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 // A Disassembler object is used to disassemble a block of code instruction by
29 // instruction. The default implementation of the NameConverter object can be
30 // overriden to modify register names or to do symbol lookup on addresses.
31 //
32 // The example below will disassemble a block of code and print it to stdout.
33 //
34 // NameConverter converter;
35 // Disassembler d(converter);
36 // for (byte* pc = begin; pc < end;) {
37 // v8::internal::EmbeddedVector<char, 256> buffer;
38 // byte* prev_pc = pc;
39 // pc += d.InstructionDecode(buffer, pc);
40 // printf("%p %08x %s\n",
41 // prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer);
42 // }
43 //
44 // The Disassembler class also has a convenience method to disassemble a block
45 // of code into a FILE*, meaning that the above functionality could also be
46 // achieved by just calling Disassembler::Disassemble(stdout, begin, end);
47
48
49 #include <assert.h>
50 #include <stdio.h>
51 #include <stdarg.h>
52 #include <string.h>
53 #ifndef WIN32
54 #include <stdint.h>
55 #endif
56
57 #include "v8.h"
58
59 #if defined(V8_TARGET_ARCH_ARM)
60
61 #include "constants-arm.h"
62 #include "disasm.h"
63 #include "macro-assembler.h"
64 #include "platform.h"
65
66
67 namespace v8 {
68 namespace internal {
69
70
71 //------------------------------------------------------------------------------
72
73 // Decoder decodes and disassembles instructions into an output buffer.
74 // It uses the converter to convert register names and call destinations into
75 // more informative description.
76 class Decoder {
77 public:
Decoder(const disasm::NameConverter & converter,Vector<char> out_buffer)78 Decoder(const disasm::NameConverter& converter,
79 Vector<char> out_buffer)
80 : converter_(converter),
81 out_buffer_(out_buffer),
82 out_buffer_pos_(0) {
83 out_buffer_[out_buffer_pos_] = '\0';
84 }
85
~Decoder()86 ~Decoder() {}
87
88 // Writes one disassembled instruction into 'buffer' (0-terminated).
89 // Returns the length of the disassembled machine instruction in bytes.
90 int InstructionDecode(byte* instruction);
91
92 static bool IsConstantPoolAt(byte* instr_ptr);
93 static int ConstantPoolSizeAt(byte* instr_ptr);
94
95 private:
96 // Bottleneck functions to print into the out_buffer.
97 void PrintChar(const char ch);
98 void Print(const char* str);
99
100 // Printing of common values.
101 void PrintRegister(int reg);
102 void PrintSRegister(int reg);
103 void PrintDRegister(int reg);
104 int FormatVFPRegister(Instruction* instr, const char* format);
105 void PrintMovwMovt(Instruction* instr);
106 int FormatVFPinstruction(Instruction* instr, const char* format);
107 void PrintCondition(Instruction* instr);
108 void PrintShiftRm(Instruction* instr);
109 void PrintShiftImm(Instruction* instr);
110 void PrintShiftSat(Instruction* instr);
111 void PrintPU(Instruction* instr);
112 void PrintSoftwareInterrupt(SoftwareInterruptCodes svc);
113
114 // Handle formatting of instructions and their options.
115 int FormatRegister(Instruction* instr, const char* option);
116 int FormatOption(Instruction* instr, const char* option);
117 void Format(Instruction* instr, const char* format);
118 void Unknown(Instruction* instr);
119
120 // Each of these functions decodes one particular instruction type, a 3-bit
121 // field in the instruction encoding.
122 // Types 0 and 1 are combined as they are largely the same except for the way
123 // they interpret the shifter operand.
124 void DecodeType01(Instruction* instr);
125 void DecodeType2(Instruction* instr);
126 void DecodeType3(Instruction* instr);
127 void DecodeType4(Instruction* instr);
128 void DecodeType5(Instruction* instr);
129 void DecodeType6(Instruction* instr);
130 // Type 7 includes special Debugger instructions.
131 int DecodeType7(Instruction* instr);
132 // For VFP support.
133 void DecodeTypeVFP(Instruction* instr);
134 void DecodeType6CoprocessorIns(Instruction* instr);
135
136 void DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instruction* instr);
137 void DecodeVCMP(Instruction* instr);
138 void DecodeVCVTBetweenDoubleAndSingle(Instruction* instr);
139 void DecodeVCVTBetweenFloatingPointAndInteger(Instruction* instr);
140
141 const disasm::NameConverter& converter_;
142 Vector<char> out_buffer_;
143 int out_buffer_pos_;
144
145 DISALLOW_COPY_AND_ASSIGN(Decoder);
146 };
147
148
149 // Support for assertions in the Decoder formatting functions.
150 #define STRING_STARTS_WITH(string, compare_string) \
151 (strncmp(string, compare_string, strlen(compare_string)) == 0)
152
153
154 // Append the ch to the output buffer.
PrintChar(const char ch)155 void Decoder::PrintChar(const char ch) {
156 out_buffer_[out_buffer_pos_++] = ch;
157 }
158
159
160 // Append the str to the output buffer.
Print(const char * str)161 void Decoder::Print(const char* str) {
162 char cur = *str++;
163 while (cur != '\0' && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
164 PrintChar(cur);
165 cur = *str++;
166 }
167 out_buffer_[out_buffer_pos_] = 0;
168 }
169
170
171 // These condition names are defined in a way to match the native disassembler
172 // formatting. See for example the command "objdump -d <binary file>".
173 static const char* cond_names[kNumberOfConditions] = {
174 "eq", "ne", "cs" , "cc" , "mi" , "pl" , "vs" , "vc" ,
175 "hi", "ls", "ge", "lt", "gt", "le", "", "invalid",
176 };
177
178
179 // Print the condition guarding the instruction.
PrintCondition(Instruction * instr)180 void Decoder::PrintCondition(Instruction* instr) {
181 Print(cond_names[instr->ConditionValue()]);
182 }
183
184
185 // Print the register name according to the active name converter.
PrintRegister(int reg)186 void Decoder::PrintRegister(int reg) {
187 Print(converter_.NameOfCPURegister(reg));
188 }
189
190 // Print the VFP S register name according to the active name converter.
PrintSRegister(int reg)191 void Decoder::PrintSRegister(int reg) {
192 Print(VFPRegisters::Name(reg, false));
193 }
194
195 // Print the VFP D register name according to the active name converter.
PrintDRegister(int reg)196 void Decoder::PrintDRegister(int reg) {
197 Print(VFPRegisters::Name(reg, true));
198 }
199
200
201 // These shift names are defined in a way to match the native disassembler
202 // formatting. See for example the command "objdump -d <binary file>".
203 static const char* const shift_names[kNumberOfShifts] = {
204 "lsl", "lsr", "asr", "ror"
205 };
206
207
208 // Print the register shift operands for the instruction. Generally used for
209 // data processing instructions.
