1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #if V8_TARGET_ARCH_ARM
6
7 #include "src/regexp/arm/regexp-macro-assembler-arm.h"
8
9 #include "src/codegen/assembler-inl.h"
10 #include "src/codegen/macro-assembler.h"
11 #include "src/heap/factory.h"
12 #include "src/logging/log.h"
13 #include "src/objects/objects-inl.h"
14 #include "src/regexp/regexp-macro-assembler.h"
15 #include "src/regexp/regexp-stack.h"
16 #include "src/snapshot/embedded/embedded-data.h"
17 #include "src/strings/unicode.h"
18
19 namespace v8 {
20 namespace internal {
21
22 /*
23 * This assembler uses the following register assignment convention
24 * - r4 : Temporarily stores the index of capture start after a matching pass
25 * for a global regexp.
26 * - r5 : Pointer to current Code object including heap object tag.
27 * - r6 : Current position in input, as negative offset from end of string.
28 * Please notice that this is the byte offset, not the character offset!
29 * - r7 : Currently loaded character. Must be loaded using
30 * LoadCurrentCharacter before using any of the dispatch methods.
31 * - r8 : Points to tip of backtrack stack
32 * - r9 : Unused, might be used by C code and expected unchanged.
33 * - r10 : End of input (points to byte after last character in input).
34 * - r11 : Frame pointer. Used to access arguments, local variables and
35 * RegExp registers.
36 * - r12 : IP register, used by assembler. Very volatile.
37 * - r13/sp : Points to tip of C stack.
38 *
39 * The remaining registers are free for computations.
40 * Each call to a public method should retain this convention.
41 *
42 * The stack will have the following structure:
43 * - fp[56] Address regexp (address of the JSRegExp object; unused in
44 * native code, passed to match signature of
45 * the interpreter)
46 * - fp[52] Isolate* isolate (address of the current isolate)
47 * - fp[48] direct_call (if 1, direct call from JavaScript code,
48 * if 0, call through the runtime system).
49 * - fp[44] stack_area_base (high end of the memory area to use as
50 * backtracking stack).
51 * - fp[40] capture array size (may fit multiple sets of matches)
52 * - fp[36] int* capture_array (int[num_saved_registers_], for output).
53 * --- sp when called ---
54 * - fp[32] return address (lr).
55 * - fp[28] old frame pointer (r11).
56 * - fp[0..24] backup of registers r4..r10.
57 * --- frame pointer ----
58 * - fp[-4] end of input (address of end of string).
59 * - fp[-8] start of input (address of first character in string).
60 * - fp[-12] start index (character index of start).
61 * - fp[-16] void* input_string (location of a handle containing the string).
62 * - fp[-20] success counter (only for global regexps to count matches).
63 * - fp[-24] Offset of location before start of input (effectively character
64 * string start - 1). Used to initialize capture registers to a
65 * non-position.
66 * - fp[-28] At start (if 1, we are starting at the start of the
67 * string, otherwise 0)
68 * - fp[-32] register 0 (Only positions must be stored in the first
69 * - register 1 num_saved_registers_ registers)
70 * - ...
71 * - register num_registers-1
72 * --- sp ---
73 *
74 * The first num_saved_registers_ registers are initialized to point to
75 * "character -1" in the string (i.e., char_size() bytes before the first
76 * character of the string). The remaining registers start out as garbage.
77 *
78 * The data up to the return address must be placed there by the calling
79 * code and the remaining arguments are passed in registers, e.g. by calling the
80 * code entry as cast to a function with the signature:
81 * int (*match)(String input_string,
82 * int start_index,
83 * Address start,
84 * Address end,
85 * int* capture_output_array,
86 * int num_capture_registers,
87 * byte* stack_area_base,
88 * bool direct_call = false,
89 * Isolate* isolate,
90 * Address regexp);
91 * The call is performed by NativeRegExpMacroAssembler::Execute()
92 * (in regexp-macro-assembler.cc) via the GeneratedCode wrapper.
93 */
94
95 #define __ ACCESS_MASM(masm_)
96
97 const int RegExpMacroAssemblerARM::kRegExpCodeSize;
98
RegExpMacroAssemblerARM(Isolate * isolate,Zone * zone,Mode mode,int registers_to_save)99 RegExpMacroAssemblerARM::RegExpMacroAssemblerARM(Isolate* isolate, Zone* zone,
100 Mode mode,
101 int registers_to_save)
102 : NativeRegExpMacroAssembler(isolate, zone),
103 masm_(new MacroAssembler(isolate, CodeObjectRequired::kYes,
104 NewAssemblerBuffer(kRegExpCodeSize))),
105 mode_(mode),
106 num_registers_(registers_to_save),
107 num_saved_registers_(registers_to_save),
108 entry_label_(),
109 start_label_(),
110 success_label_(),
111 backtrack_label_(),
112 exit_label_() {
113 masm_->set_root_array_available(false);
114
115 DCHECK_EQ(0, registers_to_save % 2);
116 __ jmp(&entry_label_); // We'll write the entry code later.
117 __ bind(&start_label_); // And then continue from here.
118 }
119
~RegExpMacroAssemblerARM()120 RegExpMacroAssemblerARM::~RegExpMacroAssemblerARM() {
121 delete masm_;
122 // Unuse labels in case we throw away the assembler without calling GetCode.
123 entry_label_.Unuse();
124 start_label_.Unuse();
125 success_label_.Unuse();
126 backtrack_label_.Unuse();
127 exit_label_.Unuse();
128 check_preempt_label_.Unuse();
129 stack_overflow_label_.Unuse();
130 }
131
132
stack_limit_slack()133 int RegExpMacroAssemblerARM::stack_limit_slack() {
134 return RegExpStack::kStackLimitSlack;
135 }
136
137
AdvanceCurrentPosition(int by)138 void RegExpMacroAssemblerARM::AdvanceCurrentPosition(int by) {
139 if (by != 0) {
140 __ add(current_input_offset(),
141 current_input_offset(), Operand(by * char_size()));
142 }
143 }
144
145
AdvanceRegister(int reg,int by)146 void RegExpMacroAssemblerARM::AdvanceRegister(int reg, int by) {
147 DCHECK_LE(0, reg);
148 DCHECK_GT(num_registers_, reg);
149 if (by != 0) {
150 __ ldr(r0, register_location(reg));
151 __ add(r0, r0, Operand(by));
152 __ str(r0, register_location(reg));
153 }
154 }
155
156
Backtrack()157 void RegExpMacroAssemblerARM::Backtrack() {
158 CheckPreemption();
159 if (has_backtrack_limit()) {
160 Label next;
161 __ ldr(r0, MemOperand(frame_pointer(), kBacktrackCount));
162 __ add(r0, r0, Operand(1));
163 __ str(r0, MemOperand(frame_pointer(), kBacktrackCount));
164 __ cmp(r0, Operand(backtrack_limit()));
165 __ b(ne, &next);
166
167 // Exceeded limits are treated as a failed match.
