architecture Reference 113 // Manual" from July 2005 (available at http://www.arm.com/miscPDFs/14128.pdf) 114 // 115 // Constants for specific fields are defined in their respective named enums. 116 // General constants are in an anonymous enum in class Instr. 117 118 // Values for the condition field as defined in section A3.2 119 enum Condition { 120 kNoCondition = -1, 121 122 eq = 0 << 28, // Z set Equal. 123 ne = 1 << 28, // Z clear Not equal. 124 cs = 2 << 28, // C set Unsigned higher or same. 125 cc = 3 << 28, // C clear Unsigned lower. 126 mi = 4 << 28, // N set Negative. 127 pl = 5 << 28, // N clear Positive or zero. 128 vs = 6 << 28, // V set Overflow. 129 vc = 7 << 28, // V clear No overflow. 130 hi = 8 << 28, // C set, Z clear Unsigned higher. 131 ls = 9 << 28, // C clear or Z set Unsigned lower or same. 132 ge = 10 << 28, // N == V Greater or equal. 133 lt = 11 << 28, // N != V Less than. 134 gt = 12 << 28, // Z clear, N == V Greater than. 135 le = 13 << 28, // Z set or N != V Less then or equal 136 al = 14 << 28, // Always. 137 138 kSpecialCondition = 15 << 28, // Special condition (refer to section A3.2.1). 139 kNumberOfConditions = 16, 140 141 // Aliases. 142 hs = cs, // C set Unsigned higher or same. 143 lo = cc // C clear Unsigned lower. 144 }; 145 146 147 inline Condition NegateCondition(Condition cond) { 148 ASSERT(cond != al); 149 return static_cast<Condition>(cond ^ ne); 150 } 151 152 153 // Corresponds to transposing the operands of a comparison. 154 inline Condition ReverseCondition(Condition cond) { 155 switch (cond) { 156 case lo: 157 return hi; 158 case hi: 159 return lo; 160 case hs: 161 return ls; 162 case ls: 163 return hs; 164 case lt: 165 return gt; 166 case gt: 167 return lt; 168 case ge: 169 return le; 170 case le: 171 return ge; 172 default: 173 return cond; 174 }; 175 } 176 177 178 // ----------------------------------------------------------------------------- 179 // Instructions encoding. 180 181 // Instr is merely used by the Assembler to distinguish 32bit integers 182 // representing instructions from usual 32 bit values. 183 // Instruction objects are pointers to 32bit values, and provide methods to 184 // access the various ISA fields. 185 typedef int32_t Instr; 186 187 188 // Opcodes for Data-processing instructions (instructions with a type 0 and 1) 189 // as defined in section A3.4 190 enum Opcode { 191 AND = 0 << 21, // Logical AND. 192 EOR = 1 << 21, // Logical Exclusive OR. 193 SUB = 2 << 21, // Subtract. 194 RSB = 3 << 21, // Reverse Subtract. 195 ADD = 4 << 21, // Add. 196 ADC = 5 << 21, // Add with Carry. 197 SBC = 6 << 21, // Subtract with Carry. 198 RSC = 7 << 21, // Reverse Subtract with Carry. 199 TST = 8 << 21, // Test. 200 TEQ = 9 << 21, // Test Equivalence. 201 CMP = 10 << 21, // Compare. 202 CMN = 11 << 21, // Compare Negated. 203 ORR = 12 << 21, // Logical (inclusive) OR. 204 MOV = 13 << 21, // Move. 205 BIC = 14 << 21, // Bit Clear. 206 MVN = 15 << 21 // Move Not. 207 }; 208 209 210 // The bits for bit 7-4 for some type 0 miscellaneous instructions. 211 enum MiscInstructionsBits74 { 212 // With bits 22-21 01. 213 BX = 1 << 4, 214 BXJ = 2 << 4, 215 BLX = 3 << 4, 216 BKPT = 7 << 4, 217 218 // With bits 22-21 11. 219 CLZ = 1 << 4 220 }; 221 222 223 // Instruction encoding bits and masks. 224 enum { 225 H = 1 << 5, // Halfword (or byte). 226 S6 = 1 << 6, // Signed (or unsigned). 227 L = 1 << 20, // Load (or store). 228 S = 1 << 20, // Set condition code (or leave unchanged). 229 W = 1 << 21, // Writeback base register (or leave unchanged). 230 A = 1 << 21, // Accumulate in multiply instruction (or not). 231 B = 1 << 22, // Unsigned byte (or word). 232 N = 1 << 22, // Long (or short). 233 U = 1 << 23, // Positive (or negative) offset/index. 