[Lapack] Patches to test suite of BLAS for LAPACK-3.4.0
From: Sven Hammarling
Date: Thu, 19 Jan 2012 15:48:29 +0000
I echo Julien's thanks.
Just to say that you should beware of switches such as -Ofast in
numerical work. For example, with gfortran it specifically says
"Disregard strict standards compliance."
So, for instance, carefully placed brackets might be ignored thus
perhaps damaging numerical stability.
On 18/01/12 22:40, Harald Anlauf wrote:
some tests of the BLAS fail on Intel and AMD processors when
compiling with high optimization level (e.g. gfortran -Ofast).
The reason is that the determination of machine precision in
these tests only works without optimization.
I recommend to always use the Fortran 90+ intrinsic EPSILON()
See the attached for details.
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