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| 1 // Copyright (c) 1994-2006 Sun Microsystems Inc. |
| 2 // All Rights Reserved. |
| 3 // |
| 4 // Redistribution and use in source and binary forms, with or without |
| 5 // modification, are permitted provided that the following conditions |
| 6 // are met: |
| 7 // |
| 8 // - Redistributions of source code must retain the above copyright notice, |
| 9 // this list of conditions and the following disclaimer. |
| 10 // |
| 11 // - Redistribution in binary form must reproduce the above copyright |
| 12 // notice, this list of conditions and the following disclaimer in the |
| 13 // documentation and/or other materials provided with the |
| 14 // distribution. |
| 15 // |
| 16 // - Neither the name of Sun Microsystems or the names of contributors may |
| 17 // be used to endorse or promote products derived from this software without |
| 18 // specific prior written permission. |
| 19 // |
| 20 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 23 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 24 // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 25 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 26 // (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| 27 // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 29 // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 30 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 31 // OF THE POSSIBILITY OF SUCH DAMAGE. |
| 32 |
| 33 // The original source code covered by the above license above has been modified |
| 34 // significantly by Google Inc. |
| 35 // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| 36 |
| 37 // A light-weight ARM Assembler |
| 38 // Generates user mode instructions for the ARM architecture up to version 5 |
| 39 |
| 40 #ifndef V8_ASSEMBLER_ARM_H_ |
| 41 #define V8_ASSEMBLER_ARM_H_ |
| 42 |
| 43 #include "assembler.h" |
| 44 |
| 45 namespace v8 { namespace internal { |
| 46 |
| 47 // CPU Registers. |
| 48 // |
| 49 // 1) We would prefer to use an enum, but enum values are assignment- |
| 50 // compatible with int, which has caused code-generation bugs. |
| 51 // |
| 52 // 2) We would prefer to use a class instead of a struct but we don't like |
| 53 // the register initialization to depend on the particular initialization |
| 54 // order (which appears to be different on OS X, Linux, and Windows for the |
| 55 // installed versions of C++ we tried). Using a struct permits C-style |
| 56 // "initialization". Also, the Register objects cannot be const as this |
| 57 // forces initialization stubs in MSVC, making us dependent on initialization |
| 58 // order. |
| 59 // |
| 60 // 3) By not using an enum, we are possibly preventing the compiler from |
| 61 // doing certain constant folds, which may significantly reduce the |
| 62 // code generated for some assembly instructions (because they boil down |
| 63 // to a few constants). If this is a problem, we could change the code |
| 64 // such that we use an enum in optimized mode, and the struct in debug |
| 65 // mode. This way we get the compile-time error checking in debug mode |
| 66 // and best performance in optimized code. |
| 67 // |
| 68 // Core register |
| 69 struct Register { |
| 70 bool is_valid() const { return 0 <= code_ && code_ < 16; } |
| 71 bool is(Register reg) const { return code_ == reg.code_; } |
| 72 int code() const { |
| 73 ASSERT(is_valid()); |
| 74 return code_; |
| 75 } |
| 76 int bit() const { |
| 77 ASSERT(is_valid()); |
| 78 return 1 << code_; |
| 79 } |
| 80 |
| 81 // (unfortunately we can't make this private in a struct) |
| 82 int code_; |
| 83 }; |
| 84 |
| 85 |
| 86 const int kNumRegisters = 16; |
| 87 |
| 88 extern Register no_reg; |
| 89 extern Register r0; |
| 90 extern Register r1; |
| 91 extern Register r2; |
| 92 extern Register r3; |
| 93 extern Register r4; |
| 94 extern Register r5; |
| 95 extern Register r6; |
