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[newlib-cygwin] Cygwin: Fix x86_64 memcpy/memset for n > 2GB
- From: Corinna Vinschen <corinna at sourceware dot org>
- To: cygwin-cvs at sourceware dot org
- Date: 29 Jul 2015 20:09:49 -0000
- Subject: [newlib-cygwin] Cygwin: Fix x86_64 memcpy/memset for n > 2GB
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7666b3634b3124a0057e22238658aca665b285da
commit 7666b3634b3124a0057e22238658aca665b285da
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Wed Jul 29 22:09:34 2015 +0200
Cygwin: Fix x86_64 memcpy/memset for n > 2GB
https://cygwin.com/ml/cygwin/2015-07/msg00344.html:
RtlFillMemory and RtlCopyMemory only work for size values
up to 2GB. Fix this problem by using NetBSD code for
memset and memcpy. Add entry points for memmove, wmemset,
wmemmove, wmemcpy. Thanks to Roman Petrovski
<RPetrovski@illumina.com> for pointing this out.
* miscfuncs.cc (memset): x86_64 only: Implement in assembler.
(memmove,memcpy): x86_64 only: Ditto.
(wmemmove,wmemcpy): x86_64 only: Ditto.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/ChangeLog | 6 ++
winsup/cygwin/miscfuncs.cc | 192 +++++++++++++++++++++++++++++++++++++++-----
winsup/cygwin/release/2.2.0 | 4 +
3 files changed, 183 insertions(+), 19 deletions(-)
diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 1fb4c79..2cc3677 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,11 @@
2015-07-29 Corinna Vinschen <corinna@vinschen.de>
+ * miscfuncs.cc (memset): x86_64 only: Implement in assembler.
+ (memmove,memcpy): x86_64 only: Ditto.
+ (wmemmove,wmemcpy): x86_64 only: Ditto.
+
+2015-07-29 Corinna Vinschen <corinna@vinschen.de>
+
* cygtls.h: Include cygtls_padsize.h and define CYGTLS_PADSIZE there.
* cygtls_padsize.h: New file. Define CYGTLS_PADSIZE.
* environ.cc (parse_options): Fix NULL pointer access.
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index 4a7a1b8..2b3c6b8 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -898,23 +898,177 @@ err:
}
#ifdef __x86_64__
-// TODO: The equivalent newlib functions only work for SYSV ABI so far.
-#undef RtlFillMemory
-#undef RtlCopyMemory
-extern "C" void NTAPI RtlFillMemory (PVOID, SIZE_T, BYTE);
-extern "C" void NTAPI RtlCopyMemory (PVOID, const VOID *, SIZE_T);
-
-extern "C" void *
-memset (void *s, int c, size_t n)
-{
- RtlFillMemory (s, n, c);
- return s;
-}
-
-extern "C" void *
-memcpy(void *__restrict dest, const void *__restrict src, size_t n)
-{
- RtlCopyMemory (dest, src, n);
- return dest;
-}
+/* These functions are almost verbatim NetBSD code, just wrapped in the
+ minimum required code to make them work with the MS AMD64 ABI.
+ See NetBSD src/lib/libc/amd64/string/memset.S
+ and NetBSD src/lib/libc/amd64/string/bcopy.S */
+
+asm volatile (" \n\
+/* \n\
+ * Written by J.T. Conklin <jtc@NetBSD.org>. \n\
+ * Public domain. \n\
+ * Adapted for NetBSD/x86_64 by \n\
+ * Frank van der Linden <fvdl@wasabisystems.com> \n\
+ */ \n\
+ \n\
+ .globl memset \n\
+ .seh_proc memset \n\
+memset: \n\
+ movq %rsi,8(%rsp) \n\
+ movq %rdi,16(%rsp) \n\
+ .seh_endprologue \n\
+ movq %rcx,%rdi \n\
+ movq %rdx,%rsi \n\
+ movq %r8,%rdx \n\
+ \n\
+ movq %rsi,%rax \n\
+ andq $0xff,%rax \n\
+ movq %rdx,%rcx \n\
+ movq %rdi,%r11 \n\
+ \n\
+ cld /* set fill direction forward */ \n\
+ \n\
+ /* if the string is too short, it's really not worth the \n\
+ * overhead of aligning to word boundries, etc. So we jump to \n\
+ * a plain unaligned set. */ \n\
+ cmpq $0x0f,%rcx \n\
+ jle L1 \n\
+ \n\
+ movb %al,%ah /* copy char to all bytes in word */\n\
+ movl %eax,%edx \n\
+ sall $16,%eax \n\
+ orl %edx,%eax \n\
+ \n\
+ movl %eax,%edx \n\
+ salq $32,%rax \n\
+ orq %rdx,%rax \n\
+ \n\
+ movq %rdi,%rdx /* compute misalignment */ \n\
+ negq %rdx \n\
+ andq $7,%rdx \n\
+ movq %rcx,%r8 \n\
+ subq %rdx,%r8 \n\
+ \n\
+ movq %rdx,%rcx /* set until word aligned */ \n\
