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| author | Mateusz Guzik <mjg@FreeBSD.org> | 2018-12-01 14:20:32 +0000 |
|---|---|---|
| committer | Mateusz Guzik <mjg@FreeBSD.org> | 2018-12-01 14:20:32 +0000 |
| commit | ddf6571230dd508f458982c911ba332da0fcbab4 (patch) | |
| tree | 64e0c9ef61c5768dae12e66b81a486619d1a2c74 /lib/libc/amd64 | |
| parent | df5ceb3b666f4a6492219040cf36f6114fa234f6 (diff) | |
| download | src-ddf6571230dd508f458982c911ba332da0fcbab4.tar.gz src-ddf6571230dd508f458982c911ba332da0fcbab4.zip | |
amd64: align target memmove buffer to 16 bytes before using rep movs
See the review for sample test results.
Reviewed by: kib (kernel part)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18401
Notes
Notes:
svn path=/head/; revision=341364
Diffstat (limited to 'lib/libc/amd64')
| -rw-r--r-- | lib/libc/amd64/string/memmove.S | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/lib/libc/amd64/string/memmove.S b/lib/libc/amd64/string/memmove.S index 5a466f7a7d69..accc86440610 100644 --- a/lib/libc/amd64/string/memmove.S +++ b/lib/libc/amd64/string/memmove.S @@ -139,6 +139,8 @@ __FBSDID("$FreeBSD$"); ALIGN_TEXT 1256: + testb $15,%dil + jnz 100f .if \erms == 1 rep movsb @@ -152,6 +154,34 @@ __FBSDID("$FreeBSD$"); .endif \end ret +100: + movq (%rsi),%r8 + movq 8(%rsi),%r9 + movq %rdi,%r10 + movq %rdi,%rcx + andq $15,%rcx + leaq -16(%rdx,%rcx),%rdx + neg %rcx + leaq 16(%rdi,%rcx),%rdi + leaq 16(%rsi,%rcx),%rsi + movq %rdx,%rcx +.if \erms == 1 + rep + movsb + movq %r8,(%r10) + movq %r9,8(%r10) +.else + shrq $3,%rcx /* copy by 64-bit words */ + rep + movsq + movq %r8,(%r10) + movq %r9,8(%r10) + movq %rdx,%rcx + andl $7,%ecx /* any bytes left? */ + jne 100408b +.endif + \end + ret .if \overlap == 1 /* |