https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79665
--- Comment #19 from Wilco <wilco at gcc dot gnu.org> --- Author: wilco Date: Wed Jun 28 14:13:02 2017 New Revision: 249740 URL: https://gcc.gnu.org/viewcvs?rev=249740&root=gcc&view=rev Log: Improve Cortex-A53 shift bypass The aarch_forward_to_shift_is_not_shifted_reg bypass always returns true on AArch64 shifted instructions. This causes the bypass to activate in too many cases, resulting in slower execution on Cortex-A53 like reported in PR79665. This patch uses the arm_no_early_alu_shift_dep condition instead which improves the example in PR79665 by ~7%. Given it is no longer used, remove aarch_forward_to_shift_is_not_shifted_reg. Also remove an unnecessary REG_P check. gcc/ PR target/79665 * config/arm/aarch-common.c (arm_no_early_alu_shift_dep): Remove redundant if. (aarch_forward_to_shift_is_not_shifted_reg): Remove. * config/arm/aarch-common-protos.h (aarch_forward_to_shift_is_not_shifted_re): Remove. * config/arm/cortex-a53.md: Use arm_no_early_alu_shift_dep in bypass. Modified: trunk/gcc/ChangeLog trunk/gcc/config/arm/aarch-common-protos.h trunk/gcc/config/arm/aarch-common.c trunk/gcc/config/arm/cortex-a53.md
