diff options
| author | Jan Hubicka <jh@suse.cz> | 2020-05-22 12:31:34 +0200 |
|---|---|---|
| committer | Jan Hubicka <jh@suse.cz> | 2020-05-22 12:31:34 +0200 |
| commit | 1089a367c4b05b5e3f072adca8913904ed65928c (patch) | |
| tree | dc3005726895465873d326c1c26a4189f61e28da /gcc/ChangeLog | |
| parent | 47273df0bcdd552385f25049dce71943aac8321e (diff) | |
Fix hashing of prestreamed nodes
this patch seems to solve basically all collisions while building cc1.
From:
[WPA] read 3312246 unshared trees
[WPA] read 1144381 mergeable SCCs of average size 4.833785
[WPA] 8843938 tree bodies read in total
[WPA] tree SCC table: size 524287, 197767 elements, collision ratio: 0.506446
[WPA] tree SCC max chain length 43 (size 1)
[WPA] Compared 946614 SCCs, 775077 collisions (0.818789)
to
[WPA] read 3314520 unshared trees
[WPA] read 1144763 mergeable SCCs of average size 4.835021
[WPA] 8849473 tree bodies read in total
[WPA] tree SCC table: size 524287, 200574 elements, collision ratio: 0.486418
[WPA] tree SCC max chain length 2 (size 1)
[WPA] Compared 944189 SCCs, 179 collisions (0.000190)
The problem is that preloaded nodes all have hash code 0 because
cache->nodes.length is not updated while streaming out.
I also added an arbitrary constant to avoid clash with constant of 0 used to
hash NULL pointers and 1 used to hash pointers inside SCC.
* tree-streamer.c (record_common_node): Fix hash value of pre-streamed
nodes.
Diffstat (limited to 'gcc/ChangeLog')
| -rw-r--r-- | gcc/ChangeLog | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 820240fc827..d22e9aa250e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2020-05-22 Jan Hubicka <hubicka@ucw.cz> + * tree-streamer.c (record_common_node): Fix hash value of pre-streamed + nodes. + +2020-05-22 Jan Hubicka <hubicka@ucw.cz> + * lto-streamer-in.c (lto_read_tree): Do not stream end markers. (lto_input_scc): Optimize streaming of entry lengths. * lto-streamer-out.c (lto_write_tree): Do not stream end markers |