1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2014 Damien P. George
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27#include <stdint.h>
28#include <stdio.h>
29#include <assert.h>
30#include <string.h>
31
32#include "py/mpconfig.h"
33
34// wrapper around everything in this file
35#if MICROPY_EMIT_X86
36
37#include "py/asmx86.h"
38
39/* all offsets are measured in multiples of 4 bytes */
40#define WORD_SIZE (4)
41
42#define OPCODE_NOP (0x90)
43#define OPCODE_PUSH_R32 (0x50)
44// #define OPCODE_PUSH_I32 (0x68)
45// #define OPCODE_PUSH_M32 (0xff) /* /6 */
46#define OPCODE_POP_R32 (0x58)
47#define OPCODE_RET (0xc3)
48// #define OPCODE_MOV_I8_TO_R8 (0xb0) /* +rb */
49#define OPCODE_MOV_I32_TO_R32 (0xb8)
50// #define OPCODE_MOV_I32_TO_RM32 (0xc7)
51#define OPCODE_MOV_R8_TO_RM8 (0x88) /* /r */
52#define OPCODE_MOV_R32_TO_RM32 (0x89) /* /r */
53#define OPCODE_MOV_RM32_TO_R32 (0x8b) /* /r */
54#define OPCODE_MOVZX_RM8_TO_R32 (0xb6) /* 0x0f 0xb6/r */
55#define OPCODE_MOVZX_RM16_TO_R32 (0xb7) /* 0x0f 0xb7/r */
56#define OPCODE_LEA_MEM_TO_R32 (0x8d) /* /r */
57#define OPCODE_AND_R32_TO_RM32 (0x21) /* /r */
58#define OPCODE_OR_R32_TO_RM32 (0x09) /* /r */
59#define OPCODE_XOR_R32_TO_RM32 (0x31) /* /r */
60#define OPCODE_ADD_R32_TO_RM32 (0x01)
61#define OPCODE_ADD_I32_TO_RM32 (0x81) /* /0 */
62#define OPCODE_ADD_I8_TO_RM32 (0x83) /* /0 */
63#define OPCODE_SUB_R32_FROM_RM32 (0x29)
64#define OPCODE_SUB_I32_FROM_RM32 (0x81) /* /5 */
65#define OPCODE_SUB_I8_FROM_RM32 (0x83) /* /5 */
66// #define OPCODE_SHL_RM32_BY_I8 (0xc1) /* /4 */
67// #define OPCODE_SHR_RM32_BY_I8 (0xc1) /* /5 */
68// #define OPCODE_SAR_RM32_BY_I8 (0xc1) /* /7 */
69#define OPCODE_SHL_RM32_CL (0xd3) /* /4 */
70#define OPCODE_SHR_RM32_CL (0xd3) /* /5 */
71#define OPCODE_SAR_RM32_CL (0xd3) /* /7 */
72// #define OPCODE_CMP_I32_WITH_RM32 (0x81) /* /7 */
73// #define OPCODE_CMP_I8_WITH_RM32 (0x83) /* /7 */
74#define OPCODE_CMP_R32_WITH_RM32 (0x39)
75// #define OPCODE_CMP_RM32_WITH_R32 (0x3b)
76#define OPCODE_TEST_R8_WITH_RM8 (0x84) /* /r */
77#define OPCODE_TEST_R32_WITH_RM32 (0x85) /* /r */
78#define OPCODE_JMP_REL8 (0xeb)
79#define OPCODE_JMP_REL32 (0xe9)
80#define OPCODE_JMP_RM32 (0xff) /* /4 */
81#define OPCODE_JCC_REL8 (0x70) /* | jcc type */
82#define OPCODE_JCC_REL32_A (0x0f)
83#define OPCODE_JCC_REL32_B (0x80) /* | jcc type */
84#define OPCODE_SETCC_RM8_A (0x0f)
85#define OPCODE_SETCC_RM8_B (0x90) /* | jcc type, /0 */
86#define OPCODE_CALL_REL32 (0xe8)
87#define OPCODE_CALL_RM32 (0xff) /* /2 */
88#define OPCODE_LEAVE (0xc9)
89
90#define MODRM_R32(x) ((x) << 3)
91#define MODRM_RM_DISP0 (0x00)
92#define MODRM_RM_DISP8 (0x40)
93#define MODRM_RM_DISP32 (0x80)
94#define MODRM_RM_REG (0xc0)
95#define MODRM_RM_R32(x) (x)
96
97#define OP_SIZE_PREFIX (0x66)
98
99#define IMM32_L0(x) ((x) & 0xff)
100#define IMM32_L1(x) (((x) >> 8) & 0xff)
101#define IMM32_L2(x) (((x) >> 16) & 0xff)
102#define IMM32_L3(x) (((x) >> 24) & 0xff)
103
104#define SIGNED_FIT8(x) (((x) & 0xffffff80) == 0) || (((x) & 0xffffff80) == 0xffffff80)
105
106STATIC void asm_x86_write_byte_1(asm_x86_t *as, byte b1) {
