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Remove scary memcpy hack

This commit is contained in:
Andrew Nelless 2017-12-13 16:18:22 +00:00
parent 1fb01f6833
commit 0e11b8777f
1 changed files with 0 additions and 70 deletions
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70
src/lib/synwinhk/synwinhk.cpp
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@ -27,9 +27,6 @@
#else #else
#define assert(_X_) __noop() #define assert(_X_) __noop()
#endif #endif
// VS2005 is a bit more smart than VC6 and optimize simple copy loop to
// intrinsic memcpy.
#pragma function(memcpy)
// //
// debugging compile flag. when not zero the server doesn't grab // debugging compile flag. when not zero the server doesn't grab
@ -627,79 +624,12 @@ DllMain(HINSTANCE instance, DWORD reason, LPVOID)
extern "C" { extern "C" {
// VS2005 hack to not link with the CRT
#if _MSC_VER >= 1400
BOOL WINAPI _DllMainCRTStartup( BOOL WINAPI _DllMainCRTStartup(
HINSTANCE instance, DWORD reason, LPVOID lpreserved) HINSTANCE instance, DWORD reason, LPVOID lpreserved)
{ {
return DllMain(instance, reason, lpreserved); return DllMain(instance, reason, lpreserved);
} }
// VS2005 is a bit more bright than VC6 and optimize simple copy loop to
// intrinsic memcpy.
void * __cdecl memcpy(void * _Dst, const void * _Src, size_t _MaxCount)
{
void * _DstBackup = _Dst;
switch (_MaxCount & 3) {
case 3:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
--_MaxCount;
case 2:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
--_MaxCount;
case 1:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
--_MaxCount;
break;
case 0:
break;
default:
__assume(0);
break;
}
// I think it's faster on intel to deference than modify the pointer.
const size_t max = _MaxCount / sizeof(UINT_PTR);
for (size_t i = 0; i < max; ++i) {
((UINT_PTR*)_Dst)[i] = ((UINT_PTR*)_Src)[i];
}
(UINT_PTR*&)_Dst += max;
(UINT_PTR*&)_Src += max;
switch (_MaxCount & 3) {
case 3:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
case 2:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
case 1:
((char*)_Dst)[0] = ((char*)_Src)[0];
++(char*&)_Dst;
++(char*&)_Src;
break;
case 0:
break;
default:
__assume(0);
break;
}
return _DstBackup;
}
#endif
int int
init(DWORD threadID, BOOL isPrimary) init(DWORD threadID, BOOL isPrimary)
{ {