1 /*
2  *    Stack-less Just-In-Time compiler
3  *
4  *    Copyright 2009-2012 Zoltan Herczeg (hzmester@freemail.hu). All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without modification, are
7  * permitted provided that the following conditions are met:
8  *
9  *   1. Redistributions of source code must retain the above copyright notice, this list of
10  *      conditions and the following disclaimer.
11  *
12  *   2. Redistributions in binary form must reproduce the above copyright notice, this list
13  *      of conditions and the following disclaimer in the documentation and/or other materials
14  *      provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) AND CONTRIBUTORS ``AS IS'' AND ANY
17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
19  * SHALL THE COPYRIGHT HOLDER(S) OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
21  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 /* x86 64-bit arch dependent functions. */
28 
emit_load_imm64(struct sljit_compiler * compiler,sljit_si reg,sljit_sw imm)29 static sljit_si emit_load_imm64(struct sljit_compiler *compiler, sljit_si reg, sljit_sw imm)
30 {
31 	sljit_ub *inst;
32 
33 	inst = (sljit_ub*)ensure_buf(compiler, 1 + 2 + sizeof(sljit_sw));
34 	FAIL_IF(!inst);
35 	INC_SIZE(2 + sizeof(sljit_sw));
36 	*inst++ = REX_W | ((reg_map[reg] <= 7) ? 0 : REX_B);
37 	*inst++ = MOV_r_i32 + (reg_map[reg] & 0x7);
38 	*(sljit_sw*)inst = imm;
39 	return SLJIT_SUCCESS;
40 }
41 
generate_far_jump_code(struct sljit_jump * jump,sljit_ub * code_ptr,sljit_si type)42 static sljit_ub* generate_far_jump_code(struct sljit_jump *jump, sljit_ub *code_ptr, sljit_si type)
43 {
44 	if (type < SLJIT_JUMP) {
45 		/* Invert type. */
46 		*code_ptr++ = get_jump_code(type ^ 0x1) - 0x10;
47 		*code_ptr++ = 10 + 3;
48 	}
49 
50 	SLJIT_COMPILE_ASSERT(reg_map[TMP_REG3] == 9, tmp3_is_9_first);
51 	*code_ptr++ = REX_W | REX_B;
52 	*code_ptr++ = MOV_r_i32 + 1;
53 	jump->addr = (sljit_uw)code_ptr;
54 
55 	if (jump->flags & JUMP_LABEL)
56 		jump->flags |= PATCH_MD;
57 	else
58 		*(sljit_sw*)code_ptr = jump->u.target;
59 
60 	code_ptr += sizeof(sljit_sw);
61 	*code_ptr++ = REX_B;
62 	*code_ptr++ = GROUP_FF;
63 	*code_ptr++ = (type >= SLJIT_FAST_CALL) ? (MOD_REG | CALL_rm | 1) : (MOD_REG | JMP_rm | 1);
64 
65 	return code_ptr;
66 }
67 
generate_fixed_jump(sljit_ub * code_ptr,sljit_sw addr,sljit_si type)68 static sljit_ub* generate_fixed_jump(sljit_ub *code_ptr, sljit_sw addr, sljit_si type)
69 {
70 	sljit_sw delta = addr - ((sljit_sw)code_ptr + 1 + sizeof(sljit_si));
71 
72 	if (delta <= HALFWORD_MAX && delta >= HALFWORD_MIN) {
73 		*code_ptr++ = (type == 2) ? CALL_i32 : JMP_i32;
74 		*(sljit_sw*)code_ptr = delta;
75 	}
76 	else {
77 		SLJIT_COMPILE_ASSERT(reg_map[TMP_REG3] == 9, tmp3_is_9_second);
78 		*code_ptr++ = REX_W | REX_B;
79 		*code_ptr++ = MOV_r_i32 + 1;
80 		*(sljit_sw*)code_ptr = addr;
81 		code_ptr += sizeof(sljit_sw);
82 		*code_ptr++ = REX_B;
83 		*code_ptr++ = GROUP_FF;
84 		*code_ptr++ = (type == 2) ? (MOD_REG | CALL_rm | 1) : (MOD_REG | JMP_rm | 1);
85 	}
86 
87 	return code_ptr;
88 }
89 
