On Tue, 3 Nov 2015, Michael Meissner wrote: > > Another thing that would help find missing libgcc functions is enabling > > libquadmath for powerpc (building with -mvsx) - though there isn't a > > libquadmath testsuite - missing functions would mean it fails to link > > (though this wouldn't find more obscure missing functions such as TImode > > conversions). > > Once the basic support is in, I was planning on looking at what is needed with > libquadmath.
Thanks. Given a large, complicated series of patches like this, it's hard to have confidence that the code (both in the back end and in libgcc) is working correctly (or that back-end changes don't break it) without building a substantial body of __float128 code (such as libquadmath) using it. The libquadmath maintainers had a way of hacking up the glibc libm testsuite to use it for testing libquadmath <https://gcc.gnu.org/ml/gcc-patches/2012-10/msg02958.html>. To use that you'd need to take a three-year-old version of the glibc libm tests (since they've been massively reworked since then, which would require major reworking of the hacks), and I suppose compare the results with the (not-clean) results for x86_64 reported in that thread, since those hacks were never close to having clean test results (whereas the current libm testsuite itself does produce clean results for ldbl-128 testing on architectures using binary128 long double, given an up-to-date libm-test-ulps file). Enabling the libm testsuite to be used cleanly for other types would be several of the maybe 50 or more patches involved in getting _Float128 support into glibc (which might have the side-effect of facilitating libquadmath updates and testing). -- Joseph S. Myers jos...@codesourcery.com