168 Fail();
169
170 __ bind(&next);
171 }
172 // Pop Code offset from backtrack stack, add Code and jump to location.
173 Pop(r0);
174 __ add(pc, r0, Operand(code_pointer()));
175 }
176
177
Bind(Label * label)178 void RegExpMacroAssemblerARM::Bind(Label* label) {
179 __ bind(label);
180 }
181
182
CheckCharacter(uint32_t c,Label * on_equal)183 void RegExpMacroAssemblerARM::CheckCharacter(uint32_t c, Label* on_equal) {
184 __ cmp(current_character(), Operand(c));
185 BranchOrBacktrack(eq, on_equal);
186 }
187
188
CheckCharacterGT(uc16 limit,Label * on_greater)189 void RegExpMacroAssemblerARM::CheckCharacterGT(uc16 limit, Label* on_greater) {
190 __ cmp(current_character(), Operand(limit));
191 BranchOrBacktrack(gt, on_greater);
192 }
193
CheckAtStart(int cp_offset,Label * on_at_start)194 void RegExpMacroAssemblerARM::CheckAtStart(int cp_offset, Label* on_at_start) {
195 __ ldr(r1, MemOperand(frame_pointer(), kStringStartMinusOne));
196 __ add(r0, current_input_offset(),
197 Operand(-char_size() + cp_offset * char_size()));
198 __ cmp(r0, r1);
199 BranchOrBacktrack(eq, on_at_start);
200 }
201
CheckNotAtStart(int cp_offset,Label * on_not_at_start)202 void RegExpMacroAssemblerARM::CheckNotAtStart(int cp_offset,
203 Label* on_not_at_start) {
204 __ ldr(r1, MemOperand(frame_pointer(), kStringStartMinusOne));
205 __ add(r0, current_input_offset(),
206 Operand(-char_size() + cp_offset * char_size()));
207 __ cmp(r0, r1);
208 BranchOrBacktrack(ne, on_not_at_start);
209 }
210
211
CheckCharacterLT(uc16 limit,Label * on_less)212 void RegExpMacroAssemblerARM::CheckCharacterLT(uc16 limit, Label* on_less) {
213 __ cmp(current_character(), Operand(limit));
214 BranchOrBacktrack(lt, on_less);
215 }
216
217
CheckGreedyLoop(Label * on_equal)218 void RegExpMacroAssemblerARM::CheckGreedyLoop(Label* on_equal) {
219 __ ldr(r0, MemOperand(backtrack_stackpointer(), 0));
220 __ cmp(current_input_offset(), r0);
221 __ add(backtrack_stackpointer(),
222 backtrack_stackpointer(), Operand(kPointerSize), LeaveCC, eq);
223 BranchOrBacktrack(eq, on_equal);
224 }
225
CheckNotBackReferenceIgnoreCase(int start_reg,bool read_backward,Label * on_no_match)226 void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
227 int start_reg, bool read_backward, Label* on_no_match) {
228 Label fallthrough;
229 __ ldr(r0, register_location(start_reg)); // Index of start of capture
230 __ ldr(r1, register_location(start_reg + 1)); // Index of end of capture
231 __ sub(r1, r1, r0, SetCC); // Length of capture.
232
233 // At this point, the capture registers are either both set or both cleared.
234 // If the capture length is zero, then the capture is either empty or cleared.
235 // Fall through in both cases.
236 __ b(eq, &fallthrough);
237
238 // Check that there are enough characters left in the input.
239 if (read_backward) {
240 __ ldr(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
241 __ add(r3, r3, r1);
242 __ cmp(current_input_offset(), r3);
243 BranchOrBacktrack(le, on_no_match);
244 } else {
245 __ cmn(r1, Operand(current_input_offset()));
246 BranchOrBacktrack(gt, on_no_match);
247 }
248
249 if (mode_ == LATIN1) {
250 Label success;
251 Label fail;
252 Label loop_check;
253
254 // r0 - offset of start of capture
255 // r1 - length of capture
256 __ add(r0, r0, end_of_input_address());
257 __ add(r2, end_of_input_address(), current_input_offset());
258 if (read_backward) {
259 __ sub(r2, r2, r1); // Offset by length when matching backwards.
260 }
261 __ add(r1, r0, r1);
262
263 // r0 - Address of start of capture.
264 // r1 - Address of end of capture
265 // r2 - Address of current input position.
266
267 Label loop;
268 __ bind(&loop);
269 __ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
270 __ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
271 __ cmp(r4, r3);
272 __ b(eq, &loop_check);
273
274 // Mismatch, try case-insensitive match (converting letters to lower-case).
275 __ orr(r3, r3, Operand(0x20)); // Convert capture character to lower-case.
276 __ orr(r4, r4, Operand(0x20)); // Also convert input character.
277 __ cmp(r4, r3);
278 __ b(ne, &fail);
279 __ sub(r3, r3, Operand('a'));
280 __ cmp(r3, Operand('z' - 'a')); // Is r3 a lowercase letter?
281 __ b(ls, &loop_check); // In range 'a'-'z'.
282 // Latin-1: Check for values in range [224,254] but not 247.
283 __ sub(r3, r3, Operand(224 - 'a'));
284 __ cmp(r3, Operand(254 - 224));
285 __ b(hi, &fail); // Weren't Latin-1 letters.
286 __ cmp(r3, Operand(247 - 224)); // Check for 247.
287 __ b(eq, &fail);
288
289 __ bind(&loop_check);
290 __ cmp(r0, r1);
291 __ b(lt, &loop);
292 __ jmp(&success);
293
294 __ bind(&fail);
295 BranchOrBacktrack(al, on_no_match);
296
297 __ bind(&success);
298 // Compute new value of character position after the matched part.
299 __ sub(current_input_offset(), r2, end_of_input_address());
300 if (read_backward) {
301 __ ldr(r0, register_location(start_reg)); // Index of start of capture
302 __ ldr(r1, register_location(start_reg + 1)); // Index of end of capture
303 __ add(current_input_offset(), current_input_offset(), r0);
304 __ sub(current_input_offset(), current_input_offset(), r1);
305 }
306 } else {
307 DCHECK(mode_ == UC16);
308 int argument_count = 4;
309 __ PrepareCallCFunction(argument_count);
310
311 // r0 - offset of start of capture
312 // r1 - length of capture
313
314 // Put arguments into arguments registers.
315 // Parameters are
316 // r0: Address byte_offset1 - Address captured substring's start.
317 // r1: Address byte_offset2 - Address of current character position.
318 // r2: size_t byte_length - length of capture in bytes(!)