PrintShiftRm(Instruction * instr)210 void Decoder::PrintShiftRm(Instruction* instr) {
211 ShiftOp shift = instr->ShiftField();
212 int shift_index = instr->ShiftValue();
213 int shift_amount = instr->ShiftAmountValue();
214 int rm = instr->RmValue();
215
216 PrintRegister(rm);
217
218 if ((instr->RegShiftValue() == 0) && (shift == LSL) && (shift_amount == 0)) {
219 // Special case for using rm only.
220 return;
221 }
222 if (instr->RegShiftValue() == 0) {
223 // by immediate
224 if ((shift == ROR) && (shift_amount == 0)) {
225 Print(", RRX");
226 return;
227 } else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) {
228 shift_amount = 32;
229 }
230 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
231 ", %s #%d",
232 shift_names[shift_index],
233 shift_amount);
234 } else {
235 // by register
236 int rs = instr->RsValue();
237 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
238 ", %s ", shift_names[shift_index]);
239 PrintRegister(rs);
240 }
241 }
242
243
244 // Print the immediate operand for the instruction. Generally used for data
245 // processing instructions.
PrintShiftImm(Instruction * instr)246 void Decoder::PrintShiftImm(Instruction* instr) {
247 int rotate = instr->RotateValue() * 2;
248 int immed8 = instr->Immed8Value();
249 int imm = (immed8 >> rotate) | (immed8 << (32 - rotate));
250 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
251 "#%d", imm);
252 }
253
254
255 // Print the optional shift and immediate used by saturating instructions.
PrintShiftSat(Instruction * instr)256 void Decoder::PrintShiftSat(Instruction* instr) {
257 int shift = instr->Bits(11, 7);
258 if (shift > 0) {
259 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
260 ", %s #%d",
261 shift_names[instr->Bit(6) * 2],
262 instr->Bits(11, 7));
263 }
264 }
265
266
267 // Print PU formatting to reduce complexity of FormatOption.
PrintPU(Instruction * instr)268 void Decoder::PrintPU(Instruction* instr) {
269 switch (instr->PUField()) {
270 case da_x: {
271 Print("da");
272 break;
273 }
274 case ia_x: {
275 Print("ia");
276 break;
277 }
278 case db_x: {
279 Print("db");
280 break;
281 }
282 case ib_x: {
283 Print("ib");
284 break;
285 }
286 default: {
287 UNREACHABLE();
288 break;
289 }
290 }
291 }
292
293
294 // Print SoftwareInterrupt codes. Factoring this out reduces the complexity of
295 // the FormatOption method.
PrintSoftwareInterrupt(SoftwareInterruptCodes svc)296 void Decoder::PrintSoftwareInterrupt(SoftwareInterruptCodes svc) {
297 switch (svc) {
298 case kCallRtRedirected:
299 Print("call rt redirected");
300 return;
301 case kBreakpoint:
302 Print("breakpoint");
303 return;
304 default:
305 if (svc >= kStopCode) {
306 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
307 "%d - 0x%x",
308 svc & kStopCodeMask,
309 svc & kStopCodeMask);
310 } else {
311 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
312 "%d",
313 svc);
314 }
315 return;
316 }
317 }
318
319
320 // Handle all register based formatting in this function to reduce the
321 // complexity of FormatOption.
FormatRegister(Instruction * instr,const char * format)322 int Decoder::FormatRegister(Instruction* instr, const char* format) {
323 ASSERT(format[0] == 'r');
324 if (format[1] == 'n') { // 'rn: Rn register
325 int reg = instr->RnValue();
326 PrintRegister(reg);
327 return 2;
328 } else if (format[1] == 'd') { // 'rd: Rd register
329 int reg = instr->RdValue();
330 PrintRegister(reg);
331 return 2;
332 } else if (format[1] == 's') { // 'rs: Rs register
333 int reg = instr->RsValue();
334 PrintRegister(reg);
335 return 2;
336 } else if (format[1] == 'm') { // 'rm: Rm register
337 int reg = instr->RmValue();
338 PrintRegister(reg);
339 return 2;
340 } else if (format[1] == 't') { // 'rt: Rt register
341 int reg = instr->RtValue();
342 PrintRegister(reg);
343 return 2;
344 } else if (format[1] == 'l') {
345 // 'rlist: register list for load and store multiple instructions
346 ASSERT(STRING_STARTS_WITH(format, "rlist"));
347 int rlist = instr->RlistValue();
348 int reg = 0;
349 Print("{");
350 // Print register list in ascending order, by scanning the bit mask.
351 while (rlist != 0) {
352 if ((rlist & 1) != 0) {
353 PrintRegister(reg);
354 if ((rlist >> 1) != 0) {
355 Print(", ");
356 }
357 }
358 reg++;
359 rlist >>= 1;
360 }
361 Print("}");
362 return 5;
363 }
364 UNREACHABLE();
365 return -1;
366 }
367
368
369 // Handle all VFP register based formatting in this function to reduce the
370 // complexity of FormatOption.
FormatVFPRegister(Instruction * instr,const char * format)371 int Decoder::FormatVFPRegister(Instruction* instr, const char* format) {
372 ASSERT((format[0] == 'S') || (format[0] == 'D'));
373
374 VFPRegPrecision precision =
375 format[0] == 'D' ? kDoublePrecision : kSinglePrecision;
376
377 int retval = 2;
378 int reg = -1;
379 if (format[1] == 'n') {
380 reg = instr->VFPNRegValue(precision);
381 } else if (format[1] == 'm') {
382 reg = instr->VFPMRegValue(precision);
383 } else if (format[1] == 'd') {
384 reg = instr->VFPDRegValue(precision);
385 if (format[2] == '+') {
386 int immed8 = instr->Immed8Value();
387 if (format[0] == 'S') reg += immed8 - 1;
388 if (format[0] == 'D') reg += (immed8 / 2 - 1);
389 }
390 if (format[2] == '+') retval = 3;
391 } else {
392 UNREACHABLE();
393 }
394
395 if (precision == kSinglePrecision) {
396 PrintSRegister(reg);
397 } else {
398 PrintDRegister(reg);
399 }
400
401 return retval;
402 }
403
404
FormatVFPinstruction(Instruction * instr,const char * format)405 int Decoder::FormatVFPinstruction(Instruction* instr, const char* format) {
406 Print(format);
407 return 0;
408 }
409
410
411 // Print the movw or movt instruction.
PrintMovwMovt(Instruction * instr)412 void Decoder::PrintMovwMovt(Instruction* instr) {
413 int imm = instr->ImmedMovwMovtValue();
414 int rd = instr->RdValue();
415 PrintRegister(rd);
416 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
417 ", #%d", imm);
418 }
419
420
421 // FormatOption takes a formatting string and interprets it based on
422 // the current instructions. The format string points to the first
423 // character of the option string (the option escape has already been
424 // consumed by the caller.) FormatOption returns the number of
425 // characters that were consumed from the formatting string.
