[PATCH] Use -frounding-math for math testsuite

[Joseph S. Myers]

On Wed, 2 May 2012, Joseph S. Myers wrote:

> Please commit this.  Strictly we should compile all the libraries with 
> -frounding-math as well, since library functions may be called in any 
> rounding mode (and without -frounding-math, round-to-nearest is assumed); 
> the only things for which it's not needed are the miscellaneous 
> executables, and those testcases (i.e. all except the ones this patch 
> addresses) that don't change the rounding mode.

Incidentally, compiling libraries with -frounding-math should fix bugs 
such as <http://sourceware.org/bugzilla/show_bug.cgi?id=10846> with 
missing underflow exceptions (it's still a GCC bug that it folds these 
underflowing operations with -ftrapping-math -fno-rounding-math, but 
-frounding-math works around the GCC bug by disabling that folding since 
the result is inexact).

-- 
Joseph S. Myers
joseph@codesourcery.com