xref: /netbsd-src/sys/external/bsd/sljit/dist/sljit_src/sljitNativeX86_32.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /*	$NetBSD: sljitNativeX86_32.c,v 1.4 2014/06/17 19:33:20 alnsn Exp $	*/
2 
3 /*
4  *    Stack-less Just-In-Time compiler
5  *
6  *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without modification, are
9  * permitted provided that the following conditions are met:
10  *
11  *   1. Redistributions of source code must retain the above copyright notice, this list of
12  *      conditions and the following disclaimer.
13  *
14  *   2. Redistributions in binary form must reproduce the above copyright notice, this list
15  *      of conditions and the following disclaimer in the documentation and/or other materials
16  *      provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
21  * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
23  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
24  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
26  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /* x86 32-bit arch dependent functions. */
30 
31 static sljit_si emit_do_imm(struct sljit_compiler *compiler, sljit_ub opcode, sljit_sw imm)
32 {
33 	sljit_ub *inst;
34 
35 	inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + sizeof(sljit_sw));
36 	FAIL_IF(!inst);
37 	INC_SIZE(1 + sizeof(sljit_sw));
38 	*inst++ = opcode;
39 	*(sljit_sw*)inst = imm;
40 	return SLJIT_SUCCESS;
41 }
42 
43 static sljit_ub* generate_far_jump_code(struct sljit_jump *jump, sljit_ub *code_ptr, sljit_si type)
44 {
45 	if (type == SLJIT_JUMP) {
46 		*code_ptr++ = JMP_i32;
47 		jump->addr++;
48 	}
49 	else if (type >= SLJIT_FAST_CALL) {
50 		*code_ptr++ = CALL_i32;
51 		jump->addr++;
52 	}
53 	else {
54 		*code_ptr++ = GROUP_0F;
55 		*code_ptr++ = get_jump_code(type);
56 		jump->addr += 2;
57 	}
58 
59 	if (jump->flags & JUMP_LABEL)
60 		jump->flags |= PATCH_MW;
61 	else
62 		*(sljit_sw*)code_ptr = jump->u.target - (jump->addr + 4);
63 	code_ptr += 4;
64 
65 	return code_ptr;
66 }
67 
68 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)
69 {
70 	sljit_si size;
71 	sljit_si locals_offset;
72 	sljit_ub *inst;
73 
74 	CHECK_ERROR();
75 	check_sljit_emit_enter(compiler, args, scratches, saveds, local_size);
76 
77 	compiler->scratches = scratches;
78 	compiler->saveds = saveds;
79 	compiler->args = args;
80 	compiler->flags_saved = 0;
81 #if (defined SLJIT_DEBUG && SLJIT_DEBUG)
82 	compiler->logical_local_size = local_size;
83 #endif
84 
85 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
86 	size = 1 + (saveds <= 3 ? saveds : 3) + (args > 0 ? (args * 2) : 0) + (args > 2 ? 2 : 0);
87 #else
88 	size = 1 + (saveds <= 3 ? saveds : 3) + (args > 0 ? (2 + args * 3) : 0);
89 #endif
90 	inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
91 	FAIL_IF(!inst);
92 
93 	INC_SIZE(size);
94 	PUSH_REG(reg_map[TMP_REG1]);
95 #if !(defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
96 	if (args > 0) {
97 		*inst++ = MOV_r_rm;
98 		*inst++ = MOD_REG | (reg_map[TMP_REG1] << 3) | 0x4 /* esp */;
