https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102976
--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-11 branch has been updated by Peter Bergner <berg...@gcc.gnu.org>: https://gcc.gnu.org/g:2b6cfe7c4ee98b2c38e6a6d98742f1efb2fc9a79 commit r11-9341-g2b6cfe7c4ee98b2c38e6a6d98742f1efb2fc9a79 Author: Peter Bergner <berg...@linux.ibm.com> Date: Tue Nov 16 12:14:22 2021 -0600 rs6000: MMA test case emits wrong code when building a vector pair [PR102976] PR102976 shows a test case where we generate wrong code when building a vector pair from 2 vector registers. The bug here is that with unlucky register assignments, we can clobber one of the input operands before we write both registers of the output operand. The solution is to use early-clobbers in the assemble pair and accumulator patterns. 2021-11-16 Peter Bergner <berg...@linux.ibm.com> gcc/ PR target/102976 * config/rs6000/mma.md (*vsx_assemble_pair): Add early-clobber for output operand. (*mma_assemble_acc): Likewise. gcc/testsuite/ PR target/102976 * gcc.target/powerpc/pr102976.c: New test. (cherry picked from commit 4cdf7db9a39d18bd536d816a5751d4d3cf23808b)
