+++ /dev/null
-*> \brief \b DGEMV
-*
-* =========== DOCUMENTATION ===========
-*
-* Online html documentation available at
-* http://www.netlib.org/lapack/explore-html/
-*
-* Definition:
-* ===========
-*
-* SUBROUTINE DGEMV(TRANS,M,N,ALPHA,A,LDA,X,INCX,BETA,Y,INCY)
-*
-* .. Scalar Arguments ..
-* DOUBLE PRECISION ALPHA,BETA
-* INTEGER INCX,INCY,LDA,M,N
-* CHARACTER TRANS
-* ..
-* .. Array Arguments ..
-* DOUBLE PRECISION A(LDA,*),X(*),Y(*)
-* ..
-*
-*
-*> \par Purpose:
-* =============
-*>
-*> \verbatim
-*>
-*> DGEMV performs one of the matrix-vector operations
-*>
-*> y := alpha*A*x + beta*y, or y := alpha*A**T*x + beta*y,
-*>
-*> where alpha and beta are scalars, x and y are vectors and A is an
-*> m by n matrix.
-*> \endverbatim
-*
-* Arguments:
-* ==========
-*
-*> \param[in] TRANS
-*> \verbatim
-*> TRANS is CHARACTER*1
-*> On entry, TRANS specifies the operation to be performed as
-*> follows:
-*>
-*> TRANS = 'N' or 'n' y := alpha*A*x + beta*y.
-*>
-*> TRANS = 'T' or 't' y := alpha*A**T*x + beta*y.
-*>
-*> TRANS = 'C' or 'c' y := alpha*A**T*x + beta*y.
-*> \endverbatim
-*>
-*> \param[in] M
-*> \verbatim
-*> M is INTEGER
-*> On entry, M specifies the number of rows of the matrix A.
-*> M must be at least zero.
-*> \endverbatim
-*>
-*> \param[in] N
-*> \verbatim
-*> N is INTEGER
-*> On entry, N specifies the number of columns of the matrix A.
-*> N must be at least zero.
-*> \endverbatim
-*>
-*> \param[in] ALPHA
-*> \verbatim
-*> ALPHA is DOUBLE PRECISION.
-*> On entry, ALPHA specifies the scalar alpha.
-*> \endverbatim
-*>
-*> \param[in] A
-*> \verbatim
-*> A is DOUBLE PRECISION array of DIMENSION ( LDA, n ).
-*> Before entry, the leading m by n part of the array A must
-*> contain the matrix of coefficients.
-*> \endverbatim
-*>
-*> \param[in] LDA
-*> \verbatim
-*> LDA is INTEGER
-*> On entry, LDA specifies the first dimension of A as declared
-*> in the calling (sub) program. LDA must be at least
-*> max( 1, m ).
-*> \endverbatim
-*>
-*> \param[in] X
-*> \verbatim
-*> X is DOUBLE PRECISION array of DIMENSION at least
-*> ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
-*> and at least
-*> ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
-*> Before entry, the incremented array X must contain the
-*> vector x.
-*> \endverbatim
-*>
-*> \param[in] INCX
-*> \verbatim
-*> INCX is INTEGER
-*> On entry, INCX specifies the increment for the elements of
-*> X. INCX must not be zero.
-*> \endverbatim
-*>
-*> \param[in] BETA
-*> \verbatim
-*> BETA is DOUBLE PRECISION.
-*> On entry, BETA specifies the scalar beta. When BETA is
-*> supplied as zero then Y need not be set on input.
-*> \endverbatim
-*>
-*> \param[in,out] Y
-*> \verbatim
-*> Y is DOUBLE PRECISION array of DIMENSION at least
-*> ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
-*> and at least
-*> ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
-*> Before entry with BETA non-zero, the incremented array Y
-*> must contain the vector y. On exit, Y is overwritten by the
-*> updated vector y.
-*> \endverbatim
-*>
-*> \param[in] INCY
-*> \verbatim
-*> INCY is INTEGER
-*> On entry, INCY specifies the increment for the elements of
-*> Y. INCY must not be zero.
-*> \endverbatim
-*
-* Authors:
-* ========
-*
-*> \author Univ. of Tennessee
-*> \author Univ. of California Berkeley
-*> \author Univ. of Colorado Denver
-*> \author NAG Ltd.
-*
-*> \date November 2015
-*
-*> \ingroup double_blas_level2
-*
-*> \par Further Details:
-* =====================
-*>
-*> \verbatim
-*>
-*> Level 2 Blas routine.
-*> The vector and matrix arguments are not referenced when N = 0, or M = 0
-*>
-*> -- Written on 22-October-1986.
-*> Jack Dongarra, Argonne National Lab.
-*> Jeremy Du Croz, Nag Central Office.
-*> Sven Hammarling, Nag Central Office.
-*> Richard Hanson, Sandia National Labs.
-*> \endverbatim
-*>
-* =====================================================================
- SUBROUTINE DGEMV(TRANS,M,N,ALPHA,A,LDA,X,INCX,BETA,Y,INCY)
-*
-* -- Reference BLAS level2 routine (version 3.6.0) --
-* -- Reference BLAS is a software package provided by Univ. of Tennessee, --
-* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-* November 2015
-*
-* .. Scalar Arguments ..
