#include "clapack.h" /* Table of constant values */ static integer c__1 = 1; static integer c_n1 = -1; static integer c__2 = 2; static integer c__65 = 65; /* Subroutine */ int sormql_(char *side, char *trans, integer *m, integer *n, integer *k, real *a, integer *lda, real *tau, real *c__, integer *ldc, real *work, integer *lwork, integer *info) { /* System generated locals */ address a__1[2]; integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__3[2], i__4, i__5; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ integer i__; real t[4160] /* was [65][64] */; integer i1, i2, i3, ib, nb, mi, ni, nq, nw, iws; logical left; extern logical lsame_(char *, char *); integer nbmin, iinfo; extern /* Subroutine */ int sorm2l_(char *, char *, integer *, integer *, integer *, real *, integer *, real *, real *, integer *, real *, integer *), slarfb_(char *, char *, char *, char * , integer *, integer *, integer *, real *, integer *, real *, integer *, real *, integer *, real *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *); extern /* Subroutine */ int slarft_(char *, char *, integer *, integer *, real *, integer *, real *, real *, integer *); logical notran; integer ldwork, lwkopt; logical lquery; /* -- LAPACK routine (version 3.1) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* SORMQL overwrites the general real M-by-N matrix C with */ /* SIDE = 'L' SIDE = 'R' */ /* TRANS = 'N': Q * C C * Q */ /* TRANS = 'T': Q**T * C C * Q**T */ /* where Q is a real orthogonal matrix defined as the product of k */ /* elementary reflectors */ /* Q = H(k) . . . H(2) H(1) */ /* as returned by SGEQLF. Q is of order M if SIDE = 'L' and of order N */ /* if SIDE = 'R'. */ /* Arguments */ /* ========= */ /* SIDE (input) CHARACTER*1 */ /* = 'L': apply Q or Q**T from the Left; */ /* = 'R': apply Q or Q**T from the Right. */ /* TRANS (input) CHARACTER*1 */ /* = 'N': No transpose, apply Q; */ /* = 'T': Transpose, apply Q**T. */ /* M (input) INTEGER */ /* The number of rows of the matrix C. M >= 0. */ /* N (input) INTEGER */ /* The number of columns of the matrix C. N >= 0. */ /* K (input) INTEGER */ /* The number of elementary reflectors whose product defines */ /* the matrix Q. */ /* If SIDE = 'L', M >= K >= 0; */ /* if SIDE = 'R', N >= K >= 0. */ /* A (input) REAL array, dimension (LDA,K) */ /* The i-th column must contain the vector which defines the */ /* elementary reflector H(i), for i = 1,2,...,k, as returned by */ /* SGEQLF in the last k columns of its array argument A. */ /* A is modified by the routine but restored on exit. */ /* LDA (input) INTEGER */ /* The leading dimension of the array A. */ /* If SIDE = 'L', LDA >= max(1,M); */ /* if SIDE = 'R', LDA >= max(1,N). */ /* TAU (input) REAL array, dimension (K) */ /* TAU(i) must contain the scalar factor of the elementary */ /* reflector H(i), as returned by SGEQLF. */ /* C (input/output) REAL array, dimension (LDC,N) */ /* On entry, the M-by-N matrix C. */ /* On exit, C is overwritten by Q*C or Q**T*C or C*Q**T or C*Q. */ /* LDC (input) INTEGER */ /* The leading dimension of the array C. LDC >= max(1,M). */ /* WORK (workspace/output) REAL array, dimension (MAX(1,LWORK)) */ /* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */ /* LWORK (input) INTEGER */ /* The dimension of the array WORK. */ /* If SIDE = 'L', LWORK >= max(1,N); */ /* if SIDE = 'R', LWORK >= max(1,M). */ /* For optimum performance LWORK >= N*NB if SIDE = 