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HPC/Project1/project_1_maggioni_claudio/matmult/dgemm-blocked.c

75 lines
2.5 KiB
C

#include <string.h>
/*
Please include compiler name below (you may also include any other modules you would like to be loaded)
COMPILER= gnu
Please include All compiler flags and libraries as you want them run. You can simply copy this over from the Makefile's first few lines
CC = cc
OPT = -O3
CFLAGS = -Wall -std=gnu99 $(OPT)
MKLROOT = /opt/intel/composer_xe_2013.1.117/mkl
LDLIBS = -lrt -Wl,--start-group $(MKLROOT)/lib/intel64/libmkl_intel_lp64.a $(MKLROOT)/lib/intel64/libmkl_sequential.a $(MKLROOT)/lib/intel64/libmkl_core.a -Wl,--end-group -lpthread -lm
*/
const char* dgemm_desc = "Block-based dgemm.";
const int block_size = 27;
inline int min(int a, int b) {
return a < b ? a : b;
}
inline void naivemm(int r_min, int r_max, int k_min, int k_max, int c_min, int c_max, int n, double* A_row, double* B, double* C_temp) {
for (int i = r_min, ii = 0; i < r_max; ++i, ++ii) {
for (int j = c_min, jj = 0; j < c_max; ++j, ++jj) {
for (int k = k_min; k < k_max; k++) {
C_temp[ii + jj * block_size] += A_row[i * n + k] * B[k + j * n];
}
}
}
}
inline void store_c(double* C, double* C_temp, int r_min, int r_max, int c_min, int c_max, int n) {
for (int j = c_min, jj = 0; j < c_max; ++j, ++jj) {
memcpy(C + j * n + r_min, C_temp + jj * block_size, (r_max - r_min) * sizeof(double));
}
}
/* This routine performs a dgemm operation
* C := C + A * B
* where A, B, and C are lda-by-lda matrices stored in column-major format.
* On exit, A and B maintain their input values. */
void square_dgemm(int n, double* A, double* B, double* C) {
double A_row[n * n];
double C_temp[block_size * block_size];
for (int m = 0; m < n; ++m) {
double row_tmp[n];
memcpy(row_tmp, A + m * n, n * sizeof(double));
for (int l = 0; l < n; ++l) {
A_row[l * n + m] = row_tmp[l];
}
}
for (int i = 0; i < n; i += block_size) {
int i_next = min(i + block_size, n);
for (int j = 0; j < n; j += block_size) {
int j_next = min(j + block_size, n);
memset(C_temp, 0, block_size * block_size * sizeof(double));
for (int k = 0; k < n; k += block_size) {
int k_next = min(k + block_size, n);
naivemm(i, i_next, k, k_next, j, j_next, n, A_row, B, C_temp);
}
store_c(C, C_temp, i, i_next, j, j_next, n);
}
}
}