sljit_emit_enter(struct sljit_compiler * compiler,sljit_si options,sljit_si args,sljit_si scratches,sljit_si saveds,sljit_si fscratches,sljit_si fsaveds,sljit_si local_size)90 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_enter(struct sljit_compiler *compiler,
91 	sljit_si options, sljit_si args, sljit_si scratches, sljit_si saveds,
92 	sljit_si fscratches, sljit_si fsaveds, sljit_si local_size)
93 {
94 	sljit_si i, tmp, size, saved_register_size;
95 	sljit_ub *inst;
96 
97 	CHECK_ERROR();
98 	check_sljit_emit_enter(compiler, options, args, scratches, saveds, fscratches, fsaveds, local_size);
99 
100 	compiler->options = options;
101 	compiler->scratches = scratches;
102 	compiler->saveds = saveds;
103 	compiler->fscratches = fscratches;
104 	compiler->fsaveds = fsaveds;
105 	compiler->flags_saved = 0;
106 #if (defined SLJIT_DEBUG && SLJIT_DEBUG)
107 	compiler->logical_local_size = local_size;
108 #endif
109 
110 	/* Including the return address saved by the call instruction. */
111 	saved_register_size = GET_SAVED_REGISTERS_SIZE(scratches, saveds, 1);
112 
113 	tmp = saveds < SLJIT_NUMBER_OF_SAVED_REGISTERS ? (SLJIT_S0 + 1 - saveds) : SLJIT_FIRST_SAVED_REG;
114 	for (i = SLJIT_S0; i >= tmp; i--) {
115 		size = reg_map[i] >= 8 ? 2 : 1;
116 		inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
117 		FAIL_IF(!inst);
118 		INC_SIZE(size);
119 		if (reg_map[i] >= 8)
120 			*inst++ = REX_B;
121 		PUSH_REG(reg_lmap[i]);
122 	}
123 
124 	for (i = scratches; i >= SLJIT_FIRST_SAVED_REG; i--) {
125 		size = reg_map[i] >= 8 ? 2 : 1;
126 		inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
127 		FAIL_IF(!inst);
128 		INC_SIZE(size);
129 		if (reg_map[i] >= 8)
130 			*inst++ = REX_B;
131 		PUSH_REG(reg_lmap[i]);
132 	}
133 
134 	if (args > 0) {
135 		size = args * 3;
136 		inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
137 		FAIL_IF(!inst);
138 
139 		INC_SIZE(size);
140 
141 #ifndef _WIN64
142 		if (args > 0) {
143 			*inst++ = REX_W;
144 			*inst++ = MOV_r_rm;
145 			*inst++ = MOD_REG | (reg_map[SLJIT_S0] << 3) | 0x7 /* rdi */;
146 		}
147 		if (args > 1) {
148 			*inst++ = REX_W | REX_R;
149 			*inst++ = MOV_r_rm;
150 			*inst++ = MOD_REG | (reg_lmap[SLJIT_S1] << 3) | 0x6 /* rsi */;
151 		}
152 		if (args > 2) {
153 			*inst++ = REX_W | REX_R;
154 			*inst++ = MOV_r_rm;
155 			*inst++ = MOD_REG | (reg_lmap[SLJIT_S2] << 3) | 0x2 /* rdx */;
156 		}
157 #else
158 		if (args > 0) {
159 			*inst++ = REX_W;
160 			*inst++ = MOV_r_rm;
161 			*inst++ = MOD_REG | (reg_map[SLJIT_S0] << 3) | 0x1 /* rcx */;
162 		}
163 		if (args > 1) {
164 			*inst++ = REX_W;
165 			*inst++ = MOV_r_rm;
166 			*inst++ = MOD_REG | (reg_map[SLJIT_S1] << 3) | 0x2 /* rdx */;
167 		}
168 		if (args > 2) {
169 			*inst++ = REX_W | REX_B;
170 			*inst++ = MOV_r_rm;
171 			*inst++ = MOD_REG | (reg_map[SLJIT_S2] << 3) | 0x0 /* r8 */;
172 		}
173 #endif
174 	}
175 
176 	local_size = ((local_size + FIXED_LOCALS_OFFSET + saved_register_size + 16 - 1) & ~(16 - 1)) - saved_register_size;
177 	compiler->local_size = local_size;
178 
179 #ifdef _WIN64
180 	if (local_size > 1024) {
181 		/* Allocate stack for the callback, which grows the stack. */
182 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 4 + (3 + sizeof(sljit_si)));