107 byte *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 1);
108 if (c != NULL) {
109 c[0] = b1;
110 }
111}
112
113STATIC void asm_x86_write_byte_2(asm_x86_t *as, byte b1, byte b2) {
114 byte *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 2);
115 if (c != NULL) {
116 c[0] = b1;
117 c[1] = b2;
118 }
119}
120
121STATIC void asm_x86_write_byte_3(asm_x86_t *as, byte b1, byte b2, byte b3) {
122 byte *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 3);
123 if (c != NULL) {
124 c[0] = b1;
125 c[1] = b2;
126 c[2] = b3;
127 }
128}
129
130STATIC void asm_x86_write_word32(asm_x86_t *as, int w32) {
131 byte *c = mp_asm_base_get_cur_to_write_bytes(&as->base, 4);
132 if (c != NULL) {
133 c[0] = IMM32_L0(w32);
134 c[1] = IMM32_L1(w32);
135 c[2] = IMM32_L2(w32);
136 c[3] = IMM32_L3(w32);
137 }
138}
139
140STATIC void asm_x86_write_r32_disp(asm_x86_t *as, int r32, int disp_r32, int disp_offset) {
141 uint8_t rm_disp;
142 if (disp_offset == 0 && disp_r32 != ASM_X86_REG_EBP) {
143 rm_disp = MODRM_RM_DISP0;
144 } else if (SIGNED_FIT8(disp_offset)) {
145 rm_disp = MODRM_RM_DISP8;
146 } else {
147 rm_disp = MODRM_RM_DISP32;
148 }
149 asm_x86_write_byte_1(as, MODRM_R32(r32) | rm_disp | MODRM_RM_R32(disp_r32));
150 if (disp_r32 == ASM_X86_REG_ESP) {
151 // Special case for esp, it needs a SIB byte
152 asm_x86_write_byte_1(as, 0x24);
153 }
154 if (rm_disp == MODRM_RM_DISP8) {
155 asm_x86_write_byte_1(as, IMM32_L0(disp_offset));
156 } else if (rm_disp == MODRM_RM_DISP32) {
157 asm_x86_write_word32(as, disp_offset);
158 }
159}
160
161STATIC void asm_x86_generic_r32_r32(asm_x86_t *as, int dest_r32, int src_r32, int op) {
162 asm_x86_write_byte_2(as, op, MODRM_R32(src_r32) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
163}
164
165#if 0
166STATIC void asm_x86_nop(asm_x86_t *as) {
167 asm_x86_write_byte_1(as, OPCODE_NOP);
168}
169#endif
170
171STATIC void asm_x86_push_r32(asm_x86_t *as, int src_r32) {
172 asm_x86_write_byte_1(as, OPCODE_PUSH_R32 | src_r32);
173}
174
175#if 0
176void asm_x86_push_i32(asm_x86_t *as, int src_i32) {
177 asm_x86_write_byte_1(as, OPCODE_PUSH_I32);
178 asm_x86_write_word32(as, src_i32);
179}
180
181void asm_x86_push_disp(asm_x86_t *as, int src_r32, int src_offset) {
182 asm_x86_write_byte_1(as, OPCODE_PUSH_M32);
183 asm_x86_write_r32_disp(as, 6, src_r32, src_offset);
184}
185#endif
186
187STATIC void asm_x86_pop_r32(asm_x86_t *as, int dest_r32) {
188 asm_x86_write_byte_1(as, OPCODE_POP_R32 | dest_r32);
189}
190
191STATIC void asm_x86_ret(asm_x86_t *as) {
192 asm_x86_write_byte_1(as, OPCODE_RET);
193}
194
195void asm_x86_mov_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
196 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_MOV_R32_TO_RM32);
197}
198
199void asm_x86_mov_r8_to_mem8(asm_x86_t *as, int src_r32, int dest_r32, int dest_disp) {
200 asm_x86_write_byte_1(as, OPCODE_MOV_R8_TO_RM8);
201 asm_x86_write_r32_disp(as, src_r32, dest_r32, dest_disp);
202}
203
204void asm_x86_mov_r16_to_mem16(asm_x86_t *as, int src_r32, int dest_r32, int dest_disp) {
205 asm_x86_write_byte_2(as, OP_SIZE_PREFIX, OPCODE_MOV_R32_TO_RM32);
