--- /dev/null
+#include "clapack.h"
+
+/* Subroutine */ int sgemv_(char *trans, integer *m, integer *n, real *alpha,
+ real *a, integer *lda, real *x, integer *incx, real *beta, real *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;
+ real temp;
+ integer lenx, leny;
+ extern logical lsame_(char *, char *);
+ extern /* Subroutine */ int xerbla_(char *, integer *);
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* SGEMV 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 - REAL . */
+/* On entry, ALPHA specifies the scalar alpha. */
+/* Unchanged on exit. */
+
+/* A - REAL 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 - REAL 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 - REAL . */
+/* 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 - REAL 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_("SGEMV ", &info);
+ return 0;
+ }
+
+/* Quick return if possible. */
+
+ if (*m == 0 || *n == 0 || *alpha == 0.f && *beta == 1.f) {
+ 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.f) {
+ if (*incy == 1) {
+ if (*beta == 0.f) {
+ i__1 = leny;
+ for (i__ = 1; i__ <= i__1; ++i__) {
+ y[i__] = 0.f;
+/* L10: */
+ }
+ } else {
+ i__1 = leny;
+ for (i__ = 1; i__ <= i__1; ++i__) {
+ y[i__] = *beta * y[i__];
+/* L20: */
+ }
+ }
+ } else {
+ iy = ky;
+ if (*beta == 0.f) {
+ i__1 = leny;
+ for (i__ = 1; i__ <= i__1; ++i__) {
+ y[iy] = 0.f;
+ 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.f) {
+ 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.f) {
+ 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.f) {
+ 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.f;
+ 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.f;
+ 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 SGEMV . */
+
+} /* sgemv_ */
projects / opencv / blobdiff