neon

IMX6系列查看CPU ID的方法 想要查看CPU的ID信息，可以通过cat /proc/cpuinfo命令来查看：（以下是我用（电鱼）SAIL-IMX6实现的） 具体步骤： Imx6dl： root@imx6qdlsolo:~# cat /proc/cpuinfo processor : 0 model name : ARMv7 Processor rev 10 (v7l) BogoMIPS : 6.00 Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpd32 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x2 CPU part : 0xc09 CPU revision : 10 processor : 1 model name : ARMv7 Processor rev 10 (v7l) BogoMIPS : 6.00 Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpd32 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x2 CPU part : 0xc09 CPU revision : 10

I want to copy an image on an ARMv7 core. The naive implementation is to call memcpy per line. for(i = 0; i < h; i++) { memcpy(d, s, w); s += sp; d += dp; } I know that the following d, dp, s, sp, w are all 32-byte aligned, so my next (still quite naive) implementation was along the lines of for (int i = 0; i < h; i++) { uint8_t* dst = d; const uint8_t* src = s; int remaining = w; asm volatile ( "1: \n" "subs %[rem], %[rem], #32 \n" "vld1.u8 {d0, d1, d2, d3}, [%[src],:256]! \n" "vst1.u8 {d0, d1, d2, d3}, [%[dst],:256]! \n" "bgt 1b \n" : [dst]"+r"(dst), [src]"+r"(src), [rem]"+r"(remaining) : :

I would like to enable NEON vectorization on my ARM cortex-a9, but I get this output at compile: "not vectorized: relevant stmt not supported: D.14140_82 = D.14143_77 * D.14141_81" Here is my loop: void my_mul(float32_t * __restrict data1, float32_t * __restrict data2, float32_t * __restrict out){ for(int i=0; i<SIZE*4; i+=1){ out[i] = data1[i]*data2[i]; } } And the options used at compile: -march=armv7-a -mcpu=cortex-a9 -mfpu=neon -mfloat-abi=softfp -ftree-vectorize -mvectorize-with-neon-quad -ftree-vectorizer-verbose=2 I am using arm-linux-gnueabi (v4.6 ) compiler . It is important to note

I'm working on a SIMD optimization of BGR to grayscale conversion which is equivalent to OpenCV's cvtColor() function . There is an Intel SSE version of this function and I'm referring to it. (What I'm doing is basically converting SSE code to NEON code.) I've almost finished writing the code, and can compile it with g++, but I can't get the proper output. Does anyone have any ideas what the error could be? What I'm getting (incorrect): What I should be getting: Here's my code: #include <opencv/cv.hpp> #include <opencv/highgui.h> #include <arm_neon.h> //#include <iostream> using namespace std;

I'm trying to optimize an image format conversion on iOS using the NEON vector instruction set. I assumed this would map well to that because it processes a bunch of similar data. My attempts haven't gone that well, though, achieving only a marginal speedup vs the naive c implementation: for(int i = 0; i < pixelCount; ++i, ++inPixel32) { const unsigned int r = ((*inPixel32 >> 0 ) & 0xFF); const unsigned int g = ((*inPixel32 >> 8 ) & 0xFF); const unsigned int b = ((*inPixel32 >> 16) & 0xFF); *outPixel16++ = ((r >> 3) << 11) | ((g >> 2) << 5) | ((b >> 3) << 0); } 1 megapixel image array on iPad

I'm processing an image by four pixels at the time, this on a armv7 for an Android application. I want to divide a float32x4_t vector by another vector but the numbers in it are varying from circa 0.7 to 3.85 , and it seems to me that the only way to divide is using right shift but that is for a number which is 2^n . Also, I'm new in this, so any constructive help or comment is welcomed. Example: How can I perform these operations with NEON intrinsics? float32x4_t a = {25.3,34.1,11.0,25.1}; float32x4_t b = {1.2,3.5,2.5,2.0}; // somthing like this float32x4 resultado = a/b; // {21.08,9.74,4.4