183 		FAIL_IF(!inst);
184 		INC_SIZE(4 + (3 + sizeof(sljit_si)));
185 		*inst++ = REX_W;
186 		*inst++ = GROUP_BINARY_83;
187 		*inst++ = MOD_REG | SUB | 4;
188 		/* Allocated size for registers must be divisible by 8. */
189 		SLJIT_ASSERT(!(saved_register_size & 0x7));
190 		/* Aligned to 16 byte. */
191 		if (saved_register_size & 0x8) {
192 			*inst++ = 5 * sizeof(sljit_sw);
193 			local_size -= 5 * sizeof(sljit_sw);
194 		} else {
195 			*inst++ = 4 * sizeof(sljit_sw);
196 			local_size -= 4 * sizeof(sljit_sw);
197 		}
198 		/* Second instruction */
199 		SLJIT_COMPILE_ASSERT(reg_map[SLJIT_R0] < 8, temporary_reg1_is_loreg);
200 		*inst++ = REX_W;
201 		*inst++ = MOV_rm_i32;
202 		*inst++ = MOD_REG | reg_lmap[SLJIT_R0];
203 		*(sljit_si*)inst = local_size;
204 #if (defined SLJIT_VERBOSE && SLJIT_VERBOSE) || (defined SLJIT_DEBUG && SLJIT_DEBUG)
205 		compiler->skip_checks = 1;
206 #endif
207 		FAIL_IF(sljit_emit_ijump(compiler, SLJIT_CALL1, SLJIT_IMM, SLJIT_FUNC_OFFSET(sljit_grow_stack)));
208 	}
209 #endif
210 
211 	SLJIT_ASSERT(local_size > 0);
212 	if (local_size <= 127) {
213 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 4);
214 		FAIL_IF(!inst);
215 		INC_SIZE(4);
216 		*inst++ = REX_W;
217 		*inst++ = GROUP_BINARY_83;
218 		*inst++ = MOD_REG | SUB | 4;
219 		*inst++ = local_size;
220 	}
221 	else {
222 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 7);
223 		FAIL_IF(!inst);
224 		INC_SIZE(7);
225 		*inst++ = REX_W;
226 		*inst++ = GROUP_BINARY_81;
227 		*inst++ = MOD_REG | SUB | 4;
228 		*(sljit_si*)inst = local_size;
229 		inst += sizeof(sljit_si);
230 	}
231 
232 #ifdef _WIN64
233 	/* Save xmm6 register: movaps [rsp + 0x20], xmm6 */
234 	if (fscratches >= 6 || fsaveds >= 1) {
235 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 5);
236 		FAIL_IF(!inst);
237 		INC_SIZE(5);
238 		*inst++ = GROUP_0F;
239 		*(sljit_si*)inst = 0x20247429;
240 	}
241 #endif
242 
243 	return SLJIT_SUCCESS;
244 }
245 
sljit_set_context(struct sljit_compiler * compiler,sljit_si options,sljit_si args,sljit_si scratches,sljit_si saveds,sljit_si fscratches,sljit_si fsaveds,sljit_si local_size)246 SLJIT_API_FUNC_ATTRIBUTE void sljit_set_context(struct sljit_compiler *compiler,
247 	sljit_si options, sljit_si args, sljit_si scratches, sljit_si saveds,
248 	sljit_si fscratches, sljit_si fsaveds, sljit_si local_size)
249 {
250 	sljit_si saved_register_size;
251 
252 	CHECK_ERROR_VOID();
253 	check_sljit_set_context(compiler, options, args, scratches, saveds, fscratches, fsaveds, local_size);
254 
255 	compiler->options = options;
256 	compiler->scratches = scratches;
257 	compiler->saveds = saveds;
258 	compiler->fscratches = fscratches;
259 	compiler->fsaveds = fsaveds;
260 #if (defined SLJIT_DEBUG && SLJIT_DEBUG)
261 	compiler->logical_local_size = local_size;
262 #endif
263 
264 	/* Including the return address saved by the call instruction. */
265 	saved_register_size = GET_SAVED_REGISTERS_SIZE(scratches, saveds, 1);
266 	compiler->local_size = ((local_size + FIXED_LOCALS_OFFSET + saved_register_size + 16 - 1) & ~(16 - 1)) - saved_register_size;
267 }
268 
