--- /dev/null
+#include "clapack.h"
+
+/* Table of constant values */
+
+static integer c__1 = 1;
+static doublereal c_b14 = 1.;
+static doublereal c_b25 = -1.;
+
+/* Subroutine */ int dlarfb_(char *side, char *trans, char *direct, char *
+ storev, integer *m, integer *n, integer *k, doublereal *v, integer *
+ ldv, doublereal *t, integer *ldt, doublereal *c__, integer *ldc,
+ doublereal *work, integer *ldwork)
+{
+ /* System generated locals */
+ integer c_dim1, c_offset, t_dim1, t_offset, v_dim1, v_offset, work_dim1,
+ work_offset, i__1, i__2;
+
+ /* Local variables */
+ integer i__, j;
+ extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *,
+ integer *, doublereal *, doublereal *, integer *, doublereal *,
+ integer *, doublereal *, doublereal *, integer *);
+ extern logical lsame_(char *, char *);
+ extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *,
+ doublereal *, integer *), dtrmm_(char *, char *, char *, char *,
+ integer *, integer *, doublereal *, doublereal *, integer *,
+ doublereal *, integer *);
+ char transt[1];
+
+
+/* -- LAPACK auxiliary routine (version 3.1) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* DLARFB applies a real block reflector H or its transpose H' to a */
+/* real m by n matrix C, from either the left or the right. */
+
+/* Arguments */
+/* ========= */
+
+/* SIDE (input) CHARACTER*1 */
+/* = 'L': apply H or H' from the Left */
+/* = 'R': apply H or H' from the Right */
+
+/* TRANS (input) CHARACTER*1 */
+/* = 'N': apply H (No transpose) */
+/* = 'T': apply H' (Transpose) */
+
+/* DIRECT (input) CHARACTER*1 */
+/* Indicates how H is formed from a product of elementary */
+/* reflectors */
+/* = 'F': H = H(1) H(2) . . . H(k) (Forward) */
+/* = 'B': H = H(k) . . . H(2) H(1) (Backward) */
+
+/* STOREV (input) CHARACTER*1 */
+/* Indicates how the vectors which define the elementary */
+/* reflectors are stored: */
+/* = 'C': Columnwise */
+/* = 'R': Rowwise */
+
+/* M (input) INTEGER */
+/* The number of rows of the matrix C. */
+
+/* N (input) INTEGER */
+/* The number of columns of the matrix C. */
+
+/* K (input) INTEGER */
+/* The order of the matrix T (= the number of elementary */
+/* reflectors whose product defines the block reflector). */
+
+/* V (input) DOUBLE PRECISION array, dimension */
+/* (LDV,K) if STOREV = 'C' */
+/* (LDV,M) if STOREV = 'R' and SIDE = 'L' */
+/* (LDV,N) if STOREV = 'R' and SIDE = 'R' */
+/* The matrix V. See further details. */
+
+/* LDV (input) INTEGER */
+/* The leading dimension of the array V. */
+/* If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); */
+/* if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); */
+/* if STOREV = 'R', LDV >= K. */
+
+/* T (input) DOUBLE PRECISION array, dimension (LDT,K) */
+/* The triangular k by k matrix T in the representation of the */
+/* block reflector. */
+
+/* LDT (input) INTEGER */
+/* The leading dimension of the array T. LDT >= K. */
+
+/* C (input/output) DOUBLE PRECISION array, dimension (LDC,N) */
+/* On entry, the m by n matrix C. */
+/* On exit, C is overwritten by H*C or H'*C or C*H or C*H'. */
+
+/* LDC (input) INTEGER */
+/* The leading dimension of the array C. LDA >= max(1,M). */
+
+/* WORK (workspace) DOUBLE PRECISION array, dimension (LDWORK,K) */
+
+/* LDWORK (input) INTEGER */
+/* The leading dimension of the array WORK. */
+/* If SIDE = 'L', LDWORK >= max(1,N); */
+/* if SIDE = 'R', LDWORK >= max(1,M). */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. External Functions .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Executable Statements .. */
+
+/* Quick return if possible */
+
+ /* Parameter adjustments */
+ v_dim1 = *ldv;
+ v_offset = 1 + v_dim1;
+ v -= v_offset;
+ t_dim1 = *ldt;
+ t_offset = 1 + t_dim1;
+ t -= t_offset;
+ c_dim1 = *ldc;
+ c_offset = 1 + c_dim1;
+ c__ -= c_offset;
+ work_dim1 = *ldwork;
