Well, why including x86intrin.h header within our platform-headers?
Why not including instead - as we did in the past - including intrin.h
header instead?!?!
"In the past", we DID include x86intrin.h. Back before I even started
with the project (r5579), winnt.h was already including x86intrin.h.
Ideally, I'd like to remove x86intrin.h from winnt.h too. The only
reason I didn't do this at the same time as I removed intrin.h was that
winnt.h needs implementations for _mm_lfence, _mm_mfence, _mm_sfence,
_mm_pause, and _mm_prefetch, which all come from that include. And I
couldn't just copy these implementations into winnt.h and/or intrin.h,
because they would have conflicted with x86intrin.h if it got included
later.
intrin.h also includes a dozen other include files which define hundreds
(thousands?) of other functions. Aside from the possibility of
introducing conflicts, including this much additional code has an impact
on compile times. And of course it is inconsistent with what the MS
PSDK does.
Again, we don't need to FIX OUR PROTOTYPES. This is wrong point of
view here.
I disagree. Here's the existing code:
#ifdef __x86_64__
__MINGW_EXTENSION unsigned long long __cdecl _lrotl(unsigned long
long _Val,int _Shift);
__MINGW_EXTENSION unsigned long long __cdecl _lrotr(unsigned long
long _Val,int _Shift);
#else
unsigned long __cdecl _lrotl(unsigned long _Val,int _Shift);
unsigned long __cdecl _lrotr(unsigned long _Val,int _Shift);
#endif
What is the purpose of the #if here? It appears it is intended to
change the prototype based on the size of longs, which it assumes will
change based on whether __x86_64__ is defined. However, that assumption
is false. Using msvc (or gcc built for native windows), longs are
32bits for both x86 and x64. Forcing the prototype to "unsigned long
long" just because __x86_64__ is defined is the incorrect solution.
A slightly improved version might look like this:
#if __SIZEOF_LONG__ == 8
__MINGW_EXTENSION unsigned long long __cdecl _lrotl(unsigned long
long _Val,int _Shift);
__MINGW_EXTENSION unsigned long long __cdecl _lrotr(unsigned long
long _Val,int _Shift);
#else
unsigned long __cdecl _lrotl(unsigned long _Val,int _Shift);
unsigned long __cdecl _lrotr(unsigned long _Val,int _Shift);
#endif
But (as you have pointed out before) the "__SIZEOF_LONG__" macro may not
be supported by all compilers. However, there is an even simpler
declaration that works correctly for x86, x64, cygwin, cygwin64, IA64, etc:
unsigned long __cdecl _lrotl(unsigned long _Val,int _Shift);
unsigned long __cdecl _lrotr(unsigned long _Val,int _Shift);
Using these definitions, if "longs" are 4 bytes, this prototype will
give 4 byte definitions. If longs are 8 bytes, this will give 8 byte
definitions. No #if required.
We need to provide to users the PROPER prototypes as they
expect to have by reading documentation of msdn.
I agree. Which is exactly what I did
<http://msdn.microsoft.com/en-us/library/a0w705h5.aspx>.
To address that in x86intrin.h header
would be fine, but was rejected in the past already.
Do you have a link to the last discussion? Before I try to convince
them, it might help to see why this wasn't accepted last time.
dw
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