https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84114
--- Comment #7 from Wilco <wilco at gcc dot gnu.org> --- Author: wilco Date: Mon Mar 5 14:40:55 2018 New Revision: 258248 URL: https://gcc.gnu.org/viewcvs?rev=258248&root=gcc&view=rev Log: [AArch64] PR84114: Avoid reassociating FMA As discussed in the PR, the reassociation phase runs before FMAs are formed and so can significantly reduce FMA opportunities. Although reassociation could be switched off, it helps in many cases, so a better alternative is to only avoid reassociation of floating point additions. This fixes the testcase and gives 1% speedup on SPECFP2017, fixing the performance regression. gcc/ PR tree-optimization/84114 * config/aarch64/aarch64.c (aarch64_reassociation_width) Avoid reassociation of FLOAT_MODE addition. Modified: trunk/gcc/ChangeLog trunk/gcc/config/aarch64/aarch64.c