234 P = 1 << 24, // Offset/pre-indexed addressing (or post-indexed addressing). 235 I = 1 << 25, // Immediate shifter operand (or not). 236 237 B4 = 1 << 4, 238 B5 = 1 << 5, 239 B6 = 1 << 6, 240 B7 = 1 << 7, 241 B8 = 1 << 8, 242 B9 = 1 << 9, 243 B12 = 1 << 12, 244 B16 = 1 << 16, 245 B18 = 1 << 18, 246 B19 = 1 << 19, 247 B20 = 1 << 20, 248 B21 = 1 << 21, 249 B22 = 1 << 22, 250 B23 = 1 << 23, 251 B24 = 1 << 24, 252 B25 = 1 << 25, 253 B26 = 1 << 26, 254 B27 = 1 << 27, 255 B28 = 1 << 28, 256 257 // Instruction bit masks. 258 kCondMask = 15 << 28, 259 kALUMask = 0x6f << 21, 260 kRdMask = 15 << 12, // In str instruction. 261 kCoprocessorMask = 15 << 8, 262 kOpCodeMask = 15 << 21, // In data-processing instructions. 263 kImm24Mask = (1 << 24) - 1, 264 kOff12Mask = (1 << 12) - 1 265 }; 266 267 268 // ----------------------------------------------------------------------------- 269 // Addressing modes and instruction variants. 270 271 // Condition code updating mode. 272 enum SBit { 273 SetCC = 1 << 20, // Set condition code. 274 LeaveCC = 0 << 20 // Leave condition code unchanged. 275 }; 276 277 278 // Status register selection. 279 enum SRegister { 280 CPSR = 0 << 22, 281 SPSR = 1 << 22 282 }; 283 284 285 // Shifter types for Data-processing operands as defined in section A5.1.2. 286 enum ShiftOp { 287 LSL = 0 << 5, // Logical shift left. 288 LSR = 1 << 5, // Logical shift right. 289 ASR = 2 << 5, // Arithmetic shift right. 290 ROR = 3 << 5, // Rotate right. 291 292 // RRX is encoded as ROR with shift_imm == 0. 293 // Use a special code to make the distinction. The RRX ShiftOp is only used 294 // as an argument, and will never actually be encoded. The Assembler will 295 // detect it and emit the correct ROR shift operand with shift_imm == 0. 296 RRX = -1, 297 kNumberOfShifts = 4 298 }; 299 300 301 // Status register fields. 302 enum SRegisterField { 303 CPSR_c = CPSR | 1 << 16, 304 CPSR_x = CPSR | 1 << 17, 305 CPSR_s = CPSR | 1 << 18, 306 CPSR_f = CPSR | 1 << 19, 307 SPSR_c = SPSR | 1 << 16, 308 SPSR_x = SPSR | 1 << 17, 309 SPSR_s = SPSR | 1 << 18, 310 SPSR_f = SPSR | 1 << 19 311 }; 312 313 // Status register field mask (or'ed SRegisterField enum values). 314 typedef uint32_t SRegisterFieldMask; 315 316 317 // Memory operand addressing mode. 318 enum AddrMode { 319 // Bit encoding P U W. 320 Offset = (8|4|0) << 21, // Offset (without writeback to base). 321 PreIndex = (8|4|1) << 21, // Pre-indexed addressing with writeback. 322 PostIndex = (0|4|0) << 21, // Post-indexed addressing with writeback. 323 NegOffset = (8|0|0) << 21, // Negative offset (without writeback to base). 324 NegPreIndex = (8|0|1) << 21, // Negative pre-indexed with writeback. 325 NegPostIndex = (0|0|0) << 21 // Negative post-indexed with writeback. 326 }; 327 328 329 // Load/store multiple addressing mode. 330 enum BlockAddrMode { 331 // Bit encoding P U W . 332 da = (0|0|0) << 21, // Decrement after. 333 ia = (0|4|0) << 21, // Increment after. 334 db = (8|0|0) << 21, // Decrement before. 335 ib = (8|4|0) << 21, // Increment before. 336 da_w = (0|0|1) << 21, // Decrement after with writeback to base. 337 ia_w = (0|4|1) << 21, // Increment after with writeback to base. 338 db_w = (8|0|1) << 21, // Decrement before with writeback to base. 339 ib_w = (8|4|1) << 21, // Increment before with writeback to base. 340 341 // Alias modes for comparison when writeback does not matter. 342 da_x = (0|0|0) << 21, // Decrement after. 343 ia_x = (0|4|0) << 21, // Increment after. 344 db_x = (8|0|0) << 21, // Decrement before. 345 ib_x = (8|4|0) << 21, // Increment before. 346 347 kBlockAddrModeMask = (8|4|1) << 21 348 }; 349 350 351 // Coprocessor load/store operand size. 352 enum LFlag { 353 Long = 1 << 22, // Long load/store coprocessor. 354 Short = 0 << 22 // Short load/store coprocessor. 