https://gcc.gnu.org/g:0bb90322f81ffb2e4ca84546b04ce7535fffe40f
commit r17-1139-g0bb90322f81ffb2e4ca84546b04ce7535fffe40f Author: Kyrylo Tkachov <[email protected]> Date: Sun May 31 02:05:56 2026 -0700 aarch64: Adjust alignment tunings for Olympus After some more benchmarking and evaluation I'd like to increase the alignments needed for -mcpu=olympus. All three of loop_align, function_align and jump_align are needed to get a good mix of improvements. I've added skip amounts to keep the code size bloat down. There is some, but the performance benefit on -mcpu=olympus binaries is worth it (cpython from SPEC2026 in particular benefits consistently). As an aside, I do think we'll want a more fine-grained description of alignment in our CPU tuning structs for -O3 binaries. -O3 may be willing to pay the extra padding cost for speed-tuned functions and loops and may want to avoid the skip amount if the CPU is good enough at skipping past them. But the -O2 settings may still want to use skip amount to avoid excessive distro binary bloat. Bootstrapped and tested on aarch64-none-linux-gnu. Signed-off-by: Kyrylo Tkachov <[email protected]> gcc/ChangeLog * config/aarch64/tuning_models/olympus.h (olympus_tunings): Adjust loop_align, function_align, jump_align. Diff: --- gcc/config/aarch64/tuning_models/olympus.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/gcc/config/aarch64/tuning_models/olympus.h b/gcc/config/aarch64/tuning_models/olympus.h index c83e35adc2b9..ca7f7b95f71e 100644 --- a/gcc/config/aarch64/tuning_models/olympus.h +++ b/gcc/config/aarch64/tuning_models/olympus.h @@ -545,9 +545,9 @@ static struct tune_params olympus_tunings = }, /* memmov_cost. */ 10, /* issue_rate */ AARCH64_FUSE_NEOVERSE_BASE, /* fusible_ops */ - "32:16", /* function_align. */ - "4", /* jump_align. */ - "64:16", /* loop_align. */ + "32:25", /* function_align. */ + "16:9", /* jump_align. */ + "64:33:32", /* loop_align. */ 8, /* int_reassoc_width. */ 6, /* fp_reassoc_width. */ 4, /* fma_reassoc_width. */
