* Fix compilation on clang-cl.exe
Fixes https://github.com/ikawrakow/ik_llama.cpp/issues/1169
See bitwise ariphmetics here: https://clang.llvm.org/doxygen/avx512fintrin_8h_source.html
Clang (and GCC) supports a language feature called Vector Extensions.
To Clang, `__m512i` is not just a "struct" or a "bag of bits"; it is recognized by the compiler as a native vector type.
Because it is a native vector type, Clang automatically maps standard C operators to the corresponding hardware instructions.
When you write `a | b`, Clang sees that a and b are 512-bit integer vectors.
It implicitly understands that the bitwise OR operator (|) applies to these vectors.
It automatically generates the VPORQ (or VPORD) instruction without needing any helper function.
MSVC follows a stricter, more traditional C++ model regarding intrinsics.
In MSVC, __m512i is defined in the header files (<immintrin.h>) as a struct or union (e.g., typedef struct __m512i { ... } __m512i). To the MSVC compiler, it is essentially a user-defined data type, not a fundamental language primitive like int or float.
Standard C++ does not define what `|` means for a user-defined struct.
MSVC does not have the same "Vector Extensions" that automatically apply operators to these structs.
When you write `a | b` in MSVC, the compiler looks for a definition of `operator|` for the __m512i struct. Since the standard headers don't provide one, the compiler throws an error.
You must use the explicit intrinsic function provided by Intel/MSVC: _mm512_or_si512(a, b).
To get the nice syntax `(a | b)` in MSVC, you have to manually "teach" the compiler what `|` means by defining the `operator|` overload yourself.
* Update README.md with build instructions for Windows
Current README lacks any guide for Windows users, whereas build process on that platform is quite compicated
* Update build.md with instruction about clang-cl.exe
Brings step-by-step build instruction for Windows
* Apply suggestions from code review
Co-authored-by: Kawrakow <iwankawrakow@gmail.com>
* Polish build.md for Windows usage
Added example of use for Windows
* Apply suggestions from code review
---------
Co-authored-by: Kawrakow <iwankawrakow@gmail.com>
* Merging mainline - WIP
* Merging mainline - WIP
AVX2 and CUDA appear to work.
CUDA performance seems slightly (~1-2%) lower as it is so often
the case with llama.cpp/ggml after some "improvements" have been made.
* Merging mainline - fix Metal
* Remove check
---------
Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>
