reduce1.cu File Reference

Compute blockwise sums of a vector x of length n. More...

#include "../include/mycuda.h"

Go to the source code of this file.

Functions
__device__ void	reduce1_dev (float *x, int n)
	__device__ function that does actual reduction More...
__global__ void	reduce1 (float *xsum, float *x, int stride)
	Reduction kernel. More...
int	main ()

Variables
const int	blocksize = 256

Detailed Description

Compute blockwise sums of a vector x of length n.

Definition in file reduce1.cu.

Function Documentation

int main

(

void

)

Definition at line 85 of file reduce1.cu.

__global__ void reduce1	(	float *	xsum,
		float *	x,
		int	stride
	)

Reduction kernel.

Given an M x N array, return the column sums.

Notes

• Uses static shared memory allocation.
• Each block reduces one column.

Requires

• gridsize = N
• blocksize = M

Definition at line 65 of file reduce1.cu.

__device__ void reduce1_dev	(	float *	x,
		int	n
	)

__device__ function that does actual reduction

Notes

• The sum is computed in place and returned in x[0].
• x should be stored in shared memory for best performance (accessing shared memory is much faster than global memory).
• Note use of synchronization!!

Requires

• n <= 2*blocksize

Definition at line 25 of file reduce1.cu.

Variable Documentation

const int blocksize = 256

Definition at line 8 of file reduce1.cu.