ref: bd6c2aad586814b091ce5aca9d41cf2c51adb37b
dir: /libmath/gemm.c/
#include "lib9.h"
#include "mathi.h"
void
gemm(int transa, int transb, int m, int n, int k, double alpha,
double *a, int lda,
double *b, int ldb, double beta,
double *c, int ldc)
{
int i1, i2, i3, nota, notb, i, j, jb, jc, l, la;
double temp;
nota = transa=='N';
notb = transb=='N';
if(m == 0 || n == 0 || (alpha == 0. || k == 0) && beta == 1.){
return;
}
if(alpha == 0.){
if(beta == 0.){
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = 0.;
}
}
}else{
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = beta * c[i + jc];
}
}
}
return;
}
if(!a){
if(notb){ /* C := alpha*B + beta*C. */
i1 = n;
for(j = 0; j < i1; ++j){
jb = j*ldb;
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = alpha*b[i+jb] + beta*c[i+jc];
}
}
}else{ /* C := alpha*B' + beta*C. */
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = alpha*b[j+i*ldb] + beta*c[i+jc];
}
}
}
return;
}
if(notb){
if(nota){
/* Form C := alpha*A*B + beta*C. */
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
if(beta == 0.){
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = 0.;
}
}else if(beta != 1.){
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = beta * c[i + jc];
}
}
i2 = k;
for(l = 0; l < i2; ++l){
la = l*lda;
if(b[l + j*ldb] != 0.){
temp = alpha * b[l + j*ldb];
i3 = m;
for(i = 0; i < i3; ++i){
c[i + jc] += temp * a[i + la];
}
}
}
}
}else{
/* Form C := alpha*A'*B + beta*C */
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
temp = 0.;
i3 = k;
for(l = 0; l < i3; ++l){
temp += a[l + i*lda] * b[l + j*ldb];
}
if(beta == 0.){
c[i + jc] = alpha * temp;
}else{
c[i + jc] = alpha * temp + beta * c[i + jc];
}
}
}
}
}else{
if(nota){
/* Form C := alpha*A*B' + beta*C */
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
if(beta == 0.){
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = 0.;
}
}else if(beta != 1.){
i2 = m;
for(i = 0; i < i2; ++i){
c[i + jc] = beta * c[i + jc];
}
}
i2 = k;
for(l = 0; l < i2; ++l){
if(b[j + l*ldb] != 0.){
temp = alpha * b[j + l*ldb];
i3 = m;
for(i = 0; i < i3; ++i){
c[i + jc] += temp * a[i + l*lda];
}
}
}
}
}else{
/* Form C := alpha*A'*B' + beta*C */
i1 = n;
for(j = 0; j < i1; ++j){
jc = j*ldc;
i2 = m;
for(i = 0; i < i2; ++i){
temp = 0.;
i3 = k;
for(l = 0; l < i3; ++l){
temp += a[l + i*lda] * b[j + l*ldb];
}
if(beta == 0.){
c[i + jc] = alpha * temp;
}else{
c[i + jc] = alpha * temp + beta * c[i + jc];
}
}
}
}
}
}