cse: Size insn_hash_table more realistically, speeding up CSE significantly

Profiling showed that Sparse spent much of its time doing CSE, which involved
traversing every bucket of insn_hash_table repeatedly.  insn_hash_table had
64K buckets, but never more than a few dozen entries.  Shrink insn_hash_table
to 256 entries.  This makes Sparse 2-4 times faster for me.

Signed-off-by: Josh Triplett <josh@freedesktop.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/cse.c b/cse.c
index 9370a6c..2a15745 100644
--- a/cse.c
+++ b/cse.c
@@ -17,7 +17,7 @@
 #include "linearize.h"
 #include "flow.h"
 
-#define INSN_HASH_SIZE 65536
+#define INSN_HASH_SIZE 256
 static struct instruction_list *insn_hash_table[INSN_HASH_SIZE];
 
 int repeat_phase;