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* Re: libm accuracy, eglibc compared to glibc -- solved
@ 2014-03-21 12:10 Mats Kärrman
  2014-03-21 16:45 ` Mark Hatle
  0 siblings, 1 reply; 5+ messages in thread
From: Mats Kärrman @ 2014-03-21 12:10 UTC (permalink / raw)
  To: openembedded-core@lists.openembedded.org

Hi,

On: Thursday, March 13, 2014 11:36 AM, Mats Kärrman wrote:
> My "home made" hard float tune for PowerPC looks like this:
> 
> ------------------------------------------------------------------
> # Tune for the e300c3 core
> require conf/machine/include/tune-ppce300c3.inc
> 
> # Use hardware floating point
> AVAILTUNES += "ppce300c3hf"
> TUNE_FEATURES_tune-ppce300c3hf = "m32 fpu-hard ppce300c3"
> TUNE_PKGARCH_tune-ppce300c3hf = "ppce300c3hf"
> PACKAGE_EXTRA_ARCHS_tune-ppce300c3hf = "${PACKAGE_EXTRA_ARCHS_tune-powerpc} ppce300c3hf"
> DEFAULTTUNE = "ppce300c3hf"
> ------------------------------------------------------------------
> 

I found the reason for the error (deviance) in the sqrt function. glibc has
special code for PowerPC 603e core (e300 is an optimized variant of 603e).
By adding the following line to the tuning I now get the same result as
for all other environments that I've tried:

GLIBC_EXTRA_OECONF += "${@bb.utils.contains("TUNE_FEATURES", "ppce300c3", "-with-cpu=603e", "", d)}"

Does anyone know about the reason for having soft-float as the default and
only available alternative for e300c2/3 tunings?

Would it be worthwhile to send a patch to add the hf tuning to OE-core?

In that case what tests should be performed before that and what (related)
tests are performed by the OE auto-builder?

BR // Mats


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2014-03-27 16:00 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-03-21 12:10 libm accuracy, eglibc compared to glibc -- solved Mats Kärrman
2014-03-21 16:45 ` Mark Hatle
2014-03-21 17:06   ` Khem Raj
2014-03-27 15:16     ` Mats Kärrman
2014-03-27 16:00       ` Khem Raj

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