sse

I've noticed that accessing __m128 fields by index is possible in gcc , without using the union trick. __m128 t; float r(t[0] + t[1] + t[2] + t[3]); I can also load a __m128 just like an array: __m128 t{1.f, 2.f, 3.f, 4.f}; This is all in line with gcc 's vector extensions. These, however, may not be available elsewhere. Are the loading and accessing features supported by the intel compiler and msvc? To load a __m128 , you can write _mm_setr_ps(1.f, 2.f, 3.f, 4.f) , which is supported by GCC, ICC, MSVC and clang. So far as I know, clang and recent versions of GCC support accessing __m128

I would like to know if the following is possible in any of the SIMD families of instructions. I have a qword input with 63 significant bits (never negative). Each sequential 7 bits starting from the LSB is shuffle-aligned to a byte, with a left-padding of 1 (except for the most significant non-zero byte). To illustrate, I'll use letters for clarity's sake. The result is only the significant bytes, thus 0 - 9 in size, which is converted to a byte array. In: 0|kjihgfe|dcbaZYX|WVUTSRQ|PONMLKJ|IHGFEDC|BAzyxwv|utsrqpo|nmlkjih|gfedcba Out: 0kjihgfe|1dcbaZYX|1WVUTSRQ|1PONMLKJ|1IHGFEDC|1BAzyxwv

How would I add 1 or 2 to the register xmm0 (double)? I can do it like this, but sure there must be an easier way: movsd xmm0, [ecx] xor eax, eax inc eax cvtsi2sd xmm1, eax addsd xmm0, xmm1 movsd [ecx], xmm0 Also would it be possible to do this with the floating point x87 instructions? This doesn't work for me: fld dword ptr [ecx] fld1 faddp fstp dword ptr [ecx] You can keep a constant in memory or in another register: _1 dq 1.0 and addsd xmm1,[_1] or movsd xmm0,[_1] addsd xmm1,xmm0 If you are on x64, you can do this: mov rax,1.0 movq xmm0,rax addsd xmm1,xmm0 or use the stack if the type

I'm trying to call a native function from a managed assembly. I've done this on pre-compiled libraries and everything has went well. At this moment I'm building my own library, and I can't get this work. The native DLL source is the following: #define DERM_SIMD_EXPORT __declspec(dllexport) #define DERM_SIMD_API __cdecl extern "C" { DERM_SIMD_EXPORT void DERM_SIMD_API Matrix4x4_Multiply_SSE(float *result, float *left, float *right); } void DERM_SIMD_API Matrix4x4_Multiply_SSE(float *result, float *left, float *right) { __asm { .... } } Hereafter we have the managed code which loads the library