+ work_offset = 1 + work_dim1;
+ work -= work_offset;
+
+ /* Function Body */
+ if (*m <= 0 || *n <= 0) {
+ return 0;
+ }
+
+ if (lsame_(trans, "N")) {
+ *(unsigned char *)transt = 'T';
+ } else {
+ *(unsigned char *)transt = 'N';
+ }
+
+ if (lsame_(storev, "C")) {
+
+ if (lsame_(direct, "F")) {
+
+/* Let V = ( V1 ) (first K rows) */
+/* ( V2 ) */
+/* where V1 is unit lower triangular. */
+
+ if (lsame_(side, "L")) {
+
+/* Form H * C or H' * C where C = ( C1 ) */
+/* ( C2 ) */
+
+/* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) */
+
+/* W := C1' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
+ &c__1);
+/* L10: */
+ }
+
+/* W := W * V1 */
+
+ dtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
+ &v[v_offset], ldv, &work[work_offset], ldwork);
+ if (*m > *k) {
+
+/* W := W + C2'*V2 */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
+ c__[*k + 1 + c_dim1], ldc, &v[*k + 1 + v_dim1],
+ ldv, &c_b14, &work[work_offset], ldwork);
+ }
+
+/* W := W * T' or W * T */
+
+ dtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - V * W' */
+
+ if (*m > *k) {
+
+/* C2 := C2 - V2 * W' */
+
+ i__1 = *m - *k;
+ dgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
+ v[*k + 1 + v_dim1], ldv, &work[work_offset],
+ ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
+ }
+
+/* W := W * V1' */
+
+ dtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
+ v[v_offset], ldv, &work[work_offset], ldwork);
+
+/* C1 := C1 - W' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *n;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
+/* L20: */
+ }
+/* L30: */
+ }
+
+ } else if (lsame_(side, "R")) {
+
+/* Form C * H or C * H' where C = ( C1 C2 ) */
+
+/* W := C * V = (C1*V1 + C2*V2) (stored in WORK) */
+
+/* W := C1 */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j *
+ work_dim1 + 1], &c__1);
+/* L40: */
+ }
+
+/* W := W * V1 */
+
+ dtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
+ &v[v_offset], ldv, &work[work_offset], ldwork);
+ if (*n > *k) {
+
+/* W := W + C2 * V2 */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "No transpose", m, k, &i__1, &
+ c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc, &v[*k +
+ 1 + v_dim1], ldv, &c_b14, &work[work_offset],
+ ldwork);
+ }
+
+/* W := W * T or W * T' */
+
+ dtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - W * V' */
+
+ if (*n > *k) {
+
+/* C2 := C2 - W * V2' */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
+ work[work_offset], ldwork, &v[*k + 1 + v_dim1],
+ ldv, &c_b14, &c__[(*k + 1) * c_dim1 + 1], ldc);
+ }
+
+/* W := W * V1' */
+
+ dtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
+ v[v_offset], ldv, &work[work_offset], ldwork);
+
+/* C1 := C1 - W */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *m;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
+/* L50: */
+ }
+/* L60: */
+ }
+ }
+
+ } else {
+
+/* Let V = ( V1 ) */
+/* ( V2 ) (last K rows) */
+/* where V2 is unit upper triangular. */
+
+ if (lsame_(side, "L")) {
+
+/* Form H * C or H' * C where C = ( C1 ) */
+/* ( C2 ) */
+
+/* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) */
+
+/* W := C2' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j *
+ work_dim1 + 1], &c__1);
+/* L70: */
+ }
+
+/* W := W * V2 */
+
+ dtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
+ &v[*m - *k + 1 + v_dim1], ldv, &work[work_offset],
+ ldwork);
+ if (*m > *k) {
+
+/* W := W + C1'*V1 */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "No transpose", n, k, &i__1, &c_b14, &
+ c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
+ work[work_offset], ldwork);
+ }
+
+/* W := W * T' or W * T */
+
+ dtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - V * W' */
+
+ if (*m > *k) {
+
+/* C1 := C1 - V1 * W' */
+
+ i__1 = *m - *k;
+ dgemm_("No transpose", "Transpose", &i__1, n, k, &c_b25, &
