On Fri, Dec 21, 2007 at 10:11:24AM -0800, Bakul Shah wrote: > Peter Jeremy <[EMAIL PROTECTED]> wrote: > > On Wed, Dec 19, 2007 at 09:40:34PM -0800, Carl Shapiro wrote: > > >The default setting of the x87 floating point control word on the i386 > > >port is 0x127F. Among other things, this value sets the precision > > >control to double precision. The default setting of the x87 floating > > >point control word on the AMD64 is 0x37F. > > ... > > >It seems clear that the right thing to do is to set the floating point > > >environment to the i386 default for i386 binaries. Is the current > > >behavior intended? > > > > I believe this is an oversight. See the thread beginning > > http://lists.freebsd.org/pipermail/freebsd-stable/2007-November/037947.html > > >From reading Bruce's last message in that thread, seems to me > may be default for 64bit binaries should be the same as on > i386. Anyone wanting different behavior can always call > fpsetprec() etc. > > I think the fix is to change __INITIAL_FPUCW__ in > /sys/amd64/include/fpu.h to 0x127F like on i386. I think this shall be done for 32-bit processes only, or we get into another ABI breaking nightmare. > > Also, while at it, comments above this constant in this file > and above __INITIAL_NPXCW__ in /sys/i386/include/npx.h needs > to reflect what was chosen and why. > > Filing a PR would help ensure this doesn't get lost.
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