ergo
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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_IDAMAX_HEADER 00036 #define TEMPLATE_BLAS_IDAMAX_HEADER 00037 00038 00039 template<class Treal> 00040 integer template_blas_idamax(const integer *n, const Treal *dx, const integer *incx) 00041 { 00042 /* System generated locals */ 00043 integer ret_val, i__1; 00044 Treal d__1; 00045 /* Local variables */ 00046 Treal dmax__; 00047 integer i__, ix; 00048 /* finds the index of element having max. absolute value. 00049 jack dongarra, linpack, 3/11/78. 00050 modified 3/93 to return if incx .le. 0. 00051 modified 12/3/93, array(1) declarations changed to array(*) 00052 Parameter adjustments */ 00053 --dx; 00054 /* Function Body */ 00055 ret_val = 0; 00056 if (*n < 1 || *incx <= 0) { 00057 return ret_val; 00058 } 00059 ret_val = 1; 00060 if (*n == 1) { 00061 return ret_val; 00062 } 00063 if (*incx == 1) { 00064 goto L20; 00065 } 00066 /* code for increment not equal to 1 */ 00067 ix = 1; 00068 dmax__ = absMACRO(dx[1]); 00069 ix += *incx; 00070 i__1 = *n; 00071 for (i__ = 2; i__ <= i__1; ++i__) { 00072 if ((d__1 = dx[ix], absMACRO(d__1)) <= dmax__) { 00073 goto L5; 00074 } 00075 ret_val = i__; 00076 dmax__ = (d__1 = dx[ix], absMACRO(d__1)); 00077 L5: 00078 ix += *incx; 00079 /* L10: */ 00080 } 00081 return ret_val; 00082 /* code for increment equal to 1 */ 00083 L20: 00084 dmax__ = absMACRO(dx[1]); 00085 i__1 = *n; 00086 for (i__ = 2; i__ <= i__1; ++i__) { 00087 if ((d__1 = dx[i__], absMACRO(d__1)) <= dmax__) { 00088 goto L30; 00089 } 00090 ret_val = i__; 00091 dmax__ = (d__1 = dx[i__], absMACRO(d__1)); 00092 L30: 00093 ; 00094 } 00095 return ret_val; 00096 } /* idamax_ */ 00097 00098 #endif