https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114623
--- Comment #8 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:481ba4fb5fce8257f5dbeb994dac2748c0237fa2 commit r14-9853-g481ba4fb5fce8257f5dbeb994dac2748c0237fa2 Author: Jakub Jelinek <ja...@redhat.com> Date: Tue Apr 9 08:17:25 2024 +0200 libquadmath: Use soft-fp for sqrtq finite positive arguments [PR114623] sqrt should be 0.5ulp precise, but the current implementation is less precise than that. The following patch uses the soft-fp code (like e.g. glibc for x86) for it if possible. I didn't want to replicate the libgcc infrastructure for choosing the right sfp-machine.h, so the patch just uses a single generic implementation. As the code is used solely for the finite positive arguments, it shouldn't generate NaNs (so the exact form of canonical QNaN/SNaN is irrelevant), and sqrt for these shouldn't produce underflows/overflows either, for < 1.0 arguments it always returns larger values than the argument and for > 1.0 smaller values than the argument. 2024-04-09 Jakub Jelinek <ja...@redhat.com> PR libquadmath/114623 * sfp-machine.h: New file. * math/sqrtq.c: Include from libgcc/soft-fp also soft-fp.h and quad.h if possible. (USE_SOFT_FP): Define in that case. (sqrtq): Use soft-fp based implementation for the finite positive arguments if possible.