| 96 extern Register r7; |
| 97 extern Register r8; |
| 98 extern Register r9; |
| 99 extern Register r10; |
| 100 extern Register fp; |
| 101 extern Register ip; |
| 102 extern Register sp; |
| 103 extern Register lr; |
| 104 extern Register pc; |
| 105 |
| 106 |
| 107 // Coprocessor register |
| 108 struct CRegister { |
| 109 bool is_valid() const { return 0 <= code_ && code_ < 16; } |
| 110 bool is(CRegister creg) const { return code_ == creg.code_; } |
| 111 int code() const { |
| 112 ASSERT(is_valid()); |
| 113 return code_; |
| 114 } |
| 115 int bit() const { |
| 116 ASSERT(is_valid()); |
| 117 return 1 << code_; |
| 118 } |
| 119 |
| 120 // (unfortunately we can't make this private in a struct) |
| 121 int code_; |
| 122 }; |
| 123 |
| 124 |
| 125 extern CRegister no_creg; |
| 126 extern CRegister cr0; |
| 127 extern CRegister cr1; |
| 128 extern CRegister cr2; |
| 129 extern CRegister cr3; |
| 130 extern CRegister cr4; |
| 131 extern CRegister cr5; |
| 132 extern CRegister cr6; |
| 133 extern CRegister cr7; |
| 134 extern CRegister cr8; |
| 135 extern CRegister cr9; |
| 136 extern CRegister cr10; |
| 137 extern CRegister cr11; |
| 138 extern CRegister cr12; |
| 139 extern CRegister cr13; |
| 140 extern CRegister cr14; |
| 141 extern CRegister cr15; |
| 142 |
| 143 |
| 144 // Coprocessor number |
| 145 enum Coprocessor { |
| 146 p0 = 0, |
| 147 p1 = 1, |
| 148 p2 = 2, |
| 149 p3 = 3, |
| 150 p4 = 4, |
| 151 p5 = 5, |
| 152 p6 = 6, |
| 153 p7 = 7, |
| 154 p8 = 8, |
| 155 p9 = 9, |
| 156 p10 = 10, |
| 157 p11 = 11, |
| 158 p12 = 12, |
| 159 p13 = 13, |
| 160 p14 = 14, |
| 161 p15 = 15 |
| 162 }; |
| 163 |
| 164 |
| 165 // Condition field in instructions |
| 166 enum Condition { |
| 167 eq = 0 << 28, |
| 168 ne = 1 << 28, |
| 169 cs = 2 << 28, |
| 170 hs = 2 << 28, |
| 171 cc = 3 << 28, |
| 172 lo = 3 << 28, |
| 173 mi = 4 << 28, |
| 174 pl = 5 << 28, |
| 175 vs = 6 << 28, |
| 176 vc = 7 << 28, |
| 177 hi = 8 << 28, |
| 178 ls = 9 << 28, |
| 179 ge = 10 << 28, |
| 180 lt = 11 << 28, |
| 181 gt = 12 << 28, |
| 182 le = 13 << 28, |
| 183 al = 14 << 28 |
| 184 }; |
| 185 |
| 186 |
| 187 // Returns the equivalent of !cc. |
| 188 INLINE(Condition NegateCondition(Condition cc)); |
| 189 |
| 190 |
| 191 // Corresponds to transposing the operands of a comparison. |
| 192 inline Condition ReverseCondition(Condition cc) { |
| 193 switch (cc) { |
| 194 case lo: |
| 195 return hi; |
| 196 case hi: |
| 197 return lo; |
| 198 case hs: |
| 199 return ls; |
| 200 case ls: |
| 201 return hs; |
| 202 case lt: |
| 203 return gt; |
| 204 case gt: |
| 205 return lt; |
| 206 case ge: |
| 207 return le; |
| 208 case le: |
| 209 return ge; |
| 210 default: |
| 211 return cc; |
| 212 }; |
| 213 } |
| 214 |
| 215 |
| 216 // Branch hints are not used on the ARM. They are defined so that they can |
| 217 // appear in shared function signatures, but will be ignored in ARM |
| 218 // implementations. |
| 219 enum Hint { no_hint }; |
| 220 |
| 221 // Hints are not used on the arm. Negating is trivial. |
| 222 inline Hint NegateHint(Hint ignored) { return no_hint; } |
| 223 |
| 224 |
| 225 // ----------------------------------------------------------------------------- |
| 226 // Addressing modes and instruction variants |
| 227 |
| 228 // Shifter operand shift operation |
| 229 enum ShiftOp { |
| 230 LSL = 0 << 5, |
| 231 LSR = 1 << 5, |
| 232 ASR = 2 << 5, |
| 233 ROR = 3 << 5, |
| 234 RRX = -1 |
| 235 }; |
| 236 |
| 237 |
| 238 // Condition code updating mode |
| 239 enum SBit { |
| 240 SetCC = 1 << 20, // set condition code |
| 241 LeaveCC = 0 << 20 // leave condition code unchanged |
| 242 }; |
| 243 |
| 244 |
| 245 // Status register selection |
| 246 enum SRegister { |
| 247 CPSR = 0 << 22, |
| 248 SPSR = 1 << 22 |
| 249 }; |
| 250 |
| 251 |
| 252 // Status register fields |
| 253 enum SRegisterField { |
| 254 CPSR_c = CPSR | 1 << 16, |
| 255 CPSR_x = CPSR | 1 << 17, |
