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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>
This commit is contained in:
Corinna Vinschen 2017-11-30 10:47:38 +01:00
parent 7161622514
commit aea710b5fb
1 changed files with 44 additions and 16 deletions
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60
winsup/cygwin/miscfuncs.cc
View File

@ -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