FormatOption(Instruction * instr,const char * format)426 int Decoder::FormatOption(Instruction* instr, const char* format) {
427 switch (format[0]) {
428 case 'a': { // 'a: accumulate multiplies
429 if (instr->Bit(21) == 0) {
430 Print("ul");
431 } else {
432 Print("la");
433 }
434 return 1;
435 }
436 case 'b': { // 'b: byte loads or stores
437 if (instr->HasB()) {
438 Print("b");
439 }
440 return 1;
441 }
442 case 'c': { // 'cond: conditional execution
443 ASSERT(STRING_STARTS_WITH(format, "cond"));
444 PrintCondition(instr);
445 return 4;
446 }
447 case 'd': { // 'd: vmov double immediate.
448 double d = instr->DoubleImmedVmov();
449 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
450 "#%g", d);
451 return 1;
452 }
453 case 'f': { // 'f: bitfield instructions - v7 and above.
454 uint32_t lsbit = instr->Bits(11, 7);
455 uint32_t width = instr->Bits(20, 16) + 1;
456 if (instr->Bit(21) == 0) {
457 // BFC/BFI:
458 // Bits 20-16 represent most-significant bit. Covert to width.
459 width -= lsbit;
460 ASSERT(width > 0);
461 }
462 ASSERT((width + lsbit) <= 32);
463 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
464 "#%d, #%d", lsbit, width);
465 return 1;
466 }
467 case 'h': { // 'h: halfword operation for extra loads and stores
468 if (instr->HasH()) {
469 Print("h");
470 } else {
471 Print("b");
472 }
473 return 1;
474 }
475 case 'i': { // 'i: immediate value from adjacent bits.
476 // Expects tokens in the form imm%02d@%02d, i.e. imm05@07, imm10@16
477 int width = (format[3] - '0') * 10 + (format[4] - '0');
478 int lsb = (format[6] - '0') * 10 + (format[7] - '0');
479
480 ASSERT((width >= 1) && (width <= 32));
481 ASSERT((lsb >= 0) && (lsb <= 31));
482 ASSERT((width + lsb) <= 32);
483
484 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
485 "%d",
486 instr->Bits(width + lsb - 1, lsb));
487 return 8;
488 }
489 case 'l': { // 'l: branch and link
490 if (instr->HasLink()) {
491 Print("l");
492 }
493 return 1;
494 }
495 case 'm': {
496 if (format[1] == 'w') {
497 // 'mw: movt/movw instructions.
498 PrintMovwMovt(instr);
499 return 2;
500 }
501 if (format[1] == 'e') { // 'memop: load/store instructions.
502 ASSERT(STRING_STARTS_WITH(format, "memop"));
503 if (instr->HasL()) {
504 Print("ldr");
505 } else {
506 if ((instr->Bits(27, 25) == 0) && (instr->Bit(20) == 0) &&
507 (instr->Bits(7, 6) == 3) && (instr->Bit(4) == 1)) {
508 if (instr->Bit(5) == 1) {
509 Print("strd");
510 } else {
511 Print("ldrd");
512 }
513 return 5;
514 }
515 Print("str");
516 }
517 return 5;
518 }
519 // 'msg: for simulator break instructions
520 ASSERT(STRING_STARTS_WITH(format, "msg"));
521 byte* str =
522 reinterpret_cast<byte*>(instr->InstructionBits() & 0x0fffffff);
523 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
524 "%s", converter_.NameInCode(str));
525 return 3;
526 }
527 case 'o': {
528 if ((format[3] == '1') && (format[4] == '2')) {
529 // 'off12: 12-bit offset for load and store instructions
530 ASSERT(STRING_STARTS_WITH(format, "off12"));
531 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
532 "%d", instr->Offset12Value());
533 return 5;
534 } else if (format[3] == '0') {
535 // 'off0to3and8to19 16-bit immediate encoded in bits 19-8 and 3-0.
536 ASSERT(STRING_STARTS_WITH(format, "off0to3and8to19"));
537 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
538 "%d",
539 (instr->Bits(19, 8) << 4) +
540 instr->Bits(3, 0));
541 return 15;
542 }
543 // 'off8: 8-bit offset for extra load and store instructions
544 ASSERT(STRING_STARTS_WITH(format, "off8"));
545 int offs8 = (instr->ImmedHValue() << 4) | instr->ImmedLValue();
546 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
547 "%d", offs8);
548 return 4;
549 }
550 case 'p': { // 'pu: P and U bits for load and store instructions
551 ASSERT(STRING_STARTS_WITH(format, "pu"));
552 PrintPU(instr);
553 return 2;
554 }
555 case 'r': {
556 return FormatRegister(instr, format);
557 }
558 case 's': {
559 if (format[1] == 'h') { // 'shift_op or 'shift_rm or 'shift_sat.
560 if (format[6] == 'o') { // 'shift_op
561 ASSERT(STRING_STARTS_WITH(format, "shift_op"));
562 if (instr->TypeValue() == 0) {
563 PrintShiftRm(instr);
564 } else {
565 ASSERT(instr->TypeValue() == 1);
566 PrintShiftImm(instr);
567 }
568 return 8;
569 } else if (format[6] == 's') { // 'shift_sat.
570 ASSERT(STRING_STARTS_WITH(format, "shift_sat"));
571 PrintShiftSat(instr);
572 return 9;
573 } else { // 'shift_rm
574 ASSERT(STRING_STARTS_WITH(format, "shift_rm"));
575 PrintShiftRm(instr);
576 return 8;
577 }
578 } else if (format[1] == 'v') { // 'svc
579 ASSERT(STRING_STARTS_WITH(format, "svc"));
580 PrintSoftwareInterrupt(instr->SvcValue());
581 return 3;
582 } else if (format[1] == 'i') { // 'sign: signed extra loads and stores
583 ASSERT(STRING_STARTS_WITH(format, "sign"));
584 if (instr->HasSign()) {
585 Print("s");
586 }
587 return 4;
588 }
589 // 's: S field of data processing instructions
590 if (instr->HasS()) {
591 Print("s");
592 }
593 return 1;
594 }
595 case 't': { // 'target: target of branch instructions
596 ASSERT(STRING_STARTS_WITH(format, "target"));
597 int off = (instr->SImmed24Value() << 2) + 8;
598 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
599 "%+d -> %s",
600 off,
601 converter_.NameOfAddress(
602 reinterpret_cast<byte*>(instr) + off));
603 return 6;
604 }
605 case 'u': { // 'u: signed or unsigned multiplies
606 // The manual gets the meaning of bit 22 backwards in the multiply
607 // instruction overview on page A3.16.2. The instructions that
608 // exist in u and s variants are the following:
609 // smull A4.1.87
610 // umull A4.1.129
611 // umlal A4.1.128
612 // smlal A4.1.76
613 // For these 0 means u and 1 means s. As can be seen on their individual
614 // pages. The other 18 mul instructions have the bit set or unset in
615 // arbitrary ways that are unrelated to the signedness of the instruction.