| 256 CPSR_s = CPSR | 1 << 18, |
| 257 CPSR_f = CPSR | 1 << 19, |
| 258 SPSR_c = SPSR | 1 << 16, |
| 259 SPSR_x = SPSR | 1 << 17, |
| 260 SPSR_s = SPSR | 1 << 18, |
| 261 SPSR_f = SPSR | 1 << 19 |
| 262 }; |
| 263 |
| 264 // Status register field mask (or'ed SRegisterField enum values) |
| 265 typedef uint32_t SRegisterFieldMask; |
| 266 |
| 267 |
| 268 // Memory operand addressing mode |
| 269 enum AddrMode { |
| 270 // bit encoding P U W |
| 271 Offset = (8|4|0) << 21, // offset (without writeback to base) |
| 272 PreIndex = (8|4|1) << 21, // pre-indexed addressing with writeback |
| 273 PostIndex = (0|4|0) << 21, // post-indexed addressing with writeback |
| 274 NegOffset = (8|0|0) << 21, // negative offset (without writeback to base) |
| 275 NegPreIndex = (8|0|1) << 21, // negative pre-indexed with writeback |
| 276 NegPostIndex = (0|0|0) << 21 // negative post-indexed with writeback |
| 277 }; |
| 278 |
| 279 |
| 280 // Load/store multiple addressing mode |
| 281 enum BlockAddrMode { |
| 282 // bit encoding P U W |
| 283 da = (0|0|0) << 21, // decrement after |
| 284 ia = (0|4|0) << 21, // increment after |
| 285 db = (8|0|0) << 21, // decrement before |
| 286 ib = (8|4|0) << 21, // increment before |
| 287 da_w = (0|0|1) << 21, // decrement after with writeback to base |
| 288 ia_w = (0|4|1) << 21, // increment after with writeback to base |
| 289 db_w = (8|0|1) << 21, // decrement before with writeback to base |
| 290 ib_w = (8|4|1) << 21 // increment before with writeback to base |
| 291 }; |
| 292 |
| 293 |
| 294 // Coprocessor load/store operand size |
| 295 enum LFlag { |
| 296 Long = 1 << 22, // long load/store coprocessor |
| 297 Short = 0 << 22 // short load/store coprocessor |
| 298 }; |
| 299 |
| 300 |
| 301 // ----------------------------------------------------------------------------- |
| 302 // Machine instruction Operands |
| 303 |
| 304 // Class Operand represents a shifter operand in data processing instructions |
| 305 class Operand BASE_EMBEDDED { |
| 306 public: |
| 307 // immediate |
| 308 INLINE(explicit Operand(int32_t immediate, |
| 309 RelocInfo::Mode rmode = RelocInfo::NONE)); |
| 310 INLINE(explicit Operand(const ExternalReference& f)); |
| 311 INLINE(explicit Operand(const char* s)); |
| 312 INLINE(explicit Operand(Object** opp)); |
| 313 INLINE(explicit Operand(Context** cpp)); |
| 314 explicit Operand(Handle<Object> handle); |
| 315 INLINE(explicit Operand(Smi* value)); |
| 316 |
| 317 // rm |
| 318 INLINE(explicit Operand(Register rm)); |
| 319 |
| 320 // rm <shift_op> shift_imm |
| 321 explicit Operand(Register rm, ShiftOp shift_op, int shift_imm); |
| 322 |
| 323 // rm <shift_op> rs |
| 324 explicit Operand(Register rm, ShiftOp shift_op, Register rs); |
| 325 |
| 326 // Return true if this is a register operand. |
| 327 INLINE(bool is_reg() const); |
| 328 |
| 329 Register rm() const { return rm_; } |
| 330 |
| 331 private: |
| 332 Register rm_; |
| 333 Register rs_; |
| 334 ShiftOp shift_op_; |
| 335 int shift_imm_; // valid if rm_ != no_reg && rs_ == no_reg |
| 336 int32_t imm32_; // valid if rm_ == no_reg |
| 337 RelocInfo::Mode rmode_; |
| 338 |
| 339 friend class Assembler; |
| 340 }; |
| 341 |
| 342 |
| 343 // Class MemOperand represents a memory operand in load and store instructions |
| 344 class MemOperand BASE_EMBEDDED { |
| 345 public: |
| 346 // [rn +/- offset] Offset/NegOffset |
| 347 // [rn +/- offset]! PreIndex/NegPreIndex |
| 348 // [rn], +/- offset PostIndex/NegPostIndex |
| 349 // offset is any signed 32-bit value; offset is first loaded to register ip if |
| 350 // it does not fit the addressing mode (12-bit unsigned and sign bit) |
| 351 explicit MemOperand(Register rn, int32_t offset = 0, AddrMode am = Offset); |
| 352 |
| 353 // [rn +/- rm] Offset/NegOffset |
| 354 // [rn +/- rm]! PreIndex/NegPreIndex |
| 355 // [rn], +/- rm PostIndex/NegPostIndex |
| 356 explicit MemOperand(Register rn, Register rm, AddrMode am = Offset); |
