[Bug middle-end/40106] Time increase with inlining for the Polyhedron test air.f90

[hubicka at gcc dot gnu dot org]

------- Comment #1 from hubicka at gcc dot gnu dot org  2009-05-12 11:52 -------
Hmm, the inlined functions has loop depth of 4, that makes it predicted to
iterate quite few times. My guess would be that inlining increases loop depth
that in turn makes GCC to conclude that one of loops that are in fact internal
hot loops are cold. decreasing --param hot-bb-frequency-fraction might help in
this case.

I've seen this in past, just hope it is quite rare.
If we find enough testcases like this, it might make sense to alter the
predicate deciding on hot-bb to always consider innermost loops hot no mater on
their relative frequency.  Woud need to have flag on BB or loop structure
always available though.

Honza


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40106