'L', and */ /* LWORK >= M*NB if SIDE = 'R', where NB is the optimal */ /* blocksize. */ /* If LWORK = -1, then a workspace query is assumed; the routine */ /* only calculates the optimal size of the WORK array, returns */ /* this value as the first entry of the WORK array, and no error */ /* message related to LWORK is issued by XERBLA. */ /* INFO (output) INTEGER */ /* = 0: successful exit */ /* < 0: if INFO = -i, the i-th argument had an illegal value */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. Local Arrays .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Test the input arguments */ /* Parameter adjustments */ a_dim1 = *lda; a_offset = 1 + a_dim1; a -= a_offset; --tau; c_dim1 = *ldc; c_offset = 1 + c_dim1; c__ -= c_offset; --work; /* Function Body */ *info = 0; left = lsame_(side, "L"); notran = lsame_(trans, "N"); lquery = *lwork == -1; /* NQ is the order of Q and NW is the minimum dimension of WORK */ if (left) { nq = *m; nw = max(1,*n); } else { nq = *n; nw = max(1,*m); } if (! left && ! lsame_(side, "R")) { *info = -1; } else if (! notran && ! lsame_(trans, "T")) { *info = -2; } else if (*m < 0) { *info = -3; } else if (*n < 0) { *info = -4; } else if (*k < 0 || *k > nq) { *info = -5; } else if (*lda < max(1,nq)) { *info = -7; } else if (*ldc < max(1,*m)) { *info = -10; } if (*info == 0) { if (*m == 0 || *n == 0) { lwkopt = 1; } else { /* Determine the block size. NB may be at most NBMAX, where */ /* NBMAX is used to define the local array T. */ /* Computing MIN */ /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 64, i__2 = ilaenv_(&c__1, "SORMQL", ch__1, m, n, k, &c_n1); nb = min(i__1,i__2); lwkopt = nw * nb; } work[1] = (real) lwkopt; if (*lwork < nw && ! lquery) { *info = -12; } } if (*info != 0) { i__1 = -(*info); xerbla_("SORMQL", &i__1); return 0; } else if (lquery) { return 0; } /* Quick return if possible */ if (*m == 0 || *n == 0) { return 0; } nbmin = 2; ldwork = nw; if (nb > 1 && nb < *k) { iws = nw * nb; if (*lwork < iws) { nb = *lwork / ldwork; /* Computing MAX */ /* Writing concatenation */ i__3[0] = 1, a__1[0] = side; i__3[1] = 1, a__1[1] = trans; s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2); i__1 = 2, i__2 = ilaenv_(&c__2, "SORMQL", ch__1, m, n, k, &c_n1); nbmin = max(i__1,i__2); } } else { iws = nw; } if (nb < nbmin || nb >= *k) { /* Use unblocked code */ sorm2l_(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo); } else { /* Use blocked code */ if (left && notran || ! left && ! notran) { i1 = 1; i2 = *k; i3 = nb; } else { i1 = (*k - 1) / nb * nb + 1; i2 = 1; i3 = -nb; } if (left) { ni = *n; } else { mi = *m; } i__1 = i2; i__2 = i3; for (i__ = i1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { /* Computing MIN */ i__4 = nb, i__5 = *k - i__ + 1; ib = min(i__4,i__5); /* Form the triangular factor of the block reflector */ /* H = H(i+ib-1) . . . H(i+1) H(i) */ i__4 = nq - *k + i__ + ib - 1; slarft_("Backward", "Columnwise", &i__4, &ib, &a[i__ * a_dim1 + 1] , lda, &tau[i__], t, &c__65); if (left) { /* H or H' is applied to C(1:m-k+i+ib-1,1:n) */ mi = *m - *k + i__ + ib - 1; } else { /* H or H' is applied to C(1:m,1:n-k+i+ib-1) */ ni = *n - *k + i__ + ib - 1; } /* Apply H or H' */ slarfb_(side, trans, "Backward", "Columnwise", &mi, &ni, &ib, &a[ i__ * a_dim1 + 1], lda, t, &c__65, &c__[c_offset], ldc, & work[1], &ldwork); /* L10: */ } } work[1] = (real) lwkopt; return 0; /* End of SORMQL */ } /* sormql_ */