| 357 |
| 358 // [rn +/- rm <shift_op> shift_imm] Offset/NegOffset |
| 359 // [rn +/- rm <shift_op> shift_imm]! PreIndex/NegPreIndex |
| 360 // [rn], +/- rm <shift_op> shift_imm PostIndex/NegPostIndex |
| 361 explicit MemOperand(Register rn, Register rm, |
| 362 ShiftOp shift_op, int shift_imm, AddrMode am = Offset); |
| 363 |
| 364 private: |
| 365 Register rn_; // base |
| 366 Register rm_; // register offset |
| 367 int32_t offset_; // valid if rm_ == no_reg |
| 368 ShiftOp shift_op_; |
| 369 int shift_imm_; // valid if rm_ != no_reg && rs_ == no_reg |
| 370 AddrMode am_; // bits P, U, and W |
| 371 |
| 372 friend class Assembler; |
| 373 }; |
| 374 |
| 375 |
| 376 typedef int32_t Instr; |
| 377 |
| 378 |
| 379 class Assembler : public Malloced { |
| 380 public: |
| 381 // Create an assembler. Instructions and relocation information are emitted |
| 382 // into a buffer, with the instructions starting from the beginning and the |
| 383 // relocation information starting from the end of the buffer. See CodeDesc |
| 384 // for a detailed comment on the layout (globals.h). |
| 385 // |
| 386 // If the provided buffer is NULL, the assembler allocates and grows its own |
| 387 // buffer, and buffer_size determines the initial buffer size. The buffer is |
| 388 // owned by the assembler and deallocated upon destruction of the assembler. |
| 389 // |
| 390 // If the provided buffer is not NULL, the assembler uses the provided buffer |
| 391 // for code generation and assumes its size to be buffer_size. If the buffer |
| 392 // is too small, a fatal error occurs. No deallocation of the buffer is done |
| 393 // upon destruction of the assembler. |
| 394 Assembler(void* buffer, int buffer_size); |
| 395 ~Assembler(); |
| 396 |
| 397 // GetCode emits any pending (non-emitted) code and fills the descriptor |
| 398 // desc. GetCode() is idempotent; it returns the same result if no other |
| 399 // Assembler functions are invoked in between GetCode() calls. |
| 400 void GetCode(CodeDesc* desc); |
| 401 |
| 402 // Label operations & relative jumps (PPUM Appendix D) |
| 403 // |
| 404 // Takes a branch opcode (cc) and a label (L) and generates |
| 405 // either a backward branch or a forward branch and links it |
| 406 // to the label fixup chain. Usage: |
| 407 // |
| 408 // Label L; // unbound label |
| 409 // j(cc, &L); // forward branch to unbound label |
| 410 // bind(&L); // bind label to the current pc |
| 411 // j(cc, &L); // backward branch to bound label |
| 412 // bind(&L); // illegal: a label may be bound only once |
| 413 // |
| 414 // Note: The same Label can be used for forward and backward branches |
| 415 // but it may be bound only once. |
| 416 |
| 417 void bind(Label* L); // binds an unbound label L to the current code position |
| 418 |
| 419 // Returns the branch offset to the given label from the current code position |
| 420 // Links the label to the current position if it is still unbound |
| 421 // Manages the jump elimination optimization if the second parameter is true. |
| 422 int branch_offset(Label* L, bool jump_elimination_allowed); |
| 423 |
| 424 // Return the address in the constant pool of the code target address used by |
| 425 // the branch/call instruction at pc. |
| 426 INLINE(static Address target_address_address_at(Address pc)); |
| 427 |
| 428 // Read/Modify the code target address in the branch/call instruction at pc. |
| 429 INLINE(static Address target_address_at(Address pc)); |
| 430 INLINE(static void set_target_address_at(Address pc, Address target)); |
| 431 |
| 432 // Distance between the instruction referring to the address of the call |
| 433 // target (ldr pc, [target addr in const pool]) and the return address |
| 434 static const int kTargetAddrToReturnAddrDist = sizeof(Instr); |
| 435 |
| 436 |
| 437 // --------------------------------------------------------------------------- |
| 438 // Code generation |
