optimized ddot.c for increments != 1

diff --git a/kernel/x86_64/ddot.c b/kernel/x86_64/ddot.c
index c17741c..0f77d5f 100644 (file)
--- a/kernel/x86_64/ddot.c
+++ b/kernel/x86_64/ddot.c
@@ -101,15 +101,40 @@ FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y)
 
        }
 
+       FLOAT temp1 = 0.0;
+       FLOAT temp2 = 0.0;
+
+        BLASLONG n1 = n & -4;  
+
+       while(i < n1)
+       {
+
+               FLOAT m1 = y[iy]       * x[ix] ;
+               FLOAT m2 = y[iy+inc_y] * x[ix+inc_x] ;
+
+               FLOAT m3 = y[iy+2*inc_y] * x[ix+2*inc_x] ;
+               FLOAT m4 = y[iy+3*inc_y] * x[ix+3*inc_x] ;
+
+               ix  += inc_x*4 ;
+               iy  += inc_y*4 ;
+
+               temp1 += m1+m3;
+               temp2 += m2+m4;
+
+               i+=4 ;
+
+       }
+
        while(i < n)
        {
 
-               dot += y[iy] * x[ix] ;
+               temp1 += y[iy] * x[ix] ;
                ix  += inc_x ;
                iy  += inc_y ;
                i++ ;
 
        }
+       dot = temp1 + temp2;
        return(dot);
 
 }