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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-02-08 10:08:39 -0300
committerH.J. Lu <hjl.tools@gmail.com>2024-02-13 08:49:13 -0800
commit272708884cb750f12f5c74a00e6620c19dc6d567 (patch)
treef6c6fdc807ba59154f501111a69c4c6ef812e9d9
parent0c0d39fe4aeb0f69b26e76337c5dfd5530d5d44e (diff)
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x86: Do not prefer ERMS for memset on Zen3+
For AMD Zen3+ architecture, the performance of the vectorized loop is slightly better than ERMS. Checked on x86_64-linux-gnu on Zen3. Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
-rw-r--r--sysdeps/x86/dl-cacheinfo.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h
index f34d12846c..5a98f70364 100644
--- a/sysdeps/x86/dl-cacheinfo.h
+++ b/sysdeps/x86/dl-cacheinfo.h
@@ -1021,6 +1021,11 @@ dl_init_cacheinfo (struct cpu_features *cpu_features)
minimum value is fixed. */
rep_stosb_threshold = TUNABLE_GET (x86_rep_stosb_threshold,
long int, NULL);
+ if (cpu_features->basic.kind == arch_kind_amd
+ && !TUNABLE_IS_INITIALIZED (x86_rep_stosb_threshold))
+ /* For AMD Zen3+ architecture, the performance of the vectorized loop is
+ slightly better than ERMS. */
+ rep_stosb_threshold = SIZE_MAX;
TUNABLE_SET_WITH_BOUNDS (x86_data_cache_size, data, 0, SIZE_MAX);
TUNABLE_SET_WITH_BOUNDS (x86_shared_cache_size, shared, 0, SIZE_MAX);