| 439 |
| 440 // Insert the smallest number of nop instructions |
| 441 // possible to align the pc offset to a multiple |
| 442 // of m. m must be a power of 2 (>= 4). |
| 443 void Align(int m); |
| 444 |
| 445 // Branch instructions |
| 446 void b(int branch_offset, Condition cond = al); |
| 447 void bl(int branch_offset, Condition cond = al); |
| 448 void blx(int branch_offset); // v5 and above |
| 449 void blx(Register target, Condition cond = al); // v5 and above |
| 450 void bx(Register target, Condition cond = al); // v5 and above, plus v4t |
| 451 |
| 452 // Convenience branch instructions using labels |
| 453 void b(Label* L, Condition cond = al) { |
| 454 b(branch_offset(L, cond == al), cond); |
| 455 } |
| 456 void b(Condition cond, Label* L) { b(branch_offset(L, cond == al), cond); } |
| 457 void bl(Label* L, Condition cond = al) { bl(branch_offset(L, false), cond); } |
| 458 void bl(Condition cond, Label* L) { bl(branch_offset(L, false), cond); } |
| 459 void blx(Label* L) { blx(branch_offset(L, false)); } // v5 and above |
| 460 |
| 461 // Data-processing instructions |
| 462 void and_(Register dst, Register src1, const Operand& src2, |
| 463 SBit s = LeaveCC, Condition cond = al); |
| 464 |
| 465 void eor(Register dst, Register src1, const Operand& src2, |
| 466 SBit s = LeaveCC, Condition cond = al); |
| 467 |
| 468 void sub(Register dst, Register src1, const Operand& src2, |
| 469 SBit s = LeaveCC, Condition cond = al); |
| 470 void sub(Register dst, Register src1, Register src2, |
| 471 SBit s = LeaveCC, Condition cond = al) { |
| 472 sub(dst, src1, Operand(src2), s, cond); |
| 473 } |
| 474 |
| 475 void rsb(Register dst, Register src1, const Operand& src2, |
| 476 SBit s = LeaveCC, Condition cond = al); |
| 477 |
| 478 void add(Register dst, Register src1, const Operand& src2, |
| 479 SBit s = LeaveCC, Condition cond = al); |
| 480 |
| 481 void adc(Register dst, Register src1, const Operand& src2, |
| 482 SBit s = LeaveCC, Condition cond = al); |
| 483 |
| 484 void sbc(Register dst, Register src1, const Operand& src2, |
| 485 SBit s = LeaveCC, Condition cond = al); |
| 486 |
| 487 void rsc(Register dst, Register src1, const Operand& src2, |
| 488 SBit s = LeaveCC, Condition cond = al); |
| 489 |
| 490 void tst(Register src1, const Operand& src2, Condition cond = al); |
| 491 void tst(Register src1, Register src2, Condition cond = al) { |
| 492 tst(src1, Operand(src2), cond); |
| 493 } |
| 494 |
| 495 void teq(Register src1, const Operand& src2, Condition cond = al); |
| 496 |
| 497 void cmp(Register src1, const Operand& src2, Condition cond = al); |
| 498 void cmp(Register src1, Register src2, Condition cond = al) { |
| 499 cmp(src1, Operand(src2), cond); |
| 500 } |
| 501 |
| 502 void cmn(Register src1, const Operand& src2, Condition cond = al); |
| 503 |
| 504 void orr(Register dst, Register src1, const Operand& src2, |
| 505 SBit s = LeaveCC, Condition cond = al); |
| 506 void orr(Register dst, Register src1, Register src2, |
| 507 SBit s = LeaveCC, Condition cond = al) { |
| 508 orr(dst, src1, Operand(src2), s, cond); |
| 509 } |
| 510 |
| 511 void mov(Register dst, const Operand& src, |
| 512 SBit s = LeaveCC, Condition cond = al); |
| 513 void mov(Register dst, Register src, SBit s = LeaveCC, Condition cond = al) { |
| 514 mov(dst, Operand(src), s, cond); |
| 515 } |
| 516 |
| 517 void bic(Register dst, Register src1, const Operand& src2, |
| 518 SBit s = LeaveCC, Condition cond = al); |
| 519 |
| 520 void mvn(Register dst, const Operand& src, |
| 521 SBit s = LeaveCC, Condition cond = al); |
| 522 |
| 523 // Multiply instructions |
| 524 |
| 525 void mla(Register dst, Register src1, Register src2, Register srcA, |
| 526 SBit s = LeaveCC, Condition cond = al); |
| 527 |
| 528 void mul(Register dst, Register src1, Register src2, |
| 529 SBit s = LeaveCC, Condition cond = al); |
| 530 |
| 531 void smlal(Register dstL, Register dstH, Register src1, Register src2, |