616 // None of these 18 instructions exist in both a 'u' and an 's' variant.
617
618 if (instr->Bit(22) == 0) {
619 Print("u");
620 } else {
621 Print("s");
622 }
623 return 1;
624 }
625 case 'v': {
626 return FormatVFPinstruction(instr, format);
627 }
628 case 'S':
629 case 'D': {
630 return FormatVFPRegister(instr, format);
631 }
632 case 'w': { // 'w: W field of load and store instructions
633 if (instr->HasW()) {
634 Print("!");
635 }
636 return 1;
637 }
638 default: {
639 UNREACHABLE();
640 break;
641 }
642 }
643 UNREACHABLE();
644 return -1;
645 }
646
647
648 // Format takes a formatting string for a whole instruction and prints it into
649 // the output buffer. All escaped options are handed to FormatOption to be
650 // parsed further.
Format(Instruction * instr,const char * format)651 void Decoder::Format(Instruction* instr, const char* format) {
652 char cur = *format++;
653 while ((cur != 0) && (out_buffer_pos_ < (out_buffer_.length() - 1))) {
654 if (cur == '\'') { // Single quote is used as the formatting escape.
655 format += FormatOption(instr, format);
656 } else {
657 out_buffer_[out_buffer_pos_++] = cur;
658 }
659 cur = *format++;
660 }
661 out_buffer_[out_buffer_pos_] = '\0';
662 }
663
664
665 // The disassembler may end up decoding data inlined in the code. We do not want
666 // it to crash if the data does not ressemble any known instruction.
667 #define VERIFY(condition) \
668 if(!(condition)) { \
669 Unknown(instr); \
670 return; \
671 }
672
673
674 // For currently unimplemented decodings the disassembler calls Unknown(instr)
675 // which will just print "unknown" of the instruction bits.
Unknown(Instruction * instr)676 void Decoder::Unknown(Instruction* instr) {
677 Format(instr, "unknown");
678 }
679
680
DecodeType01(Instruction * instr)681 void Decoder::DecodeType01(Instruction* instr) {
682 int type = instr->TypeValue();
683 if ((type == 0) && instr->IsSpecialType0()) {
684 // multiply instruction or extra loads and stores
685 if (instr->Bits(7, 4) == 9) {
686 if (instr->Bit(24) == 0) {
687 // multiply instructions
688 if (instr->Bit(23) == 0) {
689 if (instr->Bit(21) == 0) {
690 // The MUL instruction description (A 4.1.33) refers to Rd as being
691 // the destination for the operation, but it confusingly uses the
692 // Rn field to encode it.
693 Format(instr, "mul'cond's 'rn, 'rm, 'rs");
694 } else {
695 // The MLA instruction description (A 4.1.28) refers to the order
696 // of registers as "Rd, Rm, Rs, Rn". But confusingly it uses the
697 // Rn field to encode the Rd register and the Rd field to encode
698 // the Rn register.
699 Format(instr, "mla'cond's 'rn, 'rm, 'rs, 'rd");
700 }
701 } else {
702 // The signed/long multiply instructions use the terms RdHi and RdLo
703 // when referring to the target registers. They are mapped to the Rn
704 // and Rd fields as follows:
705 // RdLo == Rd field
706 // RdHi == Rn field
707 // The order of registers is: <RdLo>, <RdHi>, <Rm>, <Rs>
708 Format(instr, "'um'al'cond's 'rd, 'rn, 'rm, 'rs");
709 }
710 } else {
711 Unknown(instr); // not used by V8
712 }
713 } else if ((instr->Bit(20) == 0) && ((instr->Bits(7, 4) & 0xd) == 0xd)) {
714 // ldrd, strd
715 switch (instr->PUField()) {
716 case da_x: {
717 if (instr->Bit(22) == 0) {
718 Format(instr, "'memop'cond's 'rd, ['rn], -'rm");
719 } else {
720 Format(instr, "'memop'cond's 'rd, ['rn], #-'off8");
721 }
722 break;
723 }
724 case ia_x: {
725 if (instr->Bit(22) == 0) {
726 Format(instr, "'memop'cond's 'rd, ['rn], +'rm");
727 } else {
728 Format(instr, "'memop'cond's 'rd, ['rn], #+'off8");
729 }
730 break;
731 }
732 case db_x: {
733 if (instr->Bit(22) == 0) {
734 Format(instr, "'memop'cond's 'rd, ['rn, -'rm]'w");
735 } else {
736 Format(instr, "'memop'cond's 'rd, ['rn, #-'off8]'w");
737 }
738 break;
739 }
740 case ib_x: {
741 if (instr->Bit(22) == 0) {
742 Format(instr, "'memop'cond's 'rd, ['rn, +'rm]'w");
743 } else {
744 Format(instr, "'memop'cond's 'rd, ['rn, #+'off8]'w");
745 }
746 break;
747 }
748 default: {
749 // The PU field is a 2-bit field.
750 UNREACHABLE();
751 break;
752 }
753 }
754 } else {
755 // extra load/store instructions
756 switch (instr->PUField()) {
757 case da_x: {
758 if (instr->Bit(22) == 0) {
759 Format(instr, "'memop'cond'sign'h 'rd, ['rn], -'rm");
760 } else {
761 Format(instr, "'memop'cond'sign'h 'rd, ['rn], #-'off8");
762 }
763 break;
764 }
765 case ia_x: {
766 if (instr->Bit(22) == 0) {
767 Format(instr, "'memop'cond'sign'h 'rd, ['rn], +'rm");
768 } else {
769 Format(instr, "'memop'cond'sign'h 'rd, ['rn], #+'off8");
770 }
771 break;
772 }
773 case db_x: {
774 if (instr->Bit(22) == 0) {
775 Format(instr, "'memop'cond'sign'h 'rd, ['rn, -'rm]'w");
776 } else {
777 Format(instr, "'memop'cond'sign'h 'rd, ['rn, #-'off8]'w");
778 }
779 break;
780 }
781 case ib_x: {
782 if (instr->Bit(22) == 0) {
783 Format(instr, "'memop'cond'sign'h 'rd, ['rn, +'rm]'w");
784 } else {
785 Format(instr, "'memop'cond'sign'h 'rd, ['rn, #+'off8]'w");
786 }
787 break;
788 }
789 default: {
790 // The PU field is a 2-bit field.