99 	}
100 #endif
101 	if (saveds > 2)
102 		PUSH_REG(reg_map[SLJIT_SAVED_REG3]);
103 	if (saveds > 1)
104 		PUSH_REG(reg_map[SLJIT_SAVED_REG2]);
105 	if (saveds > 0)
106 		PUSH_REG(reg_map[SLJIT_SAVED_REG1]);
107 
108 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
109 	if (args > 0) {
110 		*inst++ = MOV_r_rm;
111 		*inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG1] << 3) | reg_map[SLJIT_SCRATCH_REG3];
112 	}
113 	if (args > 1) {
114 		*inst++ = MOV_r_rm;
115 		*inst++ = MOD_REG | (reg_map[SLJIT_SAVED_REG2] << 3) | reg_map[SLJIT_SCRATCH_REG2];
116 	}
117 	if (args > 2) {
118 		*inst++ = MOV_r_rm;
119 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG3] << 3) | 0x4 /* esp */;
120 		*inst++ = 0x24;
121 		*inst++ = sizeof(sljit_sw) * (3 + 2); /* saveds >= 3 as well. */
122 	}
123 #else
124 	if (args > 0) {
125 		*inst++ = MOV_r_rm;
126 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG1] << 3) | reg_map[TMP_REG1];
127 		*inst++ = sizeof(sljit_sw) * 2;
128 	}
129 	if (args > 1) {
130 		*inst++ = MOV_r_rm;
131 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG2] << 3) | reg_map[TMP_REG1];
132 		*inst++ = sizeof(sljit_sw) * 3;
133 	}
134 	if (args > 2) {
135 		*inst++ = MOV_r_rm;
136 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SAVED_REG3] << 3) | reg_map[TMP_REG1];
137 		*inst++ = sizeof(sljit_sw) * 4;
138 	}
139 #endif
140 
141 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
142 	locals_offset = 2 * sizeof(sljit_uw);
143 #else
144 	SLJIT_COMPILE_ASSERT(FIXED_LOCALS_OFFSET >= 2 * sizeof(sljit_uw), require_at_least_two_words);
145 	locals_offset = FIXED_LOCALS_OFFSET;
146 #endif
147 	compiler->scratches_start = locals_offset;
148 	if (scratches > 3)
149 		locals_offset += (scratches - 3) * sizeof(sljit_uw);
150 	compiler->saveds_start = locals_offset;
151 	if (saveds > 3)
152 		locals_offset += (saveds - 3) * sizeof(sljit_uw);
153 	compiler->locals_offset = locals_offset;
154 #if defined(__APPLE__)
155 	saveds = (2 + (saveds <= 3 ? saveds : 3)) * sizeof(sljit_uw);
156 	local_size = ((locals_offset + saveds + local_size + 15) & ~15) - saveds;
157 #else
158 	local_size = locals_offset + ((local_size + sizeof(sljit_uw) - 1) & ~(sizeof(sljit_uw) - 1));
159 #endif
160 
161 	compiler->local_size = local_size;
162 #ifdef _WIN32
163 	if (local_size > 1024) {
164 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
165 		FAIL_IF(emit_do_imm(compiler, MOV_r_i32 + reg_map[SLJIT_SCRATCH_REG1], local_size));
166 #else
167 		local_size -= FIXED_LOCALS_OFFSET;
168 		FAIL_IF(emit_do_imm(compiler, MOV_r_i32 + reg_map[SLJIT_SCRATCH_REG1], local_size));
169 		FAIL_IF(emit_non_cum_binary(compiler, SUB_r_rm, SUB_rm_r, SUB, SUB_EAX_i32,
170 			SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, FIXED_LOCALS_OFFSET));
171 #endif
172 		FAIL_IF(sljit_emit_ijump(compiler, SLJIT_CALL1, SLJIT_IMM, SLJIT_FUNC_OFFSET(sljit_grow_stack)));
173 	}
174 #endif
175 
176 	SLJIT_ASSERT(local_size > 0);
177 	return emit_non_cum_binary(compiler, SUB_r_rm, SUB_rm_r, SUB, SUB_EAX_i32,
