summaryrefslogtreecommitdiff
path: root/sljit/sljitNativeX86_32.c
blob: 2866e8f2a151a73dccb905e5ba1341857efdbdea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
/*
 *    Stack-less Just-In-Time compiler
 *
 *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright notice, this list of
 *      conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright notice, this list
 *      of conditions and the following disclaimer in the documentation and/or other materials
 *      provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* x86 32-bit arch dependent functions. */

static sljit_si emit_do_imm(struct sljit_compiler *compiler, sljit_ub opcode, sljit_sw imm)
{
	sljit_ub *inst;

	inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + sizeof(sljit_sw));
	FAIL_IF(!inst);
	INC_SIZE(1 + sizeof(sljit_sw));
	*inst++ = opcode;
	*(sljit_sw*)inst = imm;
	return SLJIT_SUCCESS;
}

static sljit_ub* generate_far_jump_code(struct sljit_jump *jump, sljit_ub *code_ptr, sljit_si type)
{
	if (type == SLJIT_JUMP) {
		*code_ptr++ = JMP_i32;
		jump->addr++;
	}
	else if (type >= SLJIT_FAST_CALL) {
		*code_ptr++ = CALL_i32;
		jump->addr++;
	}
	else {
		*code_ptr++ = GROUP_0F;
		*code_ptr++ = get_jump_code(type);
		jump->addr += 2;
	}

	if (jump->flags & JUMP_LABEL)
		jump->flags |= PATCH_MW;
	else
		*(sljit_sw*)code_ptr = jump->u.target - (jump->addr + 4);
	code_ptr += 4;

	return code_ptr;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_enter(struct sljit_compiler *compiler, sljit_si args, sljit_si scratches, sljit_si saveds, sljit_si local_size)
{
	sljit_si size;
	sljit_si locals_offset;
	sljit_ub *inst;

	CHECK_ERROR();
	check_sljit_emit_enter(compiler, args, scratches, saveds, local_size);

	compiler->scratches = scratches;
	compiler->saveds = saveds;
	compiler->args = args;
	compiler->flags_saved = 0;
#if (defined SLJIT_DEBUG && SLJIT_DEBUG)
	compiler->logical_local_size = local_size;
#endif

#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	size = 1 + (saveds <= 3 ? saveds : 3) + (args > 0 ? (args * 2) : 0) + (args > 2 ? 2 : 0);
#else
	size = 1 + (saveds <= 3 ? saveds : 3) + (args > 0 ? (2 + args * 3) : 0);
#endif
	inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
	FAIL_IF(!inst);

	INC_SIZE(size);
	PUSH_REG(reg_map[TMP_REGISTER]);
#if !(defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	if (args > 0) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_REG | (reg_map[TMP_REGISTER] << 3) | 0x4 /* esp */;
	}
#endif
	if (saveds > 2)
		PUSH_REG(reg_map[SLJIT_SAVED_REG3]);
	if (saveds > 1)
		PUSH_REG(reg_map[SLJIT_SAVED_REG2]);
	if (saveds > 0)
		PUSH_REG(reg_map[SLJIT_SAVED_REG1]);

#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	if (args > 0) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG1] << 3) | reg_map[SLJIT_SCRATCH_REG3];
	}
	if (args > 1) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG2] << 3) | reg_map[SLJIT_SCRATCH_REG2];
	}
	if (args > 2) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG3] << 3) | 0x4 /* esp */;
		*inst++ = 0x24;
		*inst++ = sizeof(sljit_sw) * (3 + 2); /* saveds >= 3 as well. */
	}
#else
	if (args > 0) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG1] << 3) | reg_map[TMP_REGISTER];
		*inst++ = sizeof(sljit_sw) * 2;
	}
	if (args > 1) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG2] << 3) | reg_map[TMP_REGISTER];
		*inst++ = sizeof(sljit_sw) * 3;
	}
	if (args > 2) {
		*inst++ = MOV_r_rm;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG3] << 3) | reg_map[TMP_REGISTER];
		*inst++ = sizeof(sljit_sw) * 4;
	}
#endif