355 }; 356 357 358 // ----------------------------------------------------------------------------- 359 // Supervisor Call (svc) specific support. 360 361 // Special Software Interrupt codes when used in the presence of the ARM 362 // simulator. 363 // svc (formerly swi) provides a 24bit immediate value. Use bits 22:0 for 364 // standard SoftwareInterrupCode. Bit 23 is reserved for the stop feature. 365 enum SoftwareInterruptCodes { 366 // transition to C code 367 kCallRtRedirected= 0x10, 368 // break point 369 kBreakpoint= 0x20, 370 // stop 371 kStopCode = 1 << 23 372 }; 373 const uint32_t kStopCodeMask = kStopCode - 1; 374 const uint32_t kMaxStopCode = kStopCode - 1; 375 const int32_t kDefaultStopCode = -1; 376 377 378 // Type of VFP register. Determines register encoding. 379 enum VFPRegPrecision { 380 kSinglePrecision = 0, 381 kDoublePrecision = 1 382 }; 383 384 385 // VFP FPSCR constants. 386 enum VFPConversionMode { 387 kFPSCRRounding = 0, 388 kDefaultRoundToZero = 1 389 }; 390 391 // This mask does not include the "inexact" or "input denormal" cumulative 392 // exceptions flags, because we usually don't want to check for it. 393 const uint32_t kVFPExceptionMask = 0xf; 394 const uint32_t kVFPInvalidOpExceptionBit = 1 << 0; 395 const uint32_t kVFPOverflowExceptionBit = 1 << 2; 396 const uint32_t kVFPUnderflowExceptionBit = 1 << 3; 397 const uint32_t kVFPInexactExceptionBit = 1 << 4; 398 const uint32_t kVFPFlushToZeroMask = 1 << 24; 399 400 const uint32_t kVFPNConditionFlagBit = 1 << 31; 401 const uint32_t kVFPZConditionFlagBit = 1 << 30; 402 const uint32_t kVFPCConditionFlagBit = 1 << 29; 403 const uint32_t kVFPVConditionFlagBit = 1 << 28; 404 405 406 // VFP rounding modes. See ARM DDI 0406B Page A2-29. 407 enum VFPRoundingMode { 408 RN = 0 << 22, // Round to Nearest. 409 RP = 1 << 22, // Round towards Plus Infinity. 410 RM = 2 << 22, // Round towards Minus Infinity. 411 RZ = 3 << 22, // Round towards zero. 412 413 // Aliases. 414 kRoundToNearest = RN, 415 kRoundToPlusInf = RP, 416 kRoundToMinusInf = RM, 417 kRoundToZero = RZ 418 }; 419 420 const uint32_t kVFPRoundingModeMask = 3 << 22; 421 422 enum CheckForInexactConversion { 423 kCheckForInexactConversion, 424 kDontCheckForInexactConversion 425 }; 426 427 // ----------------------------------------------------------------------------- 428 // Hints. 429 430 // Branch hints are not used on the ARM. They are defined so that they can 431 // appear in shared function signatures, but will be ignored in ARM 432 // implementations. 433 enum Hint { no_hint }; 434 435 // Hints are not used on the arm. Negating is trivial. 436 inline Hint NegateHint(Hint ignored) { return no_hint; } 437 438 439 // ----------------------------------------------------------------------------- 440 // Specific instructions, constants, and masks. 441 // These constants are declared in assembler-arm.cc, as they use named registers 442 // and other constants. 443 444 445 // add(sp, sp, 4) instruction (aka Pop()) 446 extern const Instr kPopInstruction; 447 448 // str(r, MemOperand(sp, 4, NegPreIndex), al) instruction (aka push(r)) 449 // register r is not encoded. 450 extern const Instr kPushRegPattern; 451 452 // ldr(r, MemOperand(sp, 4, PostIndex), al) instruction (aka pop(r)) 453 // register r is not encoded. 454 extern const Instr kPopRegPattern; 455 456 // mov lr, pc 457 extern const Instr kMovLrPc; 458 // ldr rd, [pc, #offset] 459 extern const Instr kLdrPCMask; 460 extern const Instr kLdrPCPattern; 461 // blxcc rm 462 extern const Instr kBlxRegMask; 463 464 extern const Instr kBlxRegPattern; 465 466 extern const Instr kMovMvnMask; 467 extern const Instr kMovMvnPattern; 468 extern const Instr kMovMvnFlip; 469 extern const Instr kMovLeaveCCMask; 470 extern const Instr kMovLeaveCCPattern; 471 extern const Instr kMovwMask; 472 extern const Instr kMovwPattern; 473 extern const Instr kMovwLeaveCCFlip; 474 extern const Instr kCmpCmnMask; 475 extern const Instr kCmpCmnPattern; 476 extern const Instr kCmpCmnFlip; 477 extern const Instr kAddSubFlip; 478 extern const Instr kAndBicFlip; 479 480 // A mask for the Rd register for push, pop, ldr, str instructions. 