206 asm_x86_write_r32_disp(as, src_r32, dest_r32, dest_disp);
207}
208
209void asm_x86_mov_r32_to_mem32(asm_x86_t *as, int src_r32, int dest_r32, int dest_disp) {
210 asm_x86_write_byte_1(as, OPCODE_MOV_R32_TO_RM32);
211 asm_x86_write_r32_disp(as, src_r32, dest_r32, dest_disp);
212}
213
214void asm_x86_mov_mem8_to_r32zx(asm_x86_t *as, int src_r32, int src_disp, int dest_r32) {
215 asm_x86_write_byte_2(as, 0x0f, OPCODE_MOVZX_RM8_TO_R32);
216 asm_x86_write_r32_disp(as, dest_r32, src_r32, src_disp);
217}
218
219void asm_x86_mov_mem16_to_r32zx(asm_x86_t *as, int src_r32, int src_disp, int dest_r32) {
220 asm_x86_write_byte_2(as, 0x0f, OPCODE_MOVZX_RM16_TO_R32);
221 asm_x86_write_r32_disp(as, dest_r32, src_r32, src_disp);
222}
223
224void asm_x86_mov_mem32_to_r32(asm_x86_t *as, int src_r32, int src_disp, int dest_r32) {
225 asm_x86_write_byte_1(as, OPCODE_MOV_RM32_TO_R32);
226 asm_x86_write_r32_disp(as, dest_r32, src_r32, src_disp);
227}
228
229STATIC void asm_x86_lea_disp_to_r32(asm_x86_t *as, int src_r32, int src_disp, int dest_r32) {
230 asm_x86_write_byte_1(as, OPCODE_LEA_MEM_TO_R32);
231 asm_x86_write_r32_disp(as, dest_r32, src_r32, src_disp);
232}
233
234#if 0
235void asm_x86_mov_i8_to_r8(asm_x86_t *as, int src_i8, int dest_r32) {
236 asm_x86_write_byte_2(as, OPCODE_MOV_I8_TO_R8 | dest_r32, src_i8);
237}
238#endif
239
240size_t asm_x86_mov_i32_to_r32(asm_x86_t *as, int32_t src_i32, int dest_r32) {
241 asm_x86_write_byte_1(as, OPCODE_MOV_I32_TO_R32 | dest_r32);
242 size_t loc = mp_asm_base_get_code_pos(&as->base);
243 asm_x86_write_word32(as, src_i32);
244 return loc;
245}
246
247void asm_x86_and_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
248 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_AND_R32_TO_RM32);
249}
250
251void asm_x86_or_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
252 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_OR_R32_TO_RM32);
253}
254
255void asm_x86_xor_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
256 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_XOR_R32_TO_RM32);
257}
258
259void asm_x86_shl_r32_cl(asm_x86_t *as, int dest_r32) {
260 asm_x86_generic_r32_r32(as, dest_r32, 4, OPCODE_SHL_RM32_CL);
261}
262
263void asm_x86_shr_r32_cl(asm_x86_t *as, int dest_r32) {
264 asm_x86_generic_r32_r32(as, dest_r32, 5, OPCODE_SHR_RM32_CL);
265}
266
267void asm_x86_sar_r32_cl(asm_x86_t *as, int dest_r32) {
268 asm_x86_generic_r32_r32(as, dest_r32, 7, OPCODE_SAR_RM32_CL);
269}
270
271void asm_x86_add_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
272 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_ADD_R32_TO_RM32);
273}
274
275STATIC void asm_x86_add_i32_to_r32(asm_x86_t *as, int src_i32, int dest_r32) {
276 if (SIGNED_FIT8(src_i32)) {
277 asm_x86_write_byte_2(as, OPCODE_ADD_I8_TO_RM32, MODRM_R32(0) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
278 asm_x86_write_byte_1(as, src_i32 & 0xff);
279 } else {
280 asm_x86_write_byte_2(as, OPCODE_ADD_I32_TO_RM32, MODRM_R32(0) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
281 asm_x86_write_word32(as, src_i32);
282 }
283}
284
