void asm_x64_mov_reg_pcrel(asm_x64_t *as, int dest_r64, mp_uint_t label) { assert(dest_r64 < 8); mp_uint_t dest = get_label_dest(as, label); mp_int_t rel = dest - (as->base.code_offset + 7); asm_x64_write_byte_3(as, REX_PREFIX | REX_W, OPCODE_LEA_MEM_TO_R64, MODRM_R64(dest_r64) | MODRM_RM_R64(5)); asm_x64_write_word32(as, rel); }
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 { 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); } }
void asm_x64_jmp_label(asm_x64_t *as, mp_uint_t label) { mp_uint_t dest = get_label_dest(as, label); mp_int_t rel = dest - as->base.code_offset; if (dest != (mp_uint_t)-1 && 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; } } 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); } }