#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	locals_offset = 2 * sizeof(sljit_uw);
#else
	SLJIT_COMPILE_ASSERT(FIXED_LOCALS_OFFSET >= 2 * sizeof(sljit_uw), require_at_least_two_words);
	locals_offset = FIXED_LOCALS_OFFSET;
#endif
	compiler->scratches_start = locals_offset;
	if (scratches > 3)
		locals_offset += (scratches - 3) * sizeof(sljit_uw);
	compiler->saveds_start = locals_offset;
	if (saveds > 3)
		locals_offset += (saveds - 3) * sizeof(sljit_uw);
	compiler->locals_offset = locals_offset;
#if defined(__APPLE__)
	saveds = (2 + (saveds <= 3 ? saveds : 3)) * sizeof(sljit_uw);
	local_size = ((locals_offset + saveds + local_size + 15) & ~15) - saveds;
#else
	local_size = locals_offset + ((local_size + sizeof(sljit_uw) - 1) & ~(sizeof(sljit_uw) - 1));
#endif

	compiler->local_size = local_size;
#ifdef _WIN32
	if (local_size > 1024) {
#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
		FAIL_IF(emit_do_imm(compiler, MOV_r_i32 + reg_map[SLJIT_SCRATCH_REG1], local_size));
#else
		local_size -= FIXED_LOCALS_OFFSET;
		FAIL_IF(emit_do_imm(compiler, MOV_r_i32 + reg_map[SLJIT_SCRATCH_REG1], local_size));
		FAIL_IF(emit_non_cum_binary(compiler, SUB_r_rm, SUB_rm_r, SUB, SUB_EAX_i32,
			SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, FIXED_LOCALS_OFFSET));
#endif
		FAIL_IF(sljit_emit_ijump(compiler, SLJIT_CALL1, SLJIT_IMM, SLJIT_FUNC_OFFSET(sljit_grow_stack)));
	}
#endif

	SLJIT_ASSERT(local_size > 0);
	return emit_non_cum_binary(compiler, SUB_r_rm, SUB_rm_r, SUB, SUB_EAX_i32,
		SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, local_size);
}

SLJIT_API_FUNC_ATTRIBUTE void sljit_set_context(struct sljit_compiler *compiler, sljit_si args, sljit_si scratches, sljit_si saveds, sljit_si local_size)
{
	sljit_si locals_offset;

	CHECK_ERROR_VOID();
	check_sljit_set_context(compiler, args, scratches, saveds, local_size);

	compiler->scratches = scratches;
	compiler->saveds = saveds;
	compiler->args = args;
#if (defined SLJIT_DEBUG && SLJIT_DEBUG)
	compiler->logical_local_size = local_size;
#endif

#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	locals_offset = 2 * sizeof(sljit_uw);
#else
	locals_offset = FIXED_LOCALS_OFFSET;
#endif
	compiler->scratches_start = locals_offset;
	if (scratches > 3)
		locals_offset += (scratches - 3) * sizeof(sljit_uw);
	compiler->saveds_start = locals_offset;
	if (saveds > 3)
		locals_offset += (saveds - 3) * sizeof(sljit_uw);
	compiler->locals_offset = locals_offset;
#if defined(__APPLE__)
	saveds = (2 + (saveds <= 3 ? saveds : 3)) * sizeof(sljit_uw);
	compiler->local_size = ((locals_offset + saveds + local_size + 15) & ~15) - saveds;
#else
	compiler->local_size = locals_offset + ((local_size + sizeof(sljit_uw) - 1) & ~(sizeof(sljit_uw) - 1));
#endif
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_return(struct sljit_compiler *compiler, sljit_si op, sljit_si src, sljit_sw srcw)
{
	sljit_si size;
	sljit_ub *inst;

	CHECK_ERROR();
	check_sljit_emit_return(compiler, op, src, srcw);
	SLJIT_ASSERT(compiler->args >= 0);

	compiler->flags_saved = 0;
	FAIL_IF(emit_mov_before_return(compiler, op, src, srcw));

