1/*
2 * This file is part of the MicroPython project, http://micropython.org/
3 *
4 * The MIT License (MIT)
5 *
6 * Copyright (c) 2016 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 <assert.h>
28#include <string.h>
29
30#include "py/obj.h"
31#include "py/misc.h"
32#include "py/asmbase.h"
33
34#if MICROPY_EMIT_MACHINE_CODE
35
36void mp_asm_base_init(mp_asm_base_t *as, size_t max_num_labels) {
37 as->max_num_labels = max_num_labels;
38 as->label_offsets = m_new(size_t, max_num_labels);
39}
40
41void mp_asm_base_deinit(mp_asm_base_t *as, bool free_code) {
42 if (free_code) {
43 MP_PLAT_FREE_EXEC(as->code_base, as->code_size);
44 }
45 m_del(size_t, as->label_offsets, as->max_num_labels);
46}
47
48void mp_asm_base_start_pass(mp_asm_base_t *as, int pass) {
49 if (pass < MP_ASM_PASS_EMIT) {
50 // Reset labels so we can detect backwards jumps (and verify unique assignment)
51 memset(as->label_offsets, -1, as->max_num_labels * sizeof(size_t));
52 } else {
53 // allocating executable RAM is platform specific
54 MP_PLAT_ALLOC_EXEC(as->code_offset, (void **)&as->code_base, &as->code_size);
55 assert(as->code_base != NULL);
56 }
57 as->pass = pass;
58 as->code_offset = 0;
59}
60
61// all functions must go through this one to emit bytes
62// if as->pass < MP_ASM_PASS_EMIT, then this function just counts the number
63// of bytes needed and returns NULL, and callers should not store any data
64uint8_t *mp_asm_base_get_cur_to_write_bytes(mp_asm_base_t *as, size_t num_bytes_to_write) {
65 uint8_t *c = NULL;
66 if (as->pass == MP_ASM_PASS_EMIT) {
67 assert(as->code_offset + num_bytes_to_write <= as->code_size);
68 c = as->code_base + as->code_offset;
69 }
70 as->code_offset += num_bytes_to_write;
71 return c;
72}
73
74void mp_asm_base_label_assign(mp_asm_base_t *as, size_t label) {
75 assert(label < as->max_num_labels);
76 if (as->pass < MP_ASM_PASS_EMIT) {
77 // assign label offset
78 assert(as->label_offsets[label] == (size_t)-1);
79 as->label_offsets[label] = as->code_offset;
80 } else {
81 // ensure label offset has not changed from PASS_COMPUTE to PASS_EMIT
82 assert(as->label_offsets[label] == as->code_offset);
83 }
84}
85
86// align must be a multiple of 2
87void mp_asm_base_align(mp_asm_base_t *as, unsigned int align) {
88 as->code_offset = (as->code_offset + align - 1) & (~(align - 1));
89}
90
91// this function assumes a little endian machine
92void mp_asm_base_data(mp_asm_base_t *as, unsigned int bytesize, uintptr_t val) {
93 uint8_t *c = mp_asm_base_get_cur_to_write_bytes(as, bytesize);
94 if (c != NULL) {
95 for (unsigned int i = 0; i < bytesize; i++) {
96 *c++ = val;
97 val >>= 8;
98 }
99 }
100}
101
102#endif // MICROPY_EMIT_MACHINE_CODE
103