refactor: pointer arithmetic

Author: aayush0325

lib/node_modules/@stdlib/lapack/base/dgtts2/lib/base.js

@@ -69,76 +69,95 @@ function transpose( N, nrhs, DL, strideDL, offsetDL, D, strideD, offsetD, DU, st
 	var ipi;
 	var idu;
 	var idl;
+	var ib1;
+	var ib2;
 	var id;
 	var ip;
 	var i;
 	var j;
 
 	if ( nrhs <= 1 ) {
+		ib1 = offsetB; // 			ib1 = offsetB + (j*strideB2);
 		for ( j = 0; j < nrhs; j++) {
 			ip = offsetIPIV + ( (N-2) * strideIPIV );
 			idl = offsetDL + ( (N-2) * strideDL );
 			id = offsetD;
 			idu = offsetDU;
 			idu2 = offsetDU2;
 
-			B[ offsetB + (strideB2*j) ] = B[ offsetB + (strideB2*j) ] / D[ id ];
+			B[ ib1 ] /= D[ id ];
 			if ( N > 1 ) {
-				B[ offsetB + strideB1 + (strideB2*j) ] = ( B[ offsetB + strideB1 + (strideB2*j) ] - ( DU[ idu ] * B[ offsetB + (strideB2*j) ] ) ) / D[ id + strideD ];
+				B[ ib1 + strideB1 ] = ( B[ ib1 + strideB1 ] - ( DU[ idu ] * B[ ib1 ] ) ) / D[ id + strideD ];
 			}
 
 			idu = offsetDU + strideDU;
 			id = offsetD + ( 2 * strideD );
+
+			ib2 = strideB1 * 2;
 			for ( i = 2; i < N; i++ ) {
-				B[ offsetB + (strideB1*i) + (strideB2*j) ] = ( B[ offsetB + (strideB1*i) + (strideB2*j) ] - ( DU[ idu ] * B[ offsetB + (strideB1*(i-1)) + (strideB2*j) ] ) - ( DU2[ idu2 ] * B[ offsetB + (strideB1*(i-2)) + (strideB2*j) ] ) ) / D[ id ];
+				B[ ib1 + ib2 ] = ( B[ ib1 + ib2 ] - ( DU[ idu ] * B[ ib1 + ib2 - strideB1 ] ) - ( DU2[ idu2 ] * B[ ib1 + ib2 - (2*strideB1) ] ) ) / D[ id ];
 
 				idu += strideDU;
 				idu2 += strideDU2;
 				id += strideD;
+				ib2 += strideB1;
 			}
+
+			ib2 = strideB1 * ( N-2 );
 			for ( i = N - 2; i >= 0; i-- ) {
 				ipi = IPIV[ ip ];
-				temp = B[ offsetB + (strideB1*i) + (strideB2*j) ] - ( DL[ idl ] * B[ offsetB + (strideB1*(i+1)) + (strideB2*j) ] );
-				B[ offsetB + (strideB1*i) + (strideB2*j) ] = B[ offsetB + (strideB1*ipi) + (strideB2*j) ];
+				temp = B[ ib1 + ib2 ] - ( DL[ idl ] * B[ ib1 + ib2 + strideB1 ] );
+				B[ ib1 + ib2 ] = B[ offsetB + (strideB1*ipi) + (strideB2*j) ];
 				B[ offsetB + (strideB1*ipi) + (strideB2*j) ] = temp;
 
 				ip -= strideIPIV;
 				idl -= strideDL;
+				ib2 -= strideB1;
 			}
+
+			ib1 += strideB2;
 		}
 	} else {
+		ib1 = offsetB;
 		for ( j = 0; j < nrhs; j++ ) {
 			idu = offsetDU;
 			id = offsetD;
 			idu2 = offsetDU2;
 			ip = offsetIPIV + ( (N-2) * strideIPIV );
-			idl = offsetDL + ( (N-2) * strideDL );
 
-			B[ offsetB + (strideB2*j) ] /= D[ id ];
+			B[ ib1 ] /= D[ id ];
 			if ( N > 1 ) {
-				B[ offsetB + strideB1 + (strideB2*j) ] = ( B[ offsetB + strideB1 + (strideB2*j) ] - ( DU[ idu ] * B[ offsetB + (strideB2*j) ] ) ) / D[ id + strideD ];
+				B[ ib1 + strideB1 ] = ( B[ ib1 + strideB1 ] - ( DU[ idu ] * B[ ib1 ] ) ) / D[ id + strideD ];
 			}
 			idu = offsetDU + strideDU;
 			id = offsetD + ( 2 * strideD );
+			ib2 = 2 * strideB1;
 			for ( i = 2; i < N; i++ ) {
-				B[ offsetB + (strideB1*i) + (strideB2*j) ] = ( B[ offsetB + (strideB1*i) + (strideB2*j) ] - ( DU[ idu ] * B[ offsetB + (strideB1*(i-1)) + (strideB2*j) ] ) - ( DU2[ idu2 ] * B[ offsetB + (strideB1*(i-2)) + (strideB2*j) ] ) ) / D[ id ];
+				B[ ib1 + ib2 ] = ( B[ ib1 + ib2 ] - ( DU[ idu ] * B[ ib1 + ib2 - strideB1 ] ) - ( DU2[ idu2 ] * B[ ib1 + ib2 - (2*strideB1) ] ) ) / D[ id ];
 
 				idu += strideDU;
 				id += strideD;
 				idu2 += strideDU2;
+				ib2 += strideB1;
 			}
+
+			ib2 = ( N-2 ) * strideB1;
+			idl = offsetDL + ( (N-2) * strideDL );
 			for ( i = N - 2; i >= 0; i-- ) {
 				if ( IPIV[ ip ] === i ) {
-					B[ offsetB + (strideB1*i) + (strideB2*j) ] -= DL[ offsetDL + (strideDL*i) ] * B[ offsetB + (strideB1*(i+1)) + (strideB2*j) ];
+					B[ ib1 + ib2 ] -= DL[ idl ] * B[ ib1 + ib2 + strideB1 ];
 				} else {
-					temp = B[ offsetB + (strideB1*(i+1)) + (strideB2*j) ];
-					B[ offsetB + (strideB1*(i+1)) + (strideB2*j) ] = B[ offsetB + (strideB1*i) + (strideB2*j) ] - ( DL[ idl ] * temp );
-					B[ offsetB + (strideB1*i) + (strideB2*j) ] = temp;
+					temp = B[ ib1 + ib2 + strideB1 ];
+					B[ ib1 + ib2 + strideB1 ] = B[ ib1 + ib2 ] - ( DL[ idl ] * temp );
+					B[ ib1 + ib2 ] = temp;
 				}
 
 				ip -= strideIPIV;
 				idl -= strideDL;
+				ib2 -= strideB1;
 			}
+
+			ib1 += strideB2;
 		}
 	}