	SLJIT_ASSERT(compiler->local_size > 0);
	FAIL_IF(emit_cum_binary(compiler, ADD_r_rm, ADD_rm_r, ADD, ADD_EAX_i32,
		SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, compiler->local_size));

	size = 2 + (compiler->saveds <= 3 ? compiler->saveds : 3);
#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	if (compiler->args > 2)
		size += 2;
#else
	if (compiler->args > 0)
		size += 2;
#endif
	inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
	FAIL_IF(!inst);

	INC_SIZE(size);

	if (compiler->saveds > 0)
		POP_REG(reg_map[SLJIT_SAVED_REG1]);
	if (compiler->saveds > 1)
		POP_REG(reg_map[SLJIT_SAVED_REG2]);
	if (compiler->saveds > 2)
		POP_REG(reg_map[SLJIT_SAVED_REG3]);
	POP_REG(reg_map[TMP_REGISTER]);
#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	if (compiler->args > 2)
		RET_I16(sizeof(sljit_sw));
	else
		RET();
#else
	RET();
#endif

	return SLJIT_SUCCESS;
}

/* --------------------------------------------------------------------- */
/*  Operators                                                            */
/* --------------------------------------------------------------------- */

/* Size contains the flags as well. */
static sljit_ub* emit_x86_instruction(struct sljit_compiler *compiler, sljit_si size,
	/* The register or immediate operand. */
	sljit_si a, sljit_sw imma,
	/* The general operand (not immediate). */
	sljit_si b, sljit_sw immb)
{
	sljit_ub *inst;
	sljit_ub *buf_ptr;
	sljit_si flags = size & ~0xf;
	sljit_si inst_size;

	/* Both cannot be switched on. */
	SLJIT_ASSERT((flags & (EX86_BIN_INS | EX86_SHIFT_INS)) != (EX86_BIN_INS | EX86_SHIFT_INS));
	/* Size flags not allowed for typed instructions. */
	SLJIT_ASSERT(!(flags & (EX86_BIN_INS | EX86_SHIFT_INS)) || (flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) == 0);
	/* Both size flags cannot be switched on. */
	SLJIT_ASSERT((flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) != (EX86_BYTE_ARG | EX86_HALF_ARG));
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
	/* SSE2 and immediate is not possible. */
	SLJIT_ASSERT(!(a & SLJIT_IMM) || !(flags & EX86_SSE2));
	SLJIT_ASSERT((flags & (EX86_PREF_F2 | EX86_PREF_F3)) != (EX86_PREF_F2 | EX86_PREF_F3)
		&& (flags & (EX86_PREF_F2 | EX86_PREF_66)) != (EX86_PREF_F2 | EX86_PREF_66)
		&& (flags & (EX86_PREF_F3 | EX86_PREF_66)) != (EX86_PREF_F3 | EX86_PREF_66));
#endif

	size &= 0xf;
	inst_size = size;

#if (defined SLJIT_SSE2 && SLJIT_SSE2)
	if (flags & (EX86_PREF_F2 | EX86_PREF_F3))
		inst_size++;
#endif
	if (flags & EX86_PREF_66)
		inst_size++;

	/* Calculate size of b. */
	inst_size += 1; /* mod r/m byte. */
	if (b & SLJIT_MEM) {
		if ((b & 0x0f) == SLJIT_UNUSED)
			inst_size += sizeof(sljit_sw);
		else if (immb != 0 && !(b & 0xf0)) {
			/* Immediate operand. */
			if (immb <= 127 && immb >= -128)
				inst_size += sizeof(sljit_sb);
			else
				inst_size += sizeof(sljit_sw);
		}

		if ((b & 0xf) == SLJIT_LOCALS_REG && !(b & 0xf0))
			b |= SLJIT_LOCALS_REG << 4;

