update: x86-64: libm-test-ulps for AMD Piledriver?

[Joseph S. Myers]

Once we freeze for 2.18, I propose to truncate the x86 and x86_64 
libm-test-ulps files and regenerate them from scratch, so as to get ulps 
removals or reductions arising from changes to the libm implementation 
over the past several years.  (Architecture maintainers are generally 
encouraged to do likewise for their architectures.)  It will then be 
useful for people with a range of processors to run "make regen-ulps" for 
both x86 and x86_64 to get any processor-specific additional ulps needed, 
and for people with a range of compilers to do so for x86 (the compiler 
issue being unpredictability of register spills with excess precision; see 
bug 15487; the processor issues are that the x87 instructions for 
transcendental operations do not produce bit-identical results on all 
processors).

So although there's nothing wrong with putting a patch such as this in 
now, it may be more useful to generate such a patch after the files have 
been fully regenerated at the start of the freeze.

-- 
Joseph S. Myers
joseph@codesourcery.com