static void emit_ia32_SwitchJmp(const ir_node *irn, ia32_emit_env_t *emit_env) {
unsigned long interval;
char buf[SNPRINTF_BUF_LEN];
- int last_value, i, pn, do_jmp_tbl = 1;
+ int last_value, i, pn;
jmp_tbl_t tbl;
ir_node *proj;
const ir_edge_t *edge;
/* two-complement's magic make this work without overflow */
interval = tbl.max_value - tbl.min_value;
- /* check value interval */
- if (interval > 16 * 1024) {
- do_jmp_tbl = 0;
- }
+ /* emit the table */
+ if (tbl.min_value != 0) {
+ lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "sub [%1S-%d], %u", irn, tbl.min_value * 4, interval);
+ lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "cmp DWORD PTR [%1S-%d], %u", irn, tbl.min_value * 4, interval);
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* first switch value is not 0 */");
- /* check ratio of value interval to number of branches */
- if ((float)(interval + 1) / (float)tbl.num_branches > 8.0) {
- do_jmp_tbl = 0;
+ IA32_DO_EMIT(irn);
}
+ else {
+ lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "cmp %1S, %u", irn, interval);
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* compare for switch */");
- if (do_jmp_tbl) {
- /* emit the table */
- if (tbl.min_value != 0) {
- lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "cmpl %lu, -%d(%1S)",
- interval, tbl.min_value, irn);
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* first switch value is not 0 */");
+ IA32_DO_EMIT(irn);
+ }
- IA32_DO_EMIT(irn);
- }
- else {
- lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "cmpl %lu, %1S", interval, irn);
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* compare for switch */");
+ snprintf(cmd_buf, SNPRINTF_BUF_LEN, "ja %s", get_cfop_target(tbl.defProj, buf));
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* default jump if out of range */");
+ IA32_DO_EMIT(irn);
- IA32_DO_EMIT(irn);
- }
+ if (tbl.num_branches > 1) {
+ /* create table */
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, "ja %s", get_cfop_target(tbl.defProj, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* default jump if out of range */");
+ lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "jmp %s[%1S*4]", tbl.label, irn);
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* get jump table entry as target */");
IA32_DO_EMIT(irn);
- if (tbl.num_branches > 1) {
- /* create table */
-
- lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "jmp [%1S*4+%s]", irn, tbl.label);
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* get jump table entry as target */");
- IA32_DO_EMIT(irn);
+ fprintf(F, "\t.section\t.rodata\n");
+ fprintf(F, "\t.align 4\n");
- fprintf(F, "\t.section\t.rodata\n");
- fprintf(F, "\t.align 4\n");
+ fprintf(F, "%s:\n", tbl.label);
- fprintf(F, "%s:\n", tbl.label);
-
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.branches[0].target, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* case %d */\n", tbl.branches[0].value);
- IA32_DO_EMIT(irn);
+ snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.branches[0].target, buf));
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* case %d */\n", tbl.branches[0].value);
+ IA32_DO_EMIT(irn);
- last_value = tbl.branches[0].value;
- for (i = 1; i < tbl.num_branches; ++i) {
- while (++last_value < tbl.branches[i].value) {
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.defProj, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* default case */");
- IA32_DO_EMIT(irn);
- }
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.branches[i].target, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* case %d */", last_value);
+ last_value = tbl.branches[0].value;
+ for (i = 1; i < tbl.num_branches; ++i) {
+ while (++last_value < tbl.branches[i].value) {
+ snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.defProj, buf));
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* default case */");
IA32_DO_EMIT(irn);
}
-
- fprintf(F, "\t.text");
- }
- else {
- /* one jump is enough */
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, "jmp %s", get_cfop_target(tbl.branches[0].target, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* only one case given */");
- IA32_DO_EMIT(irn);
- }
- }
- else { // no jump table
- for (i = 0; i < tbl.num_branches; ++i) {
- lc_esnprintf(env, cmd_buf, SNPRINTF_BUF_LEN, "cmpl %d, %1S", tbl.branches[i].value, irn);
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* case %d */", i);
+ snprintf(cmd_buf, SNPRINTF_BUF_LEN, ".long %s", get_cfop_target(tbl.branches[i].target, buf));
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* case %d */", last_value);
IA32_DO_EMIT(irn);
- fprintf(F, "\tje %s\n", get_cfop_target(tbl.branches[i].target, buf));
}
- snprintf(cmd_buf, SNPRINTF_BUF_LEN, "jmp %s", get_cfop_target(tbl.defProj, buf));
- snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* default case */");
+ fprintf(F, "\t.text");
+ }
+ else {
+ /* one jump is enough */
+ snprintf(cmd_buf, SNPRINTF_BUF_LEN, "jmp %s", get_cfop_target(tbl.branches[0].target, buf));
+ snprintf(cmnt_buf, SNPRINTF_BUF_LEN, "/* only one case given */");
IA32_DO_EMIT(irn);
}