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diff libcruft/blas/chemv.f @ 7789:82be108cc558

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First attempt at single precision tyeps * * * corrections to qrupdate single precision routines * * * prefer demotion to single over promotion to double * * * Add single precision support to log2 function * * * Trivial PROJECT file update * * * Cache optimized hermitian/transpose methods * * * Add tests for tranpose/hermitian and ChangeLog entry for new transpose code
author David Bateman <dbateman@free.fr>
date Sun, 27 Apr 2008 22:34:17 +0200
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcruft/blas/chemv.f	Sun Apr 27 22:34:17 2008 +0200
@@ -0,0 +1,266 @@
+      SUBROUTINE CHEMV(UPLO,N,ALPHA,A,LDA,X,INCX,BETA,Y,INCY)
+*     .. Scalar Arguments ..
+      COMPLEX ALPHA,BETA
+      INTEGER INCX,INCY,LDA,N
+      CHARACTER UPLO
+*     ..
+*     .. Array Arguments ..
+      COMPLEX A(LDA,*),X(*),Y(*)
+*     ..
+*
+*  Purpose
+*  =======
+*
+*  CHEMV  performs the matrix-vector  operation
+*
+*     y := alpha*A*x + beta*y,
+*
+*  where alpha and beta are scalars, x and y are n element vectors and
+*  A is an n by n hermitian matrix.
+*
+*  Arguments
+*  ==========
+*
+*  UPLO   - CHARACTER*1.
+*           On entry, UPLO specifies whether the upper or lower
+*           triangular part of the array A is to be referenced as
+*           follows:
+*
+*              UPLO = 'U' or 'u'   Only the upper triangular part of A
+*                                  is to be referenced.
+*
+*              UPLO = 'L' or 'l'   Only the lower triangular part of A
+*                                  is to be referenced.
+*
+*           Unchanged on exit.
+*
+*  N      - INTEGER.
+*           On entry, N specifies the order of the matrix A.
+*           N must be at least zero.
+*           Unchanged on exit.
+*
+*  ALPHA  - COMPLEX         .
+*           On entry, ALPHA specifies the scalar alpha.
+*           Unchanged on exit.
+*
+*  A      - COMPLEX          array of DIMENSION ( LDA, n ).
+*           Before entry with  UPLO = 'U' or 'u', the leading n by n
+*           upper triangular part of the array A must contain the upper
+*           triangular part of the hermitian matrix and the strictly
+*           lower triangular part of A is not referenced.
+*           Before entry with UPLO = 'L' or 'l', the leading n by n
+*           lower triangular part of the array A must contain the lower
+*           triangular part of the hermitian matrix and the strictly
+*           upper triangular part of A is not referenced.
+*           Note that the imaginary parts of the diagonal elements need
+*           not be set and are assumed to be zero.
+*           Unchanged on exit.
+*
+*  LDA    - INTEGER.
+*           On entry, LDA specifies the first dimension of A as declared
+*           in the calling (sub) program. LDA must be at least
+*           max( 1, n ).
+*           Unchanged on exit.
+*
+*  X      - COMPLEX          array of dimension at least
+*           ( 1 + ( n - 1 )*abs( INCX ) ).
+*           Before entry, the incremented array X must contain the n
+*           element vector x.
+*           Unchanged on exit.
+*
+*  INCX   - INTEGER.
+*           On entry, INCX specifies the increment for the elements of
+*           X. INCX must not be zero.
+*           Unchanged on exit.
+*
+*  BETA   - COMPLEX         .
+*           On entry, BETA specifies the scalar beta. When BETA is
+*           supplied as zero then Y need not be set on input.
+*           Unchanged on exit.
+*
+*  Y      - COMPLEX          array of dimension at least
+*           ( 1 + ( n - 1 )*abs( INCY ) ).
+*           Before entry, the incremented array Y must contain the n
+*           element vector y. On exit, Y is overwritten by the updated
+*           vector y.
+*
+*  INCY   - INTEGER.
+*           On entry, INCY specifies the increment for the elements of
+*           Y. INCY must not be zero.
+*           Unchanged on exit.
+*
+*
+*  Level 2 Blas routine.
+*
+*  -- 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.
+*
+*
+*     .. Parameters ..
+      COMPLEX ONE
+      PARAMETER (ONE= (1.0E+0,0.0E+0))
+      COMPLEX ZERO
+      PARAMETER (ZERO= (0.0E+0,0.0E+0))
+*     ..
+*     .. Local Scalars ..
+      COMPLEX TEMP1,TEMP2
+      INTEGER I,INFO,IX,IY,J,JX,JY,KX,KY
+*     ..
+*     .. External Functions ..
+      LOGICAL LSAME
+      EXTERNAL LSAME
+*     ..
+*     .. External Subroutines ..
+      EXTERNAL XERBLA
+*     ..
+*     .. Intrinsic Functions ..
+      INTRINSIC CONJG,MAX,REAL
+*     ..
+*
+*     Test the input parameters.