		if ((b & 0xf0) != SLJIT_UNUSED)
			inst_size += 1; /* SIB byte. */
	}

	/* Calculate size of a. */
	if (a & SLJIT_IMM) {
		if (flags & EX86_BIN_INS) {
			if (imma <= 127 && imma >= -128) {
				inst_size += 1;
				flags |= EX86_BYTE_ARG;
			} else
				inst_size += 4;
		}
		else if (flags & EX86_SHIFT_INS) {
			imma &= 0x1f;
			if (imma != 1) {
				inst_size ++;
				flags |= EX86_BYTE_ARG;
			}
		} else if (flags & EX86_BYTE_ARG)
			inst_size++;
		else if (flags & EX86_HALF_ARG)
			inst_size += sizeof(short);
		else
			inst_size += sizeof(sljit_sw);
	}
	else
		SLJIT_ASSERT(!(flags & EX86_SHIFT_INS) || a == SLJIT_PREF_SHIFT_REG);

	inst = (sljit_ub*)ensure_buf(compiler, 1 + inst_size);
	PTR_FAIL_IF(!inst);

	/* Encoding the byte. */
	INC_SIZE(inst_size);
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
	if (flags & EX86_PREF_F2)
		*inst++ = 0xf2;
	if (flags & EX86_PREF_F3)
		*inst++ = 0xf3;
#endif
	if (flags & EX86_PREF_66)
		*inst++ = 0x66;

	buf_ptr = inst + size;

	/* Encode mod/rm byte. */
	if (!(flags & EX86_SHIFT_INS)) {
		if ((flags & EX86_BIN_INS) && (a & SLJIT_IMM))
			*inst = (flags & EX86_BYTE_ARG) ? GROUP_BINARY_83 : GROUP_BINARY_81;

		if ((a & SLJIT_IMM) || (a == 0))
			*buf_ptr = 0;
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
		else if (!(flags & EX86_SSE2))
			*buf_ptr = reg_map[a] << 3;
		else
			*buf_ptr = a << 3;
#else
		else
			*buf_ptr = reg_map[a] << 3;
#endif
	}
	else {
		if (a & SLJIT_IMM) {
			if (imma == 1)
				*inst = GROUP_SHIFT_1;
			else
				*inst = GROUP_SHIFT_N;
		} else
			*inst = GROUP_SHIFT_CL;
		*buf_ptr = 0;
	}

	if (!(b & SLJIT_MEM))
#if (defined SLJIT_SSE2 && SLJIT_SSE2)
		*buf_ptr++ |= MOD_REG + ((!(flags & EX86_SSE2)) ? reg_map[b] : b);
#else
		*buf_ptr++ |= MOD_REG + reg_map[b];
#endif
	else if ((b & 0x0f) != SLJIT_UNUSED) {
		if ((b & 0xf0) == SLJIT_UNUSED || (b & 0xf0) == (SLJIT_LOCALS_REG << 4)) {
			if (immb != 0) {
				if (immb <= 127 && immb >= -128)
					*buf_ptr |= 0x40;
				else
					*buf_ptr |= 0x80;
			}

			if ((b & 0xf0) == SLJIT_UNUSED)
				*buf_ptr++ |= reg_map[b & 0x0f];
			else {
				*buf_ptr++ |= 0x04;
				*buf_ptr++ = reg_map[b & 0x0f] | (reg_map[(b >> 4) & 0x0f] << 3);
			}

			if (immb != 0) {
				if (immb <= 127 && immb >= -128)
					*buf_ptr++ = immb; /* 8 bit displacement. */
				else {
					*(sljit_sw*)buf_ptr = immb; /* 32 bit displacement. */
					buf_ptr += sizeof(sljit_sw);
				}
			}
		}
		else {
			*buf_ptr++ |= 0x04;
			*buf_ptr++ = reg_map[b & 0x0f] | (reg_map[(b >> 4) & 0x0f] << 3) | (immb << 6);
		}
	}
	else {
		*buf_ptr++ |= 0x05;
		*(sljit_sw*)buf_ptr = immb; /* 32 bit displacement. */
		buf_ptr += sizeof(sljit_sw);
	}

	if (a & SLJIT_IMM) {
		if (flags & EX86_BYTE_ARG)
			*buf_ptr = imma;
		else if (flags & EX86_HALF_ARG)
			*(short*)buf_ptr = imma;
		else if (!(flags & EX86_SHIFT_INS))
			*(sljit_sw*)buf_ptr = imma;
	}

	return !(flags & EX86_SHIFT_INS) ? inst : (inst + 1);
}

/* --------------------------------------------------------------------- */
/*  Call / return instructions                                           */
/* --------------------------------------------------------------------- */

static SLJIT_INLINE sljit_si call_with_args(struct sljit_compiler *compiler, sljit_si type)
{
	sljit_ub *inst;

