On Sun, Feb 21, 2010 at 6:58 AM, Joseph S. Myers <jos...@codesourcery.com> wrote: > On Sun, 21 Feb 2010, Richard Guenther wrote: > >> > The biggest change we need to make for x86 is to enable SSE2, >> > so we can get proper rounding behavior for float and double, >> > as well as significant performance increases. >> >> I think Joseph fixed the rounding behavior for 4.5. Also without an adjusted > > Well, I provided the option for rounding that is predictable and in > accordance with C99 when using the default -mfpmath=387. But that option > does carry the performance cost of storing to / loading from memory at > various points, as required to get the rounding on 387 (and there are > still cases where excess precision means double rounding). >
I think your C99 change caused a regression on ia32: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43128#c10 -- H.J.
