sse

问题 When using persistent memory like Intel optane DCPMM, is it possible to see partial result after reboot if system crash(power outage) in execution of movnt instruction? For: 4 or 8 byte movnti which x86 guarantees atomic for other purposes? 16-byte SSE movntdq / movntps which aren't guaranteed atomic but which in practice probably are on CPUs supporting persistent memory. 32-byte AVX vmovntdq / vmovntps 64-byte AVX512 vmovntdq / vmovntps full-line stores bonus question: MOVDIR64B which has

问题 I want to find the minimum/maximum value into an array of byte using SIMD operations. So far I was able to go through the array and store the minimum/maximum value into a __m128i variable, but it means that the value I am looking for is mixed among others (15 others to be exact). I've found these discussions here and here for integer, and this page for float, but I don't understand how works _mm_shuffle*. So my questions are: What SIMD operations do I have to perform in order to extract the

问题 I want to find the minimum/maximum value into an array of byte using SIMD operations. So far I was able to go through the array and store the minimum/maximum value into a __m128i variable, but it means that the value I am looking for is mixed among others (15 others to be exact). I've found these discussions here and here for integer, and this page for float, but I don't understand how works _mm_shuffle*. So my questions are: What SIMD operations do I have to perform in order to extract the

问题 I am currently writing a vectorized version of the QR decomposition (linear system solver) using SSE and AVX intrinsics. One of the substeps requires to select the sign of a value opposite/equal to another value. In the serial version, I used std::copysign for this. Now I want to create a similar function for SSE/AVX registers. Unfortunately, the STL uses a built-in function for that, so I can't just copy the code and turn it into SSE/AVX instructions. I have not tried it yet (so I have no

问题 Upon defining a __m128i variable in this manner: __m128i a; a.m128i_i32[0] = 65000; I get the following error: error: request for member ‘m128i_i32’ in ‘a’, which is of non-class type ‘__m128i {aka __vector(2) long long int}’ a.m128i_i32[0] = 65000; I have included the followinf header files: #include <x86intrin.h> #include <emmintrin.h> #include <smmintrin.h> 回答1: Your code will work under Visual where __m128 is defined as typedef union __declspec(intrin_type) __declspec(align(16)) __m128i {

问题 I have an input vector of 16384 signed four bit integers. They are packed into 8192 Bytes. I need to interleave the values and unpack into signed 8 bit integers in two separate arrays. a,b,c,d are 4 bit values. A,B,C,D are 8 bit values. Input = [ab,cd,...] Out_1 = [A,C, ...] Out_2 = [B,D, ...] I can do this quite easily in C++. constexpr size_t size = 32768; int8_t input[size]; // raw packed 4bit integers int8_t out_1[size]; int8_t out_2[size]; for (int i = 0; i < size; i++) { out_1[i] =

问题 I have an input vector of 16384 signed four bit integers. They are packed into 8192 Bytes. I need to interleave the values and unpack into signed 8 bit integers in two separate arrays. a,b,c,d are 4 bit values. A,B,C,D are 8 bit values. Input = [ab,cd,...] Out_1 = [A,C, ...] Out_2 = [B,D, ...] I can do this quite easily in C++. constexpr size_t size = 32768; int8_t input[size]; // raw packed 4bit integers int8_t out_1[size]; int8_t out_2[size]; for (int i = 0; i < size; i++) { out_1[i] =

问题 I have an input vector of 16384 signed four bit integers. They are packed into 8192 Bytes. I need to interleave the values and unpack into signed 8 bit integers in two separate arrays. a,b,c,d are 4 bit values. A,B,C,D are 8 bit values. Input = [ab,cd,...] Out_1 = [A,C, ...] Out_2 = [B,D, ...] I can do this quite easily in C++. constexpr size_t size = 32768; int8_t input[size]; // raw packed 4bit integers int8_t out_1[size]; int8_t out_2[size]; for (int i = 0; i < size; i++) { out_1[i] =

问题 I have an input vector of 16384 signed four bit integers. They are packed into 8192 Bytes. I need to interleave the values and unpack into signed 8 bit integers in two separate arrays. a,b,c,d are 4 bit values. A,B,C,D are 8 bit values. Input = [ab,cd,...] Out_1 = [A,C, ...] Out_2 = [B,D, ...] I can do this quite easily in C++. constexpr size_t size = 32768; int8_t input[size]; // raw packed 4bit integers int8_t out_1[size]; int8_t out_2[size]; for (int i = 0; i < size; i++) { out_1[i] =

问题 I have an input vector of 16384 signed four bit integers. They are packed into 8192 Bytes. I need to interleave the values and unpack into signed 8 bit integers in two separate arrays. a,b,c,d are 4 bit values. A,B,C,D are 8 bit values. Input = [ab,cd,...] Out_1 = [A,C, ...] Out_2 = [B,D, ...] I can do this quite easily in C++. constexpr size_t size = 32768; int8_t input[size]; // raw packed 4bit integers int8_t out_1[size]; int8_t out_2[size]; for (int i = 0; i < size; i++) { out_1[i] =