voidmatrixMulCPU(float*C,constfloat*A,constfloat*B,unsignedintwA, unsignedintwC,unsignedinthC){ unsignedinthA = hC; unsignedintwB = wC; for(unsignedinti =0; i < hA; ++i) for(unsignedintj =0; j < wB; ++j) { doublesum =0; for(unsignedintk...
X86下采用80bit进行double计算,可以解释程序移植到GPU后出现的精度损失的现象二、当跨过上述问题之后,我们能够写出一个结果正确的CUDA kernel,但是距离“高性能”这一目标还有路要走1、内存层次结构:Global Memory, Constant Memory, Texture Memory, Share Memory, L1/L2 Cache, Register等。使用这些内存在得到性能...
Type Time(%) Time Calls Avg Min Max Name GPU activities: 29.49% 190.45ms 100 1.9045ms 1.8181ms 2.0072ms reduce_syncwarp(float const *, float*, int) 27.84% 179.82ms 100 1.7982ms 1.7960ms 1.8183ms reduce_shfl(float const *, float*, int) 27.82% 179.65ms 100 1.7965ms 1.7957ms 1.7976ms ...
39.4 Conclusion The scan operation is a simple and powerful parallel primitive with a broad range of applications. In this chapter we have explained an efficient implementation of scan using CUDA, which achieves a significant speedup compared to a sequential implementation on a fast CPU, and ...
doubleElements<<<number_of_blocks, threads_per_block>>>(a, N); cudaDeviceSynchronize(); bool areDoubled = checkElementsAreDoubled(a, N); printf("All elements were doubled? %s\n", areDoubled ? "TRUE" : "FALSE"); /* * Refactor to free memory that has been allocated to be ...
要避免double向float的自动转换。我们要在常数后面加f来避免这种事情的发生,因为它会增加多余的时钟周期。并且对于单精度浮点数,建议使用单精度的数学函数和操作。而且在普遍意义上来说,单精度比双精度快。 11.1.4. 小指数取幂 这是啥意思呢,看这个表就知道了: ...
float *cloud_target, int nQCount, int Maxiterate, double threshold, Eigen::Matrix4f &transformation_matrix, stream); CUDA-ICP 计算的输出是 transformation_matrix,代表的含义如下: 源点云(P)* transformation = 目标坐标系的点云(Q) 因为激光类型的输出点云的数量为固定值,所以CUDA-ICP在输出化的时候,...
上面的 device API 在每次调用时,只会生成一个 float/double 的随机数。Nvidia 同样提供了一次可以生成 2个或4个 device API: Bash __device__ uint4 curand4 (curandStatePhilox4_32_10_t *state); __device__ float4 curand_uniform4 (curandStatePhilox4_32_10_t *state); __device__ float4 cura...
这里主要提到2个问题. 第一个问题是涉及到寄存器的bank conflict, 这点如同本优化指南说的,用户无法控制这个问题, 这个是编译器在生成目标代码的时候, 自动尽量规避的.这点我赞同. 同时本手册说了, 不用考虑用int4, float4, double2类似这种数据类型所可能带来的寄存器的bank conflict, 该用/不改用就用(不用...
float time_cpu_cost = ((float)(end-start))/CLOCKS_PER_SEC; printf("CPU cost %f sectonds.\n", time_cpu_cost); start = clock(); double *gpu_a, *gpu_b, *gpu_c; cudaMalloc((void**)&gpu_a, size); cudaMalloc((void**)&gpu_b, size); ...