+ v[v_offset], ldv, &work[work_offset], ldwork, &
+ c_b14, &c__[c_offset], ldc)
+ ;
+ }
+
+/* W := W * V2' */
+
+ dtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
+ v[*m - *k + 1 + v_dim1], ldv, &work[work_offset],
+ ldwork);
+
+/* C2 := C2 - W' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *n;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j *
+ work_dim1];
+/* L80: */
+ }
+/* L90: */
+ }
+
+ } else if (lsame_(side, "R")) {
+
+/* Form C * H or C * H' where C = ( C1 C2 ) */
+
+/* W := C * V = (C1*V1 + C2*V2) (stored in WORK) */
+
+/* W := C2 */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
+ j * work_dim1 + 1], &c__1);
+/* L100: */
+ }
+
+/* W := W * V2 */
+
+ dtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
+ &v[*n - *k + 1 + v_dim1], ldv, &work[work_offset],
+ ldwork);
+ if (*n > *k) {
+
+/* W := W + C1 * V1 */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "No transpose", m, k, &i__1, &
+ c_b14, &c__[c_offset], ldc, &v[v_offset], ldv, &
+ c_b14, &work[work_offset], ldwork);
+ }
+
+/* W := W * T or W * T' */
+
+ dtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - W * V' */
+
+ if (*n > *k) {
+
+/* C1 := C1 - W * V1' */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "Transpose", m, &i__1, k, &c_b25, &
+ work[work_offset], ldwork, &v[v_offset], ldv, &
+ c_b14, &c__[c_offset], ldc)
+ ;
+ }
+
+/* W := W * V2' */
+
+ dtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
+ v[*n - *k + 1 + v_dim1], ldv, &work[work_offset],
+ ldwork);
+
+/* C2 := C2 - W */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *m;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j *
+ work_dim1];
+/* L110: */
+ }
+/* L120: */
+ }
+ }
+ }
+
+ } else if (lsame_(storev, "R")) {
+
+ if (lsame_(direct, "F")) {
+
+/* Let V = ( V1 V2 ) (V1: first K columns) */
+/* where V1 is unit upper triangular. */
+
+ if (lsame_(side, "L")) {
+
+/* Form H * C or H' * C where C = ( C1 ) */
+/* ( C2 ) */
+
+/* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) */
+
+/* W := C1' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(n, &c__[j + c_dim1], ldc, &work[j * work_dim1 + 1],
+ &c__1);
+/* L130: */
+ }
+
+/* W := W * V1' */
+
+ dtrmm_("Right", "Upper", "Transpose", "Unit", n, k, &c_b14, &
+ v[v_offset], ldv, &work[work_offset], ldwork);
+ if (*m > *k) {
+
+/* W := W + C2'*V2' */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
+ c__[*k + 1 + c_dim1], ldc, &v[(*k + 1) * v_dim1 +
+ 1], ldv, &c_b14, &work[work_offset], ldwork);
+ }
+
+/* W := W * T' or W * T */
+
+ dtrmm_("Right", "Upper", transt, "Non-unit", n, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - V' * W' */
+
+ if (*m > *k) {
+
+/* C2 := C2 - V2' * W' */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[(
+ *k + 1) * v_dim1 + 1], ldv, &work[work_offset],
+ ldwork, &c_b14, &c__[*k + 1 + c_dim1], ldc);
+ }
+
+/* W := W * V1 */
+
+ dtrmm_("Right", "Upper", "No transpose", "Unit", n, k, &c_b14,
+ &v[v_offset], ldv, &work[work_offset], ldwork);
+
+/* C1 := C1 - W' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *n;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[j + i__ * c_dim1] -= work[i__ + j * work_dim1];
+/* L140: */
+ }
+/* L150: */
+ }
+
+ } else if (lsame_(side, "R")) {
+
+/* Form C * H or C * H' where C = ( C1 C2 ) */
+
+/* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) */
+
+/* W := C1 */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(m, &c__[j * c_dim1 + 1], &c__1, &work[j *
+ work_dim1 + 1], &c__1);
+/* L160: */
+ }
+
+/* W := W * V1' */
+
+ dtrmm_("Right", "Upper", "Transpose", "Unit", m, k, &c_b14, &
+ v[v_offset], ldv, &work[work_offset], ldwork);
+ if (*n > *k) {
+
+/* W := W + C2 * V2' */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
+ c__[(*k + 1) * c_dim1 + 1], ldc, &v[(*k + 1) *
+ v_dim1 + 1], ldv, &c_b14, &work[work_offset],
+ ldwork);
+ }
+
+/* W := W * T or W * T' */
