#include <mmintrin.h> breaks compilation on Windows ARM

[GregSlazinski]

Trying to compile on Windows ARM (UWP), I get the error:
zstd_decompress.c:

#if defined(_MSC_VER)
#  include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
#  define ZSTD_PREFETCH(ptr)   _mm_prefetch((const char*)ptr, _MM_HINT_T0)

1>C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\mmintrin.h(21): fatal error C1189: #error: This header is specific to X86 and X64 targets

You can't use mmintrin.h on ARM

A quick workaround is to use:

#if defined(_MSC_VER) && !defined _M_ARM && !defined _M_ARM64
#  include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */

[Cyan4973]

Thanks for feedback @GregSlazinski .
Indeed, we haven't tested MS Visual on ARM so far.

Maybe we could make the test even stronger, by allowing <mmintrin.h> only on x86/x64 target.

It should be sth. defined like this:

#if defined(_MSC_VER) && defined(_M_X64 || _M_I86)
#  include <mmintrin.h>

Not tested, but sth. like this ... As I currently know, these don't work:

• _M_ARM64
• _M_ARM
• _M_IA64

So it should easier to just add the two which will work...

[Cyan4973]

Totally agreed @mcmilk ,
suggested solution pushed to dev branch