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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-02-08 10:08:40 -0300
committerH.J. Lu <hjl.tools@gmail.com>2024-02-13 08:49:43 -0800
commit491e55beab7457ed310a4a47496f4a333c5d1032 (patch)
tree8ebab1cf64eb413c6eb325466b3de4ea76d643a0
parent272708884cb750f12f5c74a00e6620c19dc6d567 (diff)
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x86: Expand the comment on when REP STOSB is used on memset
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
-rw-r--r--sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S4
1 files changed, 3 insertions, 1 deletions
diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
index 9984c3ca0f..97839a2248 100644
--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
@@ -21,7 +21,9 @@
2. If size is less than VEC, use integer register stores.
3. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores.
4. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores.
- 5. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with
+ 5. On machines ERMS feature, if size is greater or equal than
+ __x86_rep_stosb_threshold then REP STOSB will be used.
+ 6. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with
4 VEC stores and store 4 * VEC at a time until done. */
#include <sysdep.h>