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-rw-r--r--py/asmthumb.c102
1 files changed, 46 insertions, 56 deletions
diff --git a/py/asmthumb.c b/py/asmthumb.c
index ea7547d4b1..9850bec30c 100644
--- a/py/asmthumb.c
+++ b/py/asmthumb.c
@@ -28,7 +28,7 @@ struct _asm_thumb_t {
uint stack_adjust;
};
-asm_thumb_t *asm_thumb_new() {
+asm_thumb_t *asm_thumb_new(uint max_num_labels) {
asm_thumb_t *as;
as = m_new(asm_thumb_t, 1);
@@ -36,7 +36,8 @@ asm_thumb_t *asm_thumb_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);
as->num_locals = 0;
return as;
@@ -65,23 +66,13 @@ void asm_thumb_start_pass(asm_thumb_t *as, int pass) {
as->pass = pass;
as->code_offset = 0;
as->next_label = 1;
- if (pass == ASM_THUMB_PASS_1) {
- as->max_num_labels = 0;
- } else {
- if (pass == ASM_THUMB_PASS_2) {
- memset(as->label_offsets, -1, as->max_num_labels * sizeof(int));
- }
+ if (pass == ASM_THUMB_PASS_2) {
+ memset(as->label_offsets, -1, as->max_num_labels * sizeof(int));
}
}
void asm_thumb_end_pass(asm_thumb_t *as) {
- if (as->pass == ASM_THUMB_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_THUMB_PASS_2) {
+ if (as->pass == ASM_THUMB_PASS_2) {
// calculate size of code in bytes
as->code_size = as->code_offset;
as->code_base = m_new(byte, as->code_size);
@@ -226,20 +217,23 @@ int asm_thumb_label_new(asm_thumb_t *as) {
}
void asm_thumb_label_assign(asm_thumb_t *as, int label) {
- if (as->pass > ASM_THUMB_PASS_1) {
- assert(label < as->max_num_labels);
- if (as->pass == ASM_THUMB_PASS_2) {
- // assign label offset
- assert(as->label_offsets[label] == -1);
- as->label_offsets[label] = as->code_offset;
- } else if (as->pass == ASM_THUMB_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_THUMB_PASS_2) {
+ // assign label offset
+ assert(as->label_offsets[label] == -1);
+ as->label_offsets[label] = as->code_offset;
+ } else if (as->pass == ASM_THUMB_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);
}
}
+static int get_label_dest(asm_thumb_t *as, int label) {
+ assert(label < as->max_num_labels);
+ return as->label_offsets[label];
+}
+
// the i8 value will be zero extended into the r32 register!
void asm_thumb_mov_reg_i8(asm_thumb_t *as, uint rlo_dest, int i8) {
assert(rlo_dest < REG_R8);
@@ -339,23 +333,21 @@ void asm_thumb_ite_ge(asm_thumb_t *as) {
#define OP_BW_LO(byte_offset) (0xb800 | (((byte_offset) >> 1) & 0x07ff))
void asm_thumb_b_label(asm_thumb_t *as, int label) {
- if (as->pass > ASM_THUMB_PASS_1) {
- int dest = as->label_offsets[label];
- int rel = dest - as->code_offset;
- rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
- if (dest >= 0 && rel <= -4) {
- // is a backwards jump, so we know the size of the jump on the first pass
- // calculate rel assuming 12 bit relative jump
- if (SIGNED_FIT12(rel)) {
- asm_thumb_write_op16(as, OP_B(rel));
- } else {
- goto large_jump;
- }
+ int dest = get_label_dest(as, label);
+ int rel = dest - as->code_offset;
+ rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
+ if (dest >= 0 && rel <= -4) {
+ // is a backwards jump, so we know the size of the jump on the first pass
+ // calculate rel assuming 12 bit relative jump
+ if (SIGNED_FIT12(rel)) {
+ asm_thumb_write_op16(as, OP_B(rel));
} else {
- // is a forwards jump, so need to assume it's large
- large_jump:
- asm_thumb_write_op32(as, OP_BW_HI(rel), OP_BW_LO(rel));
+ goto large_jump;
}
+ } else {
+ // is a forwards jump, so need to assume it's large
+ large_jump:
+ asm_thumb_write_op32(as, OP_BW_HI(rel), OP_BW_LO(rel));
}
}
@@ -372,23 +364,21 @@ void asm_thumb_cmp_reg_bz_label(asm_thumb_t *as, uint rlo, int label) {
asm_thumb_write_op16(as, OP_CMP_REG_IMM(rlo, 0));
// branch if equal
- if (as->pass > ASM_THUMB_PASS_1) {
- int dest = as->label_offsets[label];
- int rel = dest - as->code_offset;
- rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
- if (dest >= 0 && rel <= -4) {
- // is a backwards jump, so we know the size of the jump on the first pass
- // calculate rel assuming 12 bit relative jump
- if (SIGNED_FIT9(rel)) {
- asm_thumb_write_op16(as, OP_BEQ(rel));
- } else {
- goto large_jump;
- }
+ int dest = get_label_dest(as, label);
+ int rel = dest - as->code_offset;
+ rel -= 4; // account for instruction prefetch, PC is 4 bytes ahead of this instruction
+ if (dest >= 0 && rel <= -4) {
+ // is a backwards jump, so we know the size of the jump on the first pass
+ // calculate rel assuming 12 bit relative jump
+ if (SIGNED_FIT9(rel)) {
+ asm_thumb_write_op16(as, OP_BEQ(rel));
} else {
- // is a forwards jump, so need to assume it's large
- large_jump:
- asm_thumb_write_op32(as, OP_BEQW_HI(rel), OP_BEQW_LO(rel));
+ goto large_jump;
}
+ } else {
+ // is a forwards jump, so need to assume it's large
+ large_jump:
+ asm_thumb_write_op32(as, OP_BEQW_HI(rel), OP_BEQW_LO(rel));
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-11 14:04:48 +0000