Cuda Matrix multiplication program can't pass, very strange error code - c

Question

I am doing a matrix multiplication using cuda. I think I am about to success, but some very strange error stops me, I can't find out where the code goes wrong. Below is the code sample:
#include <stdio.h>
#include <cuda.h>
#define BLOCK_SIZE 16;
__global__ void matmulKernel(float* mat_in1,float* mat_in2, float* mat_out,int mat_dim);
int main() {
float *h_M, *h_N, *h_P, *d_M, *d_N, *d_P;
int i,width=10;
int size=width*width*sizeof(float);
dim3 block_dim(BLOCK_SIZE,BLOCK_SIZE,1);
int grid_size=width/BLOCK_SIZE;
if(width%BLOCK_SIZE) grid_size++;
dim3 grid_dim (grid_size,grid_size,1);
h_M=(float*)malloc(size);
h_N=(float*)malloc(size);
h_P=(float*)malloc(size);
cudaMalloc((void**)&d_M,size);
cudaMalloc((void**)&d_N,size);
cudaMalloc((void**)&d_P,size);
if(h_M==0||h_N==0||h_P==0||d_M==0||d_N==0||d_P==0) {
printf("memory locate fail!\n");
}
for(i=0;i<width*width;i++) {
h_M[i]=1.2*i;
h_N[i]=1.4*i;
}
cudaMemcpy(d_M,h_M,size,cudaMemcpyHostToDevice);
cudaMemcpy(d_N,h_N,size,cudaMemcpyHostToDevice);
matmulKernel<<<grid_dim,block_dim>>>(d_M,d_N,d_P,width);
cudaMemcpy(h_P,d_P,size,cudaMemcpyDeviceToHost);
printf("firt row of the results matrix P:\n");
for(i=0;i<width;i++) {
printf("%f, %f",h_P[i]);
}
printf("\n");
return 0;
}
__global__ void matmulKernel(float* mat1,float* mat2, float* matP,int dim) {
int thread_x,thread_y,i;
thread_x=blockIdx.x*blockDim.x+threadIdx.x;
thread_y=blockIdx.y*blockDim.y+threadIdx.y;
if(thread_x<dim&&thread_y<dim) {
float P_value=0.;
for(i=0;i<dim;i++) {
P_value+=mat1[thread_y*dim+i]*mat2[i*dim+thread_x];
}
matP[thread_y*dim+thread_x]=P_value;
}
}
Using nvcc compile, the error is :
matmul.cu(11): error: expected a ")"
matmul.cu(11): error: expected an expression
matmul.cu(11): error: expected an expression
matmul.cu(13): error: expected a ")"
I cannot see why the compiler report this error, anyone please tell me where I am wrong.

Answer 1

You have a stray semicolon.
Change:
#define BLOCK_SIZE 16;
to:
#define BLOCK_SIZE 16