00001 /* Ergo, version 3.2, a program for linear scaling electronic structure 00002 * calculations. 00003 * Copyright (C) 2012 Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek. 00004 * 00005 * This program is free software: you can redistribute it and/or modify 00006 * it under the terms of the GNU General Public License as published by 00007 * the Free Software Foundation, either version 3 of the License, or 00008 * (at your option) any later version. 00009 * 00010 * This program is distributed in the hope that it will be useful, 00011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00013 * GNU General Public License for more details. 00014 * 00015 * You should have received a copy of the GNU General Public License 00016 * along with this program. If not, see <http://www.gnu.org/licenses/>. 00017 * 00018 * Primary academic reference: 00019 * KohnâSham Density Functional Theory Electronic Structure Calculations 00020 * with Linearly Scaling Computational Time and Memory Usage, 00021 * Elias Rudberg, Emanuel H. Rubensson, and Pawel Salek, 00022 * J. Chem. Theory Comput. 7, 340 (2011), 00023 * <http://dx.doi.org/10.1021/ct100611z> 00024 * 00025 * For further information about Ergo, see <http://www.ergoscf.org>. 00026 */ 00027 00028 /* This file belongs to the template_lapack part of the Ergo source 00029 * code. The source files in the template_lapack directory are modified 00030 * versions of files originally distributed as CLAPACK, see the 00031 * Copyright/license notice in the file template_lapack/COPYING. 00032 */ 00033 00034 00035 #ifndef TEMPLATE_BLAS_AXPY_HEADER 00036 #define TEMPLATE_BLAS_AXPY_HEADER 00037 00038 #include "template_blas_common.h" 00039 00040 template<class Treal> 00041 int template_blas_axpy(const integer *n, const Treal *da, const Treal *dx, 00042 const integer *incx, Treal *dy, const integer *incy) 00043 { 00044 /* System generated locals */ 00045 integer i__1; 00046 /* Local variables */ 00047 integer i__, m, ix, iy, mp1; 00048 /* constant times a vector plus a vector. 00049 uses unrolled loops for increments equal to one. 00050 jack dongarra, linpack, 3/11/78. 00051 modified 12/3/93, array(1) declarations changed to array(*) 00052 Parameter adjustments */ 00053 --dy; 00054 --dx; 00055 /* Function Body */ 00056 if (*n <= 0) { 00057 return 0; 00058 } 00059 if (*da == 0.) { 00060 return 0; 00061 } 00062 if (*incx == 1 && *incy == 1) { 00063 goto L20; 00064 } 00065 /* code for unequal increments or equal increments 00066 not equal to 1 */ 00067 ix = 1; 00068 iy = 1; 00069 if (*incx < 0) { 00070 ix = (-(*n) + 1) * *incx + 1; 00071 } 00072 if (*incy < 0) { 00073 iy = (-(*n) + 1) * *incy + 1; 00074 } 00075 i__1 = *n; 00076 for (i__ = 1; i__ <= i__1; ++i__) { 00077 dy[iy] += *da * dx[ix]; 00078 ix += *incx; 00079 iy += *incy; 00080 /* L10: */ 00081 } 00082 return 0; 00083 /* code for both increments equal to 1 00084 clean-up loop */ 00085 L20: 00086 m = *n % 4; 00087 if (m == 0) { 00088 goto L40; 00089 } 00090 i__1 = m; 00091 for (i__ = 1; i__ <= i__1; ++i__) { 00092 dy[i__] += *da * dx[i__]; 00093 /* L30: */ 00094 } 00095 if (*n < 4) { 00096 return 0; 00097 } 00098 L40: 00099 mp1 = m + 1; 00100 i__1 = *n; 00101 for (i__ = mp1; i__ <= i__1; i__ += 4) { 00102 dy[i__] += *da * dx[i__]; 00103 dy[i__ + 1] += *da * dx[i__ + 1]; 00104 dy[i__ + 2] += *da * dx[i__ + 2]; 00105 dy[i__ + 3] += *da * dx[i__ + 3]; 00106 /* L50: */ 00107 } 00108 return 0; 00109 } /* daxpy_ */ 00110 00111 #endif