178 		SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, local_size);
179 }
180 
181 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)
182 {
183 	sljit_si locals_offset;
184 
185 	CHECK_ERROR_VOID();
186 	check_sljit_set_context(compiler, args, scratches, saveds, local_size);
187 
188 	compiler->scratches = scratches;
189 	compiler->saveds = saveds;
190 	compiler->args = args;
191 #if (defined SLJIT_DEBUG && SLJIT_DEBUG)
192 	compiler->logical_local_size = local_size;
193 #endif
194 
195 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
196 	locals_offset = 2 * sizeof(sljit_uw);
197 #else
198 	locals_offset = FIXED_LOCALS_OFFSET;
199 #endif
200 	compiler->scratches_start = locals_offset;
201 	if (scratches > 3)
202 		locals_offset += (scratches - 3) * sizeof(sljit_uw);
203 	compiler->saveds_start = locals_offset;
204 	if (saveds > 3)
205 		locals_offset += (saveds - 3) * sizeof(sljit_uw);
206 	compiler->locals_offset = locals_offset;
207 #if defined(__APPLE__)
208 	saveds = (2 + (saveds <= 3 ? saveds : 3)) * sizeof(sljit_uw);
209 	compiler->local_size = ((locals_offset + saveds + local_size + 15) & ~15) - saveds;
210 #else
211 	compiler->local_size = locals_offset + ((local_size + sizeof(sljit_uw) - 1) & ~(sizeof(sljit_uw) - 1));
212 #endif
213 }
214 
215 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_return(struct sljit_compiler *compiler, sljit_si op, sljit_si src, sljit_sw srcw)
216 {
217 	sljit_si size;
218 	sljit_ub *inst;
219 
220 	CHECK_ERROR();
221 	check_sljit_emit_return(compiler, op, src, srcw);
222 	SLJIT_ASSERT(compiler->args >= 0);
223 
224 	compiler->flags_saved = 0;
225 	FAIL_IF(emit_mov_before_return(compiler, op, src, srcw));
226 
227 	SLJIT_ASSERT(compiler->local_size > 0);
228 	FAIL_IF(emit_cum_binary(compiler, ADD_r_rm, ADD_rm_r, ADD, ADD_EAX_i32,
229 		SLJIT_LOCALS_REG, 0, SLJIT_LOCALS_REG, 0, SLJIT_IMM, compiler->local_size));
230 
231 	size = 2 + (compiler->saveds <= 3 ? compiler->saveds : 3);
232 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
233 	if (compiler->args > 2)
234 		size += 2;
235 #else
236 	if (compiler->args > 0)
237 		size += 2;
238 #endif
239 	inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
240 	FAIL_IF(!inst);
241 
242 	INC_SIZE(size);
243 
244 	if (compiler->saveds > 0)
245 		POP_REG(reg_map[SLJIT_SAVED_REG1]);
246 	if (compiler->saveds > 1)
247 		POP_REG(reg_map[SLJIT_SAVED_REG2]);
248 	if (compiler->saveds > 2)
249 		POP_REG(reg_map[SLJIT_SAVED_REG3]);
250 	POP_REG(reg_map[TMP_REG1]);
251 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
252 	if (compiler->args > 2)
253 		RET_I16(sizeof(sljit_sw));
254 	else
255 		RET();
256 #else
257 	RET();
258 #endif
259 
260 	return SLJIT_SUCCESS;
261 }
262 
263 /* --------------------------------------------------------------------- */
264 /*  Operators                                                            */
265 /* --------------------------------------------------------------------- */
266 
267 /* Size contains the flags as well. */