319 // r3: Isolate* isolate.
320
321 // Address of start of capture.
322 __ add(r0, r0, Operand(end_of_input_address()));
323 // Length of capture.
324 __ mov(r2, Operand(r1));
325 // Save length in callee-save register for use on return.
326 __ mov(r4, Operand(r1));
327 // Address of current input position.
328 __ add(r1, current_input_offset(), end_of_input_address());
329 if (read_backward) {
330 __ sub(r1, r1, r4);
331 }
332 // Isolate.
333 __ mov(r3, Operand(ExternalReference::isolate_address(isolate())));
334
335 {
336 AllowExternalCallThatCantCauseGC scope(masm_);
337 ExternalReference function =
338 ExternalReference::re_case_insensitive_compare_uc16(isolate());
339 __ CallCFunction(function, argument_count);
340 }
341
342 // Check if function returned non-zero for success or zero for failure.
343 __ cmp(r0, Operand::Zero());
344 BranchOrBacktrack(eq, on_no_match);
345
346 // On success, advance position by length of capture.
347 if (read_backward) {
348 __ sub(current_input_offset(), current_input_offset(), r4);
349 } else {
350 __ add(current_input_offset(), current_input_offset(), r4);
351 }
352 }
353
354 __ bind(&fallthrough);
355 }
356
CheckNotBackReference(int start_reg,bool read_backward,Label * on_no_match)357 void RegExpMacroAssemblerARM::CheckNotBackReference(int start_reg,
358 bool read_backward,
359 Label* on_no_match) {
360 Label fallthrough;
361
362 // Find length of back-referenced capture.
363 __ ldr(r0, register_location(start_reg));
364 __ ldr(r1, register_location(start_reg + 1));
365 __ sub(r1, r1, r0, SetCC); // Length to check.
366
367 // At this point, the capture registers are either both set or both cleared.
368 // If the capture length is zero, then the capture is either empty or cleared.
369 // Fall through in both cases.
370 __ b(eq, &fallthrough);
371
372 // Check that there are enough characters left in the input.
373 if (read_backward) {
374 __ ldr(r3, MemOperand(frame_pointer(), kStringStartMinusOne));
375 __ add(r3, r3, r1);
376 __ cmp(current_input_offset(), r3);
377 BranchOrBacktrack(le, on_no_match);
378 } else {
379 __ cmn(r1, Operand(current_input_offset()));
380 BranchOrBacktrack(gt, on_no_match);
381 }
382
383 // r0 - offset of start of capture
384 // r1 - length of capture
385 __ add(r0, r0, end_of_input_address());
386 __ add(r2, end_of_input_address(), current_input_offset());
387 if (read_backward) {
388 __ sub(r2, r2, r1); // Offset by length when matching backwards.
389 }
390 __ add(r1, r0, r1);
391
392 Label loop;
393 __ bind(&loop);
394 if (mode_ == LATIN1) {
395 __ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
396 __ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
397 } else {
398 DCHECK(mode_ == UC16);
399 __ ldrh(r3, MemOperand(r0, char_size(), PostIndex));
400 __ ldrh(r4, MemOperand(r2, char_size(), PostIndex));
401 }
402 __ cmp(r3, r4);
403 BranchOrBacktrack(ne, on_no_match);
404 __ cmp(r0, r1);
405 __ b(lt, &loop);
406
407 // Move current character position to position after match.
408 __ sub(current_input_offset(), r2, end_of_input_address());
409 if (read_backward) {
410 __ ldr(r0, register_location(start_reg)); // Index of start of capture
411 __ ldr(r1, register_location(start_reg + 1)); // Index of end of capture
412 __ add(current_input_offset(), current_input_offset(), r0);
413 __ sub(current_input_offset(), current_input_offset(), r1);
414 }
415
416 __ bind(&fallthrough);
417 }
418
419
CheckNotCharacter(unsigned c,Label * on_not_equal)420 void RegExpMacroAssemblerARM::CheckNotCharacter(unsigned c,
421 Label* on_not_equal) {
422 __ cmp(current_character(), Operand(c));
423 BranchOrBacktrack(ne, on_not_equal);
424 }
425
426
CheckCharacterAfterAnd(uint32_t c,uint32_t mask,Label * on_equal)427 void RegExpMacroAssemblerARM::CheckCharacterAfterAnd(uint32_t c,
428 uint32_t mask,
429 Label* on_equal) {
430 if (c == 0) {
431 __ tst(current_character(), Operand(mask));
432 } else {
433 __ and_(r0, current_character(), Operand(mask));
434 __ cmp(r0, Operand(c));
435 }
436 BranchOrBacktrack(eq, on_equal);
437 }
438
439
CheckNotCharacterAfterAnd(unsigned c,unsigned mask,Label * on_not_equal)440 void RegExpMacroAssemblerARM::CheckNotCharacterAfterAnd(unsigned c,
441 unsigned mask,
442 Label* on_not_equal) {
443 if (c == 0) {
444 __ tst(current_character(), Operand(mask));
445 } else {
446 __ and_(r0, current_character(), Operand(mask));
447 __ cmp(r0, Operand(c));
448 }
449 BranchOrBacktrack(ne, on_not_equal);
450 }
451
452
CheckNotCharacterAfterMinusAnd(uc16 c,uc16 minus,uc16 mask,Label * on_not_equal)453 void RegExpMacroAssemblerARM::CheckNotCharacterAfterMinusAnd(
454 uc16 c,
455 uc16 minus,
456 uc16 mask,
457 Label* on_not_equal) {
458 DCHECK_GT(String::kMaxUtf16CodeUnit, minus);
459 __ sub(r0, current_character(), Operand(minus));
460 __ and_(r0, r0, Operand(mask));
461 __ cmp(r0, Operand(c));
462 BranchOrBacktrack(ne, on_not_equal);
463 }
464
465
CheckCharacterInRange(uc16 from,uc16 to,Label * on_in_range)466 void RegExpMacroAssemblerARM::CheckCharacterInRange(
467 uc16 from,
468 uc16 to,
469 Label* on_in_range) {
470 __ sub(r0, current_character(), Operand(from));
471 __ cmp(r0, Operand(to - from));
472 BranchOrBacktrack(ls, on_in_range); // Unsigned lower-or-same condition.
473 }
474
475
CheckCharacterNotInRange(uc16 from,uc16 to,Label * on_not_in_range)476 void RegExpMacroAssemblerARM::CheckCharacterNotInRange(
477 uc16 from,
478 uc16 to,
479 Label* on_not_in_range) {
480 __ sub(r0, current_character(), Operand(from));
481 __ cmp(r0, Operand(to - from));