285void asm_x86_sub_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
286 asm_x86_generic_r32_r32(as, dest_r32, src_r32, OPCODE_SUB_R32_FROM_RM32);
287}
288
289STATIC void asm_x86_sub_r32_i32(asm_x86_t *as, int dest_r32, int src_i32) {
290 if (SIGNED_FIT8(src_i32)) {
291 // defaults to 32 bit operation
292 asm_x86_write_byte_2(as, OPCODE_SUB_I8_FROM_RM32, MODRM_R32(5) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
293 asm_x86_write_byte_1(as, src_i32 & 0xff);
294 } else {
295 // defaults to 32 bit operation
296 asm_x86_write_byte_2(as, OPCODE_SUB_I32_FROM_RM32, MODRM_R32(5) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
297 asm_x86_write_word32(as, src_i32);
298 }
299}
300
301void asm_x86_mul_r32_r32(asm_x86_t *as, int dest_r32, int src_r32) {
302 // imul reg32, reg/mem32 -- 0x0f 0xaf /r
303 asm_x86_write_byte_3(as, 0x0f, 0xaf, MODRM_R32(dest_r32) | MODRM_RM_REG | MODRM_RM_R32(src_r32));
304}
305
306#if 0
307/* shifts not tested */
308void asm_x86_shl_r32_by_imm(asm_x86_t *as, int r32, int imm) {
309 asm_x86_write_byte_2(as, OPCODE_SHL_RM32_BY_I8, MODRM_R32(4) | MODRM_RM_REG | MODRM_RM_R32(r32));
310 asm_x86_write_byte_1(as, imm);
311}
312
313void asm_x86_shr_r32_by_imm(asm_x86_t *as, int r32, int imm) {
314 asm_x86_write_byte_2(as, OPCODE_SHR_RM32_BY_I8, MODRM_R32(5) | MODRM_RM_REG | MODRM_RM_R32(r32));
315 asm_x86_write_byte_1(as, imm);
316}
317
318void asm_x86_sar_r32_by_imm(asm_x86_t *as, int r32, int imm) {
319 asm_x86_write_byte_2(as, OPCODE_SAR_RM32_BY_I8, MODRM_R32(7) | MODRM_RM_REG | MODRM_RM_R32(r32));
320 asm_x86_write_byte_1(as, imm);
321}
322#endif
323
324void asm_x86_cmp_r32_with_r32(asm_x86_t *as, int src_r32_a, int src_r32_b) {
325 asm_x86_generic_r32_r32(as, src_r32_b, src_r32_a, OPCODE_CMP_R32_WITH_RM32);
326}
327
328#if 0
329void asm_x86_cmp_i32_with_r32(asm_x86_t *as, int src_i32, int src_r32) {
330 if (SIGNED_FIT8(src_i32)) {
331 asm_x86_write_byte_2(as, OPCODE_CMP_I8_WITH_RM32, MODRM_R32(7) | MODRM_RM_REG | MODRM_RM_R32(src_r32));
332 asm_x86_write_byte_1(as, src_i32 & 0xff);
333 } else {
334 asm_x86_write_byte_2(as, OPCODE_CMP_I32_WITH_RM32, MODRM_R32(7) | MODRM_RM_REG | MODRM_RM_R32(src_r32));
335 asm_x86_write_word32(as, src_i32);
336 }
337}
338#endif
339
340void asm_x86_test_r8_with_r8(asm_x86_t *as, int src_r32_a, int src_r32_b) {
341 asm_x86_write_byte_2(as, OPCODE_TEST_R8_WITH_RM8, MODRM_R32(src_r32_a) | MODRM_RM_REG | MODRM_RM_R32(src_r32_b));
342}
343
344void asm_x86_test_r32_with_r32(asm_x86_t *as, int src_r32_a, int src_r32_b) {
345 asm_x86_generic_r32_r32(as, src_r32_b, src_r32_a, OPCODE_TEST_R32_WITH_RM32);
346}
347
348void asm_x86_setcc_r8(asm_x86_t *as, mp_uint_t jcc_type, int dest_r8) {
349 asm_x86_write_byte_3(as, OPCODE_SETCC_RM8_A, OPCODE_SETCC_RM8_B | jcc_type, MODRM_R32(0) | MODRM_RM_REG | MODRM_RM_R32(dest_r8));
350}
351
352void asm_x86_jmp_reg(asm_x86_t *as, int src_r32) {
353 asm_x86_write_byte_2(as, OPCODE_JMP_RM32, MODRM_R32(4) | MODRM_RM_REG | MODRM_RM_R32(src_r32));
354}
355
356STATIC mp_uint_t get_label_dest(asm_x86_t *as, mp_uint_t label) {
357 assert(label < as->base.max_num_labels);
