https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90178
--- Comment #8 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> --- Author: hjl Date: Sun Apr 21 18:23:00 2019 New Revision: 270484 URL: https://gcc.gnu.org/viewcvs?rev=270484&root=gcc&view=rev Log: LRA: Revert "Remove useless move insns" Useless move insn removal was added to LRA just to avoid wasting CPU cycles on such insn processing afterwards. Such insns are removed anyway later in the pass pipeline. The CPU time savings are tiny but the removal creates too many problems including PR target/90178. Vladimir pre-approved the patch to remove the code: https://gcc.gnu.org/ml/gcc-patches/2019-04/msg00834.html gcc/ PR target/90178 Revert: 2018-11-21 Uros Bizjak <ubiz...@gmail.com> Revert the revert: 2013-10-26 Vladimir Makarov <vmaka...@redhat.com> Revert: 2013-10-25 Vladimir Makarov <vmaka...@redhat.com> * lra-spills.c (lra_final_code_change): Remove useless move insns. gcc/testsuite/ PR target/90178 * gcc.target/i386/pr90178.c: New test. Added: trunk/gcc/testsuite/gcc.target/i386/pr90178.c Modified: trunk/gcc/ChangeLog trunk/gcc/lra-spills.c trunk/gcc/testsuite/ChangeLog