482 BranchOrBacktrack(hi, on_not_in_range); // Unsigned higher condition.
483 }
484
485
CheckBitInTable(Handle<ByteArray> table,Label * on_bit_set)486 void RegExpMacroAssemblerARM::CheckBitInTable(
487 Handle<ByteArray> table,
488 Label* on_bit_set) {
489 __ mov(r0, Operand(table));
490 if (mode_ != LATIN1 || kTableMask != String::kMaxOneByteCharCode) {
491 __ and_(r1, current_character(), Operand(kTableSize - 1));
492 __ add(r1, r1, Operand(ByteArray::kHeaderSize - kHeapObjectTag));
493 } else {
494 __ add(r1,
495 current_character(),
496 Operand(ByteArray::kHeaderSize - kHeapObjectTag));
497 }
498 __ ldrb(r0, MemOperand(r0, r1));
499 __ cmp(r0, Operand::Zero());
500 BranchOrBacktrack(ne, on_bit_set);
501 }
502
503
CheckSpecialCharacterClass(uc16 type,Label * on_no_match)504 bool RegExpMacroAssemblerARM::CheckSpecialCharacterClass(uc16 type,
505 Label* on_no_match) {
506 // Range checks (c in min..max) are generally implemented by an unsigned
507 // (c - min) <= (max - min) check
508 switch (type) {
509 case 's':
510 // Match space-characters
511 if (mode_ == LATIN1) {
512 // One byte space characters are '\t'..'\r', ' ' and \u00a0.
513 Label success;
514 __ cmp(current_character(), Operand(' '));
515 __ b(eq, &success);
516 // Check range 0x09..0x0D
517 __ sub(r0, current_character(), Operand('\t'));
518 __ cmp(r0, Operand('\r' - '\t'));
519 __ b(ls, &success);
520 // \u00a0 (NBSP).
521 __ cmp(r0, Operand(0x00A0 - '\t'));
522 BranchOrBacktrack(ne, on_no_match);
523 __ bind(&success);
524 return true;
525 }
526 return false;
527 case 'S':
528 // The emitted code for generic character classes is good enough.
529 return false;
530 case 'd':
531 // Match ASCII digits ('0'..'9')
532 __ sub(r0, current_character(), Operand('0'));
533 __ cmp(r0, Operand('9' - '0'));
534 BranchOrBacktrack(hi, on_no_match);
535 return true;
536 case 'D':
537 // Match non ASCII-digits
538 __ sub(r0, current_character(), Operand('0'));
539 __ cmp(r0, Operand('9' - '0'));
540 BranchOrBacktrack(ls, on_no_match);
541 return true;
542 case '.': {
543 // Match non-newlines (not 0x0A('\n'), 0x0D('\r'), 0x2028 and 0x2029)
544 __ eor(r0, current_character(), Operand(0x01));
545 // See if current character is '\n'^1 or '\r'^1, i.e., 0x0B or 0x0C
546 __ sub(r0, r0, Operand(0x0B));
547 __ cmp(r0, Operand(0x0C - 0x0B));
548 BranchOrBacktrack(ls, on_no_match);
549 if (mode_ == UC16) {
550 // Compare original value to 0x2028 and 0x2029, using the already
551 // computed (current_char ^ 0x01 - 0x0B). I.e., check for
552 // 0x201D (0x2028 - 0x0B) or 0x201E.
553 __ sub(r0, r0, Operand(0x2028 - 0x0B));
554 __ cmp(r0, Operand(1));
555 BranchOrBacktrack(ls, on_no_match);
556 }
557 return true;
558 }
559 case 'n': {
560 // Match newlines (0x0A('\n'), 0x0D('\r'), 0x2028 and 0x2029)
561 __ eor(r0, current_character(), Operand(0x01));
562 // See if current character is '\n'^1 or '\r'^1, i.e., 0x0B or 0x0C
563 __ sub(r0, r0, Operand(0x0B));
564 __ cmp(r0, Operand(0x0C - 0x0B));
565 if (mode_ == LATIN1) {
566 BranchOrBacktrack(hi, on_no_match);
567 } else {
568 Label done;
569 __ b(ls, &done);
570 // Compare original value to 0x2028 and 0x2029, using the already
571 // computed (current_char ^ 0x01 - 0x0B). I.e., check for
572 // 0x201D (0x2028 - 0x0B) or 0x201E.
573 __ sub(r0, r0, Operand(0x2028 - 0x0B));
574 __ cmp(r0, Operand(1));
575 BranchOrBacktrack(hi, on_no_match);
576 __ bind(&done);
577 }
578 return true;
579 }
580 case 'w': {
581 if (mode_ != LATIN1) {
582 // Table is 256 entries, so all Latin1 characters can be tested.
583 __ cmp(current_character(), Operand('z'));
584 BranchOrBacktrack(hi, on_no_match);
585 }
586 ExternalReference map = ExternalReference::re_word_character_map(isolate());
587 __ mov(r0, Operand(map));
588 __ ldrb(r0, MemOperand(r0, current_character()));
589 __ cmp(r0, Operand::Zero());
590 BranchOrBacktrack(eq, on_no_match);
591 return true;
592 }
593 case 'W': {
594 Label done;
595 if (mode_ != LATIN1) {
596 // Table is 256 entries, so all Latin1 characters can be tested.
597 __ cmp(current_character(), Operand('z'));
598 __ b(hi, &done);
599 }
600 ExternalReference map = ExternalReference::re_word_character_map(isolate());
601 __ mov(r0, Operand(map));
602 __ ldrb(r0, MemOperand(r0, current_character()));
603 __ cmp(r0, Operand::Zero());
604 BranchOrBacktrack(ne, on_no_match);
605 if (mode_ != LATIN1) {
606 __ bind(&done);
607 }
608 return true;
609 }
610 case '*':
611 // Match any character.
612 return true;
613 // No custom implementation (yet): s(UC16), S(UC16).
614 default:
615 return false;
616 }
617 }
618
619
Fail()620 void RegExpMacroAssemblerARM::Fail() {
621 __ mov(r0, Operand(FAILURE));
622 __ jmp(&exit_label_);
623 }
624
625
GetCode(Handle<String> source)626 Handle<HeapObject> RegExpMacroAssemblerARM::GetCode(Handle<String> source) {
627 Label return_r0;
628 // Finalize code - write the entry point code now we know how many
629 // registers we need.
630
631 // Entry code:
632 __ bind(&entry_label_);
633
634 // Tell the system that we have a stack frame. Because the type is MANUAL, no
635 // is generated.
636 FrameScope scope(masm_, StackFrame::MANUAL);
637
638 // Actually emit code to start a new stack frame.
639 // Push arguments
640 // Save callee-save registers.
641 // Start new stack frame.
642 // Store link register in existing stack-cell.
643 // Order here should correspond to order of offset constants in header file.
