https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80530
--- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- Author: rearnsha Date: Thu Apr 27 14:11:47 2017 New Revision: 247341 URL: https://gcc.gnu.org/viewcvs?rev=247341&root=gcc&view=rev Log: [AArch64] Fix for gcc-7 regression PR 80530 This patch fixes the regression caused by the changes to add square root estimation when compiling for xgene-1 or exynos-m1 targets. The issue is that the expand path for the reciprocal estimate square root pattern assumes that pattern cannot fail once it has been decided that this expansion path is available, but because the logic deep inside aarch64_emit_approx_sqrt() differs from use_rsqrt_p() the two disagree as to what is safe. This patch refactors the logic to ensure that we cannot unknowingly make different choices here. PR target/80530 * config/aarch64/aarch64.c (aarch64_emit_approx_sqrt): Ensure that the logic for permitting reciprocal estimates matches that in use_rsqrt_p. Modified: branches/gcc-7-branch/gcc/ChangeLog branches/gcc-7-branch/gcc/config/aarch64/aarch64.c
