Author: mjg Date: Sat Dec 1 14:20:32 2018 New Revision: 341364 URL: https://svnweb.freebsd.org/changeset/base/341364
Log: 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 Modified: head/lib/libc/amd64/string/memmove.S head/sys/amd64/amd64/support.S Modified: head/lib/libc/amd64/string/memmove.S ============================================================================== --- head/lib/libc/amd64/string/memmove.S Sat Dec 1 12:08:16 2018 (r341363) +++ head/lib/libc/amd64/string/memmove.S Sat Dec 1 14:20:32 2018 (r341364) @@ -139,6 +139,8 @@ __FBSDID("$FreeBSD$"); ALIGN_TEXT 1256: + testb $15,%dil + jnz 100f .if \erms == 1 rep movsb @@ -146,6 +148,34 @@ __FBSDID("$FreeBSD$"); shrq $3,%rcx /* copy by 64-bit words */ rep movsq + movq %rdx,%rcx + andl $7,%ecx /* any bytes left? */ + jne 100408b +.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 Modified: head/sys/amd64/amd64/support.S ============================================================================== --- head/sys/amd64/amd64/support.S Sat Dec 1 12:08:16 2018 (r341363) +++ head/sys/amd64/amd64/support.S Sat Dec 1 14:20:32 2018 (r341364) @@ -302,6 +302,8 @@ END(memcmp) ALIGN_TEXT 1256: + testb $15,%dil + jnz 100f .if \erms == 1 rep movsb @@ -309,6 +311,34 @@ END(memcmp) shrq $3,%rcx /* copy by 64-bit words */ rep movsq + movq %rdx,%rcx + andl $7,%ecx /* any bytes left? */ + jne 100408b +.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 _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