268 static sljit_ub* emit_x86_instruction(struct sljit_compiler *compiler, sljit_si size,
269 	/* The register or immediate operand. */
270 	sljit_si a, sljit_sw imma,
271 	/* The general operand (not immediate). */
272 	sljit_si b, sljit_sw immb)
273 {
274 	sljit_ub *inst;
275 	sljit_ub *buf_ptr;
276 	sljit_si flags = size & ~0xf;
277 	sljit_si inst_size;
278 
279 	/* Both cannot be switched on. */
280 	SLJIT_ASSERT((flags & (EX86_BIN_INS | EX86_SHIFT_INS)) != (EX86_BIN_INS | EX86_SHIFT_INS));
281 	/* Size flags not allowed for typed instructions. */
282 	SLJIT_ASSERT(!(flags & (EX86_BIN_INS | EX86_SHIFT_INS)) || (flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) == 0);
283 	/* Both size flags cannot be switched on. */
284 	SLJIT_ASSERT((flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) != (EX86_BYTE_ARG | EX86_HALF_ARG));
285 #if (defined SLJIT_SSE2 && SLJIT_SSE2)
286 	/* SSE2 and immediate is not possible. */
287 	SLJIT_ASSERT(!(a & SLJIT_IMM) || !(flags & EX86_SSE2));
288 	SLJIT_ASSERT((flags & (EX86_PREF_F2 | EX86_PREF_F3)) != (EX86_PREF_F2 | EX86_PREF_F3)
289 		&& (flags & (EX86_PREF_F2 | EX86_PREF_66)) != (EX86_PREF_F2 | EX86_PREF_66)
290 		&& (flags & (EX86_PREF_F3 | EX86_PREF_66)) != (EX86_PREF_F3 | EX86_PREF_66));
291 #endif
292 
293 	size &= 0xf;
294 	inst_size = size;
295 
296 #if (defined SLJIT_SSE2 && SLJIT_SSE2)
297 	if (flags & (EX86_PREF_F2 | EX86_PREF_F3))
298 		inst_size++;
299 #endif
300 	if (flags & EX86_PREF_66)
301 		inst_size++;
302 
303 	/* Calculate size of b. */
304 	inst_size += 1; /* mod r/m byte. */
305 	if (b & SLJIT_MEM) {
306 		if ((b & REG_MASK) == SLJIT_UNUSED)
307 			inst_size += sizeof(sljit_sw);
308 		else if (immb != 0 && !(b & OFFS_REG_MASK)) {
309 			/* Immediate operand. */
310 			if (immb <= 127 && immb >= -128)
311 				inst_size += sizeof(sljit_sb);
312 			else
313 				inst_size += sizeof(sljit_sw);
314 		}
315 
316 		if ((b & REG_MASK) == SLJIT_LOCALS_REG && !(b & OFFS_REG_MASK))
317 			b |= TO_OFFS_REG(SLJIT_LOCALS_REG);
318 
319 		if ((b & OFFS_REG_MASK) != SLJIT_UNUSED)
320 			inst_size += 1; /* SIB byte. */
321 	}
322 
323 	/* Calculate size of a. */
324 	if (a & SLJIT_IMM) {
325 		if (flags & EX86_BIN_INS) {
326 			if (imma <= 127 && imma >= -128) {
327 				inst_size += 1;
328 				flags |= EX86_BYTE_ARG;
329 			} else
330 				inst_size += 4;
331 		}
332 		else if (flags & EX86_SHIFT_INS) {
333 			imma &= 0x1f;
334 			if (imma != 1) {
335 				inst_size ++;
336 				flags |= EX86_BYTE_ARG;
337 			}
338 		} else if (flags & EX86_BYTE_ARG)
339 			inst_size++;
340 		else if (flags & EX86_HALF_ARG)
341 			inst_size += sizeof(short);
342 		else
343 			inst_size += sizeof(sljit_sw);
344 	}
345 	else
346 		SLJIT_ASSERT(!(flags & EX86_SHIFT_INS) || a == SLJIT_PREF_SHIFT_REG);
347 
348 	inst = (sljit_ub*)ensure_buf(compiler, 1 + inst_size);
349 	PTR_FAIL_IF(!inst);
350 
351 	/* Encoding the byte. */
352 	INC_SIZE(inst_size);
353 #if (defined SLJIT_SSE2 && SLJIT_SSE2)
354 	if (flags & EX86_PREF_F2)