sljit_emit_return(struct sljit_compiler * compiler,sljit_si op,sljit_si src,sljit_sw srcw)269 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_return(struct sljit_compiler *compiler, sljit_si op, sljit_si src, sljit_sw srcw)
270 {
271 	sljit_si i, tmp, size;
272 	sljit_ub *inst;
273 
274 	CHECK_ERROR();
275 	check_sljit_emit_return(compiler, op, src, srcw);
276 
277 	compiler->flags_saved = 0;
278 	FAIL_IF(emit_mov_before_return(compiler, op, src, srcw));
279 
280 #ifdef _WIN64
281 	/* Restore xmm6 register: movaps xmm6, [rsp + 0x20] */
282 	if (compiler->fscratches >= 6 || compiler->fsaveds >= 1) {
283 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 5);
284 		FAIL_IF(!inst);
285 		INC_SIZE(5);
286 		*inst++ = GROUP_0F;
287 		*(sljit_si*)inst = 0x20247428;
288 	}
289 #endif
290 
291 	SLJIT_ASSERT(compiler->local_size > 0);
292 	if (compiler->local_size <= 127) {
293 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 4);
294 		FAIL_IF(!inst);
295 		INC_SIZE(4);
296 		*inst++ = REX_W;
297 		*inst++ = GROUP_BINARY_83;
298 		*inst++ = MOD_REG | ADD | 4;
299 		*inst = compiler->local_size;
300 	}
301 	else {
302 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 7);
303 		FAIL_IF(!inst);
304 		INC_SIZE(7);
305 		*inst++ = REX_W;
306 		*inst++ = GROUP_BINARY_81;
307 		*inst++ = MOD_REG | ADD | 4;
308 		*(sljit_si*)inst = compiler->local_size;
309 	}
310 
311 	tmp = compiler->scratches;
312 	for (i = SLJIT_FIRST_SAVED_REG; i <= tmp; i++) {
313 		size = reg_map[i] >= 8 ? 2 : 1;
314 		inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
315 		FAIL_IF(!inst);
316 		INC_SIZE(size);
317 		if (reg_map[i] >= 8)
318 			*inst++ = REX_B;
319 		POP_REG(reg_lmap[i]);
320 	}
321 
322 	tmp = compiler->saveds < SLJIT_NUMBER_OF_SAVED_REGISTERS ? (SLJIT_S0 + 1 - compiler->saveds) : SLJIT_FIRST_SAVED_REG;
323 	for (i = tmp; i <= SLJIT_S0; i++) {
324 		size = reg_map[i] >= 8 ? 2 : 1;
325 		inst = (sljit_ub*)ensure_buf(compiler, 1 + size);
326 		FAIL_IF(!inst);
327 		INC_SIZE(size);
328 		if (reg_map[i] >= 8)
329 			*inst++ = REX_B;
330 		POP_REG(reg_lmap[i]);
331 	}
332 
333 	inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
334 	FAIL_IF(!inst);
335 	INC_SIZE(1);
336 	RET();
337 	return SLJIT_SUCCESS;
338 }
339 
340 /* --------------------------------------------------------------------- */
341 /*  Operators                                                            */
342 /* --------------------------------------------------------------------- */
343 
emit_do_imm32(struct sljit_compiler * compiler,sljit_ub rex,sljit_ub opcode,sljit_sw imm)344 static sljit_si emit_do_imm32(struct sljit_compiler *compiler, sljit_ub rex, sljit_ub opcode, sljit_sw imm)
345 {
346 	sljit_ub *inst;
347 	sljit_si length = 1 + (rex ? 1 : 0) + sizeof(sljit_si);
348 
349 	inst = (sljit_ub*)ensure_buf(compiler, 1 + length);
350 	FAIL_IF(!inst);
351 	INC_SIZE(length);
352 	if (rex)
353 		*inst++ = rex;
354 	*inst++ = opcode;
355 	*(sljit_si*)inst = imm;
356 	return SLJIT_SUCCESS;
357 }
358 
emit_x86_instruction(struct sljit_compiler * compiler,sljit_si size,sljit_si a,sljit_sw imma,sljit_si b,sljit_sw immb)359 static sljit_ub* emit_x86_instruction(struct sljit_compiler *compiler, sljit_si size,