+*
+      INFO = 0
+      IF (.NOT.LSAME(UPLO,'U') .AND. .NOT.LSAME(UPLO,'L')) THEN
+          INFO = 1
+      ELSE IF (N.LT.0) THEN
+          INFO = 2
+      ELSE IF (LDA.LT.MAX(1,N)) THEN
+          INFO = 5
+      ELSE IF (INCX.EQ.0) THEN
+          INFO = 7
+      ELSE IF (INCY.EQ.0) THEN
+          INFO = 10
+      END IF
+      IF (INFO.NE.0) THEN
+          CALL XERBLA('CHEMV ',INFO)
+          RETURN
+      END IF
+*
+*     Quick return if possible.
+*
+      IF ((N.EQ.0) .OR. ((ALPHA.EQ.ZERO).AND. (BETA.EQ.ONE))) RETURN
+*
+*     Set up the start points in  X  and  Y.
+*
+      IF (INCX.GT.0) THEN
+          KX = 1
+      ELSE
+          KX = 1 - (N-1)*INCX
+      END IF
+      IF (INCY.GT.0) THEN
+          KY = 1
+      ELSE
+          KY = 1 - (N-1)*INCY
+      END IF
+*
+*     Start the operations. In this version the elements of A are
+*     accessed sequentially with one pass through the triangular part
+*     of 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,N
+                      Y(I) = ZERO
+   10             CONTINUE
+              ELSE
+                  DO 20 I = 1,N
+                      Y(I) = BETA*Y(I)
+   20             CONTINUE
+              END IF
+          ELSE
+              IY = KY
+              IF (BETA.EQ.ZERO) THEN
+                  DO 30 I = 1,N
+                      Y(IY) = ZERO
+                      IY = IY + INCY
+   30             CONTINUE
+              ELSE
+                  DO 40 I = 1,N
+                      Y(IY) = BETA*Y(IY)
+                      IY = IY + INCY
+   40             CONTINUE
+              END IF
+          END IF
+      END IF
+      IF (ALPHA.EQ.ZERO) RETURN
+      IF (LSAME(UPLO,'U')) THEN
+*
+*        Form  y  when A is stored in upper triangle.
+*
+          IF ((INCX.EQ.1) .AND. (INCY.EQ.1)) THEN
+              DO 60 J = 1,N
+                  TEMP1 = ALPHA*X(J)
+                  TEMP2 = ZERO
+                  DO 50 I = 1,J - 1
+                      Y(I) = Y(I) + TEMP1*A(I,J)
+                      TEMP2 = TEMP2 + CONJG(A(I,J))*X(I)
+   50             CONTINUE
+                  Y(J) = Y(J) + TEMP1*REAL(A(J,J)) + ALPHA*TEMP2
+   60         CONTINUE
+          ELSE
+              JX = KX
+              JY = KY
+              DO 80 J = 1,N
+                  TEMP1 = ALPHA*X(JX)
+                  TEMP2 = ZERO
+                  IX = KX
+                  IY = KY
+                  DO 70 I = 1,J - 1
+                      Y(IY) = Y(IY) + TEMP1*A(I,J)
+                      TEMP2 = TEMP2 + CONJG(A(I,J))*X(IX)
+                      IX = IX + INCX
+                      IY = IY + INCY
+   70             CONTINUE
+                  Y(JY) = Y(JY) + TEMP1*REAL(A(J,J)) + ALPHA*TEMP2
+                  JX = JX + INCX
+                  JY = JY + INCY
+   80         CONTINUE
+          END IF
+      ELSE
+*
+*        Form  y  when A is stored in lower triangle.
+*
+          IF ((INCX.EQ.1) .AND. (INCY.EQ.1)) THEN
+              DO 100 J = 1,N
+                  TEMP1 = ALPHA*X(J)
+                  TEMP2 = ZERO
+                  Y(J) = Y(J) + TEMP1*REAL(A(J,J))
+                  DO 90 I = J + 1,N
+                      Y(I) = Y(I) + TEMP1*A(I,J)
+                      TEMP2 = TEMP2 + CONJG(A(I,J))*X(I)
+   90             CONTINUE
+                  Y(J) = Y(J) + ALPHA*TEMP2
+  100         CONTINUE
+          ELSE
+              JX = KX
+              JY = KY
+              DO 120 J = 1,N
+                  TEMP1 = ALPHA*X(JX)
+                  TEMP2 = ZERO
+                  Y(JY) = Y(JY) + TEMP1*REAL(A(J,J))
+                  IX = JX
+                  IY = JY
+                  DO 110 I = J + 1,N
+                      IX = IX + INCX
+                      IY = IY + INCY
+                      Y(IY) = Y(IY) + TEMP1*A(I,J)
+                      TEMP2 = TEMP2 + CONJG(A(I,J))*X(IX)
+  110             CONTINUE
+                  Y(JY) = Y(JY) + ALPHA*TEMP2
+                  JX = JX + INCX
+                  JY = JY + INCY
+  120         CONTINUE
+          END IF
+      END IF
+*
+      RETURN
+*
+*     End of CHEMV .
+*
+      END