481 extern const Instr kLdrRegFpOffsetPattern; 482 483 extern const Instr kStrRegFpOffsetPattern; 484 485 extern const Instr kLdrRegFpNegOffsetPattern; 486 487 extern const Instr kStrRegFpNegOffsetPattern; 488 489 extern const Instr kLdrStrInstrTypeMask; 490 extern const Instr kLdrStrInstrArgumentMask; 491 extern const Instr kLdrStrOffsetMask; 492 493 494 // ----------------------------------------------------------------------------- 495 // Instruction abstraction. 496 497 // The class Instruction enables access to individual fields defined in the ARM 498 // architecture instruction set encoding as described in figure A3-1. 499 // Note that the Assembler uses typedef int32_t Instr. 500 // 501 // Example: Test whether the instruction at ptr does set the condition code 502 // bits. 503 // 504 // bool InstructionSetsConditionCodes(byte* ptr) { 505 // Instruction* instr = Instruction::At(ptr); 506 // int type = instr->TypeValue(); 507 // return ((type == 0) || (type == 1)) && instr->HasS(); 508 // } 509 // 510 class Instruction { 511 public: 512 enum { 513 kInstrSize = 4, 514 kInstrSizeLog2 = 2, 515 kPCReadOffset = 8 516 }; 517 518 // Helper macro to define static accessors. 519 // We use the cast to char* trick to bypass the strict anti-aliasing rules. 520 #define DECLARE_STATIC_TYPED_ACCESSOR(return_type, Name) \ 521 static inline return_type Name(Instr instr) { \ 522 char* temp = reinterpret_cast<char*>(&instr); \ 523 return reinterpret_cast<Instruction*>(temp)->Name(); \ 524 } 525 526 #define DECLARE_STATIC_ACCESSOR(Name) DECLARE_STATIC_TYPED_ACCESSOR(int, Name) 527 528 // Get the raw instruction bits. 529 inline Instr InstructionBits() const { 530 return *reinterpret_cast<const Instr*>(this); 531 } 532 533 // Set the raw instruction bits to value. 534 inline void SetInstructionBits(Instr value) { 535 *reinterpret_cast<Instr*>(this) = value; 536 } 537 538 // Read one particular bit out of the instruction bits. 539 inline int Bit(int nr) const { 540 return (InstructionBits() >> nr) & 1; 541 } 542 543 // Read a bit field's value out of the instruction bits. 544 inline int Bits(int hi, int lo) const { 545 return (InstructionBits() >> lo) & ((2 << (hi - lo)) - 1); 546 } 547 548 // Read a bit field out of the instruction bits. 549 inline int BitField(int hi, int lo) const { 550 return InstructionBits() & (((2 << (hi - lo)) - 1) << lo); 551 } 552 553 // Static support. 554 555 // Read one particular bit out of the instruction bits. 556 static inline int Bit(Instr instr, int nr) { 557 return (instr >> nr) & 1; 558 } 559 560 // Read the value of a bit field out of the instruction bits. 561 static inline int Bits(Instr instr, int hi, int lo) { 562 return (instr >> lo) & ((2 << (hi - lo)) - 1); 563 } 564 565 566 // Read a bit field out of the instruction bits. 567 static inline int BitField(Instr instr, int hi, int lo) { 568 return instr & (((2 << (hi - lo)) - 1) << lo); 569 } 570 571 572 // Accessors for the different named fields used in the ARM encoding. 573 // The naming of these accessor corresponds to figure A3-1. 574 // 575 // Two kind of accessors are declared: 576 // - <Name>Field() will return the raw field, i.e. the field's bits at their 577 // original place in the instruction encoding. 578 // e.g. if instr is the 'addgt r0, r1, r2' instruction, encoded as 579 // 0xC0810002 ConditionField(instr) will return 0xC0000000. 580 // - <Name>Value() will return the field value, shifted back to bit 0. 