360 	/* The register or immediate operand. */
361 	sljit_si a, sljit_sw imma,
362 	/* The general operand (not immediate). */
363 	sljit_si b, sljit_sw immb)
364 {
365 	sljit_ub *inst;
366 	sljit_ub *buf_ptr;
367 	sljit_ub rex = 0;
368 	sljit_si flags = size & ~0xf;
369 	sljit_si inst_size;
370 
371 	/* The immediate operand must be 32 bit. */
372 	SLJIT_ASSERT(!(a & SLJIT_IMM) || compiler->mode32 || IS_HALFWORD(imma));
373 	/* Both cannot be switched on. */
374 	SLJIT_ASSERT((flags & (EX86_BIN_INS | EX86_SHIFT_INS)) != (EX86_BIN_INS | EX86_SHIFT_INS));
375 	/* Size flags not allowed for typed instructions. */
376 	SLJIT_ASSERT(!(flags & (EX86_BIN_INS | EX86_SHIFT_INS)) || (flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) == 0);
377 	/* Both size flags cannot be switched on. */
378 	SLJIT_ASSERT((flags & (EX86_BYTE_ARG | EX86_HALF_ARG)) != (EX86_BYTE_ARG | EX86_HALF_ARG));
379 	/* SSE2 and immediate is not possible. */
380 	SLJIT_ASSERT(!(a & SLJIT_IMM) || !(flags & EX86_SSE2));
381 	SLJIT_ASSERT((flags & (EX86_PREF_F2 | EX86_PREF_F3)) != (EX86_PREF_F2 | EX86_PREF_F3)
382 		&& (flags & (EX86_PREF_F2 | EX86_PREF_66)) != (EX86_PREF_F2 | EX86_PREF_66)
383 		&& (flags & (EX86_PREF_F3 | EX86_PREF_66)) != (EX86_PREF_F3 | EX86_PREF_66));
384 
385 	size &= 0xf;
386 	inst_size = size;
387 
388 	if (!compiler->mode32 && !(flags & EX86_NO_REXW))
389 		rex |= REX_W;
390 	else if (flags & EX86_REX)
391 		rex |= REX;
392 
393 	if (flags & (EX86_PREF_F2 | EX86_PREF_F3))
394 		inst_size++;
395 	if (flags & EX86_PREF_66)
396 		inst_size++;
397 
398 	/* Calculate size of b. */
399 	inst_size += 1; /* mod r/m byte. */
400 	if (b & SLJIT_MEM) {
401 		if (!(b & OFFS_REG_MASK)) {
402 			if (NOT_HALFWORD(immb)) {
403 				if (emit_load_imm64(compiler, TMP_REG3, immb))
404 					return NULL;
405 				immb = 0;
406 				if (b & REG_MASK)
407 					b |= TO_OFFS_REG(TMP_REG3);
408 				else
409 					b |= TMP_REG3;
410 			}
411 			else if (reg_lmap[b & REG_MASK] == 4)
412 				b |= TO_OFFS_REG(SLJIT_SP);
413 		}
414 
415 		if ((b & REG_MASK) == SLJIT_UNUSED)
416 			inst_size += 1 + sizeof(sljit_si); /* SIB byte required to avoid RIP based addressing. */
417 		else {
418 			if (reg_map[b & REG_MASK] >= 8)
419 				rex |= REX_B;
420 
421 			if (immb != 0 && (!(b & OFFS_REG_MASK) || (b & OFFS_REG_MASK) == TO_OFFS_REG(SLJIT_SP))) {
422 				/* Immediate operand. */
423 				if (immb <= 127 && immb >= -128)
424 					inst_size += sizeof(sljit_sb);
425 				else
426 					inst_size += sizeof(sljit_si);
427 			}
428 			else if (reg_lmap[b & REG_MASK] == 5)
429 				inst_size += sizeof(sljit_sb);
430 
431 			if ((b & OFFS_REG_MASK) != SLJIT_UNUSED) {
432 				inst_size += 1; /* SIB byte. */
433 				if (reg_map[OFFS_REG(b)] >= 8)
434 					rex |= REX_X;
435 			}
436 		}
437 	}
438 	else if (!(flags & EX86_SSE2_OP2) && reg_map[b] >= 8)
439 		rex |= REX_B;
440 
441 	if (a & SLJIT_IMM) {
442 		if (flags & EX86_BIN_INS) {
443 			if (imma <= 127 && imma >= -128) {
444 				inst_size += 1;
445 				flags |= EX86_BYTE_ARG;
446 			} else
447 				inst_size += 4;
448 		}
449 		else if (flags & EX86_SHIFT_INS) {
450 			imma &= compiler->mode32 ? 0x1f : 0x3f;
451 			if (imma != 1) {