+ rep \n\
+ stosb \n\
+ \n\
+ movq %r8,%rcx \n\
+ shrq $3,%rcx /* set by words */ \n\
+ rep \n\
+ stosq \n\
+ \n\
+ movq %r8,%rcx /* set remainder by bytes */ \n\
+ andq $7,%rcx \n\
+L1: rep \n\
+ stosb \n\
+ movq %r11,%rax \n\
+ \n\
+ movq 8(%rsp),%rsi \n\
+ movq 16(%rsp),%rdi \n\
+ ret \n\
+ .seh_endproc \n\
+");
+
+asm volatile (" \n\
+/*- \n\
+ * Copyright (c) 1990 The Regents of the University of California. \n\
+ * All rights reserved. \n\
+ * \n\
+ * This code is derived from locore.s. \n\
+ * \n\
+ * Redistribution and use in source and binary forms, with or without \n\
+ * modification, are permitted provided that the following conditions \n\
+ * are met: \n\
+ * 1. Redistributions of source code must retain the above copyright \n\
+ * notice, this list of conditions and the following disclaimer. \n\
+ * 2. Redistributions in binary form must reproduce the above copyright \n\
+ * notice, this list of conditions and the following disclaimer in \n\
+ * the documentation and/or other materials provided with the \n\
+ * distribution. \n\
+ * 3. Neither the name of the University nor the names of its \n\
+ * contributors may be used to endorse or promote products derived \n\
+ * from this software without specific prior written permission. \n\
+ * \n\
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' \n\
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,\n\
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A \n\
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR \n\
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,\n\
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, \n\
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR \n\
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY \n\
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT \n\
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE \n\
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH \n\
+ * DAMAGE. \n\
+ */ \n\
+ \n\
+ .globl memmove \n\
+ .seh_proc memmove \n\
+memmove: \n\
+ .seh_endprologue \n\
+ nop /* FALLTHRU */ \n\
+ .seh_endproc \n\
+ \n\
+ .globl memcpy \n\
+ .seh_proc memcpy \n\
+memcpy: \n\
+ movq %rsi,8(%rsp) \n\
+ movq %rdi,16(%rsp) \n\
+ .seh_endprologue \n\
+ movq %rcx,%rdi \n\
+ movq %rdx,%rsi \n\
+ movq %r8,%rdx \n\
+ \n\
+ movq %rdi,%rax /* return dst */ \n\
+ movq %rdx,%rcx \n\
+ movq %rdi,%r8 \n\
+ subq %rsi,%r8 \n\
+ cmpq %rcx,%r8 /* overlapping? */ \n\
+ jb 1f \n\
+ cld /* nope, copy forwards. */ \n\
+ shrq $3,%rcx /* copy by words */ \n\
+ rep movsq \n\
+ movq %rdx,%rcx \n\
+ andq $7,%rcx /* any bytes left? */ \n\
+ rep movsb \n\
+ jmp 2f \n\
+1: \n\
+ addq %rcx,%rdi /* copy backwards. */ \n\
+ addq %rcx,%rsi \n\
+ std \n\
+ andq $7,%rcx /* any fractional bytes? */ \n\
+ decq %rdi \n\
+ decq %rsi \n\
+ rep movsb \n\
+ movq %rdx,%rcx /* copy remainder by words */ \n\
+ shrq $3,%rcx \n\
+ subq $7,%rsi \n\
+ subq $7,%rdi \n\
+ rep movsq \n\
+ cld \n\
+2: \n\
+ movq 8(%rsp),%rsi \n\
+ movq 16(%rsp),%rdi \n\
+ ret \n\
+ .seh_endproc \n\
+");
+
+asm volatile (" \n\
+ .globl wmemmove \n\
+ .seh_proc wmemmove \n\
+wmemmove: \n\
+ .seh_endprologue \n\
+ nop /* FALLTHRU */ \n\
+ .seh_endproc \n\
+ \n\
+ .globl wmemcpy \n\
+ .seh_proc wmemcpy \n\
+wmemcpy: \n\
+ .seh_endprologue \n\
+ shlq $1,%r8 /* cnt * sizeof (wchar_t) */ \n\
+ jmp memcpy \n\
+ .seh_endproc \n\
+");
#endif
diff --git a/winsup/cygwin/release/2.2.0 b/winsup/cygwin/release/2.2.0
index 5d8cdd0..291283e 100644
--- a/winsup/cygwin/release/2.2.0
+++ b/winsup/cygwin/release/2.2.0
@@ -24,3 +24,7 @@ Bug Fixes
- Fix crashes under AllocationPreference=0x100000 condition
Addresses: https://cygwin.com/ml/cygwin/2015-02/msg00765.html
+
+- x86_64 only: Implement memset, memmove, memcpy, wmemmove, wmemcpy in
+ assembler derived from NetBSD.
+ Addresses: https://cygwin.com/ml/cygwin-patches/2015-q3/msg00010.html