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SUBROUTINE CHPR2( UPLO, N, ALPHA, X, INCX, Y, INCY, A )
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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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* .. Array Arguments ..
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COMPLEX A( * ), X( * ), Y( * )
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* CHPR2 performs the Hermitian rank 2 operation
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* A := alpha*x*conjg( y' ) + conjg( alpha )*y*conjg( x' ) + A,
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* where alpha is a scalar, x and y are n-element vectors and A is an n
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* by n Hermitian matrix, supplied in packed form.
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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 matrix A is supplied in the packed array A
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* UPLO = 'U' or 'u' The upper triangular part of A is
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* UPLO = 'L' or 'l' The lower triangular part of A is
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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) COMPLEX
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* On entry, ALPHA specifies the scalar alpha. When ALPHA is
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* supplied as zero then the arrays X and Y need not be set on
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* input. Unchanged on exit.
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* X (input) COMPLEX 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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* Y (input) COMPLEX array
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* On entry, Y is an incremented array of dimension at least
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* ( 1 + ( n - 1 ) * abs( INCY ) ). Before entry, the incremen-
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* ted array Y must contain the vector y. Unchanged on exit.
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* INCY (input) INTEGER
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* On entry, INCY specifies the increment for the elements of Y.
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* INCY must not be zero. Unchanged on exit.
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* A (input/output) COMPLEX array
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* On entry, A is an array of DIMENSION ( ( n*(n + 1) )/2 ).
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* Before entry with UPLO = 'U' or 'u', the array A must con-
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* tain the upper triangular part of the Hermitian matrix packed
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* sequentially, column by column, so that A(1) contains a(1,1),
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* A( 2 ) and A( 3 ) contain a(1,2) and a(2,2) respectively, and
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* so on. On exit, the array A is overwritten by the upper tri-
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* angular part of the updated matrix.
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* Before entry with UPLO = 'L' or 'l', the array A must contain
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* the lower triangular part of the Hermitian matrix packed se-
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* quentially, column by column, so that A( 1 ) contains a(1,1),
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* A( 2 ) and A( 3 ) contain a(2,1) and a(3,1) respectively, and
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* so on. On exit, the array A is overwritten by the lower tri-
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* angular part of the updated matrix.
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* Note that the imaginary parts of the diagonal elements need
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* not be set, they are assumed to be zero, and on exit they are
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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_CHPR2, XERBLA
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* .. External 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( INCY.EQ.0 ) THEN
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CALL XERBLA( 'CHPR2 ', INFO )
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CALL ATL_F77WRAP_CHPR2( IUPLO, N, ALPHA, X, INCX, Y, INCY, A )
added
removed
interfaces/blas/F77/src/chpr2.f