355 		*inst++ = 0xf2;
356 	if (flags & EX86_PREF_F3)
357 		*inst++ = 0xf3;
358 #endif
359 	if (flags & EX86_PREF_66)
360 		*inst++ = 0x66;
361 
362 	buf_ptr = inst + size;
363 
364 	/* Encode mod/rm byte. */
365 	if (!(flags & EX86_SHIFT_INS)) {
366 		if ((flags & EX86_BIN_INS) && (a & SLJIT_IMM))
367 			*inst = (flags & EX86_BYTE_ARG) ? GROUP_BINARY_83 : GROUP_BINARY_81;
368 
369 		if ((a & SLJIT_IMM) || (a == 0))
370 			*buf_ptr = 0;
371 #if (defined SLJIT_SSE2 && SLJIT_SSE2)
372 		else if (!(flags & EX86_SSE2))
373 			*buf_ptr = reg_map[a] << 3;
374 		else
375 			*buf_ptr = a << 3;
376 #else
377 		else
378 			*buf_ptr = reg_map[a] << 3;
379 #endif
380 	}
381 	else {
382 		if (a & SLJIT_IMM) {
383 			if (imma == 1)
384 				*inst = GROUP_SHIFT_1;
385 			else
386 				*inst = GROUP_SHIFT_N;
387 		} else
388 			*inst = GROUP_SHIFT_CL;
389 		*buf_ptr = 0;
390 	}
391 
392 	if (!(b & SLJIT_MEM))
393 #if (defined SLJIT_SSE2 && SLJIT_SSE2)
394 		*buf_ptr++ |= MOD_REG + ((!(flags & EX86_SSE2)) ? reg_map[b] : b);
395 #else
396 		*buf_ptr++ |= MOD_REG + reg_map[b];
397 #endif
398 	else if ((b & REG_MASK) != SLJIT_UNUSED) {
399 		if ((b & OFFS_REG_MASK) == SLJIT_UNUSED || (b & OFFS_REG_MASK) == TO_OFFS_REG(SLJIT_LOCALS_REG)) {
400 			if (immb != 0) {
401 				if (immb <= 127 && immb >= -128)
402 					*buf_ptr |= 0x40;
403 				else
404 					*buf_ptr |= 0x80;
405 			}
406 
407 			if ((b & OFFS_REG_MASK) == SLJIT_UNUSED)
408 				*buf_ptr++ |= reg_map[b & REG_MASK];
409 			else {
410 				*buf_ptr++ |= 0x04;
411 				*buf_ptr++ = reg_map[b & REG_MASK] | (reg_map[OFFS_REG(b)] << 3);
412 			}
413 
414 			if (immb != 0) {
415 				if (immb <= 127 && immb >= -128)
416 					*buf_ptr++ = immb; /* 8 bit displacement. */
417 				else {
418 					*(sljit_sw*)buf_ptr = immb; /* 32 bit displacement. */
419 					buf_ptr += sizeof(sljit_sw);
420 				}
421 			}
422 		}
423 		else {
424 			*buf_ptr++ |= 0x04;
425 			*buf_ptr++ = reg_map[b & REG_MASK] | (reg_map[OFFS_REG(b)] << 3) | (immb << 6);
426 		}
427 	}
428 	else {
429 		*buf_ptr++ |= 0x05;
430 		*(sljit_sw*)buf_ptr = immb; /* 32 bit displacement. */
431 		buf_ptr += sizeof(sljit_sw);
432 	}
433 
434 	if (a & SLJIT_IMM) {
435 		if (flags & EX86_BYTE_ARG)
436 			*buf_ptr = imma;
437 		else if (flags & EX86_HALF_ARG)
438 			*(short*)buf_ptr = imma;
439 		else if (!(flags & EX86_SHIFT_INS))
440 			*(sljit_sw*)buf_ptr = imma;
441 	}
442 
443 	return !(flags & EX86_SHIFT_INS) ? inst : (inst + 1);
444 }
445 
446 /* --------------------------------------------------------------------- */
447 /*  Call / return instructions                                           */
448 /* --------------------------------------------------------------------- */
449 
450 static SLJIT_INLINE sljit_si call_with_args(struct sljit_compiler *compiler, sljit_si type)
451 {
452 	sljit_ub *inst;
453 
454 #if (defined SLJIT_X86_32_FASTCALL && SLJIT_X86_32_FASTCALL)
455 	inst = (sljit_ub*)ensure_buf(compiler, type >= SLJIT_CALL3 ? 1 + 2 + 1 : 1 + 2);
456 	FAIL_IF(!inst);
