https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91257
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |NEW
CC| |rguenth at gcc dot gnu.org
Assignee|rguenth at gcc dot gnu.org |unassigned at gcc dot
gnu.org
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
Otherwise I'm done here. Updated numbers for trunk (release-checking,
non-bootstrapped build with GCC 4.8 host compiler) on the original testcase
time peak rss
-O3 -fwrapv -m32 112s 4.7GB
-O2 -fwrapv -m32 111s 4.7GB
-O2 -fwrapv -m32 -fno-ipa-icf 301s 4.7GB
-O1 -fwrapv -m32 204s 4.5GB
-O1 202s 4.5GB
and on the testcase with just gen_opt (the original has gen_opt{,1,2,3,4,5})
-O3 -fwrapv -m32 50s 1.7GB
-O2 -fwrapv -m32 50s 1.7GB
-O1 34s 1.4GB
so it's clear that ICF simply shrinks the testcase by identifying all
functions as 1:1 identical for the original testcase with -O2+.
Numbers show there's really no IPA component to the testcase then
and looking at a reduced one is fully sufficicent.
Time report for plain -O2:
Time variable usr sys wall
GGC
tree VRP : 5.88 ( 12%) 0.24 ( 25%) 6.10 ( 12%)
598 kB ( 0%)
tree Early VRP : 0.81 ( 2%) 0.00 ( 0%) 0.81 ( 2%)
152 kB ( 0%)
tree copy propagation : 1.42 ( 3%) 0.00 ( 0%) 1.42 ( 3%)
0 kB ( 0%)
tree PTA : 7.77 ( 16%) 0.25 ( 26%) 8.02 ( 16%)
7755 kB ( 1%)
tree SSA rewrite : 1.74 ( 3%) 0.00 ( 0%) 1.75 ( 3%)
629 kB ( 0%)
dominator optimization : 2.29 ( 5%) 0.00 ( 0%) 2.32 ( 5%)
707 kB ( 0%)
tree CCP : 3.57 ( 7%) 0.04 ( 4%) 3.61 ( 7%)
63 kB ( 0%)
tree PRE : 1.69 ( 3%) 0.02 ( 2%) 1.71 ( 3%)
357 kB ( 0%)
tree FRE : 4.15 ( 8%) 0.00 ( 0%) 4.19 ( 8%)
152 kB ( 0%)
tree backward propagate : 1.04 ( 2%) 0.02 ( 2%) 1.06 ( 2%)
0 kB ( 0%)
tree forward propagate : 1.29 ( 3%) 0.00 ( 0%) 1.31 ( 3%)
0 kB ( 0%)
out of ssa : 9.27 ( 19%) 0.00 ( 0%) 9.28 ( 18%)
47 kB ( 0%)
TOTAL : 49.80 0.97 50.79
747309 kB
Time report for plain -O1:
Time variable usr sys wall
GGC
tree copy propagation : 1.40 ( 4%) 0.00 ( 0%) 1.41 ( 4%)
0 kB ( 0%)
tree PTA : 5.78 ( 17%) 0.19 ( 32%) 5.97 ( 18%)
7679 kB ( 1%)
tree SSA rewrite : 1.63 ( 5%) 0.00 ( 0%) 1.63 ( 5%)
629 kB ( 0%)
dominator optimization : 2.29 ( 7%) 0.01 ( 2%) 2.30 ( 7%)
694 kB ( 0%)
tree CCP : 3.53 ( 11%) 0.07 ( 12%) 3.60 ( 11%)
63 kB ( 0%)
tree FRE : 2.74 ( 8%) 0.02 ( 3%) 2.75 ( 8%)
101 kB ( 0%)
tree backward propagate : 1.04 ( 3%) 0.01 ( 2%) 1.05 ( 3%)
0 kB ( 0%)
tree forward propagate : 1.29 ( 4%) 0.00 ( 0%) 1.29 ( 4%)
0 kB ( 0%)
out of ssa : 6.22 ( 19%) 0.00 ( 0%) 6.22 ( 18%)
55 kB ( 0%)
TOTAL : 33.38 0.59 33.98
744713 kB