644 RegList registers_to_retain = r4.bit() | r5.bit() | r6.bit() |
645 r7.bit() | r8.bit() | r9.bit() | r10.bit() | fp.bit();
646 RegList argument_registers = r0.bit() | r1.bit() | r2.bit() | r3.bit();
647 __ stm(db_w, sp, argument_registers | registers_to_retain | lr.bit());
648 // Set frame pointer in space for it if this is not a direct call
649 // from generated code.
650 __ add(frame_pointer(), sp, Operand(4 * kPointerSize));
651
652 STATIC_ASSERT(kSuccessfulCaptures == kInputString - kSystemPointerSize);
653 __ mov(r0, Operand::Zero());
654 __ push(r0); // Make room for success counter and initialize it to 0.
655 STATIC_ASSERT(kStringStartMinusOne ==
656 kSuccessfulCaptures - kSystemPointerSize);
657 __ push(r0); // Make room for "string start - 1" constant.
658 STATIC_ASSERT(kBacktrackCount == kStringStartMinusOne - kSystemPointerSize);
659 __ push(r0); // The backtrack counter.
660
661 // Check if we have space on the stack for registers.
662 Label stack_limit_hit;
663 Label stack_ok;
664
665 ExternalReference stack_limit =
666 ExternalReference::address_of_jslimit(isolate());
667 __ mov(r0, Operand(stack_limit));
668 __ ldr(r0, MemOperand(r0));
669 __ sub(r0, sp, r0, SetCC);
670 // Handle it if the stack pointer is already below the stack limit.
671 __ b(ls, &stack_limit_hit);
672 // Check if there is room for the variable number of registers above
673 // the stack limit.
674 __ cmp(r0, Operand(num_registers_ * kPointerSize));
675 __ b(hs, &stack_ok);
676 // Exit with OutOfMemory exception. There is not enough space on the stack
677 // for our working registers.
678 __ mov(r0, Operand(EXCEPTION));
679 __ jmp(&return_r0);
680
681 __ bind(&stack_limit_hit);
682 CallCheckStackGuardState();
683 __ cmp(r0, Operand::Zero());
684 // If returned value is non-zero, we exit with the returned value as result.
685 __ b(ne, &return_r0);
686
687 __ bind(&stack_ok);
688
689 // Allocate space on stack for registers.
690 __ AllocateStackSpace(num_registers_ * kPointerSize);
691 // Load string end.
692 __ ldr(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
693 // Load input start.
694 __ ldr(r0, MemOperand(frame_pointer(), kInputStart));
695 // Find negative length (offset of start relative to end).
696 __ sub(current_input_offset(), r0, end_of_input_address());
697 // Set r0 to address of char before start of the input string
698 // (effectively string position -1).
699 __ ldr(r1, MemOperand(frame_pointer(), kStartIndex));
700 __ sub(r0, current_input_offset(), Operand(char_size()));
701 __ sub(r0, r0, Operand(r1, LSL, (mode_ == UC16) ? 1 : 0));
702 // Store this value in a local variable, for use when clearing
703 // position registers.
704 __ str(r0, MemOperand(frame_pointer(), kStringStartMinusOne));
705
706 // Initialize code pointer register
707 __ mov(code_pointer(), Operand(masm_->CodeObject()));
708
709 Label load_char_start_regexp, start_regexp;
710 // Load newline if index is at start, previous character otherwise.
711 __ cmp(r1, Operand::Zero());
712 __ b(ne, &load_char_start_regexp);
713 __ mov(current_character(), Operand('\n'), LeaveCC, eq);
714 __ jmp(&start_regexp);
715
716 // Global regexp restarts matching here.
717 __ bind(&load_char_start_regexp);
718 // Load previous char as initial value of current character register.
719 LoadCurrentCharacterUnchecked(-1, 1);
720 __ bind(&start_regexp);
721
722 // Initialize on-stack registers.
723 if (num_saved_registers_ > 0) { // Always is, if generated from a regexp.
724 // Fill saved registers with initial value = start offset - 1
725 if (num_saved_registers_ > 8) {
726 // Address of register 0.
727 __ add(r1, frame_pointer(), Operand(kRegisterZero));
728 __ mov(r2, Operand(num_saved_registers_));
729 Label init_loop;
730 __ bind(&init_loop);
731 __ str(r0, MemOperand(r1, kPointerSize, NegPostIndex));
732 __ sub(r2, r2, Operand(1), SetCC);
733 __ b(ne, &init_loop);
734 } else {
735 for (int i = 0; i < num_saved_registers_; i++) {
736 __ str(r0, register_location(i));
737 }
738 }
739 }
740
741 // Initialize backtrack stack pointer.
742 __ ldr(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
743
744 __ jmp(&start_label_);
745
746 // Exit code:
747 if (success_label_.is_linked()) {
748 // Save captures when successful.
749 __ bind(&success_label_);
750 if (num_saved_registers_ > 0) {
751 // copy captures to output
752 __ ldr(r1, MemOperand(frame_pointer(), kInputStart));
753 __ ldr(r0, MemOperand(frame_pointer(), kRegisterOutput));
754 __ ldr(r2, MemOperand(frame_pointer(), kStartIndex));
755 __ sub(r1, end_of_input_address(), r1);
756 // r1 is length of input in bytes.
757 if (mode_ == UC16) {
758 __ mov(r1, Operand(r1, LSR, 1));
759 }
760 // r1 is length of input in characters.
761 __ add(r1, r1, Operand(r2));
762 // r1 is length of string in characters.
763
764 DCHECK_EQ(0, num_saved_registers_ % 2);
765 // Always an even number of capture registers. This allows us to
766 // unroll the loop once to add an operation between a load of a register
767 // and the following use of that register.
768 for (int i = 0; i < num_saved_registers_; i += 2) {
769 __ ldr(r2, register_location(i));
770 __ ldr(r3, register_location(i + 1));
771 if (i == 0 && global_with_zero_length_check()) {
772 // Keep capture start in r4 for the zero-length check later.
773 __ mov(r4, r2);
774 }
775 if (mode_ == UC16) {
776 __ add(r2, r1, Operand(r2, ASR, 1));
777 __ add(r3, r1, Operand(r3, ASR, 1));
778 } else {
779 __ add(r2, r1, Operand(r2));
780 __ add(r3, r1, Operand(r3));
781 }
782 __ str(r2, MemOperand(r0, kPointerSize, PostIndex));
783 __ str(r3, MemOperand(r0, kPointerSize, PostIndex));
784 }
785 }
786
787 if (global()) {
788 // Restart matching if the regular expression is flagged as global.
789 __ ldr(r0, MemOperand(frame_pointer(), kSuccessfulCaptures));
790 __ ldr(r1, MemOperand(frame_pointer(), kNumOutputRegisters));
791 __ ldr(r2, MemOperand(frame_pointer(), kRegisterOutput));
792 // Increment success counter.
