diff options
Diffstat (limited to 'py/asmx64.c')
| -rw-r--r-- | py/asmx64.c | 133 |
1 files changed, 59 insertions, 74 deletions
diff --git a/py/asmx64.c b/py/asmx64.c index ca461e0c2e..4fbd44f98c 100644 --- a/py/asmx64.c +++ b/py/asmx64.c @@ -81,8 +81,7 @@ struct _asm_x64_t { byte *code_base; byte dummy_data[8]; - int next_label; - int max_num_labels; + uint max_num_labels; int *label_offsets; }; @@ -98,7 +97,7 @@ void *alloc_mem(uint req_size, uint *alloc_size, bool is_exec) { return ptr; } -asm_x64_t* asm_x64_new() { +asm_x64_t* asm_x64_new(uint max_num_labels) { asm_x64_t* as; as = m_new(asm_x64_t, 1); @@ -106,7 +105,8 @@ asm_x64_t* asm_x64_new() { as->code_offset = 0; as->code_size = 0; as->code_base = NULL; - as->label_offsets = NULL; + as->max_num_labels = max_num_labels; + as->label_offsets = m_new(int, max_num_labels); return as; } @@ -134,29 +134,19 @@ void asm_x64_free(asm_x64_t* as, bool free_code) { void asm_x64_start_pass(asm_x64_t *as, int pass) { as->pass = pass; as->code_offset = 0; - as->next_label = 1; - if (pass == ASM_X64_PASS_1) { - as->max_num_labels = 0; - } else { - if (pass == ASM_X64_PASS_2) { - memset(as->label_offsets, -1, as->max_num_labels * sizeof(int)); - } + if (pass == ASM_X64_PASS_2) { + // reset all labels + memset(as->label_offsets, -1, as->max_num_labels * sizeof(int)); } } void asm_x64_end_pass(asm_x64_t *as) { - if (as->pass == ASM_X64_PASS_1) { - // calculate number of labels need - if (as->next_label > as->max_num_labels) { - as->max_num_labels = as->next_label; - } - as->label_offsets = m_new(int, as->max_num_labels); - } else if (as->pass == ASM_X64_PASS_2) { + if (as->pass == ASM_X64_PASS_2) { // calculate size of code in bytes as->code_size = as->code_offset; - as->code_base = m_new(byte, as->code_size); - //uint actual_alloc; - //as->code_base = alloc_mem(as->code_size, &actual_alloc, true); + //as->code_base = m_new(byte, as->code_size); need to allocale executable memory + uint actual_alloc; + as->code_base = alloc_mem(as->code_size, &actual_alloc, true); printf("code_size: %u\n", as->code_size); } @@ -458,70 +448,65 @@ void asm_x64_setcc_r8(asm_x64_t* as, int jcc_type, int dest_r8) { asm_x64_write_byte_3(as, OPCODE_SETCC_RM8_A, OPCODE_SETCC_RM8_B | jcc_type, MODRM_R64(0) | MODRM_RM_REG | MODRM_RM_R64(dest_r8)); } -int asm_x64_label_new(asm_x64_t* as) { - return as->next_label++; -} - void asm_x64_label_assign(asm_x64_t* as, int label) { - if (as->pass > ASM_X64_PASS_1) { - assert(label < as->max_num_labels); - if (as->pass == ASM_X64_PASS_2) { - // assign label offset - assert(as->label_offsets[label] == -1); - as->label_offsets[label] = as->code_offset; - } else if (as->pass == ASM_X64_PASS_3) { - // ensure label offset has not changed from PASS_2 to PASS_3 - //printf("l%d: (at %d=%ld)\n", label, as->label_offsets[label], as->code_offset); - assert(as->label_offsets[label] == as->code_offset); - } + assert(label < as->max_num_labels); + if (as->pass == ASM_X64_PASS_2) { + // assign label offset + assert(as->label_offsets[label] == -1); + as->label_offsets[label] = as->code_offset; + } else if (as->pass == ASM_X64_PASS_3) { + // ensure label offset has not changed from PASS_2 to PASS_3 + //printf("l%d: (at %d=%ld)\n", label, as->label_offsets[label], as->code_offset); + assert(as->label_offsets[label] == as->code_offset); } } -void asm_x64_jmp_label(asm_x64_t* as, int label) { - if (as->pass > ASM_X64_PASS_1) { - int dest = as->label_offsets[label]; - int rel = dest - as->code_offset; - if (dest >= 0 && rel < 0) { - // is a backwards jump, so we know the size of the jump on the first pass - // calculate rel assuming 8 bit relative jump - rel -= 2; - if (SIGNED_FIT8(rel)) { - asm_x64_write_byte_2(as, OPCODE_JMP_REL8, rel & 0xff); - } else { - rel += 2; - goto large_jump; - } +static int get_label_dest(asm_x64_t *as, int label) { + assert(label < as->max_num_labels); + return as->label_offsets[label]; +} + +void asm_x64_jmp_label(asm_x64_t *as, int label) { + int dest = get_label_dest(as, label); + int rel = dest - as->code_offset; + if (dest >= 0 && rel < 0) { + // is a backwards jump, so we know the size of the jump on the first pass + // calculate rel assuming 8 bit relative jump + rel -= 2; + if (SIGNED_FIT8(rel)) { + asm_x64_write_byte_2(as, OPCODE_JMP_REL8, rel & 0xff); } else { - // is a forwards jump, so need to assume it's large - large_jump: - rel -= 5; - asm_x64_write_byte_1(as, OPCODE_JMP_REL32); - asm_x64_write_word32(as, rel); + rel += 2; + goto large_jump; } + } else { + // is a forwards jump, so need to assume it's large + large_jump: + rel -= 5; + asm_x64_write_byte_1(as, OPCODE_JMP_REL32); + asm_x64_write_word32(as, rel); } } -void asm_x64_jcc_label(asm_x64_t* as, int jcc_type, int label) { - if (as->pass > ASM_X64_PASS_1) { - int dest = as->label_offsets[label]; - int rel = dest - as->code_offset; - if (dest >= 0 && rel < 0) { - // is a backwards jump, so we know the size of the jump on the first pass - // calculate rel assuming 8 bit relative jump - rel -= 2; - if (SIGNED_FIT8(rel)) { - asm_x64_write_byte_2(as, OPCODE_JCC_REL8 | jcc_type, rel & 0xff); - } else { - rel += 2; - goto large_jump; - } +void asm_x64_jcc_label(asm_x64_t *as, int jcc_type, int label) { + int dest = get_label_dest(as, label); + int rel = dest - as->code_offset; + if (dest >= 0 && rel < 0) { + // is a backwards jump, so we know the size of the jump on the first pass + // calculate rel assuming 8 bit relative jump + rel -= 2; + if (SIGNED_FIT8(rel)) { + asm_x64_write_byte_2(as, OPCODE_JCC_REL8 | jcc_type, rel & 0xff); } else { - // is a forwards jump, so need to assume it's large - large_jump: - rel -= 6; - asm_x64_write_byte_2(as, OPCODE_JCC_REL32_A, OPCODE_JCC_REL32_B | jcc_type); - asm_x64_write_word32(as, rel); + rel += 2; + goto large_jump; } + } else { + // is a forwards jump, so need to assume it's large + large_jump: + rel -= 6; + asm_x64_write_byte_2(as, OPCODE_JCC_REL32_A, OPCODE_JCC_REL32_B | jcc_type); + asm_x64_write_word32(as, rel); } } |