__m128i
The latest version of this topic can be found at __m128i.
Microsoft Specific
The __m128i data type, for use with the Streaming SIMD Extensions 2 (SSE2) instructions intrinsics, is defined in emmintrin.h.
// data_types__m128i.cpp
#include <emmintrin.h>
int main() {
__m128i x;
}
Remarks
You should not access the __m128i fields directly. You can, however, see these types in the debugger. A variable of type __m128i maps to the XMM[0-7] registers.
Variables of type _m128i are automatically aligned on 16-byte boundaries.
Note
Using variables of type __m128i will cause the compiler to generate the SSE2 movdqa instruction. This instruction does not cause a fault on Pentium III processors but will result in silent failure, with possible side effects caused by whatever instructions movdqa translates into on Pentium III processors.
The __m128i data type is not supported on ARM processors.