What are these data types for? __m64, __m128, __m256 ?
Thanks Mike, that's what I was looking for.
David
2010-06-04 13:40:37
Basically the answer is that they're enhanced datatypes intended for use in specialized processors, which have optimized instructions available for these types.
Mike Atlas
2010-06-04 13:49:49
+3
A:
A quick google-search gives me:
- The __m64 data type is for use with the MMX and 3DNow! intrinsics
- The __m128 data type, for use with the Streaming SIMD Extensions and Streaming SIMD Extensions 2 instructions intrinsics
Unfortunately I can't readily find what __m256 is but I suspect it is along the same lines.
Basically, data structures for MMX and similar technologies.
Lasse V. Karlsen
2010-06-04 13:32:26
+2
A:
they are SSE instructions, including new AVX extension. http://www.serc.iisc.ernet.in/ComputingFacilities/systems/Dell_Doc/Intel_C++_Compiler/en_US/compiler_c/main_cls/intref_cls/common/intref_avx_details.htm and here
they store vectors - multiple values at the same time. you can do calculations on all values in a vector simultaneously with special instructions. Chech links
Andrey
2010-06-04 13:34:03