- DOUBLE PRECISION ALPHA,BETA
- INTEGER INCX,INCY,LDA,M,N
- CHARACTER TRANS
-* ..
-* .. Array Arguments ..
- DOUBLE PRECISION A(LDA,*),X(*),Y(*)
-* ..
-*
-* =====================================================================
-*
-* .. Parameters ..
- DOUBLE PRECISION ONE,ZERO
- PARAMETER (ONE=1.0D+0,ZERO=0.0D+0)
-* ..
-* .. Local Scalars ..
- DOUBLE PRECISION TEMP
- INTEGER I,INFO,IX,IY,J,JX,JY,KX,KY,LENX,LENY
-* ..
-* .. External Functions ..
- LOGICAL LSAME
- EXTERNAL LSAME
-* ..
-* .. External Subroutines ..
- EXTERNAL XERBLA
-* ..
-* .. Intrinsic Functions ..
- INTRINSIC MAX
-* ..
-*
-* Test the input parameters.
-*
- INFO = 0
- IF (.NOT.LSAME(TRANS,'N') .AND. .NOT.LSAME(TRANS,'T') .AND.
- + .NOT.LSAME(TRANS,'C')) THEN
- INFO = 1
- ELSE IF (M.LT.0) THEN
- INFO = 2
- ELSE IF (N.LT.0) THEN
- INFO = 3
- ELSE IF (LDA.LT.MAX(1,M)) THEN
- INFO = 6
- ELSE IF (INCX.EQ.0) THEN
- INFO = 8
- ELSE IF (INCY.EQ.0) THEN
- INFO = 11
- END IF
- IF (INFO.NE.0) THEN
- CALL XERBLA('DGEMV ',INFO)
- RETURN
- END IF
-*
-* Quick return if possible.
-*
- IF ((M.EQ.0) .OR. (N.EQ.0) .OR.
- + ((ALPHA.EQ.ZERO).AND. (BETA.EQ.ONE))) RETURN
-*
-* Set LENX and LENY, the lengths of the vectors x and y, and set
-* up the start points in X and Y.
-*
- IF (LSAME(TRANS,'N')) THEN
- LENX = N
- LENY = M
- ELSE
- LENX = M
- LENY = N
- END IF
- IF (INCX.GT.0) THEN
- KX = 1
- ELSE
- KX = 1 - (LENX-1)*INCX
- END IF
- IF (INCY.GT.0) THEN
- KY = 1
- ELSE
- KY = 1 - (LENY-1)*INCY
- END IF
-*
-* Start the operations. In this version the elements of A are
-* accessed sequentially with one pass through A.
-*
-* First form y := beta*y.
-*
- IF (BETA.NE.ONE) THEN
- IF (INCY.EQ.1) THEN
- IF (BETA.EQ.ZERO) THEN
- DO 10 I = 1,LENY
- Y(I) = ZERO
- 10 CONTINUE
- ELSE
- DO 20 I = 1,LENY
- Y(I) = BETA*Y(I)
- 20 CONTINUE
- END IF
- ELSE
- IY = KY
- IF (BETA.EQ.ZERO) THEN
- DO 30 I = 1,LENY
- Y(IY) = ZERO
- IY = IY + INCY
- 30 CONTINUE
- ELSE
- DO 40 I = 1,LENY
- Y(IY) = BETA*Y(IY)
- IY = IY + INCY
- 40 CONTINUE
- END IF
- END IF
- END IF
- IF (ALPHA.EQ.ZERO) RETURN
- IF (LSAME(TRANS,'N')) THEN
-*
-* Form y := alpha*A*x + y.
-*
- JX = KX
- IF (INCY.EQ.1) THEN
- DO 60 J = 1,N
- TEMP = ALPHA*X(JX)
- DO 50 I = 1,M
- Y(I) = Y(I) + TEMP*A(I,J)
- 50 CONTINUE
- JX = JX + INCX
- 60 CONTINUE
- ELSE
- DO 80 J = 1,N
- TEMP = ALPHA*X(JX)
- IY = KY
- DO 70 I = 1,M
- Y(IY) = Y(IY) + TEMP*A(I,J)
- IY = IY + INCY
- 70 CONTINUE
- JX = JX + INCX
- 80 CONTINUE
- END IF
- ELSE
-*
-* Form y := alpha*A**T*x + y.
-*
- JY = KY
- IF (INCX.EQ.1) THEN
- DO 100 J = 1,N
- TEMP = ZERO
- DO 90 I = 1,M
- TEMP = TEMP + A(I,J)*X(I)
- 90 CONTINUE
- Y(JY) = Y(JY) + ALPHA*TEMP
- JY = JY + INCY
- 100 CONTINUE
- ELSE
- DO 120 J = 1,N
- TEMP = ZERO
- IX = KX
- DO 110 I = 1,M
- TEMP = TEMP + A(I,J)*X(IX)
- IX = IX + INCX
- 110 CONTINUE
- Y(JY) = Y(JY) + ALPHA*TEMP
- JY = JY + INCY
- 120 CONTINUE
- END IF
- END IF
-*
- RETURN
-*
-* End of DGEMV .
-*
- END
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