Re: [HACKERS] powerpc(32) point/polygon regression failures on Debian Jessie

Christoph Berg <christoph.berg@credativ.de> writes:
> Re: Tom Lane 2017-02-20 <30737.1487598355@sss.pgh.pa.us>
>> Hmph.  We haven't touched that code in awhile, and certainly not in the
>> 9.4.x branch.  I'd have to agree that this must be a toolchain change.

> FYI, in the meantime we could indeed trace it back to an libc issue on
> Jessie:

I wonder whether it's a compiler change, maybe along the lines of
rearranging the computation so that it gives a slightly different result.
Although you'd think that 10.0/10.0 would give exactly 1.0 no matter what.
Still, it'd be worth comparing the assembly code for your test program.
        regards, tom lane