https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107991
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |8.1.0
Component|rtl-optimization |middle-end
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The huge difference comes from the middle-end:
Trunk (and not working):
(insn 12 11 13 4 (parallel [
(set (reg/v:SI 85 [ i ])
(minus:SI (reg/v:SI 85 [ i ])
(reg/v:SI 86 [ j ])))
(clobber (reg:CC 17 flags))
]) "/app/example.cpp":2:14 discrim 1 -1
(nil))
vs 7.5 (working case):
(insn 13 12 22 4 (parallel [
(set (reg:SI 87 [ <retval> ])
(minus:SI (reg/v:SI 90 [ i ])
(reg/v:SI 91 [ j ])))
(clobber (reg:CC 17 flags))
]) "/app/example.cpp":2 -1
(nil))
that is coalescing the PHI node:
# iftmp.0_1 = PHI <iftmp.0_5(3), i_3(D)(2)>
to i rather than inserting a setting on the other branch.
