https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101555
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |12.0
Keywords| |needs-bisection
Summary|Compile slowdown in tree |[12 Regression] Compile
|PRE |slowdown in tree PRE
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
Status|UNCONFIRMED |ASSIGNED
Version|9.3.0 |12.0
Ever confirmed|0 |1
Last reconfirmed| |2021-07-22
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed with g++-9 (SUSE Linux) 9.3.1 20200406 [revision
6db837a5288ee3ca5ec504fbd5a765817e556ac2]
tree PRE : 645.41 ( 97%) 0.16 ( 34%) 645.60 ( 97%)
177896 kB ( 15%)
TOTAL : 665.14 0.47 665.73
1154121 kB
with -fno-code-hoisting that get's down to
tree PRE : 219.50 ( 93%) 0.04 ( 11%) 219.69 ( 93%)
87813 kB ( 11%)
TOTAL : 235.70 0.37 236.12
807306 kB
GCC 10.3.0 shows
tree PRE : 267.62 ( 93%) 0.13 ( 32%) 267.69 ( 93%)
140858 kB ( 13%)
TOTAL : 288.92 0.41 289.37
1122606 kB
GCC 11 does
tree PRE : 251.41 ( 91%) 0.10 ( 23%) 251.71 ( 91%)
137M ( 16%)
TOTAL : 275.01 0.43 275.51
837M
Note that trunk regresses again:
tree PRE : 312.12 ( 93%) 0.07 ( 15%) 312.46 ( 93%)
137M ( 16%)
TOTAL : 337.03 0.48 337.58
836M
bisection for that would be nice.
So part of this PR is a dup of PR97623, but there's still slowness of PRE
(as said elsewhere PRE is known quadratic).
I'm turning this PR into the GCC 12 regression that shows above.
