https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63155
--- Comment #43 from Richard Biener <rguenth at gcc dot gnu.org> ---
We're now down to
tree PTA : 3.92 ( 16%) 0.12 ( 36%) 4.02 ( 16%)
12445 kB ( 2%)
tree CCP : 7.43 ( 30%) 0.02 ( 6%) 7.44 ( 29%)
646 kB ( 0%)
tree FRE : 2.34 ( 9%) 0.00 ( 0%) 2.35 ( 9%)
116 kB ( 0%)
tree backward propagate : 0.62 ( 2%) 0.00 ( 0%) 0.62 ( 2%)
0 kB ( 0%)
out of ssa : 3.01 ( 12%) 0.00 ( 0%) 3.01 ( 12%)
0 kB ( 0%)
TOTAL : 24.91 0.33 25.26
573769 kB
notice the tree backward propagate improvement. This makes CCP the main
offender again but as said the rectification would probably mean pulling
back the SSA SCC discovery code from SCCVN and use that in the SSA
propagator somehow.
The out of SSA time is what was originally topic of this bug.
The tree PTA time is "new" and related to the number of PHI nodes
and edges. You can disable PTA via -fno-tree-pta.
The tree FRE time is PHI lookups/inserts, some refactoring can speed this up
a bit.
