Compiler computes labels and max_num_labels.
diff --git a/py/asmx64.c b/py/asmx64.c
index ca461e0..4fbd44f 100644
--- a/py/asmx64.c
+++ b/py/asmx64.c
@@ -81,8 +81,7 @@
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 @@
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 @@
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_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 @@
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);
}
}