Date: Sun, 16 Sep 2018 21:46:27 +0000 (UTC) From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r338702 - head/sys/amd64/amd64 Message-ID: <201809162146.w8GLkRoj093290@repo.freebsd.org>
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Author: mjg Date: Sun Sep 16 21:46:27 2018 New Revision: 338702 URL: https://svnweb.freebsd.org/changeset/base/338702 Log: Revert amd64: tidy up kernel memmove There is a braino in the non-erms variant which breaks the functionality. Will be fixed at a later time with a different patch. Reported by: Manfred Antar Approved by: re (implicit) Modified: head/sys/amd64/amd64/support.S Modified: head/sys/amd64/amd64/support.S ============================================================================== --- head/sys/amd64/amd64/support.S Sun Sep 16 21:44:36 2018 (r338701) +++ head/sys/amd64/amd64/support.S Sun Sep 16 21:46:27 2018 (r338702) @@ -108,12 +108,12 @@ END(sse2_pagezero) */ ENTRY(memmove_std) PUSH_FRAME_POINTER - movq %rdi,%rax + movq %rdi,%r9 movq %rdx,%rcx - movq %rdi,%r8 - subq %rsi,%r8 - cmpq %rcx,%r8 /* overlapping && src < dst? */ + movq %rdi,%rax + subq %rsi,%rax + cmpq %rcx,%rax /* overlapping && src < dst? */ jb 1f shrq $3,%rcx /* copy by 64-bit words */ @@ -128,6 +128,7 @@ ENTRY(memmove_std) 2: rep movsb + movq %r9,%rax POP_FRAME_POINTER ret @@ -139,10 +140,8 @@ ENTRY(memmove_std) decq %rsi andq $7,%rcx /* any fractional bytes? */ std - jne 3f rep movsb -3: movq %rdx,%rcx /* copy remainder by 32-bit words */ shrq $3,%rcx subq $7,%rsi @@ -150,22 +149,24 @@ ENTRY(memmove_std) rep movsq cld + movq %r9,%rax POP_FRAME_POINTER ret END(memmove_std) ENTRY(memmove_erms) PUSH_FRAME_POINTER - movq %rdi,%rax + movq %rdi,%r9 movq %rdx,%rcx - movq %rdi,%r8 - subq %rsi,%r8 - cmpq %rcx,%r8 /* overlapping && src < dst? */ + movq %rdi,%rax + subq %rsi,%rax + cmpq %rcx,%rax /* overlapping && src < dst? */ jb 1f rep movsb + movq %r9,%rax POP_FRAME_POINTER ret @@ -178,6 +179,7 @@ ENTRY(memmove_erms) rep movsb cld + movq %r9,%rax POP_FRAME_POINTER ret END(memmove_erms)
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