791 UNREACHABLE();
792 break;
793 }
794 }
795 return;
796 }
797 } else if ((type == 0) && instr->IsMiscType0()) {
798 if (instr->Bits(22, 21) == 1) {
799 switch (instr->BitField(7, 4)) {
800 case BX:
801 Format(instr, "bx'cond 'rm");
802 break;
803 case BLX:
804 Format(instr, "blx'cond 'rm");
805 break;
806 case BKPT:
807 Format(instr, "bkpt 'off0to3and8to19");
808 break;
809 default:
810 Unknown(instr); // not used by V8
811 break;
812 }
813 } else if (instr->Bits(22, 21) == 3) {
814 switch (instr->BitField(7, 4)) {
815 case CLZ:
816 Format(instr, "clz'cond 'rd, 'rm");
817 break;
818 default:
819 Unknown(instr); // not used by V8
820 break;
821 }
822 } else {
823 Unknown(instr); // not used by V8
824 }
825 } else {
826 switch (instr->OpcodeField()) {
827 case AND: {
828 Format(instr, "and'cond's 'rd, 'rn, 'shift_op");
829 break;
830 }
831 case EOR: {
832 Format(instr, "eor'cond's 'rd, 'rn, 'shift_op");
833 break;
834 }
835 case SUB: {
836 Format(instr, "sub'cond's 'rd, 'rn, 'shift_op");
837 break;
838 }
839 case RSB: {
840 Format(instr, "rsb'cond's 'rd, 'rn, 'shift_op");
841 break;
842 }
843 case ADD: {
844 Format(instr, "add'cond's 'rd, 'rn, 'shift_op");
845 break;
846 }
847 case ADC: {
848 Format(instr, "adc'cond's 'rd, 'rn, 'shift_op");
849 break;
850 }
851 case SBC: {
852 Format(instr, "sbc'cond's 'rd, 'rn, 'shift_op");
853 break;
854 }
855 case RSC: {
856 Format(instr, "rsc'cond's 'rd, 'rn, 'shift_op");
857 break;
858 }
859 case TST: {
860 if (instr->HasS()) {
861 Format(instr, "tst'cond 'rn, 'shift_op");
862 } else {
863 Format(instr, "movw'cond 'mw");
864 }
865 break;
866 }
867 case TEQ: {
868 if (instr->HasS()) {
869 Format(instr, "teq'cond 'rn, 'shift_op");
870 } else {
871 // Other instructions matching this pattern are handled in the
872 // miscellaneous instructions part above.
873 UNREACHABLE();
874 }
875 break;
876 }
877 case CMP: {
878 if (instr->HasS()) {
879 Format(instr, "cmp'cond 'rn, 'shift_op");
880 } else {
881 Format(instr, "movt'cond 'mw");
882 }
883 break;
884 }
885 case CMN: {
886 if (instr->HasS()) {
887 Format(instr, "cmn'cond 'rn, 'shift_op");
888 } else {
889 // Other instructions matching this pattern are handled in the
890 // miscellaneous instructions part above.
891 UNREACHABLE();
892 }
893 break;
894 }
895 case ORR: {
896 Format(instr, "orr'cond's 'rd, 'rn, 'shift_op");
897 break;
898 }
899 case MOV: {
900 Format(instr, "mov'cond's 'rd, 'shift_op");
901 break;
902 }
903 case BIC: {
904 Format(instr, "bic'cond's 'rd, 'rn, 'shift_op");
905 break;
906 }
907 case MVN: {
908 Format(instr, "mvn'cond's 'rd, 'shift_op");
909 break;
910 }
911 default: {
912 // The Opcode field is a 4-bit field.
913 UNREACHABLE();
914 break;
915 }
916 }
917 }
918 }
919
920
DecodeType2(Instruction * instr)921 void Decoder::DecodeType2(Instruction* instr) {
922 switch (instr->PUField()) {
923 case da_x: {
924 if (instr->HasW()) {
925 Unknown(instr); // not used in V8
926 return;
927 }
928 Format(instr, "'memop'cond'b 'rd, ['rn], #-'off12");
929 break;
930 }
931 case ia_x: {
932 if (instr->HasW()) {
933 Unknown(instr); // not used in V8
934 return;
935 }
936 Format(instr, "'memop'cond'b 'rd, ['rn], #+'off12");
937 break;
938 }
939 case db_x: {
940 Format(instr, "'memop'cond'b 'rd, ['rn, #-'off12]'w");
941 break;
942 }
943 case ib_x: {
944 Format(instr, "'memop'cond'b 'rd, ['rn, #+'off12]'w");
945 break;
946 }
947 default: {
948 // The PU field is a 2-bit field.
949 UNREACHABLE();
950 break;
951 }
952 }
953 }
954
955
DecodeType3(Instruction * instr)956 void Decoder::DecodeType3(Instruction* instr) {
957 switch (instr->PUField()) {
958 case da_x: {
959 VERIFY(!instr->HasW());
960 Format(instr, "'memop'cond'b 'rd, ['rn], -'shift_rm");
961 break;
962 }
963 case ia_x: {
964 if (instr->HasW()) {
965 VERIFY(instr->Bits(5, 4) == 0x1);
966 if (instr->Bit(22) == 0x1) {
967 Format(instr, "usat 'rd, #'imm05@16, 'rm'shift_sat");
968 } else {
969 UNREACHABLE(); // SSAT.
970 }
971 } else {
972 Format(instr, "'memop'cond'b 'rd, ['rn], +'shift_rm");
973 }
974 break;
975 }
976 case db_x: {
977 Format(instr, "'memop'cond'b 'rd, ['rn, -'shift_rm]'w");
978 break;
979 }
980 case ib_x: {
981 if (instr->HasW() && (instr->Bits(6, 4) == 0x5)) {
982 uint32_t widthminus1 = static_cast<uint32_t>(instr->Bits(20, 16));
983 uint32_t lsbit = static_cast<uint32_t>(instr->Bits(11, 7));
984 uint32_t msbit = widthminus1 + lsbit;
985 if (msbit <= 31) {
986 if (instr->Bit(22)) {
987 Format(instr, "ubfx'cond 'rd, 'rm, 'f");
988 } else {
989 Format(instr, "sbfx'cond 'rd, 'rm, 'f");
990 }
991 } else {
992 UNREACHABLE();
993 }
994 } else if (!instr->HasW() && (instr->Bits(6, 4) == 0x1)) {
995 uint32_t lsbit = static_cast<uint32_t>(instr->Bits(11, 7));
996 uint32_t msbit = static_cast<uint32_t>(instr->Bits(20, 16));
997 if (msbit >= lsbit) {
998 if (instr->RmValue() == 15) {
999 Format(instr, "bfc'cond 'rd, 'f");
1000 } else {
1001 Format(instr, "bfi'cond 'rd, 'rm, 'f");
1002 }
1003 } else {
1004 UNREACHABLE();
1005 }
1006 } else {
1007 Format(instr, "'memop'cond'b 'rd, ['rn, +'shift_rm]'w");
1008 }
1009 break;
1010 }
1011 default: {
1012 // The PU field is a 2-bit field.
1013 UNREACHABLE();
1014 break;
1015 }
1016 }
1017 }
1018
1019
DecodeType4(Instruction * instr)1020 void Decoder::DecodeType4(Instruction* instr) {
1021 if (instr->Bit(22) != 0) {
1022 // Privileged mode currently not supported.
