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SUBROUTINE DSYR( UPLO, N, ALPHA, X, INCX, A, LDA )
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* -- Automatically Tuned Linear Algebra Software (ATLAS)
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* (C) Copyright 2000 All Rights Reserved
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* -- ATLAS routine -- F77 Interface -- Version 3.2 -- December 15, 2000
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* -- Suggestions, comments, bugs reports should be sent to the follo-
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* wing e-mail address: atlas@cs.utk.edu
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* Author : Antoine P. Petitet
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* University of Tennessee - Innovative Computing Laboratory
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* Knoxville TN, 37996-1301, USA.
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* ---------------------------------------------------------------------
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* -- Copyright notice and Licensing terms:
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions, and the following disclaimer in
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* the documentation and/or other materials provided with the distri-
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* 3. The name of the University, the ATLAS group, or the names of its
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* contributors may not be used to endorse or promote products deri-
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* ved from this software without specific written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY
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* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
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* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
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* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEO-
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* RY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (IN-
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* CLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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* ---------------------------------------------------------------------
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* .. Scalar Arguments ..
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DOUBLE PRECISION ALPHA
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* .. Array Arguments ..
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DOUBLE PRECISION A( LDA, * ), X( * )
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* DSYR performs the symmetric rank 1 operation
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* A := alpha*x*x' + A,
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* where alpha is a scalar, x is an n-element vector and A is an n by n
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* UPLO (input) CHARACTER*1
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* On entry, UPLO specifies whether the upper or lower triangu-
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* lar part of the array A is to be referenced as follows:
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* UPLO = 'U' or 'u' Only the upper triangular part of A
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* is to be referenced.
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* UPLO = 'L' or 'l' Only the lower triangular part of A
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* is to be referenced.
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* On entry, N specifies the order of the matrix A. N must be at
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* least zero. Unchanged on exit.
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* ALPHA (input) DOUBLE PRECISION
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* On entry, ALPHA specifies the scalar alpha. When ALPHA is
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* supplied as zero then the array X need not be set on input.
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* X (input) DOUBLE PRECISION array
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* On entry, X is an incremented array of dimension at least
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* ( 1 + ( n - 1 ) * abs( INCX ) ). Before entry, the incremen-
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* ted array X must contain the vector x. Unchanged on exit.
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* INCX (input) INTEGER
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* On entry, INCX specifies the increment for the elements of X.
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* INCX must not be zero. Unchanged on exit.
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* A (input/output) DOUBLE PRECISION array
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* On entry, A is an array of DIMENSION ( LDA, n ). Before en-
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* try with UPLO = 'U' or 'u', the leading n by n upper trian-
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* gular part of the array A must contain the upper triangular
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* part of the symmetric matrix and the strictly lower triangu-
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* lar part of A is not referenced. On exit, the upper triangu-
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* lar part of the array A is overwritten by the upper triangu-
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* lar part of the updated matrix. Before entry with UPLO = 'L'
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* or 'l', the leading n by n lower triangular part of the array
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* A must contain the lower triangular part of the symmetric
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* matrix and the strictly upper triangular part of A is not
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* LDA (input) INTEGER
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* On entry, LDA specifies the first dimension of A as declared
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* in the calling (sub) program. LDA must be at least max(1,n).
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* For further information on the Level 1 BLAS specification, see:
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* ``A Proposal for Standard Linear Algebra Subprograms'' by R. Hanson,
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* F. Krogh and C. Lawson, ACM SIGNUM Newsl., 8(16), 1973,
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* ``Basic Linear Algebra Subprograms for Fortran Usage'' by C. Lawson,
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* R. Hanson, D. Kincaid and F. Krogh, ACM Transactions on Mathematical
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* Software, 5(3) pp 308-323, 1979.
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* For further information on the Level 2 BLAS specification, see:
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* ``An Extended Set of FORTRAN Basic Linear Algebra Subprograms'' by
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* J. Dongarra, J. Du Croz, S. Hammarling and R. Hanson, ACM Transac-
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* tions on Mathematical Software, 14(1) pp 1-17, 1988.
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* ``Algorithm 656: An extended Set of Basic Linear Algebra Subprograms:
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* Model Implementation and Test Programs'' by J. Dongarra, J. Du Croz,
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* S. Hammarling and R. Hanson, ACM Transactions on Mathematical Soft-
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* ware, 14(1) pp 18-32, 1988.
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* For further information on the Level 3 BLAS specification, see:
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* ``A Set of Level 3 Basic Linear Algebra Subprograms'' by J. Dongarra,
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* J. Du Croz, I. Duff and S. Hammarling, ACM Transactions on Mathemati-
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* cal Software, 16(1), pp 1-17, 1990.
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* =====================================================================
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INTEGER ILOWER, IUPPER
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PARAMETER ( IUPPER = 121, ILOWER = 122 )
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* .. Local Scalars ..
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* .. External Subroutines ..
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EXTERNAL ATL_F77WRAP_DSYR, XERBLA
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* .. External Functions ..
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* .. Intrinsic Functions ..
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* .. Executable Statements ..
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IF( LSAME( UPLO , 'U' ) ) THEN
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ELSE IF( LSAME( UPLO , 'L' ) ) THEN
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ELSE IF( INFO.EQ.0 ) THEN
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ELSE IF( INCX.EQ.0 ) THEN
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ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
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CALL XERBLA( 'DSYR ', INFO )
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CALL ATL_F77WRAP_DSYR( IUPLO, N, ALPHA, X, INCX, A, LDA )