int slarfb_(char *side, char *trans, char *direct, char *
storev, int *m, int *n, int *k, float *v, int *ldv,
float *t, int *ldt, float *c__, int *ldc, float *work, int *
ldwork)
{
/* System generated locals */
int c_dim1, c_offset, t_dim1, t_offset, v_dim1, v_offset, work_dim1,
work_offset, i__1, i__2;
/* Local variables */
int i__, j;
extern int lsame_(char *, char *);
int lastc;
extern int sgemm_(char *, char *, int *, int *,
int *, float *, float *, int *, float *, int *, float *,
float *, int *);
int lastv;
extern int scopy_(int *, float *, int *, float *,
int *), strmm_(char *, char *, char *, char *, int *,
int *, float *, float *, int *, float *, int *);
extern int ilaslc_(int *, int *, float *, int *), ilaslr_(
int *, int *, float *, int *);
char transt[1];
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLARFB applies a float block reflector H or its transpose H' to a */
/* float 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) REAL 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) REAL 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) REAL 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) REAL 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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslr_(m, k, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslc_(&lastv, n, &c__[c_offset], ldc);
/* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) */
/* W := C1' */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[j + c_dim1], ldc, &work[j * work_dim1
+ 1], &c__1);
/* L10: */
}
/* W := W * V1 */
strmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, &
c_b14, &v[v_offset], ldv, &work[work_offset], ldwork);
if (lastv > *k) {
/* W := W + C2'*V2 */
i__1 = lastv - *k;
sgemm_("Transpose", "No transpose", &lastc, 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 */
strmm_("Right", "Upper", transt, "Non-unit", &lastc, k, &
c_b14, &t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V * W' */
if (lastv > *k) {
/* C2 := C2 - V2 * W' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &i__1, &lastc, k, &
c_b25, &v[*k + 1 + v_dim1], ldv, &work[
work_offset], ldwork, &c_b14, &c__[*k + 1 +
c_dim1], ldc);
}
/* W := W * V1' */
strmm_("Right", "Lower", "Transpose", "Unit", &lastc, 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 = lastc;
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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslr_(n, k, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslr_(m, &lastv, &c__[c_offset], ldc);
/* W := C * V = (C1*V1 + C2*V2) (stored in WORK) */
/* W := C1 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[j * c_dim1 + 1], &c__1, &work[j *
work_dim1 + 1], &c__1);
/* L40: */
}
/* W := W * V1 */
strmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, &
c_b14, &v[v_offset], ldv, &work[work_offset], ldwork);
if (lastv > *k) {
/* W := W + C2 * V2 */
i__1 = lastv - *k;
sgemm_("No transpose", "No transpose", &lastc, 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' */
strmm_("Right", "Upper", trans, "Non-unit", &lastc, k, &c_b14,
&t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V' */
if (lastv > *k) {
/* C2 := C2 - W * V2' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &lastc, &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' */
strmm_("Right", "Lower", "Transpose", "Unit", &lastc, 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 = lastc;
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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslr_(m, k, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslc_(&lastv, n, &c__[c_offset], ldc);
/* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) */
/* W := C2' */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[lastv - *k + j + c_dim1], ldc, &work[
j * work_dim1 + 1], &c__1);
/* L70: */
}
/* W := W * V2 */
strmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, &
c_b14, &v[lastv - *k + 1 + v_dim1], ldv, &work[
work_offset], ldwork);
if (lastv > *k) {
/* W := W + C1'*V1 */
i__1 = lastv - *k;
sgemm_("Transpose", "No transpose", &lastc, 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 */
strmm_("Right", "Lower", transt, "Non-unit", &lastc, k, &
c_b14, &t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V * W' */
if (lastv > *k) {
/* C1 := C1 - V1 * W' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &i__1, &lastc, k, &
c_b25, &v[v_offset], ldv, &work[work_offset],
ldwork, &c_b14, &c__[c_offset], ldc);
}
/* W := W * V2' */
strmm_("Right", "Upper", "Transpose", "Unit", &lastc, k, &
c_b14, &v[lastv - *k + 1 + v_dim1], ldv, &work[
work_offset], ldwork);
/* C2 := C2 - W' */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = lastc;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[lastv - *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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslr_(n, k, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslr_(m, &lastv, &c__[c_offset], ldc);
