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29 lines
1.3 KiB
29 lines
1.3 KiB
From 491e55beab7457ed310a4a47496f4a333c5d1032 Mon Sep 17 00:00:00 2001 |
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From: Adhemerval Zanella <adhemerval.zanella@linaro.org> |
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Date: Thu, 8 Feb 2024 10:08:40 -0300 |
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Subject: [PATCH] x86: Expand the comment on when REP STOSB is used on memset |
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Content-type: text/plain; charset=UTF-8 |
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Reviewed-by: H.J. Lu <hjl.tools@gmail.com> |
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--- |
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sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S | 4 +++- |
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1 file changed, 3 insertions(+), 1 deletion(-) |
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diff --git a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S |
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index 9984c3ca0f..97839a2248 100644 |
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--- a/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S |
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+++ b/sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S |
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@@ -21,7 +21,9 @@ |
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2. If size is less than VEC, use integer register stores. |
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3. If size is from VEC_SIZE to 2 * VEC_SIZE, use 2 VEC stores. |
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4. If size is from 2 * VEC_SIZE to 4 * VEC_SIZE, use 4 VEC stores. |
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- 5. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with |
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+ 5. On machines ERMS feature, if size is greater or equal than |
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+ __x86_rep_stosb_threshold then REP STOSB will be used. |
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+ 6. If size is more to 4 * VEC_SIZE, align to 4 * VEC_SIZE with |
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4 VEC stores and store 4 * VEC at a time until done. */ |
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#include <sysdep.h> |
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-- |
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2.39.3 |
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