#if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
	inst = (sljit_ub*)ensure_buf(compiler, type >= SLJIT_CALL3 ? 1 + 2 + 1 : 1 + 2);
	FAIL_IF(!inst);
	INC_SIZE(type >= SLJIT_CALL3 ? 2 + 1 : 2);

	if (type >= SLJIT_CALL3)
		PUSH_REG(reg_map[SLJIT_SCRATCH_REG3]);
	*inst++ = MOV_r_rm;
	*inst++ = MOD_REG | (reg_map[SLJIT_SCRATCH_REG3] << 3) | reg_map[SLJIT_SCRATCH_REG1];
#else
	inst = (sljit_ub*)ensure_buf(compiler, 1 + 4 * (type - SLJIT_CALL0));
	FAIL_IF(!inst);
	INC_SIZE(4 * (type - SLJIT_CALL0));

	*inst++ = MOV_rm_r;
	*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG1] << 3) | 0x4 /* SIB */;
	*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
	*inst++ = 0;
	if (type >= SLJIT_CALL2) {
		*inst++ = MOV_rm_r;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG2] << 3) | 0x4 /* SIB */;
		*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
		*inst++ = sizeof(sljit_sw);
	}
	if (type >= SLJIT_CALL3) {
		*inst++ = MOV_rm_r;
		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG3] << 3) | 0x4 /* SIB */;
		*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
		*inst++ = 2 * sizeof(sljit_sw);
	}
#endif
	return SLJIT_SUCCESS;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_enter(struct sljit_compiler *compiler, sljit_si dst, sljit_sw dstw)
{
	sljit_ub *inst;

	CHECK_ERROR();
	check_sljit_emit_fast_enter(compiler, dst, dstw);
	ADJUST_LOCAL_OFFSET(dst, dstw);

	CHECK_EXTRA_REGS(dst, dstw, (void)0);

	/* For UNUSED dst. Uncommon, but possible. */
	if (dst == SLJIT_UNUSED)
		dst = TMP_REGISTER;

	if (dst <= TMP_REGISTER) {
		/* Unused dest is possible here. */
		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
		FAIL_IF(!inst);

		INC_SIZE(1);
		POP_REG(reg_map[dst]);
		return SLJIT_SUCCESS;
	}

	/* Memory. */
	inst = emit_x86_instruction(compiler, 1, 0, 0, dst, dstw);
	FAIL_IF(!inst);
	*inst++ = POP_rm;
	return SLJIT_SUCCESS;
}

SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_return(struct sljit_compiler *compiler, sljit_si src, sljit_sw srcw)
{
	sljit_ub *inst;

	CHECK_ERROR();
	check_sljit_emit_fast_return(compiler, src, srcw);
	ADJUST_LOCAL_OFFSET(src, srcw);

	CHECK_EXTRA_REGS(src, srcw, (void)0);

	if (src <= TMP_REGISTER) {
		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + 1);
		FAIL_IF(!inst);

		INC_SIZE(1 + 1);
		PUSH_REG(reg_map[src]);
	}
	else if (src & SLJIT_MEM) {
		inst = emit_x86_instruction(compiler, 1, 0, 0, src, srcw);
		FAIL_IF(!inst);
		*inst++ = GROUP_FF;
		*inst |= PUSH_rm;

		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
		FAIL_IF(!inst);
		INC_SIZE(1);
	}
	else {
		/* SLJIT_IMM. */
		inst = (sljit_ub*)ensure_buf(compiler, 1 + 5 + 1);
		FAIL_IF(!inst);

		INC_SIZE(5 + 1);
		*inst++ = PUSH_i32;
		*(sljit_sw*)inst = srcw;
		inst += sizeof(sljit_sw);
	}

	RET();
	return SLJIT_SUCCESS;
}