452 				inst_size ++;
453 				flags |= EX86_BYTE_ARG;
454 			}
455 		} else if (flags & EX86_BYTE_ARG)
456 			inst_size++;
457 		else if (flags & EX86_HALF_ARG)
458 			inst_size += sizeof(short);
459 		else
460 			inst_size += sizeof(sljit_si);
461 	}
462 	else {
463 		SLJIT_ASSERT(!(flags & EX86_SHIFT_INS) || a == SLJIT_PREF_SHIFT_REG);
464 		/* reg_map[SLJIT_PREF_SHIFT_REG] is less than 8. */
465 		if (!(flags & EX86_SSE2_OP1) && reg_map[a] >= 8)
466 			rex |= REX_R;
467 	}
468 
469 	if (rex)
470 		inst_size++;
471 
472 	inst = (sljit_ub*)ensure_buf(compiler, 1 + inst_size);
473 	PTR_FAIL_IF(!inst);
474 
475 	/* Encoding the byte. */
476 	INC_SIZE(inst_size);
477 	if (flags & EX86_PREF_F2)
478 		*inst++ = 0xf2;
479 	if (flags & EX86_PREF_F3)
480 		*inst++ = 0xf3;
481 	if (flags & EX86_PREF_66)
482 		*inst++ = 0x66;
483 	if (rex)
484 		*inst++ = rex;
485 	buf_ptr = inst + size;
486 
487 	/* Encode mod/rm byte. */
488 	if (!(flags & EX86_SHIFT_INS)) {
489 		if ((flags & EX86_BIN_INS) && (a & SLJIT_IMM))
490 			*inst = (flags & EX86_BYTE_ARG) ? GROUP_BINARY_83 : GROUP_BINARY_81;
491 
492 		if ((a & SLJIT_IMM) || (a == 0))
493 			*buf_ptr = 0;
494 		else if (!(flags & EX86_SSE2_OP1))
495 			*buf_ptr = reg_lmap[a] << 3;
496 		else
497 			*buf_ptr = a << 3;
498 	}
499 	else {
500 		if (a & SLJIT_IMM) {
501 			if (imma == 1)
502 				*inst = GROUP_SHIFT_1;
503 			else
504 				*inst = GROUP_SHIFT_N;
505 		} else
506 			*inst = GROUP_SHIFT_CL;
507 		*buf_ptr = 0;
508 	}
509 
510 	if (!(b & SLJIT_MEM))
511 		*buf_ptr++ |= MOD_REG + ((!(flags & EX86_SSE2_OP2)) ? reg_lmap[b] : b);
512 	else if ((b & REG_MASK) != SLJIT_UNUSED) {
513 		if ((b & OFFS_REG_MASK) == SLJIT_UNUSED || (b & OFFS_REG_MASK) == TO_OFFS_REG(SLJIT_SP)) {
514 			if (immb != 0 || reg_lmap[b & REG_MASK] == 5) {
515 				if (immb <= 127 && immb >= -128)
516 					*buf_ptr |= 0x40;
517 				else
518 					*buf_ptr |= 0x80;
519 			}
520 
521 			if ((b & OFFS_REG_MASK) == SLJIT_UNUSED)
522 				*buf_ptr++ |= reg_lmap[b & REG_MASK];
523 			else {
524 				*buf_ptr++ |= 0x04;
525 				*buf_ptr++ = reg_lmap[b & REG_MASK] | (reg_lmap[OFFS_REG(b)] << 3);
526 			}
527 
528 			if (immb != 0 || reg_lmap[b & REG_MASK] == 5) {
529 				if (immb <= 127 && immb >= -128)
530 					*buf_ptr++ = immb; /* 8 bit displacement. */
531 				else {
532 					*(sljit_si*)buf_ptr = immb; /* 32 bit displacement. */
533 					buf_ptr += sizeof(sljit_si);
534 				}
535 			}
536 		}
537 		else {
538 			if (reg_lmap[b & REG_MASK] == 5)
539 				*buf_ptr |= 0x40;
540 			*buf_ptr++ |= 0x04;
541 			*buf_ptr++ = reg_lmap[b & REG_MASK] | (reg_lmap[OFFS_REG(b)] << 3) | (immb << 6);
542 			if (reg_lmap[b & REG_MASK] == 5)
543 				*buf_ptr++ = 0;
544 		}
545 	}
546 	else {
547 		*buf_ptr++ |= 0x04;
548 		*buf_ptr++ = 0x25;
549 		*(sljit_si*)buf_ptr = immb; /* 32 bit displacement. */
550 		buf_ptr += sizeof(sljit_si);
551 	}
552 
553 	if (a & SLJIT_IMM) {
554 		if (flags & EX86_BYTE_ARG)
555 			*buf_ptr = imma;
556 		else if (flags & EX86_HALF_ARG)
557 			*(short*)buf_ptr = imma;
558 		else if (!(flags & EX86_SHIFT_INS))
559 			*(sljit_si*)buf_ptr = imma;
560 	}
561 
562 	return !(flags & EX86_SHIFT_INS) ? inst : (inst + 1);