793 __ add(r0, r0, Operand(1));
794 __ str(r0, MemOperand(frame_pointer(), kSuccessfulCaptures));
795 // Capture results have been stored, so the number of remaining global
796 // output registers is reduced by the number of stored captures.
797 __ sub(r1, r1, Operand(num_saved_registers_));
798 // Check whether we have enough room for another set of capture results.
799 __ cmp(r1, Operand(num_saved_registers_));
800 __ b(lt, &return_r0);
801
802 __ str(r1, MemOperand(frame_pointer(), kNumOutputRegisters));
803 // Advance the location for output.
804 __ add(r2, r2, Operand(num_saved_registers_ * kPointerSize));
805 __ str(r2, MemOperand(frame_pointer(), kRegisterOutput));
806
807 // Prepare r0 to initialize registers with its value in the next run.
808 __ ldr(r0, MemOperand(frame_pointer(), kStringStartMinusOne));
809
810 if (global_with_zero_length_check()) {
811 // Special case for zero-length matches.
812 // r4: capture start index
813 __ cmp(current_input_offset(), r4);
814 // Not a zero-length match, restart.
815 __ b(ne, &load_char_start_regexp);
816 // Offset from the end is zero if we already reached the end.
817 __ cmp(current_input_offset(), Operand::Zero());
818 __ b(eq, &exit_label_);
819 // Advance current position after a zero-length match.
820 Label advance;
821 __ bind(&advance);
822 __ add(current_input_offset(),
823 current_input_offset(),
824 Operand((mode_ == UC16) ? 2 : 1));
825 if (global_unicode()) CheckNotInSurrogatePair(0, &advance);
826 }
827
828 __ b(&load_char_start_regexp);
829 } else {
830 __ mov(r0, Operand(SUCCESS));
831 }
832 }
833
834 // Exit and return r0
835 __ bind(&exit_label_);
836 if (global()) {
837 __ ldr(r0, MemOperand(frame_pointer(), kSuccessfulCaptures));
838 }
839
840 __ bind(&return_r0);
841 // Skip sp past regexp registers and local variables..
842 __ mov(sp, frame_pointer());
843 // Restore registers r4..r11 and return (restoring lr to pc).
844 __ ldm(ia_w, sp, registers_to_retain | pc.bit());
845
846 // Backtrack code (branch target for conditional backtracks).
847 if (backtrack_label_.is_linked()) {
848 __ bind(&backtrack_label_);
849 Backtrack();
850 }
851
852 Label exit_with_exception;
853
854 // Preempt-code
855 if (check_preempt_label_.is_linked()) {
856 SafeCallTarget(&check_preempt_label_);
857
858 CallCheckStackGuardState();
859 __ cmp(r0, Operand::Zero());
860 // If returning non-zero, we should end execution with the given
861 // result as return value.
862 __ b(ne, &return_r0);
863
864 // String might have moved: Reload end of string from frame.
865 __ ldr(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
866 SafeReturn();
867 }
868
869 // Backtrack stack overflow code.
870 if (stack_overflow_label_.is_linked()) {
871 SafeCallTarget(&stack_overflow_label_);
872 // Reached if the backtrack-stack limit has been hit.
873
874 // Call GrowStack(backtrack_stackpointer(), &stack_base)
875 static const int num_arguments = 3;
876 __ PrepareCallCFunction(num_arguments);
877 __ mov(r0, backtrack_stackpointer());
878 __ add(r1, frame_pointer(), Operand(kStackHighEnd));
879 __ mov(r2, Operand(ExternalReference::isolate_address(isolate())));
880 ExternalReference grow_stack =
881 ExternalReference::re_grow_stack(isolate());
882 __ CallCFunction(grow_stack, num_arguments);
883 // If return nullptr, we have failed to grow the stack, and
884 // must exit with a stack-overflow exception.
885 __ cmp(r0, Operand::Zero());
886 __ b(eq, &exit_with_exception);
887 // Otherwise use return value as new stack pointer.
888 __ mov(backtrack_stackpointer(), r0);
889 // Restore saved registers and continue.
890 SafeReturn();
891 }
892
893 if (exit_with_exception.is_linked()) {
894 // If any of the code above needed to exit with an exception.
895 __ bind(&exit_with_exception);
896 // Exit with Result EXCEPTION(-1) to signal thrown exception.
897 __ mov(r0, Operand(EXCEPTION));
898 __ jmp(&return_r0);
899 }
900
901 CodeDesc code_desc;
902 masm_->GetCode(isolate(), &code_desc);
903 Handle<Code> code = Factory::CodeBuilder(isolate(), code_desc, Code::REGEXP)
904 .set_self_reference(masm_->CodeObject())
905 .Build();
906 PROFILE(masm_->isolate(),
907 RegExpCodeCreateEvent(Handle<AbstractCode>::cast(code), source));
908 return Handle<HeapObject>::cast(code);
909 }
910
911
GoTo(Label * to)912 void RegExpMacroAssemblerARM::GoTo(Label* to) {
913 BranchOrBacktrack(al, to);
914 }
915
916
IfRegisterGE(int reg,int comparand,Label * if_ge)917 void RegExpMacroAssemblerARM::IfRegisterGE(int reg,
918 int comparand,
919 Label* if_ge) {
920 __ ldr(r0, register_location(reg));
921 __ cmp(r0, Operand(comparand));
922 BranchOrBacktrack(ge, if_ge);
923 }
924
925
IfRegisterLT(int reg,int comparand,Label * if_lt)926 void RegExpMacroAssemblerARM::IfRegisterLT(int reg,
927 int comparand,
928 Label* if_lt) {
929 __ ldr(r0, register_location(reg));
930 __ cmp(r0, Operand(comparand));
931 BranchOrBacktrack(lt, if_lt);
932 }
933
934
IfRegisterEqPos(int reg,Label * if_eq)935 void RegExpMacroAssemblerARM::IfRegisterEqPos(int reg,
936 Label* if_eq) {
937 __ ldr(r0, register_location(reg));
938 __ cmp(r0, Operand(current_input_offset()));
939 BranchOrBacktrack(eq, if_eq);
940 }
941
942
943 RegExpMacroAssembler::IrregexpImplementation
Implementation()944 RegExpMacroAssemblerARM::Implementation() {
945 return kARMImplementation;
946 }
947
LoadCurrentCharacterImpl(int cp_offset,Label * on_end_of_input,bool check_bounds,int characters,int eats_at_least)948 void RegExpMacroAssemblerARM::LoadCurrentCharacterImpl(int cp_offset,
949 Label* on_end_of_input,
950 bool check_bounds,
951 int characters,
952 int eats_at_least) {
953 // It's possible to preload a small number of characters when each success
954 // path requires a large number of characters, but not the reverse.
