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[newlib-cygwin] cygwin: x86_64: implement mempcpy/wmempcpy in assembler
- From: Corinna Vinschen <corinna at sourceware dot org>
- To: cygwin-cvs at sourceware dot org
- Date: 30 Nov 2017 20:22:57 -0000
- Subject: [newlib-cygwin] cygwin: x86_64: implement mempcpy/wmempcpy in assembler
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=aea710b5fbaec09ebe29bd32424440723731ec6e
commit aea710b5fbaec09ebe29bd32424440723731ec6e
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Thu Nov 30 10:47:38 2017 +0100
cygwin: x86_64: implement mempcpy/wmempcpy in assembler
* change memcpy to internal _memcpy not setting the return value in %rax
* implement all memcpy-like functions as caller to _memcpy, setting %rax
to correct return value beforehand. This is possible because _memcpy
does not use %rax at all
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/miscfuncs.cc | 60 +++++++++++++++++++++++++++++++++-------------
1 file changed, 44 insertions(+), 16 deletions(-)
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index a6404c8..923556d 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -824,16 +824,8 @@ asm volatile (" \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\
+ .seh_proc _memcpy \n\
+_memcpy: \n\
movq %rsi,8(%rsp) \n\
movq %rdi,16(%rsp) \n\
.seh_endprologue \n\
@@ -841,7 +833,6 @@ memcpy: \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\
@@ -873,14 +864,39 @@ memcpy: \n\
movq 16(%rsp),%rdi \n\
ret \n\
.seh_endproc \n\
-");
-
-asm volatile (" \n\
+ \n\
+ .globl memmove \n\
+ .seh_proc memmove \n\
+memmove: \n\
+ .seh_endprologue \n\
+ movq %rcx,%rax /* return dst */ \n\
+ jmp _memcpy \n\
+ .seh_endproc \n\
+ \n\
+ .globl memcpy \n\
+ .seh_proc memcpy \n\
+memcpy: \n\
+ .seh_endprologue \n\
+ movq %rcx,%rax /* return dst */ \n\
+ jmp _memcpy \n\
+ .seh_endproc \n\
+ \n\
+ .globl memcpy \n\
+ .seh_proc memcpy \n\
+mempcpy: \n\
+ .seh_endprologue \n\
+ movq %rcx,%rax /* return dst */ \n\
+ addq %r8,%rax /* + n */ \n\
+ jmp _memcpy \n\
+ .seh_endproc \n\
+ \n\
.globl wmemmove \n\
.seh_proc wmemmove \n\
wmemmove: \n\
.seh_endprologue \n\
- nop /* FALLTHRU */ \n\
+ shlq $1,%r8 /* cnt * sizeof (wchar_t) */ \n\
+ movq %rcx,%rax /* return dst */ \n\
+ jmp _memcpy \n\
.seh_endproc \n\
\n\
.globl wmemcpy \n\
@@ -888,9 +904,21 @@ wmemmove: \n\
wmemcpy: \n\
.seh_endprologue \n\
shlq $1,%r8 /* cnt * sizeof (wchar_t) */ \n\
- jmp memcpy \n\
+ movq %rcx,%rax /* return dst */ \n\
+ jmp _memcpy \n\
+ .seh_endproc \n\
+ \n\
+ .globl wmemcpy \n\
+ .seh_proc wmemcpy \n\
+wmempcpy: \n\
+ .seh_endprologue \n\
+ shlq $1,%r8 /* cnt * sizeof (wchar_t) */ \n\
+ movq %rcx,%rax /* return dst */ \n\
+ addq %r8,%rax /* + n */ \n\
+ jmp _memcpy \n\
.seh_endproc \n\
");
+
#endif
/* Signal the thread name to any attached debugger