sim: ppc: collapse is_readonly & length switch tables heavily
Since we know we'll return 0 by default, we don't have to output case
statements for readonly or length fields whose values are also zero.
This is the most common case by far and thus generates a much smaller
switch table in the end.
diff --git a/sim/ppc/dgen.c b/sim/ppc/dgen.c
index d2ea922..d772771 100644
--- a/sim/ppc/dgen.c
+++ b/sim/ppc/dgen.c
@@ -238,14 +238,22 @@
spreg_table_entry *entry;
lf_printf(file, " switch (spr) {\n");
for (entry = table->sprs; entry != NULL; entry = entry->next) {
- lf_printf(file, " case %d:\n", entry->spreg_nr);
- if (strcmp(*attribute, "is_valid") == 0)
+ if (strcmp(*attribute, "is_valid") == 0) {
+ lf_printf(file, " case %d:\n", entry->spreg_nr);
/* No return -- see below. */;
- else if (strcmp(*attribute, "is_readonly") == 0)
- lf_printf(file, " return %d;\n", entry->is_readonly);
- else if (strcmp(*attribute, "length") == 0)
- lf_printf(file, " return %d;\n", entry->length);
- else
+ } else if (strcmp(*attribute, "is_readonly") == 0) {
+ /* Since we return 0 by default, only output non-zero entries. */
+ if (entry->is_readonly) {
+ lf_printf(file, " case %d:\n", entry->spreg_nr);
+ lf_printf(file, " return %d;\n", entry->is_readonly);
+ }
+ } else if (strcmp(*attribute, "length") == 0) {
+ /* Since we return 0 by default, only output non-zero entries. */
+ if (entry->length) {
+ lf_printf(file, " case %d:\n", entry->spreg_nr);
+ lf_printf(file, " return %d;\n", entry->length);
+ }
+ } else
ASSERT(0);
}
/* Output a single return for is_valid. */