581 // e.g. if instr is the 'addgt r0, r1, r2' instruction, encoded as 582 // 0xC0810002 ConditionField(instr) will return 0xC. 583 584 585 // Generally applicable fields 586 inline Condition ConditionValue() const { 587 return static_cast<Condition>(Bits(31, 28)); 588 } 589 inline Condition ConditionField() const { 590 return static_cast<Condition>(BitField(31, 28)); 591 } 592 DECLARE_STATIC_TYPED_ACCESSOR(Condition, ConditionValue); 593 DECLARE_STATIC_TYPED_ACCESSOR(Condition, ConditionField); 594 595 inline int TypeValue() const { return Bits(27, 25); } 596 597 inline int RnValue() const { return Bits(19, 16); } 598 DECLARE_STATIC_ACCESSOR(RnValue); 599 inline int RdValue() const { return Bits(15, 12); } 600 DECLARE_STATIC_ACCESSOR(RdValue); 601 602 inline int CoprocessorValue() const { return Bits(11, 8); } 603 // Support for VFP. 604 // Vn(19-16) | Vd(15-12) | Vm(3-0) 605 inline int VnValue() const { return Bits(19, 16); } 606 inline int VmValue() const { return Bits(3, 0); } 607 inline int VdValue() const { return Bits(15, 12); } 608 inline int NValue() const { return Bit(7); } 609 inline int MValue() const { return Bit(5); } 610 inline int DValue() const { return Bit(22); } 611 inline int RtValue() const { return Bits(15, 12); } 612 inline int PValue() const { return Bit(24); } 613 inline int UValue() const { return Bit(23); } 614 inline int Opc1Value() const { return (Bit(23) << 2) | Bits(21, 20); } 615 inline int Opc2Value() const { return Bits(19, 16); } 616 inline int Opc3Value() const { return Bits(7, 6); } 617 inline int SzValue() const { return Bit(8); } 618 inline int VLValue() const { return Bit(20); } 619 inline int VCValue() const { return Bit(8); } 620 inline int VAValue() const { return Bits(23, 21); } 621 inline int VBValue() const { return Bits(6, 5); } 622 inline int VFPNRegValue(VFPRegPrecision pre) { 623 return VFPGlueRegValue(pre, 16, 7); 624 } 625 inline int VFPMRegValue(VFPRegPrecision pre) { 626 return VFPGlueRegValue(pre, 0, 5); 627 } 628 inline int VFPDRegValue(VFPRegPrecision pre) { 629 return VFPGlueRegValue(pre, 12, 22); 630 } 631 632 // Fields used in Data processing instructions 633 inline int OpcodeValue() const { 634 return static_cast<Opcode>(Bits(24, 21)); 635 } 636 inline Opcode OpcodeField() const { 637 return static_cast<Opcode>(BitField(24, 21)); 638 } 639 inline int SValue() const { return Bit(20); } 640 // with register 641 inline int RmValue() const { return Bits(3, 0); } 642 DECLARE_STATIC_ACCESSOR(RmValue); 643 inline int ShiftValue() const { return static_cast<ShiftOp>(Bits(6, 5)); } 644 inline ShiftOp ShiftField() const { 645 return static_cast<ShiftOp>(BitField(6, 5)); 646 } 647 inline int RegShiftValue() const { return Bit(4); } 648 inline int RsValue() const { return Bits(11, 8); } 649 inline int ShiftAmountValue() const { return Bits(11, 7); } 650 // with immediate 651 inline int RotateValue() const { return Bits(11, 8); } 652 inline int Immed8Value() const { return Bits(7, 0); } 653 inline int Immed4Value() const { return Bits(19, 16); } 654 inline int ImmedMovwMovtValue() const { 655 return Immed4Value() << 12 | Offset12Value(); } 656 657 // Fields used in Load/Store instructions 658 inline int PUValue() const { return Bits(24, 23); } 659 inline int PUField() const { return BitField(24, 23); } 660 inline int BValue() const { return Bit(22); } 661 inline int WValue() const { return Bit(21); } 662 inline int LValue() const { return Bit(20); } 663 // with register uses same fields as Data processing instructions above 664 // with immediate 665 inline int Offset12Value() const { return Bits(11, 0); } 666 // multiple 667 inline int RlistValue() const { return Bits(15, 0); } 668 // extra loads and stores 669 inline int SignValue() const { return Bit(6); } 670 