I wrote:
> Looking at the buildfarm, our only extant member that is on x86, and
> is not using clang, and doesn't have -fexcess-precision=standard, is
> dromedary which is using Apple's old toolchain. So the fact that it
> isn't showing the problem isn't very good evidence about how widespread
> this issue might be with older gcc versions.
... and, in fact, a bit of investigation says that that compiler has
-msse2 on by default. So actually we have *no* buildfarm coverage
of x87 math.
I tried forcing the issue with -mfpmath=387, but failed to reproduce
the reported failure. Still, seeing that it's a considerably different
version of gcc, that's not so surprising.
regards, tom lane