358 return as->base.label_offsets[label];
359}
360
361void asm_x86_jmp_label(asm_x86_t *as, mp_uint_t label) {
362 mp_uint_t dest = get_label_dest(as, label);
363 mp_int_t rel = dest - as->base.code_offset;
364 if (dest != (mp_uint_t)-1 && rel < 0) {
365 // is a backwards jump, so we know the size of the jump on the first pass
366 // calculate rel assuming 8 bit relative jump
367 rel -= 2;
368 if (SIGNED_FIT8(rel)) {
369 asm_x86_write_byte_2(as, OPCODE_JMP_REL8, rel & 0xff);
370 } else {
371 rel += 2;
372 goto large_jump;
373 }
374 } else {
375 // is a forwards jump, so need to assume it's large
376 large_jump:
377 rel -= 5;
378 asm_x86_write_byte_1(as, OPCODE_JMP_REL32);
379 asm_x86_write_word32(as, rel);
380 }
381}
382
383void asm_x86_jcc_label(asm_x86_t *as, mp_uint_t jcc_type, mp_uint_t label) {
384 mp_uint_t dest = get_label_dest(as, label);
385 mp_int_t rel = dest - as->base.code_offset;
386 if (dest != (mp_uint_t)-1 && rel < 0) {
387 // is a backwards jump, so we know the size of the jump on the first pass
388 // calculate rel assuming 8 bit relative jump
389 rel -= 2;
390 if (SIGNED_FIT8(rel)) {
391 asm_x86_write_byte_2(as, OPCODE_JCC_REL8 | jcc_type, rel & 0xff);
392 } else {
393 rel += 2;
394 goto large_jump;
395 }
396 } else {
397 // is a forwards jump, so need to assume it's large
398 large_jump:
399 rel -= 6;
400 asm_x86_write_byte_2(as, OPCODE_JCC_REL32_A, OPCODE_JCC_REL32_B | jcc_type);
401 asm_x86_write_word32(as, rel);
402 }
403}
404
405void asm_x86_entry(asm_x86_t *as, int num_locals) {
406 assert(num_locals >= 0);
407 asm_x86_push_r32(as, ASM_X86_REG_EBP);
408 asm_x86_push_r32(as, ASM_X86_REG_EBX);
409 asm_x86_push_r32(as, ASM_X86_REG_ESI);
410 asm_x86_push_r32(as, ASM_X86_REG_EDI);
411 num_locals |= 3; // make it odd so stack is aligned on 16 byte boundary
412 asm_x86_sub_r32_i32(as, ASM_X86_REG_ESP, num_locals * WORD_SIZE);
413 as->num_locals = num_locals;
414}
415
416void asm_x86_exit(asm_x86_t *as) {
417 asm_x86_sub_r32_i32(as, ASM_X86_REG_ESP, -as->num_locals * WORD_SIZE);
418 asm_x86_pop_r32(as, ASM_X86_REG_EDI);
419 asm_x86_pop_r32(as, ASM_X86_REG_ESI);
420 asm_x86_pop_r32(as, ASM_X86_REG_EBX);
421 asm_x86_pop_r32(as, ASM_X86_REG_EBP);
422 asm_x86_ret(as);
423}
424
425STATIC int asm_x86_arg_offset_from_esp(asm_x86_t *as, size_t arg_num) {
426 // Above esp are: locals, 4 saved registers, return eip, arguments
427 return (as->num_locals + 4 + 1 + arg_num) * WORD_SIZE;
428}
429
430#if 0
431void asm_x86_push_arg(asm_x86_t *as, int src_arg_num) {
432 asm_x86_push_disp(as, ASM_X86_REG_ESP, asm_x86_arg_offset_from_esp(as, src_arg_num));
433}
434#endif
435
436void asm_x86_mov_arg_to_r32(asm_x86_t *as, int src_arg_num, int dest_r32) {
437 asm_x86_mov_mem32_to_r32(as, ASM_X86_REG_ESP, asm_x86_arg_offset_from_esp(as, src_arg_num), dest_r32);
438}
439
440#if 0
441void asm_x86_mov_r32_to_arg(asm_x86_t *as, int src_r32, int dest_arg_num) {
442 asm_x86_mov_r32_to_mem32(as, src_r32, ASM_X86_REG_ESP, asm_x86_arg_offset_from_esp(as, dest_arg_num));
443}
444#endif
445
446// locals:
447// - stored on the stack in ascending order
448// - numbered 0 through as->num_locals-1