955 DCHECK_GE(eats_at_least, characters);
956
957 DCHECK(cp_offset < (1<<30)); // Be sane! (And ensure negation works)
958 if (check_bounds) {
959 if (cp_offset >= 0) {
960 CheckPosition(cp_offset + eats_at_least - 1, on_end_of_input);
961 } else {
962 CheckPosition(cp_offset, on_end_of_input);
963 }
964 }
965 LoadCurrentCharacterUnchecked(cp_offset, characters);
966 }
967
PopCurrentPosition()968 void RegExpMacroAssemblerARM::PopCurrentPosition() {
969 Pop(current_input_offset());
970 }
971
972
PopRegister(int register_index)973 void RegExpMacroAssemblerARM::PopRegister(int register_index) {
974 Pop(r0);
975 __ str(r0, register_location(register_index));
976 }
977
978
PushBacktrack(Label * label)979 void RegExpMacroAssemblerARM::PushBacktrack(Label* label) {
980 __ mov_label_offset(r0, label);
981 Push(r0);
982 CheckStackLimit();
983 }
984
985
PushCurrentPosition()986 void RegExpMacroAssemblerARM::PushCurrentPosition() {
987 Push(current_input_offset());
988 }
989
990
PushRegister(int register_index,StackCheckFlag check_stack_limit)991 void RegExpMacroAssemblerARM::PushRegister(int register_index,
992 StackCheckFlag check_stack_limit) {
993 __ ldr(r0, register_location(register_index));
994 Push(r0);
995 if (check_stack_limit) CheckStackLimit();
996 }
997
998
ReadCurrentPositionFromRegister(int reg)999 void RegExpMacroAssemblerARM::ReadCurrentPositionFromRegister(int reg) {
1000 __ ldr(current_input_offset(), register_location(reg));
1001 }
1002
1003
ReadStackPointerFromRegister(int reg)1004 void RegExpMacroAssemblerARM::ReadStackPointerFromRegister(int reg) {
1005 __ ldr(backtrack_stackpointer(), register_location(reg));
1006 __ ldr(r0, MemOperand(frame_pointer(), kStackHighEnd));
1007 __ add(backtrack_stackpointer(), backtrack_stackpointer(), Operand(r0));
1008 }
1009
1010
SetCurrentPositionFromEnd(int by)1011 void RegExpMacroAssemblerARM::SetCurrentPositionFromEnd(int by) {
1012 Label after_position;
1013 __ cmp(current_input_offset(), Operand(-by * char_size()));
1014 __ b(ge, &after_position);
1015 __ mov(current_input_offset(), Operand(-by * char_size()));
1016 // On RegExp code entry (where this operation is used), the character before
1017 // the current position is expected to be already loaded.
1018 // We have advanced the position, so it's safe to read backwards.
1019 LoadCurrentCharacterUnchecked(-1, 1);
1020 __ bind(&after_position);
1021 }
1022
1023
SetRegister(int register_index,int to)1024 void RegExpMacroAssemblerARM::SetRegister(int register_index, int to) {
1025 DCHECK(register_index >= num_saved_registers_); // Reserved for positions!
1026 __ mov(r0, Operand(to));
1027 __ str(r0, register_location(register_index));
1028 }
1029
1030
Succeed()1031 bool RegExpMacroAssemblerARM::Succeed() {
1032 __ jmp(&success_label_);
1033 return global();
1034 }
1035
1036
WriteCurrentPositionToRegister(int reg,int cp_offset)1037 void RegExpMacroAssemblerARM::WriteCurrentPositionToRegister(int reg,
1038 int cp_offset) {
1039 if (cp_offset == 0) {
1040 __ str(current_input_offset(), register_location(reg));
1041 } else {
1042 __ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
1043 __ str(r0, register_location(reg));
1044 }
1045 }
1046
1047
ClearRegisters(int reg_from,int reg_to)1048 void RegExpMacroAssemblerARM::ClearRegisters(int reg_from, int reg_to) {
1049 DCHECK(reg_from <= reg_to);
1050 __ ldr(r0, MemOperand(frame_pointer(), kStringStartMinusOne));
1051 for (int reg = reg_from; reg <= reg_to; reg++) {
1052 __ str(r0, register_location(reg));
1053 }
1054 }
1055
1056
WriteStackPointerToRegister(int reg)1057 void RegExpMacroAssemblerARM::WriteStackPointerToRegister(int reg) {
1058 __ ldr(r1, MemOperand(frame_pointer(), kStackHighEnd));
1059 __ sub(r0, backtrack_stackpointer(), r1);
1060 __ str(r0, register_location(reg));
1061 }
1062
1063
1064 // Private methods:
1065
CallCheckStackGuardState()1066 void RegExpMacroAssemblerARM::CallCheckStackGuardState() {
1067 DCHECK(!isolate()->IsGeneratingEmbeddedBuiltins());
1068 DCHECK(!masm_->options().isolate_independent_code);
1069
1070 __ PrepareCallCFunction(3);
1071
1072 // RegExp code frame pointer.
1073 __ mov(r2, frame_pointer());
1074 // Code of self.
1075 __ mov(r1, Operand(masm_->CodeObject()));
1076
1077 // We need to make room for the return address on the stack.
1078 int stack_alignment = base::OS::ActivationFrameAlignment();
1079 DCHECK(IsAligned(stack_alignment, kPointerSize));
1080 __ AllocateStackSpace(stack_alignment);
1081
1082 // r0 will point to the return address, placed by DirectCEntry.
1083 __ mov(r0, sp);
1084
1085 ExternalReference stack_guard_check =
1086 ExternalReference::re_check_stack_guard_state(isolate());
1087 __ mov(ip, Operand(stack_guard_check));
1088
1089 EmbeddedData d = EmbeddedData::FromBlob();
1090 CHECK(Builtins::IsIsolateIndependent(Builtins::kDirectCEntry));
1091 Address entry = d.InstructionStartOfBuiltin(Builtins::kDirectCEntry);
1092 __ mov(lr, Operand(entry, RelocInfo::OFF_HEAP_TARGET));
1093 __ Call(lr);
1094
1095 // Drop the return address from the stack.
1096 __ add(sp, sp, Operand(stack_alignment));
1097
1098 DCHECK_NE(0, stack_alignment);
1099 __ ldr(sp, MemOperand(sp, 0));
1100
1101 __ mov(code_pointer(), Operand(masm_->CodeObject()));
1102 }
1103
1104
1105 // Helper function for reading a value out of a stack frame.
