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

Merge from branch clapack-included

+/* dtrmv.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 dtrmv_(char *uplo, char *trans, char *diag, integer *n, 
+	doublereal *a, integer *lda, doublereal *x, integer *incx)
+{
+    /* System generated locals */
+    integer a_dim1, a_offset, i__1, i__2;
+
+    /* Local variables */
+    integer i__, j, ix, jx, kx, info;
+    doublereal temp;
+    extern logical lsame_(char *, char *);
+    extern /* Subroutine */ int xerbla_(char *, integer *);
+    logical nounit;
+
+/*     .. Scalar Arguments .. */
+/*     .. */
+/*     .. Array Arguments .. */
+/*     .. */
+
+/*  Purpose */
+/*  ======= */
+
+/*  DTRMV  performs one of the matrix-vector operations */
+
+/*     x := A*x,   or   x := A'*x, */
+
+/*  where x is an n element vector and  A is an n by n unit, or non-unit, */
+/*  upper or lower triangular matrix. */
+
+/*  Arguments */
+/*  ========== */
+
+/*  UPLO   - CHARACTER*1. */
+/*           On entry, UPLO specifies whether the matrix is an upper or */
+/*           lower triangular matrix as follows: */
+
+/*              UPLO = 'U' or 'u'   A is an upper triangular matrix. */
+
+/*              UPLO = 'L' or 'l'   A is a lower triangular matrix. */
+
+/*           Unchanged on exit. */
+
+/*  TRANS  - CHARACTER*1. */
+/*           On entry, TRANS specifies the operation to be performed as */
+/*           follows: */
+
+/*              TRANS = 'N' or 'n'   x := A*x. */
+
+/*              TRANS = 'T' or 't'   x := A'*x. */
+
+/*              TRANS = 'C' or 'c'   x := A'*x. */
+
+/*           Unchanged on exit. */
+
+/*  DIAG   - CHARACTER*1. */
+/*           On entry, DIAG specifies whether or not A is unit */
+/*           triangular as follows: */
+
+/*              DIAG = 'U' or 'u'   A is assumed to be unit triangular. */
+
+/*              DIAG = 'N' or 'n'   A is not assumed to be unit */
+/*                                  triangular. */
+
+/*           Unchanged on exit. */
+
+/*  N      - INTEGER. */
+/*           On entry, N specifies the order of the matrix A. */
+/*           N must be at least zero. */
+/*           Unchanged on exit. */
+
+/*  A      - DOUBLE PRECISION 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 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 matrix and the strictly upper triangular part of */
+/*           A is not referenced. */
+/*           Note that when  DIAG = 'U' or 'u', the diagonal elements of */
+/*           A are not referenced either, but are assumed to be unity. */
+/*           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      - DOUBLE PRECISION array of dimension at least */
+/*           ( 1 + ( n - 1 )*abs( INCX ) ). */
+/*           Before entry, the incremented array X must contain the n */
+/*           element vector x. On exit, X is overwritten with the */
+/*           tranformed vector x. */
+
+/*  INCX   - INTEGER. */
+/*           On entry, INCX specifies the increment for the elements of */
+/*           X. INCX 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;
+
+    /* Function Body */
+    info = 0;
+    if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
+	info = 1;
+    } else if (! lsame_(trans, "N") && ! lsame_(trans, 
+	    "T") && ! lsame_(trans, "C")) {
+	info = 2;
+    } else if (! lsame_(diag, "U") && ! lsame_(diag, 
+	    "N")) {
+	info = 3;
+    } else if (*n < 0) {
+	info = 4;
+    } else if (*lda < max(1,*n)) {
+	info = 6;
+    } else if (*incx == 0) {
+	info = 8;
+    }
+    if (info != 0) {
