From 40466c48e843221e010209e4baa4197debf7a092 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Thu, 10 Nov 2022 02:24:41 +0700 Subject: [PATCH] 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. --- sim/ppc/dgen.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/sim/ppc/dgen.c b/sim/ppc/dgen.c index d2ea922ffc9..d772771b9fa 100644 --- a/sim/ppc/dgen.c +++ b/sim/ppc/dgen.c @@ -238,14 +238,22 @@ gen_spreg_c(spreg_table *table, lf *file) 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. */ -- 2.30.2