[Bug middle-end/28283] SuperH: Very unoptimal code generated for 64-bit ints

["joern dot rennecke at st dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #6 from joern dot rennecke at st dot com  2006-07-06 19:59 -------
Subject: Re:  SuperH: Very unoptimal code generated for 64-bit ints

roger at eyesopen dot com wrote:

>------- Comment #5 from roger at eyesopen dot com  2006-07-06 19:47 -------
>No the rtx_costs for a DImode shift really are wrong.  The use of the constant
>10000 in sh.c:shift_costs instructs the middle-end to avoid using DImode
>shifts at all costs.  The semantics of rtx_costs is that it is expected to
>provide an estimate of the cost of performing an instruction (either in
>size when optimize_size or in performance whrn !optimize_size)
>
If the RTX is not valid, the md is not required to give a valid rtx cost 
estimates.

> 
>As for the little-endian vs. big-endian issue that looks like a second bug.
>  
>
Yes, but it's hard to debug as long as you have to poke internal data 
structures to get
the compiler to use SImode shifts.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28283