1023 Unknown(instr);
1024 } else {
1025 if (instr->HasL()) {
1026 Format(instr, "ldm'cond'pu 'rn'w, 'rlist");
1027 } else {
1028 Format(instr, "stm'cond'pu 'rn'w, 'rlist");
1029 }
1030 }
1031 }
1032
1033
DecodeType5(Instruction * instr)1034 void Decoder::DecodeType5(Instruction* instr) {
1035 Format(instr, "b'l'cond 'target");
1036 }
1037
1038
DecodeType6(Instruction * instr)1039 void Decoder::DecodeType6(Instruction* instr) {
1040 DecodeType6CoprocessorIns(instr);
1041 }
1042
1043
DecodeType7(Instruction * instr)1044 int Decoder::DecodeType7(Instruction* instr) {
1045 if (instr->Bit(24) == 1) {
1046 if (instr->SvcValue() >= kStopCode) {
1047 Format(instr, "stop'cond 'svc");
1048 // Also print the stop message. Its address is encoded
1049 // in the following 4 bytes.
1050 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
1051 "\n %p %08x stop message: %s",
1052 reinterpret_cast<int32_t*>(instr
1053 + Instruction::kInstrSize),
1054 *reinterpret_cast<char**>(instr
1055 + Instruction::kInstrSize),
1056 *reinterpret_cast<char**>(instr
1057 + Instruction::kInstrSize));
1058 // We have decoded 2 * Instruction::kInstrSize bytes.
1059 return 2 * Instruction::kInstrSize;
1060 } else {
1061 Format(instr, "svc'cond 'svc");
1062 }
1063 } else {
1064 DecodeTypeVFP(instr);
1065 }
1066 return Instruction::kInstrSize;
1067 }
1068
1069
1070 // void Decoder::DecodeTypeVFP(Instruction* instr)
1071 // vmov: Sn = Rt
1072 // vmov: Rt = Sn
1073 // vcvt: Dd = Sm
1074 // vcvt: Sd = Dm
1075 // Dd = vabs(Dm)
1076 // Dd = vneg(Dm)
1077 // Dd = vadd(Dn, Dm)
1078 // Dd = vsub(Dn, Dm)
1079 // Dd = vmul(Dn, Dm)
1080 // Dd = vdiv(Dn, Dm)
1081 // vcmp(Dd, Dm)
1082 // vmrs
1083 // vmsr
1084 // Dd = vsqrt(Dm)
DecodeTypeVFP(Instruction * instr)1085 void Decoder::DecodeTypeVFP(Instruction* instr) {
1086 VERIFY((instr->TypeValue() == 7) && (instr->Bit(24) == 0x0) );
1087 VERIFY(instr->Bits(11, 9) == 0x5);
1088
1089 if (instr->Bit(4) == 0) {
1090 if (instr->Opc1Value() == 0x7) {
1091 // Other data processing instructions
1092 if ((instr->Opc2Value() == 0x0) && (instr->Opc3Value() == 0x1)) {
1093 // vmov register to register.