457 	INC_SIZE(type >= SLJIT_CALL3 ? 2 + 1 : 2);
458 
459 	if (type >= SLJIT_CALL3)
460 		PUSH_REG(reg_map[SLJIT_SCRATCH_REG3]);
461 	*inst++ = MOV_r_rm;
462 	*inst++ = MOD_REG | (reg_map[SLJIT_SCRATCH_REG3] << 3) | reg_map[SLJIT_SCRATCH_REG1];
463 #else
464 	inst = (sljit_ub*)ensure_buf(compiler, 1 + 4 * (type - SLJIT_CALL0));
465 	FAIL_IF(!inst);
466 	INC_SIZE(4 * (type - SLJIT_CALL0));
467 
468 	*inst++ = MOV_rm_r;
469 	*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG1] << 3) | 0x4 /* SIB */;
470 	*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
471 	*inst++ = 0;
472 	if (type >= SLJIT_CALL2) {
473 		*inst++ = MOV_rm_r;
474 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG2] << 3) | 0x4 /* SIB */;
475 		*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
476 		*inst++ = sizeof(sljit_sw);
477 	}
478 	if (type >= SLJIT_CALL3) {
479 		*inst++ = MOV_rm_r;
480 		*inst++ = MOD_DISP8 | (reg_map[SLJIT_SCRATCH_REG3] << 3) | 0x4 /* SIB */;
481 		*inst++ = (0x4 /* none*/ << 3) | reg_map[SLJIT_LOCALS_REG];
482 		*inst++ = 2 * sizeof(sljit_sw);
483 	}
484 #endif
485 	return SLJIT_SUCCESS;
486 }
487 
488 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_enter(struct sljit_compiler *compiler, sljit_si dst, sljit_sw dstw)
489 {
490 	sljit_ub *inst;
491 
492 	CHECK_ERROR();
493 	check_sljit_emit_fast_enter(compiler, dst, dstw);
494 	ADJUST_LOCAL_OFFSET(dst, dstw);
495 
496 	CHECK_EXTRA_REGS(dst, dstw, (void)0);
497 
498 	/* For UNUSED dst. Uncommon, but possible. */
499 	if (dst == SLJIT_UNUSED)
500 		dst = TMP_REG1;
501 
502 	if (FAST_IS_REG(dst)) {
503 		/* Unused dest is possible here. */
504 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
505 		FAIL_IF(!inst);
506 
507 		INC_SIZE(1);
508 		POP_REG(reg_map[dst]);
509 		return SLJIT_SUCCESS;
510 	}
511 
512 	/* Memory. */
513 	inst = emit_x86_instruction(compiler, 1, 0, 0, dst, dstw);
514 	FAIL_IF(!inst);
515 	*inst++ = POP_rm;
516 	return SLJIT_SUCCESS;
517 }
518 
519 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_return(struct sljit_compiler *compiler, sljit_si src, sljit_sw srcw)
520 {
521 	sljit_ub *inst;
522 
523 	CHECK_ERROR();
524 	check_sljit_emit_fast_return(compiler, src, srcw);
525 	ADJUST_LOCAL_OFFSET(src, srcw);
526 
527 	CHECK_EXTRA_REGS(src, srcw, (void)0);
528 
529 	if (FAST_IS_REG(src)) {
530 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + 1);
531 		FAIL_IF(!inst);
532 
533 		INC_SIZE(1 + 1);
534 		PUSH_REG(reg_map[src]);
535 	}
536 	else if (src & SLJIT_MEM) {
537 		inst = emit_x86_instruction(compiler, 1, 0, 0, src, srcw);
538 		FAIL_IF(!inst);
539 		*inst++ = GROUP_FF;
540 		*inst |= PUSH_rm;
541 
542 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
543 		FAIL_IF(!inst);
544 		INC_SIZE(1);
545 	}
546 	else {
547 		/* SLJIT_IMM. */
548 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 5 + 1);
549 		FAIL_IF(!inst);
550 
551 		INC_SIZE(5 + 1);
552 		*inst++ = PUSH_i32;
553 		*(sljit_sw*)inst = srcw;
554 		inst += sizeof(sljit_sw);
555 	}
556 
557 	RET();
558 	return SLJIT_SUCCESS;
559 }
560