https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91257
Bug ID: 91257
Summary: [7/8/9/10 Regression] Compile-time and memory-hog hog
Product: gcc
Version: 9.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: rguenth at gcc dot gnu.org
Target Milestone: ---
Copied from PR63155. See https://gcc.gnu.org/bugzilla/attachment.cgi?id=46627
for the testcase.
I see with -m32 -w -O3 -pedantic -fwrapv -mstackrealign
-mpreferred-stack-boundary=4
GCC 5.5.0 55s, 3.5GB
GCC 6.5.0 79s, 3.6GB
GCC 7.4.0 131s, 5.8GB
GCC 8.3.0 113s, 5.4GB
GCC 9.1.0 117s, 5.4GB
the machine-specific flags do not make much difference so -O3 -fwrapv is
enough to see the slow compile.
Time on the GCC 9 branch head is spent here:
ipa icf : 5.41 ( 5%) 0.00 ( 0%) 5.42 ( 5%)
31 kB ( 0%)
tree VRP : 6.91 ( 6%) 0.26 ( 10%) 7.16 ( 6%)
166091 kB ( 3%)
tree Early VRP : 7.46 ( 7%) 0.10 ( 4%) 7.57 ( 6%)
497454 kB ( 9%)
tree PTA : 18.40 ( 16%) 0.49 ( 18%) 18.91 ( 16%)
46278 kB ( 1%)
tree PHI insertion : 4.07 ( 4%) 0.90 ( 34%) 4.96 ( 4%)
4254415 kB ( 80%)
tree SSA rewrite : 11.83 ( 10%) 0.00 ( 0%) 11.84 ( 10%)
3780 kB ( 0%)
dominator optimization : 3.19 ( 3%) 0.03 ( 1%) 3.21 ( 3%)
166221 kB ( 3%)
tree CCP : 9.11 ( 8%) 0.16 ( 6%) 9.29 ( 8%)
252 kB ( 0%)
tree PRE : 1.92 ( 2%) 0.03 ( 1%) 1.94 ( 2%)
364 kB ( 0%)
tree FRE : 11.54 ( 10%) 0.14 ( 5%) 11.68 ( 10%)
356 kB ( 0%)
out of ssa : 9.07 ( 8%) 0.01 ( 0%) 9.08 ( 8%)
47 kB ( 0%)
remove unused locals : 3.01 ( 3%) 0.00 ( 0%) 2.99 ( 3%)
0 kB ( 0%)
TOTAL : 114.46 2.66 117.13
5293311 kB
so it's a fairly even distribution.
