[Bug rtl-optimization/19780] Floating point computation far slower for -mfpmath=sse

[dnovillo at gcc dot gnu dot org]

------- Comment #14 from dnovillo at gcc dot gnu dot org  2007-04-05 12:49 -------
(In reply to comment #11)

> So, why does SSA pass have to interfere with computation dataflow? This
> interferece makes things worse and effectively takes away user's control on the
> flow of data.
> 

Huh?  How is it relevant whether PHIs are in different order?  Conceptually,
the ordering of PHI nodes in a basic block is completely irrelevant.  Some pass
is getting confused when it shouldn't.  Transformations should not depend on
how PHI nodes are emitted in a block as all PHI nodes are always evaluated in
parallel.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19780