[Bug target/14552] compiled trivial vector intrinsic code is inefficient

[ubizjak at gmail dot com]

------- Comment #30 from ubizjak at gmail dot com  2008-03-20 00:04 -------
(In reply to comment #28)
> (In reply to comment #27)
> > The store is not useless. Reload from "_w" is how gcc handles double stores
> > nowadays and is not mmx specific. It looks that some pass forgot to check where
> > the value came from.
> 
> Do you happen to know if there are two different modes at work here?  If so
> there are patches which fix this up in DSE and post-reload CSE.

Yes, from comment #24 (slightly changed):

typedef short mmxw  __attribute__ ((vector_size (8)));
typedef int   mmxdw __attribute__ ((vector_size (8)));

mmxdw dw;
mmxw w;

so, we have V4HI and V2SI.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14552