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_ */