https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62291
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|PRE uses too much memory |tree PRE uses too much
|and compile-time |memory and compile-time
Known to work| |10.1.0, 11.1.0, 12.1.0,
| |13.1.0
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
On a Ryzen 9 7900X I get with GCC 13.2
-O0 1.4s 430MB
-O1 17.4s 640MB
-O2 26.9s 822MB
-O2 -fdisable-tree-pre 22.3s 690MB
-O3 26.9s 824MB
it's now far from blowing up (in PRE). GCC 5.5 needs 3.5GB of memory, GCC 7
needs 5.5GB. I can't really reproduce high compile-time even with 4.9.5.
The problem that AVAIL_OUT compute requires quadratic memory isn't solved.
-ftime-report with GCC 13.2 shows
alias stmt walking : 8.42 ( 31%) 0.17 ( 18%) 8.29 ( 29%)
4743k ( 1%)
tree PTA : 7.74 ( 28%) 0.20 ( 22%) 7.95 ( 28%)
2706k ( 1%)
tree PRE : 0.29 ( 1%) 0.01 ( 1%) 0.31 ( 1%)
23M ( 4%)
and with -details
tree PRE : 0.29 ( 1%) 0.00 ( 0%) 0.34 ( 1%)
23M ( 4%)
`- tree tail merge : 0.02 ( 0%) 0.00 ( 0%) 0.03 ( 0%)
0 ( 0%)
`- loop init : 0.01 ( 0%) 0.00 ( 0%) 0.00 ( 0%)
0 ( 0%)
`- tree PTA : 2.64 ( 10%) 0.05 ( 6%) 2.69 ( 9%)
604k ( 0%)
`- alias stmt walking : 2.02 ( 7%) 0.04 ( 5%) 2.01 ( 7%)
1185k ( 0%)
