https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70243
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Michael Meissner <meiss...@gcc.gnu.org>: https://gcc.gnu.org/g:3bb91d31a272d7fd9f02301df101e3041d5aeb5d commit r12-9635-g3bb91d31a272d7fd9f02301df101e3041d5aeb5d Author: Michael Meissner <meiss...@linux.ibm.com> Date: Mon May 22 11:08:13 2023 -0400 Do not generate vmaddfp and vnmsubfp This is version 3 of the patch. This is essentially version 1 with the removal of changes to altivec.md, and cleanup of the comments. Version 2 generated the vmaddfp and vnmsubfp instructions if -Ofast was used, and those changes are deleted in this patch. The Altivec instructions vmaddfp and vnmsubfp have different rounding behaviors than the VSX xvmaddsp and xvnmsubsp instructions. In particular, generating these instructions seems to break Eigen on big endian systems. I have done bootstrap builds on power9 little endian (with both IEEE long double and IBM long double). I have also done the builds and test on a power8 big endian system (testing both 32-bit and 64-bit code generation). Chip has verified that it fixes the problem that Eigen encountered. Can I check this into the master GCC branch? After a burn-in period, can I check this patch into the active GCC branches? Thanks in advance. 2023-05-22 Michael Meissner <meiss...@linux.ibm.com> gcc/ PR target/70243 * config/rs6000/vsx.md (vsx_fmav4sf4): Do not generate vmaddfp. (vsx_nfmsv4sf4): Do not generate vnmsubfp. Back port from master 04/10/2023 change. gcc/testsuite/ PR target/70243 * gcc.target/powerpc/pr70243.c: New test. Back port from master 04/10/2023 change.