+
+ dtrmm_("Right", "Upper", trans, "Non-unit", m, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - W * V */
+
+ if (*n > *k) {
+
+/* C2 := C2 - W * V2 */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "No transpose", m, &i__1, k, &
+ c_b25, &work[work_offset], ldwork, &v[(*k + 1) *
+ v_dim1 + 1], ldv, &c_b14, &c__[(*k + 1) * c_dim1
+ + 1], ldc);
+ }
+
+/* W := W * V1 */
+
+ dtrmm_("Right", "Upper", "No transpose", "Unit", m, k, &c_b14,
+ &v[v_offset], ldv, &work[work_offset], ldwork);
+
+/* C1 := C1 - W */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *m;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[i__ + j * c_dim1] -= work[i__ + j * work_dim1];
+/* L170: */
+ }
+/* L180: */
+ }
+
+ }
+
+ } else {
+
+/* Let V = ( V1 V2 ) (V2: last K columns) */
+/* where V2 is unit lower triangular. */
+
+ if (lsame_(side, "L")) {
+
+/* Form H * C or H' * C where C = ( C1 ) */
+/* ( C2 ) */
+
+/* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) */
+
+/* W := C2' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(n, &c__[*m - *k + j + c_dim1], ldc, &work[j *
+ work_dim1 + 1], &c__1);
+/* L190: */
+ }
+
+/* W := W * V2' */
+
+ dtrmm_("Right", "Lower", "Transpose", "Unit", n, k, &c_b14, &
+ v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
+, ldwork);
+ if (*m > *k) {
+
+/* W := W + C1'*V1' */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "Transpose", n, k, &i__1, &c_b14, &
+ c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
+ work[work_offset], ldwork);
+ }
+
+/* W := W * T' or W * T */
+
+ dtrmm_("Right", "Lower", transt, "Non-unit", n, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - V' * W' */
+
+ if (*m > *k) {
+
+/* C1 := C1 - V1' * W' */
+
+ i__1 = *m - *k;
+ dgemm_("Transpose", "Transpose", &i__1, n, k, &c_b25, &v[
+ v_offset], ldv, &work[work_offset], ldwork, &
+ c_b14, &c__[c_offset], ldc);
+ }
+
+/* W := W * V2 */
+
+ dtrmm_("Right", "Lower", "No transpose", "Unit", n, k, &c_b14,
+ &v[(*m - *k + 1) * v_dim1 + 1], ldv, &work[
+ work_offset], ldwork);
+
+/* C2 := C2 - W' */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *n;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[*m - *k + j + i__ * c_dim1] -= work[i__ + j *
+ work_dim1];
+/* L200: */
+ }
+/* L210: */
+ }
+
+ } else if (lsame_(side, "R")) {
+
+/* Form C * H or C * H' where C = ( C1 C2 ) */
+
+/* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) */
+
+/* W := C2 */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ dcopy_(m, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &work[
+ j * work_dim1 + 1], &c__1);
+/* L220: */
+ }
+
+/* W := W * V2' */
+
+ dtrmm_("Right", "Lower", "Transpose", "Unit", m, k, &c_b14, &
+ v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[work_offset]
+, ldwork);
+ if (*n > *k) {
+
+/* W := W + C1 * V1' */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "Transpose", m, k, &i__1, &c_b14, &
+ c__[c_offset], ldc, &v[v_offset], ldv, &c_b14, &
+ work[work_offset], ldwork);
+ }
+
+/* W := W * T or W * T' */
+
+ dtrmm_("Right", "Lower", trans, "Non-unit", m, k, &c_b14, &t[
+ t_offset], ldt, &work[work_offset], ldwork);
+
+/* C := C - W * V */
+
+ if (*n > *k) {
+
+/* C1 := C1 - W * V1 */
+
+ i__1 = *n - *k;
+ dgemm_("No transpose", "No transpose", m, &i__1, k, &
+ c_b25, &work[work_offset], ldwork, &v[v_offset],
+ ldv, &c_b14, &c__[c_offset], ldc);
+ }
+
+/* W := W * V2 */
+
+ dtrmm_("Right", "Lower", "No transpose", "Unit", m, k, &c_b14,
+ &v[(*n - *k + 1) * v_dim1 + 1], ldv, &work[
+ work_offset], ldwork);
+
+/* C1 := C1 - W */
+
+ i__1 = *k;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *m;
+ for (i__ = 1; i__ <= i__2; ++i__) {
+ c__[i__ + (*n - *k + j) * c_dim1] -= work[i__ + j *
+ work_dim1];
+/* L230: */
+ }
+/* L240: */
+ }
+
+ }
+
+ }
+ }
+
+ return 0;
+
+/* End of DLARFB */
+
+} /* dlarfb_ */