codegen.c: fix a bug in `OP_ADDI` and `OP_SUBI` regarding negative values.
@@ -779,13 +779,16 @@ gen_addsub(codegen_scope *s, uint8_t op, uint16_t dst)
mrb_int n0;
if (addr_pc(s, data.addr) == s->lastlabel || !get_int_operand(s, &data0, &n0)) {
/* OP_ADDI/OP_SUBI takes upto 16bits */
- if (n > INT16_MAX) goto normal;
+ if (n > INT16_MAX || n < INT16_MIN) goto normal;
rewind_pc(s);
- if (op == OP_ADD) {
- genop_2(s, OP_ADDI, dst, (uint16_t)n);
+ if (n > 0) {
+ if (op == OP_ADD) genop_2(s, OP_ADDI, dst, (uint16_t)n);
+ else genop_2(s, OP_SUBI, dst, (uint16_t)n);
}
- else {
- genop_2(s, OP_SUBI, dst, (uint16_t)n);
+ else { /* n < 0 */
+ n = -n;
+ if (op == OP_ADD) genop_2(s, OP_SUBI, dst, (uint16_t)n);
+ else genop_2(s, OP_ADDI, dst, (uint16_t)n);
}
return;
}