| 532 SBit s = LeaveCC, Condition cond = al); |
| 533 |
| 534 void smull(Register dstL, Register dstH, Register src1, Register src2, |
| 535 SBit s = LeaveCC, Condition cond = al); |
| 536 |
| 537 void umlal(Register dstL, Register dstH, Register src1, Register src2, |
| 538 SBit s = LeaveCC, Condition cond = al); |
| 539 |
| 540 void umull(Register dstL, Register dstH, Register src1, Register src2, |
| 541 SBit s = LeaveCC, Condition cond = al); |
| 542 |
| 543 // Miscellaneous arithmetic instructions |
| 544 |
| 545 void clz(Register dst, Register src, Condition cond = al); // v5 and above |
| 546 |
| 547 // Status register access instructions |
| 548 |
| 549 void mrs(Register dst, SRegister s, Condition cond = al); |
| 550 void msr(SRegisterFieldMask fields, const Operand& src, Condition cond = al); |
| 551 |
| 552 // Load/Store instructions |
| 553 void ldr(Register dst, const MemOperand& src, Condition cond = al); |
| 554 void str(Register src, const MemOperand& dst, Condition cond = al); |
| 555 void ldrb(Register dst, const MemOperand& src, Condition cond = al); |
| 556 void strb(Register src, const MemOperand& dst, Condition cond = al); |
| 557 void ldrh(Register dst, const MemOperand& src, Condition cond = al); |
| 558 void strh(Register src, const MemOperand& dst, Condition cond = al); |
| 559 void ldrsb(Register dst, const MemOperand& src, Condition cond = al); |
| 560 void ldrsh(Register dst, const MemOperand& src, Condition cond = al); |
| 561 |
| 562 // Load/Store multiple instructions |
| 563 void ldm(BlockAddrMode am, Register base, RegList dst, Condition cond = al); |
| 564 void stm(BlockAddrMode am, Register base, RegList src, Condition cond = al); |
| 565 |
| 566 // Semaphore instructions |
| 567 void swp(Register dst, Register src, Register base, Condition cond = al); |
| 568 void swpb(Register dst, Register src, Register base, Condition cond = al); |
| 569 |
| 570 // Exception-generating instructions and debugging support |
| 571 void stop(const char* msg); |
| 572 |
| 573 void bkpt(uint32_t imm16); // v5 and above |
| 574 void swi(uint32_t imm24, Condition cond = al); |
| 575 |
| 576 // Coprocessor instructions |
| 577 |
| 578 void cdp(Coprocessor coproc, int opcode_1, |
| 579 CRegister crd, CRegister crn, CRegister crm, |
| 580 int opcode_2, Condition cond = al); |
| 581 |
| 582 void cdp2(Coprocessor coproc, int opcode_1, |
| 583 CRegister crd, CRegister crn, CRegister crm, |
| 584 int opcode_2); // v5 and above |
| 585 |
| 586 void mcr(Coprocessor coproc, int opcode_1, |
| 587 Register rd, CRegister crn, CRegister crm, |
| 588 int opcode_2 = 0, Condition cond = al); |
| 589 |
| 590 void mcr2(Coprocessor coproc, int opcode_1, |
| 591 Register rd, CRegister crn, CRegister crm, |
| 592 int opcode_2 = 0); // v5 and above |
| 593 |
| 594 void mrc(Coprocessor coproc, int opcode_1, |
| 595 Register rd, CRegister crn, CRegister crm, |
| 596 int opcode_2 = 0, Condition cond = al); |
| 597 |
| 598 void mrc2(Coprocessor coproc, int opcode_1, |
| 599 Register rd, CRegister crn, CRegister crm, |
| 600 int opcode_2 = 0); // v5 and above |
| 601 |
| 602 void ldc(Coprocessor coproc, CRegister crd, const MemOperand& src, |
| 603 LFlag l = Short, Condition cond = al); |
| 604 void ldc(Coprocessor coproc, CRegister crd, Register base, int option, |
| 605 LFlag l = Short, Condition cond = al); |
| 606 |
| 607 void ldc2(Coprocessor coproc, CRegister crd, const MemOperand& src, |
| 608 LFlag l = Short); // v5 and above |
| 609 void ldc2(Coprocessor coproc, CRegister crd, Register base, int option, |
| 610 LFlag l = Short); // v5 and above |
| 611 |
| 612 void stc(Coprocessor coproc, CRegister crd, const MemOperand& dst, |
| 613 LFlag l = Short, Condition cond = al); |
| 614 void stc(Coprocessor coproc, CRegister crd, Register base, int option, |
| 615 LFlag l = Short, Condition cond = al); |
| 616 |