563 }
564 
565 /* --------------------------------------------------------------------- */
566 /*  Call / return instructions                                           */
567 /* --------------------------------------------------------------------- */
568 
call_with_args(struct sljit_compiler * compiler,sljit_si type)569 static SLJIT_INLINE sljit_si call_with_args(struct sljit_compiler *compiler, sljit_si type)
570 {
571 	sljit_ub *inst;
572 
573 #ifndef _WIN64
574 	SLJIT_COMPILE_ASSERT(reg_map[SLJIT_R1] == 6 && reg_map[SLJIT_R0] < 8 && reg_map[SLJIT_R2] < 8, args_registers);
575 
576 	inst = (sljit_ub*)ensure_buf(compiler, 1 + ((type < SLJIT_CALL3) ? 3 : 6));
577 	FAIL_IF(!inst);
578 	INC_SIZE((type < SLJIT_CALL3) ? 3 : 6);
579 	if (type >= SLJIT_CALL3) {
580 		*inst++ = REX_W;
581 		*inst++ = MOV_r_rm;
582 		*inst++ = MOD_REG | (0x2 /* rdx */ << 3) | reg_lmap[SLJIT_R2];
583 	}
584 	*inst++ = REX_W;
585 	*inst++ = MOV_r_rm;
586 	*inst++ = MOD_REG | (0x7 /* rdi */ << 3) | reg_lmap[SLJIT_R0];
587 #else
588 	SLJIT_COMPILE_ASSERT(reg_map[SLJIT_R1] == 2 && reg_map[SLJIT_R0] < 8 && reg_map[SLJIT_R2] < 8, args_registers);
589 
590 	inst = (sljit_ub*)ensure_buf(compiler, 1 + ((type < SLJIT_CALL3) ? 3 : 6));
591 	FAIL_IF(!inst);
592 	INC_SIZE((type < SLJIT_CALL3) ? 3 : 6);
593 	if (type >= SLJIT_CALL3) {
594 		*inst++ = REX_W | REX_R;
595 		*inst++ = MOV_r_rm;
596 		*inst++ = MOD_REG | (0x0 /* r8 */ << 3) | reg_lmap[SLJIT_R2];
597 	}
598 	*inst++ = REX_W;
599 	*inst++ = MOV_r_rm;
600 	*inst++ = MOD_REG | (0x1 /* rcx */ << 3) | reg_lmap[SLJIT_R0];
601 #endif
602 	return SLJIT_SUCCESS;
603 }
604 
sljit_emit_fast_enter(struct sljit_compiler * compiler,sljit_si dst,sljit_sw dstw)605 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_enter(struct sljit_compiler *compiler, sljit_si dst, sljit_sw dstw)
606 {
607 	sljit_ub *inst;
608 
609 	CHECK_ERROR();
610 	check_sljit_emit_fast_enter(compiler, dst, dstw);
611 	ADJUST_LOCAL_OFFSET(dst, dstw);
612 
613 	/* For UNUSED dst. Uncommon, but possible. */
614 	if (dst == SLJIT_UNUSED)
615 		dst = TMP_REG1;
616 
617 	if (FAST_IS_REG(dst)) {
618 		if (reg_map[dst] < 8) {
619 			inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
620 			FAIL_IF(!inst);
621 			INC_SIZE(1);
622 			POP_REG(reg_lmap[dst]);
623 			return SLJIT_SUCCESS;
624 		}
625 
626 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 2);
627 		FAIL_IF(!inst);
628 		INC_SIZE(2);
629 		*inst++ = REX_B;
630 		POP_REG(reg_lmap[dst]);
631 		return SLJIT_SUCCESS;
632 	}
633 
634 	/* REX_W is not necessary (src is not immediate). */
635 	compiler->mode32 = 1;
636 	inst = emit_x86_instruction(compiler, 1, 0, 0, dst, dstw);
637 	FAIL_IF(!inst);
638 	*inst++ = POP_rm;
639 	return SLJIT_SUCCESS;
640 }
641 
sljit_emit_fast_return(struct sljit_compiler * compiler,sljit_si src,sljit_sw srcw)642 SLJIT_API_FUNC_ATTRIBUTE sljit_si sljit_emit_fast_return(struct sljit_compiler *compiler, sljit_si src, sljit_sw srcw)
643 {
644 	sljit_ub *inst;
645 
646 	CHECK_ERROR();
647 	check_sljit_emit_fast_return(compiler, src, srcw);
648 	ADJUST_LOCAL_OFFSET(src, srcw);
649 
650 	if ((src & SLJIT_IMM) && NOT_HALFWORD(srcw)) {