1094 if (instr->SzValue() == 0x1) {
1095 Format(instr, "vmov.f64'cond 'Dd, 'Dm");
1096 } else {
1097 Format(instr, "vmov.f32'cond 'Sd, 'Sm");
1098 }
1099 } else if ((instr->Opc2Value() == 0x0) && (instr->Opc3Value() == 0x3)) {
1100 // vabs
1101 Format(instr, "vabs.f64'cond 'Dd, 'Dm");
1102 } else if ((instr->Opc2Value() == 0x1) && (instr->Opc3Value() == 0x1)) {
1103 // vneg
1104 Format(instr, "vneg.f64'cond 'Dd, 'Dm");
1105 } else if ((instr->Opc2Value() == 0x7) && (instr->Opc3Value() == 0x3)) {
1106 DecodeVCVTBetweenDoubleAndSingle(instr);
1107 } else if ((instr->Opc2Value() == 0x8) && (instr->Opc3Value() & 0x1)) {
1108 DecodeVCVTBetweenFloatingPointAndInteger(instr);
1109 } else if (((instr->Opc2Value() >> 1) == 0x6) &&
1110 (instr->Opc3Value() & 0x1)) {
1111 DecodeVCVTBetweenFloatingPointAndInteger(instr);
1112 } else if (((instr->Opc2Value() == 0x4) || (instr->Opc2Value() == 0x5)) &&
1113 (instr->Opc3Value() & 0x1)) {
1114 DecodeVCMP(instr);
1115 } else if (((instr->Opc2Value() == 0x1)) && (instr->Opc3Value() == 0x3)) {
1116 Format(instr, "vsqrt.f64'cond 'Dd, 'Dm");
1117 } else if (instr->Opc3Value() == 0x0) {
1118 if (instr->SzValue() == 0x1) {
1119 Format(instr, "vmov.f64'cond 'Dd, 'd");
1120 } else {
1121 Unknown(instr); // Not used by V8.
1122 }
1123 } else {
1124 Unknown(instr); // Not used by V8.
1125 }
1126 } else if (instr->Opc1Value() == 0x3) {
1127 if (instr->SzValue() == 0x1) {
1128 if (instr->Opc3Value() & 0x1) {
1129 Format(instr, "vsub.f64'cond 'Dd, 'Dn, 'Dm");
1130 } else {
1131 Format(instr, "vadd.f64'cond 'Dd, 'Dn, 'Dm");
1132 }
1133 } else {
1134 Unknown(instr); // Not used by V8.
1135 }
1136 } else if ((instr->Opc1Value() == 0x2) && !(instr->Opc3Value() & 0x1)) {
1137 if (instr->SzValue() == 0x1) {
1138 Format(instr, "vmul.f64'cond 'Dd, 'Dn, 'Dm");
1139 } else {
1140 Unknown(instr); // Not used by V8.
1141 }
1142 } else if ((instr->Opc1Value() == 0x4) && !(instr->Opc3Value() & 0x1)) {
1143 if (instr->SzValue() == 0x1) {
1144 Format(instr, "vdiv.f64'cond 'Dd, 'Dn, 'Dm");
1145 } else {
1146 Unknown(instr); // Not used by V8.
1147 }
1148 } else {
1149 Unknown(instr); // Not used by V8.
1150 }
1151 } else {
1152 if ((instr->VCValue() == 0x0) &&
1153 (instr->VAValue() == 0x0)) {
1154 DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(instr);
1155 } else if ((instr->VCValue() == 0x0) &&
1156 (instr->VAValue() == 0x7) &&
1157 (instr->Bits(19, 16) == 0x1)) {
1158 if (instr->VLValue() == 0) {
1159 if (instr->Bits(15, 12) == 0xF) {
1160 Format(instr, "vmsr'cond FPSCR, APSR");
1161 } else {
1162 Format(instr, "vmsr'cond FPSCR, 'rt");
1163 }
1164 } else {
1165 if (instr->Bits(15, 12) == 0xF) {
1166 Format(instr, "vmrs'cond APSR, FPSCR");
1167 } else {
1168 Format(instr, "vmrs'cond 'rt, FPSCR");
1169 }
1170 }
1171 }
1172 }
1173 }
1174
1175
DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instruction * instr)1176 void Decoder::DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(
1177 Instruction* instr) {
1178 VERIFY((instr->Bit(4) == 1) && (instr->VCValue() == 0x0) &&
1179 (instr->VAValue() == 0x0));
1180
1181 bool to_arm_register = (instr->VLValue() == 0x1);
1182
1183 if (to_arm_register) {
1184 Format(instr, "vmov'cond 'rt, 'Sn");
1185 } else {
1186 Format(instr, "vmov'cond 'Sn, 'rt");
1187 }
1188 }
1189
1190
DecodeVCMP(Instruction * instr)1191 void Decoder::DecodeVCMP(Instruction* instr) {
1192 VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
1193 VERIFY(((instr->Opc2Value() == 0x4) || (instr->Opc2Value() == 0x5)) &&
1194 (instr->Opc3Value() & 0x1));
1195
1196 // Comparison.
1197 bool dp_operation = (instr->SzValue() == 1);
1198 bool raise_exception_for_qnan = (instr->Bit(7) == 0x1);
1199
1200 if (dp_operation && !raise_exception_for_qnan) {
1201 if (instr->Opc2Value() == 0x4) {
1202 Format(instr, "vcmp.f64'cond 'Dd, 'Dm");
1203 } else if (instr->Opc2Value() == 0x5) {
1204 Format(instr, "vcmp.f64'cond 'Dd, #0.0");
1205 } else {
1206 Unknown(instr); // invalid
1207 }
1208 } else {
1209 Unknown(instr); // Not used by V8.
1210 }
1211 }
1212
1213
DecodeVCVTBetweenDoubleAndSingle(Instruction * instr)1214 void Decoder::DecodeVCVTBetweenDoubleAndSingle(Instruction* instr) {
1215 VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
1216 VERIFY((instr->Opc2Value() == 0x7) && (instr->Opc3Value() == 0x3));
1217
1218 bool double_to_single = (instr->SzValue() == 1);
1219
1220 if (double_to_single) {
1221 Format(instr, "vcvt.f32.f64'cond 'Sd, 'Dm");
1222 } else {
1223 Format(instr, "vcvt.f64.f32'cond 'Dd, 'Sm");
1224 }
1225 }
1226
1227
DecodeVCVTBetweenFloatingPointAndInteger(Instruction * instr)1228 void Decoder::DecodeVCVTBetweenFloatingPointAndInteger(Instruction* instr) {
1229 VERIFY((instr->Bit(4) == 0) && (instr->Opc1Value() == 0x7));
1230 VERIFY(((instr->Opc2Value() == 0x8) && (instr->Opc3Value() & 0x1)) ||
1231 (((instr->Opc2Value() >> 1) == 0x6) && (instr->Opc3Value() & 0x1)));
1232
1233 bool to_integer = (instr->Bit(18) == 1);
1234 bool dp_operation = (instr->SzValue() == 1);
1235 if (to_integer) {
1236 bool unsigned_integer = (instr->Bit(16) == 0);
1237
1238 if (dp_operation) {
1239 if (unsigned_integer) {
1240 Format(instr, "vcvt.u32.f64'cond 'Sd, 'Dm");
1241 } else {
1242 Format(instr, "vcvt.s32.f64'cond 'Sd, 'Dm");
1243 }
1244 } else {
1245 if (unsigned_integer) {
1246 Format(instr, "vcvt.u32.f32'cond 'Sd, 'Sm");
1247 } else {
1248 Format(instr, "vcvt.s32.f32'cond 'Sd, 'Sm");
1249 }
1250 }
1251 } else {
1252 bool unsigned_integer = (instr->Bit(7) == 0);
1253
1254 if (dp_operation) {
1255 if (unsigned_integer) {
1256 Format(instr, "vcvt.f64.u32'cond 'Dd, 'Sm");
1257 } else {
1258 Format(instr, "vcvt.f64.s32'cond 'Dd, 'Sm");
1259 }
1260 } else {
1261 if (unsigned_integer) {
1262 Format(instr, "vcvt.f32.u32'cond 'Sd, 'Sm");
1263 } else {
1264 Format(instr, "vcvt.f32.s32'cond 'Sd, 'Sm");
1265 }
1266 }
1267 }
1268 }
1269
1270
1271 // Decode Type 6 coprocessor instructions.
1272 // Dm = vmov(Rt, Rt2)
1273 // <Rt, Rt2> = vmov(Dm)
1274 // Ddst = MEM(Rbase + 4*offset).
1275 // MEM(Rbase + 4*offset) = Dsrc.
DecodeType6CoprocessorIns(Instruction * instr)1276 void Decoder::DecodeType6CoprocessorIns(Instruction* instr) {
1277 VERIFY(instr->TypeValue() == 6);
1278
1279 if (instr->CoprocessorValue() == 0xA) {
1280 switch (instr->OpcodeValue()) {
1281 case 0x8:
1282 case 0xA:
1283 if (instr->HasL()) {
1284 Format(instr, "vldr'cond 'Sd, ['rn - 4*'imm08@00]");
1285 } else {
1286 Format(instr, "vstr'cond 'Sd, ['rn - 4*'imm08@00]");
1287 }
1288 break;
1289 case 0xC:
1290 case 0xE:
1291 if (instr->HasL()) {
1292 Format(instr, "vldr'cond 'Sd, ['rn + 4*'imm08@00]");
1293 } else {
1294 Format(instr, "vstr'cond 'Sd, ['rn + 4*'imm08@00]");
1295 }
1296 break;
1297 case 0x4:
1298 case 0x5:
1299 case 0x6:
1300 case 0x7:
1301 case 0x9:
1302 case 0xB: {
1303 bool to_vfp_register = (instr->VLValue() == 0x1);
1304 if (to_vfp_register) {
1305 Format(instr, "vldm'cond'pu 'rn'w, {'Sd-'Sd+}");
1306 } else {
1307 Format(instr, "vstm'cond'pu 'rn'w, {'Sd-'Sd+}");
1308 }
1309 break;
1310 }
1311 default:
1312 Unknown(instr); // Not used by V8.
1313 }
1314 } else if (instr->CoprocessorValue() == 0xB) {
1315 switch (instr->OpcodeValue()) {
1316 case 0x2:
1317 // Load and store double to two GP registers
1318 if (instr->Bits(7, 4) != 0x1) {
1319 Unknown(instr); // Not used by V8.
1320 } else if (instr->HasL()) {
1321 Format(instr, "vmov'cond 'rt, 'rn, 'Dm");
1322 } else {
1323 Format(instr, "vmov'cond 'Dm, 'rt, 'rn");
1324 }
1325 break;
1326 case 0x8:
1327 if (instr->HasL()) {
1328 Format(instr, "vldr'cond 'Dd, ['rn - 4*'imm08@00]");
1329 } else {
1330 Format(instr, "vstr'cond 'Dd, ['rn - 4*'imm08@00]");
1331 }
1332 break;
1333 case 0xC:
1334 if (instr->HasL()) {
1335 Format(instr, "vldr'cond 'Dd, ['rn + 4*'imm08@00]");
1336 } else {
1337 Format(instr, "vstr'cond 'Dd, ['rn + 4*'imm08@00]");
1338 }
1339 break;
1340 case 0x4:
1341 case 0x5:
1342 case 0x9: {
1343 bool to_vfp_register = (instr->VLValue() == 0x1);
1344 if (to_vfp_register) {
1345 Format(instr, "vldm'cond'pu 'rn'w, {'Dd-'Dd+}");
1346 } else {
1347 Format(instr, "vstm'cond'pu 'rn'w, {'Dd-'Dd+}");
1348 }
1349 break;
1350 }
1351 default:
1352 Unknown(instr); // Not used by V8.
1353 }
1354 } else {
1355 Unknown(instr); // Not used by V8.
1356 }
1357 }
1358
1359 #undef VERIFIY
1360
IsConstantPoolAt(byte * instr_ptr)1361 bool Decoder::IsConstantPoolAt(byte* instr_ptr) {
1362 int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
1363 return (instruction_bits & kConstantPoolMarkerMask) == kConstantPoolMarker;
1364 }
1365
1366
ConstantPoolSizeAt(byte * instr_ptr)1367 int Decoder::ConstantPoolSizeAt(byte* instr_ptr) {
1368 if (IsConstantPoolAt(instr_ptr)) {
1369 int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
1370 return instruction_bits & kConstantPoolLengthMask;
1371 } else {
1372 return -1;
1373 }
1374 }
1375
1376
1377 // Disassemble the instruction at *instr_ptr into the output buffer.
InstructionDecode(byte * instr_ptr)1378 int Decoder::InstructionDecode(byte* instr_ptr) {
1379 Instruction* instr = Instruction::At(instr_ptr);
1380 // Print raw instruction bytes.
1381 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
1382 "%08x ",
1383 instr->InstructionBits());
1384 if (instr->ConditionField() == kSpecialCondition) {
1385 Unknown(instr);
1386 return Instruction::kInstrSize;
1387 }
1388 int instruction_bits = *(reinterpret_cast<int*>(instr_ptr));
1389 if ((instruction_bits & kConstantPoolMarkerMask) == kConstantPoolMarker) {
1390 out_buffer_pos_ += OS::SNPrintF(out_buffer_ + out_buffer_pos_,
1391 "constant pool begin (length %d)",
1392 instruction_bits &
1393 kConstantPoolLengthMask);
1394 return Instruction::kInstrSize;
1395 }
1396 switch (instr->TypeValue()) {
1397 case 0:
1398 case 1: {
1399 DecodeType01(instr);
1400 break;
1401 }
1402 case 2: {
1403 DecodeType2(instr);
1404 break;
1405 }
1406 case 3: {
1407 DecodeType3(instr);
1408 break;
1409 }
1410 case 4: {
1411 DecodeType4(instr);
1412 break;
1413 }
1414 case 5: {
1415 DecodeType5(instr);
1416 break;
1417 }
1418 case 6: {
1419 DecodeType6(instr);
1420 break;
1421 }
1422 case 7: {
1423 return DecodeType7(instr);
1424 }
1425 default: {
1426 // The type field is 3-bits in the ARM encoding.
1427 UNREACHABLE();
1428 break;
1429 }
1430 }
1431 return Instruction::kInstrSize;
1432 }
1433
1434
1435 } } // namespace v8::internal
1436
1437
1438
1439 //------------------------------------------------------------------------------
1440
1441 namespace disasm {
1442
1443
NameOfAddress(byte * addr) const1444 const char* NameConverter::NameOfAddress(byte* addr) const {
1445 v8::internal::OS::SNPrintF(tmp_buffer_, "%p", addr);
1446 return tmp_buffer_.start();
1447 }
1448
1449
NameOfConstant(byte * addr) const1450 const char* NameConverter::NameOfConstant(byte* addr) const {
1451 return NameOfAddress(addr);
1452 }
1453
1454
NameOfCPURegister(int reg) const1455 const char* NameConverter::NameOfCPURegister(int reg) const {
1456 return v8::internal::Registers::Name(reg);
1457 }
1458
1459
NameOfByteCPURegister(int reg) const1460 const char* NameConverter::NameOfByteCPURegister(int reg) const {
1461 UNREACHABLE(); // ARM does not have the concept of a byte register
1462 return "nobytereg";
1463 }
1464
1465
NameOfXMMRegister(int reg) const1466 const char* NameConverter::NameOfXMMRegister(int reg) const {
1467 UNREACHABLE(); // ARM does not have any XMM registers
1468 return "noxmmreg";
1469 }
1470
1471
NameInCode(byte * addr) const1472 const char* NameConverter::NameInCode(byte* addr) const {
1473 // The default name converter is called for unknown code. So we will not try
1474 // to access any memory.
1475 return "";
1476 }
1477
1478
1479 //------------------------------------------------------------------------------
1480
Disassembler(const NameConverter & converter)1481 Disassembler::Disassembler(const NameConverter& converter)
1482 : converter_(converter) {}
1483
1484
~Disassembler()1485 Disassembler::~Disassembler() {}
1486
1487
InstructionDecode(v8::internal::Vector<char> buffer,byte * instruction)1488 int Disassembler::InstructionDecode(v8::internal::Vector<char> buffer,
1489 byte* instruction) {
1490 v8::internal::Decoder d(converter_, buffer);
1491 return d.InstructionDecode(instruction);
1492 }
1493
1494
ConstantPoolSizeAt(byte * instruction)1495 int Disassembler::ConstantPoolSizeAt(byte* instruction) {
1496 return v8::internal::Decoder::ConstantPoolSizeAt(instruction);
1497 }
1498
1499
Disassemble(FILE * f,byte * begin,byte * end)1500 void Disassembler::Disassemble(FILE* f, byte* begin, byte* end) {
1501 NameConverter converter;
1502 Disassembler d(converter);
1503 for (byte* pc = begin; pc < end;) {
1504 v8::internal::EmbeddedVector<char, 128> buffer;
1505 buffer[0] = '\0';
1506 byte* prev_pc = pc;
1507 pc += d.InstructionDecode(buffer, pc);
1508 fprintf(f, "%p %08x %s\n",
1509 prev_pc, *reinterpret_cast<int32_t*>(prev_pc), buffer.start());
1510 }
1511 }
1512
1513
1514 } // namespace disasm
1515
1516 #endif // V8_TARGET_ARCH_ARM
1517