| 617 void stc2(Coprocessor coproc, CRegister crd, const MemOperand& dst, |
| 618 LFlag l = Short); // v5 and above |
| 619 void stc2(Coprocessor coproc, CRegister crd, Register base, int option, |
| 620 LFlag l = Short); // v5 and above |
| 621 |
| 622 // Pseudo instructions |
| 623 void nop() { mov(r0, Operand(r0)); } |
| 624 |
| 625 void push(Register src) { |
| 626 str(src, MemOperand(sp, 4, NegPreIndex), al); |
| 627 } |
| 628 |
| 629 void pop(Register dst) { |
| 630 ldr(dst, MemOperand(sp, 4, PostIndex), al); |
| 631 } |
| 632 |
| 633 void pop() { |
| 634 add(sp, sp, Operand(kPointerSize)); |
| 635 } |
| 636 |
| 637 // Load effective address of memory operand x into register dst |
| 638 void lea(Register dst, const MemOperand& x, |
| 639 SBit s = LeaveCC, Condition cond = al); |
| 640 |
| 641 // Jump unconditionally to given label. |
| 642 void jmp(Label* L) { b(L, al); } |
| 643 |
| 644 |
| 645 // Debugging |
| 646 |
| 647 // Record a comment relocation entry that can be used by a disassembler. |
| 648 // Use --debug_code to enable. |
| 649 void RecordComment(const char* msg); |
| 650 |
| 651 void RecordPosition(int pos); |
| 652 void RecordStatementPosition(int pos); |
| 653 void WriteRecordedPositions(); |
| 654 |
| 655 int pc_offset() const { return pc_ - buffer_; } |
| 656 int current_position() const { return current_position_; } |
| 657 int current_statement_position() const { return current_position_; } |
| 658 |
| 659 protected: |
| 660 int buffer_space() const { return reloc_info_writer.pos() - pc_; } |
| 661 |
| 662 // Read/patch instructions |
| 663 Instr instr_at(byte* pc) { return *reinterpret_cast<Instr*>(pc); } |
| 664 void instr_at_put(byte* pc, Instr instr) { |
| 665 *reinterpret_cast<Instr*>(pc) = instr; |
| 666 } |
| 667 Instr instr_at(int pos) { return *reinterpret_cast<Instr*>(buffer_ + pos); } |
| 668 void instr_at_put(int pos, Instr instr) { |
| 669 *reinterpret_cast<Instr*>(buffer_ + pos) = instr; |
| 670 } |
| 671 |
| 672 // Decode branch instruction at pos and return branch target pos |
| 673 int target_at(int pos); |
| 674 |
| 675 // Patch branch instruction at pos to branch to given branch target pos |
| 676 void target_at_put(int pos, int target_pos); |
| 677 |
| 678 // Check if is time to emit a constant pool for pending reloc info entries |
| 679 void CheckConstPool(bool force_emit, bool require_jump); |
| 680 |
| 681 // Block the emission of the constant pool before pc_offset |
| 682 void BlockConstPoolBefore(int pc_offset) { |
| 683 if (no_const_pool_before_ < pc_offset) no_const_pool_before_ = pc_offset; |
| 684 } |
| 685 |
| 686 private: |
| 687 // Code buffer: |
| 688 // The buffer into which code and relocation info are generated. |
| 689 byte* buffer_; |
| 690 int buffer_size_; |
| 691 // True if the assembler owns the buffer, false if buffer is external. |
| 692 bool own_buffer_; |
| 693 |
| 694 // Buffer size and constant pool distance are checked together at regular |
| 695 // intervals of kBufferCheckInterval emitted bytes |
| 696 static const int kBufferCheckInterval = 1*KB/2; |
| 697 int next_buffer_check_; // pc offset of next buffer check |
| 698 |
| 699 // Code generation |
| 700 static const int kInstrSize = sizeof(Instr); // signed size |
| 701 // The relocation writer's position is at least kGap bytes below the end of |
| 702 // the generated instructions. This is so that multi-instruction sequences do |
| 703 // not have to check for overflow. The same is true for writes of large |
| 704 // relocation info entries. |
| 705 static const int kGap = 32; |
| 706 byte* pc_; // the program counter; moves forward |
| 707 |
| 708 // Constant pool generation |
| 709 // Pools are emitted in the instruction stream, preferably after unconditional |
| 710 // jumps or after returns from functions (in dead code locations). |
| 711 // If a long code sequence does not contain unconditional jumps, it is |