+	xerbla_("DTRMV ", &info);
+	return 0;
+    }
+
+/*     Quick return if possible. */
+
+    if (*n == 0) {
+	return 0;
+    }
+
+    nounit = lsame_(diag, "N");
+
+/*     Set up the start point in X if the increment is not unity. This */
+/*     will be  ( N - 1 )*INCX  too small for descending loops. */
+
+    if (*incx <= 0) {
+	kx = 1 - (*n - 1) * *incx;
+    } else if (*incx != 1) {
+	kx = 1;
+    }
+
+/*     Start the operations. In this version the elements of A are */
+/*     accessed sequentially with one pass through A. */
+
+    if (lsame_(trans, "N")) {
+
+/*        Form  x := A*x. */
+
+	if (lsame_(uplo, "U")) {
+	    if (*incx == 1) {
+		i__1 = *n;
+		for (j = 1; j <= i__1; ++j) {
+		    if (x[j] != 0.) {
+			temp = x[j];
+			i__2 = j - 1;
+			for (i__ = 1; i__ <= i__2; ++i__) {
+			    x[i__] += temp * a[i__ + j * a_dim1];
+/* L10: */
+			}
+			if (nounit) {
+			    x[j] *= a[j + j * a_dim1];
+			}
+		    }
+/* L20: */
+		}
+	    } else {
+		jx = kx;
+		i__1 = *n;
+		for (j = 1; j <= i__1; ++j) {
+		    if (x[jx] != 0.) {
+			temp = x[jx];
+			ix = kx;
+			i__2 = j - 1;
+			for (i__ = 1; i__ <= i__2; ++i__) {
+			    x[ix] += temp * a[i__ + j * a_dim1];
+			    ix += *incx;
+/* L30: */
+			}
+			if (nounit) {
+			    x[jx] *= a[j + j * a_dim1];
+			}
+		    }
+		    jx += *incx;
+/* L40: */
+		}
+	    }
+	} else {
+	    if (*incx == 1) {
+		for (j = *n; j >= 1; --j) {
+		    if (x[j] != 0.) {
+			temp = x[j];
+			i__1 = j + 1;
+			for (i__ = *n; i__ >= i__1; --i__) {
+			    x[i__] += temp * a[i__ + j * a_dim1];
+/* L50: */
+			}
+			if (nounit) {
+			    x[j] *= a[j + j * a_dim1];
+			}
+		    }
+/* L60: */
+		}
+	    } else {
+		kx += (*n - 1) * *incx;
+		jx = kx;
+		for (j = *n; j >= 1; --j) {
+		    if (x[jx] != 0.) {
+			temp = x[jx];
+			ix = kx;
+			i__1 = j + 1;
+			for (i__ = *n; i__ >= i__1; --i__) {
+			    x[ix] += temp * a[i__ + j * a_dim1];
+			    ix -= *incx;
+/* L70: */
+			}
+			if (nounit) {
+			    x[jx] *= a[j + j * a_dim1];
+			}
+		    }
+		    jx -= *incx;
+/* L80: */
+		}
+	    }
+	}
+    } else {
+
+/*        Form  x := A'*x. */
+
+	if (lsame_(uplo, "U")) {
+	    if (*incx == 1) {
+		for (j = *n; j >= 1; --j) {
+		    temp = x[j];
+		    if (nounit) {
+			temp *= a[j + j * a_dim1];
+		    }
+		    for (i__ = j - 1; i__ >= 1; --i__) {
+			temp += a[i__ + j * a_dim1] * x[i__];
+/* L90: */
+		    }
+		    x[j] = temp;
+/* L100: */
+		}
+	    } else {
+		jx = kx + (*n - 1) * *incx;
+		for (j = *n; j >= 1; --j) {
+		    temp = x[jx];
+		    ix = jx;
+		    if (nounit) {
+			temp *= a[j + j * a_dim1];
+		    }
+		    for (i__ = j - 1; i__ >= 1; --i__) {
+			ix -= *incx;
+			temp += a[i__ + j * a_dim1] * x[ix];
+/* L110: */
+		    }
+		    x[jx] = temp;
+		    jx -= *incx;
+/* L120: */
+		}
+	    }
+	} else {
+	    if (*incx == 1) {
+		i__1 = *n;
+		for (j = 1; j <= i__1; ++j) {
+		    temp = x[j];
+		    if (nounit) {
+			temp *= a[j + j * a_dim1];
+		    }
+		    i__2 = *n;
+		    for (i__ = j + 1; i__ <= i__2; ++i__) {
+			temp += a[i__ + j * a_dim1] * x[i__];
+/* L130: */
+		    }
+		    x[j] = temp;
+/* L140: */
+		}
+	    } else {
+		jx = kx;
+		i__1 = *n;
+		for (j = 1; j <= i__1; ++j) {
+		    temp = x[jx];
+		    ix = jx;
+		    if (nounit) {
+			temp *= a[j + j * a_dim1];
+		    }
+		    i__2 = *n;
+		    for (i__ = j + 1; i__ <= i__2; ++i__) {
+			ix += *incx;
+			temp += a[i__ + j * a_dim1] * x[ix];
+/* L150: */
+		    }
+		    x[jx] = temp;
+		    jx += *incx;
+/* L160: */
+		}
+	    }
+	}
+    }
+
+    return 0;
+
+/*     End of DTRMV . */
+
+} /* dtrmv_ */