inline int HValue() const { return Bit(5); } 671 inline int ImmedHValue() const { return Bits(11, 8); } 672 inline int ImmedLValue() const { return Bits(3, 0); } 673 674 // Fields used in Branch instructions 675 inline int LinkValue() const { return Bit(24); } 676 inline int SImmed24Value() const { return ((InstructionBits() << 8) >> 8); } 677 678 // Fields used in Software interrupt instructions 679 inline SoftwareInterruptCodes SvcValue() const { 680 return static_cast<SoftwareInterruptCodes>(Bits(23, 0)); 681 } 682 683 // Test for special encodings of type 0 instructions (extra loads and stores, 684 // as well as multiplications). 685 inline bool IsSpecialType0() const { return (Bit(7) == 1) && (Bit(4) == 1); } 686 687 // Test for miscellaneous instructions encodings of type 0 instructions. 688 inline bool IsMiscType0() const { return (Bit(24) == 1) 689 && (Bit(23) == 0) 690 && (Bit(20) == 0) 691 && ((Bit(7) == 0)); } 692 693 // Test for a stop instruction. 694 inline bool IsStop() const { 695 return (TypeValue() == 7) && (Bit(24) == 1) && (SvcValue() >= kStopCode); 696 } 697 698 // Special accessors that test for existence of a value. 699 inline bool HasS() const { return SValue() == 1; } 700 inline bool HasB() const { return BValue() == 1; } 701 inline bool HasW() const { return WValue() == 1; } 702 inline bool HasL() const { return LValue() == 1; } 703 inline bool HasU() const { return UValue() == 1; } 704 inline bool HasSign() const { return SignValue() == 1; } 705 inline bool HasH() const { return HValue() == 1; } 706 inline bool HasLink() const { return LinkValue() == 1; } 707 708 // Decoding the double immediate in the vmov instruction. 709 double DoubleImmedVmov() const; 710 711 // Instructions are read of out a code stream. The only way to get a 712 // reference to an instruction is to convert a pointer. There is no way 713 // to allocate or create instances of class Instruction. 714 // Use the At(pc) function to create references to Instruction. 715 static Instruction* At(byte* pc) { 716 return reinterpret_cast<Instruction*>(pc); 717 } 718 719 720 private: 721 // Join split register codes, depending on single or double precision. 722 // four_bit is the position of the least-significant bit of the four 723 // bit specifier. one_bit is the position of the additional single bit 724 // specifier. 725 inline int VFPGlueRegValue(VFPRegPrecision pre, int four_bit, int one_bit) { 726 if (pre == kSinglePrecision) { 727 return (Bits(four_bit + 3, four_bit) << 1) | Bit(one_bit); 728 } 729 return (Bit(one_bit) << 4) | Bits(four_bit + 3, four_bit); 730 } 731 732 // We need to prevent the creation of instances of class Instruction. 733 DISALLOW_IMPLICIT_CONSTRUCTORS(Instruction); 734 }; 735 736 737 // Helper functions for converting between register numbers and names. 738 class Registers { 739 public: 740 // Return the name of the register. 741 static const char* Name(int reg); 742 743 // Lookup the register number for the name provided. 744 static int Number(const char* name); 745 746 struct RegisterAlias { 747 int reg; 748 const char* name; 749 }; 750 751 private: 752 static const char* names_[kNumRegisters]; 753 static const RegisterAlias aliases_[]; 754 }; 755 756 // Helper functions for converting between VFP register numbers and names. 757 class VFPRegisters { 758 public: 759 // Return the name of the register. 760 static const char* Name(int reg, bool is_double); 761 762 // Lookup the register number for the name provided. 763 // Set flag pointed by is_double to true if register 764 // is double-precision. 765 static int Number(const char* name, bool* is_double); 766 767 private: 768 static const char* names_[kNumVFPRegisters]; 769 }; 770 771 772 } } // namespace v8::internal 773 774 #endif // V8_ARM_CONSTANTS_ARM_H_ 775
