comparison ext/cblas/src/dgemv.c @ 430:335af74a25b6

Merge from branch clapack-included

+/* dgemv.f -- translated by f2c (version 20061008).
+   You must link the resulting object file with libf2c:
+	on Microsoft Windows system, link with libf2c.lib;
+	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
+	or, if you install libf2c.a in a standard place, with -lf2c -lm
+	-- in that order, at the end of the command line, as in
+		cc *.o -lf2c -lm
+	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
+
+		http://www.netlib.org/f2c/libf2c.zip
+*/
+
+#include "f2c.h"
+#include "blaswrap.h"
+
+/* Subroutine */ int dgemv_(char *trans, integer *m, integer *n, doublereal *
+	alpha, doublereal *a, integer *lda, doublereal *x, integer *incx, 
+	doublereal *beta, doublereal *y, integer *incy)
+{
+    /* System generated locals */
+    integer a_dim1, a_offset, i__1, i__2;
+
+    /* Local variables */
+    integer i__, j, ix, iy, jx, jy, kx, ky, info;
+    doublereal temp;
+    integer lenx, leny;
+    extern logical lsame_(char *, char *);
+    extern /* Subroutine */ int xerbla_(char *, integer *);
+
+/*     .. Scalar Arguments .. */
+/*     .. */
+/*     .. Array Arguments .. */
+/*     .. */
+
+/*  Purpose */
+/*  ======= */
+
+/*  DGEMV  performs one of the matrix-vector operations */
+
+/*     y := alpha*A*x + beta*y,   or   y := alpha*A'*x + beta*y, */
+
+/*  where alpha and beta are scalars, x and y are vectors and A is an */
+/*  m by n matrix. */
+
+/*  Arguments */
+/*  ========== */
+
+/*  TRANS  - 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'*x + beta*y. */
+
+/*              TRANS = 'C' or 'c'   y := alpha*A'*x + beta*y. */
+
+/*           Unchanged on exit. */
+
+/*  M      - INTEGER. */
+/*           On entry, M specifies the number of rows of the matrix A. */
+/*           M must be at least zero. */
+/*           Unchanged on exit. */
+
+/*  N      - INTEGER. */
+/*           On entry, N specifies the number of columns of the matrix A. */
+/*           N must be at least zero. */
+/*           Unchanged on exit. */
+
+/*  ALPHA  - DOUBLE PRECISION. */
+/*           On entry, ALPHA specifies the scalar alpha. */
+/*           Unchanged on exit. */
+
+/*  A      - 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. */
+/*           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, m ). */
+/*           Unchanged on exit. */
+
+/*  X      - 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. */
+/*           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   - DOUBLE PRECISION. */
+/*           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      - 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. */
+
+/*  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 .. */
+/*     .. */
+/*     .. Local Scalars .. */
+/*     .. */
+/*     .. External Functions .. */
+/*     .. */
+/*     .. External Subroutines .. */
+/*     .. */
+/*     .. Intrinsic Functions .. */
+/*     .. */
+
+/*     Test the input parameters. */
+
+    /* Parameter adjustments */
+    a_dim1 = *lda;
+    a_offset = 1 + a_dim1;
+    a -= a_offset;
+    --x;
+    --y;
+
+    /* Function Body */
+    info = 0;
+    if (! lsame_(trans, "N") && ! lsame_(trans, "T") && ! lsame_(trans, "C")
+	    ) {
+	info = 1;
+    } else if (*m < 0) {
+	info = 2;
+    } else if (*n < 0) {
+	info = 3;
+    } else if (*lda < max(1,*m)) {
+	info = 6;
+    } else if (*incx == 0) {
+	info = 8;
+    } else if (*incy == 0) {
+	info = 11;
+    }
+    if (info != 0) {
+	xerbla_("DGEMV ", &info);
+	return 0;
+    }
+
+/*     Quick return if possible. */
+
+    if (*m == 0 || *n == 0 || *alpha == 0. && *beta == 1.) {
+	return 0;
+    }
+
+/*     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")) {
+	lenx = *n;
+	leny = *m;
+    } else {
+	lenx = *m;
+	leny = *n;
+    }
+    if (*incx > 0) {
+	kx = 1;
+    } else {
+	kx = 1 - (lenx - 1) * *incx;
+    }
+    if (*incy > 0) {
+	ky = 1;
+    } else {
+	ky = 1 - (leny - 1) * *incy;
+    }
+
+/*     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 != 1.) {
+	if (*incy == 1) {
+	    if (*beta == 0.) {
+		i__1 = leny;
+		for (i__ = 1; i__ <= i__1; ++i__) {
+		    y[i__] = 0.;
+/* L10: */
+		}
+	    } else {
+		i__1 = leny;
+		for (i__ = 1; i__ <= i__1; ++i__) {
+		    y[i__] = *beta * y[i__];
+/* L20: */
+		}
+	    }
+	} else {
+	    iy = ky;
+	    if (*beta == 0.) {
+		i__1 = leny;
+		for (i__ = 1; i__ <= i__1; ++i__) {
+		    y[iy] = 0.;
+		    iy += *incy;
+/* L30: */
+		}
+	    } else {
+		i__1 = leny;
+		for (i__ = 1; i__ <= i__1; ++i__) {
+		    y[iy] = *beta * y[iy];
+		    iy += *incy;
+/* L40: */
+		}
+	    }
+	}
+    }
+    if (*alpha == 0.) {
+	return 0;
+    }
+    if (lsame_(trans, "N")) {
+
+/*        Form  y := alpha*A*x + y. */
+
+	jx = kx;
+	if (*incy == 1) {
+	    i__1 = *n;
+	    for (j = 1; j <= i__1; ++j) {
+		if (x[jx] != 0.) {
+		    temp = *alpha * x[jx];
+		    i__2 = *m;
+		    for (i__ = 1; i__ <= i__2; ++i__) {
+			y[i__] += temp * a[i__ + j * a_dim1];
+/* L50: */
+		    }
+		}
+		jx += *incx;
+/* L60: */
+	    }
+	} else {
+	    i__1 = *n;
+	    for (j = 1; j <= i__1; ++j) {
+		if (x[jx] != 0.) {
+		    temp = *alpha * x[jx];
+		    iy = ky;
+		    i__2 = *m;
+		    for (i__ = 1; i__ <= i__2; ++i__) {
+			y[iy] += temp * a[i__ + j * a_dim1];
+			iy += *incy;
+/* L70: */
+		    }
+		}
+		jx += *incx;
+/* L80: */
+	    }
+	}
+    } else {
+
+/*        Form  y := alpha*A'*x + y. */
+
+	jy = ky;
+	if (*incx == 1) {
+	    i__1 = *n;
+	    for (j = 1; j <= i__1; ++j) {
+		temp = 0.;
+		i__2 = *m;
+		for (i__ = 1; i__ <= i__2; ++i__) {
+		    temp += a[i__ + j * a_dim1] * x[i__];
+/* L90: */
+		}
+		y[jy] += *alpha * temp;
+		jy += *incy;
+/* L100: */
+	    }
+	} else {
+	    i__1 = *n;
+	    for (j = 1; j <= i__1; ++j) {
+		temp = 0.;
+		ix = kx;
+		i__2 = *m;
+		for (i__ = 1; i__ <= i__2; ++i__) {
+		    temp += a[i__ + j * a_dim1] * x[ix];
+		    ix += *incx;
+/* L110: */
+		}
+		y[jy] += *alpha * temp;
+		jy += *incy;
+/* L120: */
+	    }
+	}
+    }
+
+    return 0;
+
+/*     End of DGEMV . */
+
+} /* dgemv_ */