| 712 // necessary to emit the constant pool before the pool gets too far from the |
| 713 // location it is accessed from. In this case, we emit a jump over the emitted |
| 714 // constant pool. |
| 715 // Constants in the pool may be addresses of functions that gets relocated; |
| 716 // if so, a relocation info entry is associated to the constant pool entry. |
| 717 |
| 718 // Repeated checking whether the constant pool should be emitted is rather |
| 719 // expensive. By default we only check again once a number of instructions |
| 720 // has been generated. That also means that the sizing of the buffers is not |
| 721 // an exact science, and that we rely on some slop to not overrun buffers. |
| 722 static const int kCheckConstIntervalInst = 32; |
| 723 static const int kCheckConstInterval = kCheckConstIntervalInst * kInstrSize; |
| 724 |
| 725 |
| 726 // Pools are emitted after function return and in dead code at (more or less) |
| 727 // regular intervals of kDistBetweenPools bytes |
| 728 static const int kDistBetweenPools = 1*KB; |
| 729 |
| 730 // Constants in pools are accessed via pc relative addressing, which can |
| 731 // reach +/-4KB thereby defining a maximum distance between the instruction |
| 732 // and the accessed constant. We satisfy this constraint by limiting the |
| 733 // distance between pools. |
| 734 static const int kMaxDistBetweenPools = 4*KB - 2*kBufferCheckInterval; |
| 735 |
| 736 // Emission of the constant pool may be blocked in some code sequences |
| 737 int no_const_pool_before_; // block emission before this pc offset |
| 738 |
| 739 // Keep track of the last emitted pool to guarantee a maximal distance |
| 740 int last_const_pool_end_; // pc offset following the last constant pool |
| 741 |
| 742 // Relocation info generation |
| 743 // Each relocation is encoded as a variable size value |
| 744 static const int kMaxRelocSize = RelocInfoWriter::kMaxSize; |
| 745 RelocInfoWriter reloc_info_writer; |
| 746 // Relocation info records are also used during code generation as temporary |
| 747 // containers for constants and code target addresses until they are emitted |
| 748 // to the constant pool. These pending relocation info records are temporarily |
| 749 // stored in a separate buffer until a constant pool is emitted. |
| 750 // If every instruction in a long sequence is accessing the pool, we need one |
| 751 // pending relocation entry per instruction. |
| 752 static const int kMaxNumPRInfo = kMaxDistBetweenPools/kInstrSize; |
| 753 RelocInfo prinfo_[kMaxNumPRInfo]; // the buffer of pending relocation info |
| 754 int num_prinfo_; // number of pending reloc info entries in the buffer |
| 755 |
| 756 // The bound position, before this we cannot do instruction elimination. |
| 757 int last_bound_pos_; |
| 758 |
| 759 // source position information |
| 760 int current_position_; |
| 761 int current_statement_position_; |
| 762 int written_position_; |
| 763 int written_statement_position_; |
| 764 |
| 765 // Code emission |
| 766 inline void CheckBuffer(); |
| 767 void GrowBuffer(); |
| 768 inline void emit(Instr x); |
| 769 |
| 770 // Instruction generation |
| 771 void addrmod1(Instr instr, Register rn, Register rd, const Operand& x); |
| 772 void addrmod2(Instr instr, Register rd, const MemOperand& x); |
| 773 void addrmod3(Instr instr, Register rd, const MemOperand& x); |
| 774 void addrmod4(Instr instr, Register rn, RegList rl); |
| 775 void addrmod5(Instr instr, CRegister crd, const MemOperand& x); |
| 776 |
| 777 // Labels |
| 778 void print(Label* L); |
| 779 void bind_to(Label* L, int pos); |
| 780 void link_to(Label* L, Label* appendix); |
| 781 void next(Label* L); |
| 782 |
| 783 // Record reloc info for current pc_ |
| 784 void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0); |
| 785 }; |
| 786 |
| 787 } } // namespace v8::internal |
| 788 |
| 789 #endif // V8_ASSEMBLER_ARM_H_ |
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