651 		FAIL_IF(emit_load_imm64(compiler, TMP_REG1, srcw));
652 		src = TMP_REG1;
653 	}
654 
655 	if (FAST_IS_REG(src)) {
656 		if (reg_map[src] < 8) {
657 			inst = (sljit_ub*)ensure_buf(compiler, 1 + 1 + 1);
658 			FAIL_IF(!inst);
659 
660 			INC_SIZE(1 + 1);
661 			PUSH_REG(reg_lmap[src]);
662 		}
663 		else {
664 			inst = (sljit_ub*)ensure_buf(compiler, 1 + 2 + 1);
665 			FAIL_IF(!inst);
666 
667 			INC_SIZE(2 + 1);
668 			*inst++ = REX_B;
669 			PUSH_REG(reg_lmap[src]);
670 		}
671 	}
672 	else if (src & SLJIT_MEM) {
673 		/* REX_W is not necessary (src is not immediate). */
674 		compiler->mode32 = 1;
675 		inst = emit_x86_instruction(compiler, 1, 0, 0, src, srcw);
676 		FAIL_IF(!inst);
677 		*inst++ = GROUP_FF;
678 		*inst |= PUSH_rm;
679 
680 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 1);
681 		FAIL_IF(!inst);
682 		INC_SIZE(1);
683 	}
684 	else {
685 		SLJIT_ASSERT(IS_HALFWORD(srcw));
686 		/* SLJIT_IMM. */
687 		inst = (sljit_ub*)ensure_buf(compiler, 1 + 5 + 1);
688 		FAIL_IF(!inst);
689 
690 		INC_SIZE(5 + 1);
691 		*inst++ = PUSH_i32;
692 		*(sljit_si*)inst = srcw;
693 		inst += sizeof(sljit_si);
694 	}
695 
696 	RET();
697 	return SLJIT_SUCCESS;
698 }
699 
700 
701 /* --------------------------------------------------------------------- */
702 /*  Extend input                                                         */
703 /* --------------------------------------------------------------------- */
704 
emit_mov_int(struct sljit_compiler * compiler,sljit_si sign,sljit_si dst,sljit_sw dstw,sljit_si src,sljit_sw srcw)705 static sljit_si emit_mov_int(struct sljit_compiler *compiler, sljit_si sign,
706 	sljit_si dst, sljit_sw dstw,
707 	sljit_si src, sljit_sw srcw)
708 {
709 	sljit_ub* inst;
710 	sljit_si dst_r;
711 
712 	compiler->mode32 = 0;
713 
714 	if (dst == SLJIT_UNUSED && !(src & SLJIT_MEM))
715 		return SLJIT_SUCCESS; /* Empty instruction. */
716 
717 	if (src & SLJIT_IMM) {
718 		if (FAST_IS_REG(dst)) {
719 			if (sign || ((sljit_uw)srcw <= 0x7fffffff)) {
720 				inst = emit_x86_instruction(compiler, 1, SLJIT_IMM, (sljit_sw)(sljit_si)srcw, dst, dstw);
721 				FAIL_IF(!inst);
722 				*inst = MOV_rm_i32;
723 				return SLJIT_SUCCESS;
724 			}
725 			return emit_load_imm64(compiler, dst, srcw);
726 		}
727 		compiler->mode32 = 1;
728 		inst = emit_x86_instruction(compiler, 1, SLJIT_IMM, (sljit_sw)(sljit_si)srcw, dst, dstw);
729 		FAIL_IF(!inst);
730 		*inst = MOV_rm_i32;
731 		compiler->mode32 = 0;
732 		return SLJIT_SUCCESS;
733 	}
734 
735 	dst_r = FAST_IS_REG(dst) ? dst : TMP_REG1;
736 
737 	if ((dst & SLJIT_MEM) && FAST_IS_REG(src))
738 		dst_r = src;
739 	else {
740 		if (sign) {
741 			inst = emit_x86_instruction(compiler, 1, dst_r, 0, src, srcw);
742 			FAIL_IF(!inst);
743 			*inst++ = MOVSXD_r_rm;
744 		} else {
745 			compiler->mode32 = 1;
746 			FAIL_IF(emit_mov(compiler, dst_r, 0, src, srcw));
747 			compiler->mode32 = 0;
748 		}
749 	}
750 
751 	if (dst & SLJIT_MEM) {
752 		compiler->mode32 = 1;
753 		inst = emit_x86_instruction(compiler, 1, dst_r, 0, dst, dstw);
754 		FAIL_IF(!inst);
755 		*inst = MOV_rm_r;
756 		compiler->mode32 = 0;
757 	}
758 
759 	return SLJIT_SUCCESS;
760 }
761