diff mbox series

Decrease hash-table-verification-limit from 100 to 10.

Message ID e34ef932-327d-30a6-e667-c1b8b050ee06@suse.cz
State New
Headers show
Series Decrease hash-table-verification-limit from 100 to 10. | expand

Commit Message

Martin Liška June 19, 2019, 1:15 p.m. UTC 
Hi.

The patch is about decrease of verification limit. I collected following statistics:

godot WPA:

hash-table-verification-limit=0: 66s
hash-table-verification-limit=10: 69s
hash-table-verification-limit=100: 94s

make all runtime libraries in GCC for --disable-bootstrap --disable-libsanitizer --disable-multilib

=0: 127s (17m30s user time)
=10: 130s (18m17s user time)
=100: 150s (20m37s user time)

That's why I'm suggesting default equal to 10. Moreover as items are rehashed during a hash table
growth we always compare different items.

Ready for trunk?
Thanks,
Martin

gcc/ChangeLog:

2019-06-19  Martin Liska  <mliska@suse.cz>

	* params.def (PARAM_HASH_TABLE_VERIFICATION_LIMIT): Decrease
	to 10.
---
 gcc/params.def | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jeff Law June 19, 2019, 3:54 p.m. UTC | #1 
On 6/19/19 7:15 AM, Martin Liška wrote:
> Hi.
> 
> The patch is about decrease of verification limit. I collected following statistics:
> 
> godot WPA:
> 
> hash-table-verification-limit=0: 66s
> hash-table-verification-limit=10: 69s
> hash-table-verification-limit=100: 94s
> 
> make all runtime libraries in GCC for --disable-bootstrap --disable-libsanitizer --disable-multilib
> 
> =0: 127s (17m30s user time)
> =10: 130s (18m17s user time)
> =100: 150s (20m37s user time)
> 
> That's why I'm suggesting default equal to 10. Moreover as items are rehashed during a hash table
> growth we always compare different items.
> 
> Ready for trunk?
> Thanks,
> Martin
> 
> gcc/ChangeLog:
> 
> 2019-06-19  Martin Liska  <mliska@suse.cz>
> 
> 	* params.def (PARAM_HASH_TABLE_VERIFICATION_LIMIT): Decrease
> 	to 10.
OK
jeff
diff mbox series

Patch

diff --git a/gcc/params.def b/gcc/params.def
index 0db60951413..4567c17ba60 100644
--- a/gcc/params.def
+++ b/gcc/params.def
@@ -1435,7 +1435,7 @@  DEFPARAM(PARAM_HASH_TABLE_VERIFICATION_LIMIT,
 	 "hash-table-verification-limit",
 	 "The number of elements for which hash table verification is done for "
 	 "each searched element.",
-	 100, 0, 0)
+	 10, 0, 0)
 
 /*