449// - ESP points to the first local
450//
451// | ESP
452// v
453// l0 l1 l2 ... l(n-1)
454// ^ ^
455// | low address | high address in RAM
456//
457STATIC int asm_x86_local_offset_from_esp(asm_x86_t *as, int local_num) {
458 (void)as;
459 // Stack is full descending, ESP points to local0
460 return local_num * WORD_SIZE;
461}
462
463void asm_x86_mov_local_to_r32(asm_x86_t *as, int src_local_num, int dest_r32) {
464 asm_x86_mov_mem32_to_r32(as, ASM_X86_REG_ESP, asm_x86_local_offset_from_esp(as, src_local_num), dest_r32);
465}
466
467void asm_x86_mov_r32_to_local(asm_x86_t *as, int src_r32, int dest_local_num) {
468 asm_x86_mov_r32_to_mem32(as, src_r32, ASM_X86_REG_ESP, asm_x86_local_offset_from_esp(as, dest_local_num));
469}
470
471void asm_x86_mov_local_addr_to_r32(asm_x86_t *as, int local_num, int dest_r32) {
472 int offset = asm_x86_local_offset_from_esp(as, local_num);
473 if (offset == 0) {
474 asm_x86_mov_r32_r32(as, dest_r32, ASM_X86_REG_ESP);
475 } else {
476 asm_x86_lea_disp_to_r32(as, ASM_X86_REG_ESP, offset, dest_r32);
477 }
478}
479
480void asm_x86_mov_reg_pcrel(asm_x86_t *as, int dest_r32, mp_uint_t label) {
481 asm_x86_write_byte_1(as, OPCODE_CALL_REL32);
482 asm_x86_write_word32(as, 0);
483 mp_uint_t dest = get_label_dest(as, label);
484 mp_int_t rel = dest - as->base.code_offset;
485 asm_x86_pop_r32(as, dest_r32);
486 // PC rel is usually a forward reference, so need to assume it's large
487 asm_x86_write_byte_2(as, OPCODE_ADD_I32_TO_RM32, MODRM_R32(0) | MODRM_RM_REG | MODRM_RM_R32(dest_r32));
488 asm_x86_write_word32(as, rel);
489}
490
491#if 0
492void asm_x86_push_local(asm_x86_t *as, int local_num) {
493 asm_x86_push_disp(as, ASM_X86_REG_ESP, asm_x86_local_offset_from_esp(as, local_num));
494}
495
496void asm_x86_push_local_addr(asm_x86_t *as, int local_num, int temp_r32) {
497 asm_x86_mov_r32_r32(as, temp_r32, ASM_X86_REG_ESP);
498 asm_x86_add_i32_to_r32(as, asm_x86_local_offset_from_esp(as, local_num), temp_r32);
499 asm_x86_push_r32(as, temp_r32);
500}
501#endif
502
503void asm_x86_call_ind(asm_x86_t *as, size_t fun_id, mp_uint_t n_args, int temp_r32) {
504 assert(n_args <= 4);
505
506 // Align stack on 16-byte boundary during the call
507 unsigned int align = ((n_args + 3) & ~3) - n_args;
508 if (align) {
509 asm_x86_sub_r32_i32(as, ASM_X86_REG_ESP, align * WORD_SIZE);
510 }
511
512 if (n_args > 3) {
513 asm_x86_push_r32(as, ASM_X86_REG_ARG_4);
514 }
515 if (n_args > 2) {
516 asm_x86_push_r32(as, ASM_X86_REG_ARG_3);
517 }
518 if (n_args > 1) {
519 asm_x86_push_r32(as, ASM_X86_REG_ARG_2);
520 }
521 if (n_args > 0) {
522 asm_x86_push_r32(as, ASM_X86_REG_ARG_1);
523 }
524
525 // Load the pointer to the function and make the call
526 asm_x86_mov_mem32_to_r32(as, ASM_X86_REG_FUN_TABLE, fun_id * WORD_SIZE, temp_r32);
527 asm_x86_write_byte_2(as, OPCODE_CALL_RM32, MODRM_R32(2) | MODRM_RM_REG | MODRM_RM_R32(temp_r32));
528
529 // the caller must clean up the stack
530 if (n_args > 0) {
531 asm_x86_add_i32_to_r32(as, (n_args + align) * WORD_SIZE, ASM_X86_REG_ESP);
532 }
533}
534
535#endif // MICROPY_EMIT_X86
536