1106 template <typename T>
frame_entry(Address re_frame,int frame_offset)1107 static T& frame_entry(Address re_frame, int frame_offset) {
1108 return reinterpret_cast<T&>(Memory<int32_t>(re_frame + frame_offset));
1109 }
1110
1111
1112 template <typename T>
frame_entry_address(Address re_frame,int frame_offset)1113 static T* frame_entry_address(Address re_frame, int frame_offset) {
1114 return reinterpret_cast<T*>(re_frame + frame_offset);
1115 }
1116
CheckStackGuardState(Address * return_address,Address raw_code,Address re_frame)1117 int RegExpMacroAssemblerARM::CheckStackGuardState(Address* return_address,
1118 Address raw_code,
1119 Address re_frame) {
1120 Code re_code = Code::cast(Object(raw_code));
1121 return NativeRegExpMacroAssembler::CheckStackGuardState(
1122 frame_entry<Isolate*>(re_frame, kIsolate),
1123 frame_entry<int>(re_frame, kStartIndex),
1124 static_cast<RegExp::CallOrigin>(frame_entry<int>(re_frame, kDirectCall)),
1125 return_address, re_code,
1126 frame_entry_address<Address>(re_frame, kInputString),
1127 frame_entry_address<const byte*>(re_frame, kInputStart),
1128 frame_entry_address<const byte*>(re_frame, kInputEnd));
1129 }
1130
1131
register_location(int register_index)1132 MemOperand RegExpMacroAssemblerARM::register_location(int register_index) {
1133 DCHECK(register_index < (1<<30));
1134 if (num_registers_ <= register_index) {
1135 num_registers_ = register_index + 1;
1136 }
1137 return MemOperand(frame_pointer(),
1138 kRegisterZero - register_index * kPointerSize);
1139 }
1140
1141
CheckPosition(int cp_offset,Label * on_outside_input)1142 void RegExpMacroAssemblerARM::CheckPosition(int cp_offset,
1143 Label* on_outside_input) {
1144 if (cp_offset >= 0) {
1145 __ cmp(current_input_offset(), Operand(-cp_offset * char_size()));
1146 BranchOrBacktrack(ge, on_outside_input);
1147 } else {
1148 __ ldr(r1, MemOperand(frame_pointer(), kStringStartMinusOne));
1149 __ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
1150 __ cmp(r0, r1);
1151 BranchOrBacktrack(le, on_outside_input);
1152 }
1153 }
1154
1155
BranchOrBacktrack(Condition condition,Label * to)1156 void RegExpMacroAssemblerARM::BranchOrBacktrack(Condition condition,
1157 Label* to) {
1158 if (condition == al) { // Unconditional.
1159 if (to == nullptr) {
1160 Backtrack();
1161 return;
1162 }
1163 __ jmp(to);
1164 return;
1165 }
1166 if (to == nullptr) {
1167 __ b(condition, &backtrack_label_);
1168 return;
1169 }
1170 __ b(condition, to);
1171 }
1172
1173
SafeCall(Label * to,Condition cond)1174 void RegExpMacroAssemblerARM::SafeCall(Label* to, Condition cond) {
1175 __ bl(to, cond);
1176 }
1177
1178
SafeReturn()1179 void RegExpMacroAssemblerARM::SafeReturn() {
1180 __ pop(lr);
1181 __ add(pc, lr, Operand(masm_->CodeObject()));
1182 }
1183
1184
SafeCallTarget(Label * name)1185 void RegExpMacroAssemblerARM::SafeCallTarget(Label* name) {
1186 __ bind(name);
1187 __ sub(lr, lr, Operand(masm_->CodeObject()));
1188 __ push(lr);
1189 }
1190
1191
Push(Register source)1192 void RegExpMacroAssemblerARM::Push(Register source) {
1193 DCHECK(source != backtrack_stackpointer());
1194 __ str(source,
1195 MemOperand(backtrack_stackpointer(), kPointerSize, NegPreIndex));
1196 }
1197
1198
Pop(Register target)1199 void RegExpMacroAssemblerARM::Pop(Register target) {
1200 DCHECK(target != backtrack_stackpointer());
1201 __ ldr(target,
1202 MemOperand(backtrack_stackpointer(), kPointerSize, PostIndex));
1203 }
1204
1205
CheckPreemption()1206 void RegExpMacroAssemblerARM::CheckPreemption() {
1207 // Check for preemption.
1208 ExternalReference stack_limit =
1209 ExternalReference::address_of_jslimit(isolate());
1210 __ mov(r0, Operand(stack_limit));
1211 __ ldr(r0, MemOperand(r0));
1212 __ cmp(sp, r0);
1213 SafeCall(&check_preempt_label_, ls);
1214 }
1215
1216
CheckStackLimit()1217 void RegExpMacroAssemblerARM::CheckStackLimit() {
1218 ExternalReference stack_limit =
1219 ExternalReference::address_of_regexp_stack_limit_address(isolate());
1220 __ mov(r0, Operand(stack_limit));
1221 __ ldr(r0, MemOperand(r0));
1222 __ cmp(backtrack_stackpointer(), Operand(r0));
1223 SafeCall(&stack_overflow_label_, ls);
1224 }
1225
1226
LoadCurrentCharacterUnchecked(int cp_offset,int characters)1227 void RegExpMacroAssemblerARM::LoadCurrentCharacterUnchecked(int cp_offset,
1228 int characters) {
1229 Register offset = current_input_offset();
1230 if (cp_offset != 0) {
1231 // r4 is not being used to store the capture start index at this point.
1232 __ add(r4, current_input_offset(), Operand(cp_offset * char_size()));
1233 offset = r4;
1234 }
1235 // The ldr, str, ldrh, strh instructions can do unaligned accesses, if the CPU
1236 // and the operating system running on the target allow it.
1237 // If unaligned load/stores are not supported then this function must only
1238 // be used to load a single character at a time.
1239 if (!CanReadUnaligned()) {
1240 DCHECK_EQ(1, characters);
1241 }
1242
1243 if (mode_ == LATIN1) {
1244 if (characters == 4) {
1245 __ ldr(current_character(), MemOperand(end_of_input_address(), offset));
1246 } else if (characters == 2) {
1247 __ ldrh(current_character(), MemOperand(end_of_input_address(), offset));
1248 } else {
1249 DCHECK_EQ(1, characters);
1250 __ ldrb(current_character(), MemOperand(end_of_input_address(), offset));
1251 }
1252 } else {
1253 DCHECK(mode_ == UC16);
1254 if (characters == 2) {
1255 __ ldr(current_character(), MemOperand(end_of_input_address(), offset));
1256 } else {
1257 DCHECK_EQ(1, characters);
1258 __ ldrh(current_character(), MemOperand(end_of_input_address(), offset));
1259 }
1260 }
1261 }
1262
1263
1264 #undef __
1265
1266 } // namespace internal
1267 } // namespace v8
1268
1269 #endif // V8_TARGET_ARCH_ARM
1270