/* W := C * V = (C1*V1 + C2*V2) (stored in WORK) */
/* W := C2 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[(*n - *k + j) * c_dim1 + 1], &c__1, &
work[j * work_dim1 + 1], &c__1);
/* L100: */
}
/* W := W * V2 */
strmm_("Right", "Upper", "No transpose", "Unit", &lastc, k, &
c_b14, &v[lastv - *k + 1 + v_dim1], ldv, &work[
work_offset], ldwork);
if (lastv > *k) {
/* W := W + C1 * V1 */
i__1 = lastv - *k;
sgemm_("No transpose", "No transpose", &lastc, 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' */
strmm_("Right", "Lower", trans, "Non-unit", &lastc, k, &c_b14,
&t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V' */
if (lastv > *k) {
/* C1 := C1 - W * V1' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &lastc, &i__1, k, &
c_b25, &work[work_offset], ldwork, &v[v_offset],
ldv, &c_b14, &c__[c_offset], ldc);
}
/* W := W * V2' */
strmm_("Right", "Upper", "Transpose", "Unit", &lastc, k, &
c_b14, &v[lastv - *k + 1 + v_dim1], ldv, &work[
work_offset], ldwork);
/* C2 := C2 - W */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
i__2 = lastc;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + (lastv - *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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslc_(k, m, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslc_(&lastv, n, &c__[c_offset], ldc);
/* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) */
/* W := C1' */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[j + c_dim1], ldc, &work[j * work_dim1
+ 1], &c__1);
/* L130: */
}
/* W := W * V1' */
strmm_("Right", "Upper", "Transpose", "Unit", &lastc, k, &
c_b14, &v[v_offset], ldv, &work[work_offset], ldwork);
if (lastv > *k) {
/* W := W + C2'*V2' */
i__1 = lastv - *k;
sgemm_("Transpose", "Transpose", &lastc, 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 */
strmm_("Right", "Upper", transt, "Non-unit", &lastc, k, &
c_b14, &t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V' * W' */
if (lastv > *k) {
/* C2 := C2 - V2' * W' */
i__1 = lastv - *k;
sgemm_("Transpose", "Transpose", &i__1, &lastc, 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 */
strmm_("Right", "Upper", "No transpose", "Unit", &lastc, 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 = lastc;
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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslc_(k, n, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslr_(m, &lastv, &c__[c_offset], ldc);
/* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) */
/* W := C1 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[j * c_dim1 + 1], &c__1, &work[j *
work_dim1 + 1], &c__1);
/* L160: */
}
/* W := W * V1' */
strmm_("Right", "Upper", "Transpose", "Unit", &lastc, k, &
c_b14, &v[v_offset], ldv, &work[work_offset], ldwork);
if (lastv > *k) {
/* W := W + C2 * V2' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &lastc, 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' */
strmm_("Right", "Upper", trans, "Non-unit", &lastc, k, &c_b14,
&t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V */
if (lastv > *k) {
/* C2 := C2 - W * V2 */
i__1 = lastv - *k;
sgemm_("No transpose", "No transpose", &lastc, &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 */
strmm_("Right", "Upper", "No transpose", "Unit", &lastc, 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 = lastc;
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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslc_(k, m, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslc_(&lastv, n, &c__[c_offset], ldc);
/* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) */
/* W := C2' */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[lastv - *k + j + c_dim1], ldc, &work[
j * work_dim1 + 1], &c__1);
/* L190: */
}
/* W := W * V2' */
strmm_("Right", "Lower", "Transpose", "Unit", &lastc, k, &
c_b14, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[
work_offset], ldwork);
if (lastv > *k) {
/* W := W + C1'*V1' */
i__1 = lastv - *k;
sgemm_("Transpose", "Transpose", &lastc, 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 */
strmm_("Right", "Lower", transt, "Non-unit", &lastc, k, &
c_b14, &t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - V' * W' */
if (lastv > *k) {
/* C1 := C1 - V1' * W' */
i__1 = lastv - *k;
sgemm_("Transpose", "Transpose", &i__1, &lastc, k, &c_b25,
&v[v_offset], ldv, &work[work_offset], ldwork, &
c_b14, &c__[c_offset], ldc);
}
/* W := W * V2 */
strmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, &
c_b14, &v[(lastv - *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 = lastc;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[lastv - *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 ) */
/* Computing MAX */
i__1 = *k, i__2 = ilaslc_(k, n, &v[v_offset], ldv);
lastv = MAX(i__1,i__2);
lastc = ilaslr_(m, &lastv, &c__[c_offset], ldc);
/* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) */
/* W := C2 */
i__1 = *k;
for (j = 1; j <= i__1; ++j) {
scopy_(&lastc, &c__[(lastv - *k + j) * c_dim1 + 1], &c__1,
&work[j * work_dim1 + 1], &c__1);
/* L220: */
}
/* W := W * V2' */
strmm_("Right", "Lower", "Transpose", "Unit", &lastc, k, &
c_b14, &v[(lastv - *k + 1) * v_dim1 + 1], ldv, &work[
work_offset], ldwork);
if (lastv > *k) {
/* W := W + C1 * V1' */
i__1 = lastv - *k;
sgemm_("No transpose", "Transpose", &lastc, 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' */
strmm_("Right", "Lower", trans, "Non-unit", &lastc, k, &c_b14,
&t[t_offset], ldt, &work[work_offset], ldwork);
/* C := C - W * V */
if (lastv > *k) {
/* C1 := C1 - W * V1 */
i__1 = lastv - *k;
sgemm_("No transpose", "No transpose", &lastc, &i__1, k, &
c_b25, &work[work_offset], ldwork, &v[v_offset],
ldv, &c_b14, &c__[c_offset], ldc);
}
/* W := W * V2 */
strmm_("Right", "Lower", "No transpose", "Unit", &lastc, k, &
c_b14, &v[(lastv - *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 = lastc;
for (i__ = 1; i__ <= i__2; ++i__) {
c__[i__ + (lastv - *k + j) * c_dim1] -= work[i__ + j *
work_dim1];
/* L230: */
}
/* L240: */
}
}
}
}
return 0;
/* End of SLARFB */
} /* slarfb_ */
/* Subroutine */ int slarf_(char *side, integer *m, integer *n, real *v,
integer *incv, real *tau, real *c__, integer *ldc, real *work)
{
/* System generated locals */
integer c_dim1, c_offset;
real r__1;
/* Local variables */
integer i__;
logical applyleft;
extern /* Subroutine */ int sger_(integer *, integer *, real *, real *,
integer *, real *, integer *, real *, integer *);
extern logical lsame_(char *, char *);
integer lastc;
extern /* Subroutine */ int sgemv_(char *, integer *, integer *, real *,
real *, integer *, real *, integer *, real *, real *, integer *);
integer lastv;
extern integer ilaslc_(integer *, integer *, real *, integer *), ilaslr_(
integer *, integer *, real *, integer *);
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLARF applies a real elementary reflector H to a real m by n matrix */
/* C, from either the left or the right. H is represented in the form */
/* H = I - tau * v * v' */
/* where tau is a real scalar and v is a real vector. */
/* If tau = 0, then H is taken to be the unit matrix. */
/* Arguments */
/* ========= */
/* SIDE (input) CHARACTER*1 */
/* = 'L': form H * C */
/* = 'R': form C * H */
/* M (input) INTEGER */
/* The number of rows of the matrix C. */
/* N (input) INTEGER */
/* The number of columns of the matrix C. */
/* V (input) REAL array, dimension */
/* (1 + (M-1)*abs(INCV)) if SIDE = 'L' */
/* or (1 + (N-1)*abs(INCV)) if SIDE = 'R' */
/* The vector v in the representation of H. V is not used if */
/* TAU = 0. */
/* INCV (input) INTEGER */
/* The increment between elements of v. INCV <> 0. */
/* TAU (input) REAL */
/* The value tau in the representation of H. */
/* C (input/output) REAL array, dimension (LDC,N) */
/* On entry, the m by n matrix C. */
/* On exit, C is overwritten by the matrix H * C if SIDE = 'L', */
/* or C * H if SIDE = 'R'. */
/* LDC (input) INTEGER */
/* The leading dimension of the array C. LDC >= max(1,M). */
/* WORK (workspace) REAL array, dimension */
/* (N) if SIDE = 'L' */
/* or (M) if SIDE = 'R' */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--v;
c_dim1 = *ldc;
c_offset = 1 + c_dim1;
c__ -= c_offset;
--work;
/* Function Body */
applyleft = lsame_(side, "L");
lastv = 0;
lastc = 0;
if (*tau != 0.f) {
/* Set up variables for scanning V. LASTV begins pointing to the end */
/* of V. */
if (applyleft) {
lastv = *m;
} else {
lastv = *n;
}
if (*incv > 0) {
i__ = (lastv - 1) * *incv + 1;
} else {
i__ = 1;
}
/* Look for the last non-zero row in V. */
while(lastv > 0 && v[i__] == 0.f) {
--lastv;
i__ -= *incv;
}
if (applyleft) {
/* Scan for the last non-zero column in C(1:lastv,:). */
lastc = ilaslc_(&lastv, n, &c__[c_offset], ldc);
} else {
/* Scan for the last non-zero row in C(:,1:lastv). */
lastc = ilaslr_(m, &lastv, &c__[c_offset], ldc);
}
}
/* Note that lastc.eq.0 renders the BLAS operations null; no special */
/* case is needed at this level. */
if (applyleft) {
/* Form H * C */
if (lastv > 0) {
/* w(1:lastc,1) := C(1:lastv,1:lastc)' * v(1:lastv,1) */
sgemv_("Transpose", &lastv, &lastc, &c_b4, &c__[c_offset], ldc, &
v[1], incv, &c_b5, &work[1], &c__1);
/* C(1:lastv,1:lastc) := C(...) - v(1:lastv,1) * w(1:lastc,1)' */
r__1 = -(*tau);
sger_(&lastv, &lastc, &r__1, &v[1], incv, &work[1], &c__1, &c__[
c_offset], ldc);
}
} else {
/* Form C * H */
if (lastv > 0) {
/* w(1:lastc,1) := C(1:lastc,1:lastv) * v(1:lastv,1) */
sgemv_("No transpose", &lastc, &lastv, &c_b4, &c__[c_offset], ldc,
&v[1], incv, &c_b5, &work[1], &c__1);
/* C(1:lastc,1:lastv) := C(...) - w(1:lastc,1) * v(1:lastv,1)' */
r__1 = -(*tau);
sger_(&lastc, &lastv, &r__1, &work[1], &c__1, &v[1], incv, &c__[
c_offset], ldc);
}
}
return 0;
/* End of SLARF */
} /* slarf_ */
