X-Git-Url: https://vcs.maemo.org/git/?a=blobdiff_plain;f=3rdparty%2Flapack%2Fsgebrd.c;fp=3rdparty%2Flapack%2Fsgebrd.c;h=d75449ec2b83bcfe45ad24869ac12b089f33bbfa;hb=e4c14cdbdf2fe805e79cd96ded236f57e7b89060;hp=0000000000000000000000000000000000000000;hpb=454138ff8a20f6edb9b65a910101403d8b520643;p=opencv diff --git a/3rdparty/lapack/sgebrd.c b/3rdparty/lapack/sgebrd.c new file mode 100644 index 0000000..d75449e --- /dev/null +++ b/3rdparty/lapack/sgebrd.c @@ -0,0 +1,323 @@ +#include "clapack.h" + +/* Table of constant values */ + +static integer c__1 = 1; +static integer c_n1 = -1; +static integer c__3 = 3; +static integer c__2 = 2; +static real c_b21 = -1.f; +static real c_b22 = 1.f; + +/* Subroutine */ int sgebrd_(integer *m, integer *n, real *a, integer *lda, + real *d__, real *e, real *tauq, real *taup, real *work, integer * + lwork, integer *info) +{ + /* System generated locals */ + integer a_dim1, a_offset, i__1, i__2, i__3, i__4; + + /* Local variables */ + integer i__, j, nb, nx; + real ws; + integer nbmin, iinfo; + extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *, + integer *, real *, real *, integer *, real *, integer *, real *, + real *, integer *); + integer minmn; + extern /* Subroutine */ int sgebd2_(integer *, integer *, real *, integer + *, real *, real *, real *, real *, real *, integer *), slabrd_( + integer *, integer *, integer *, real *, integer *, real *, real * +, real *, real *, real *, integer *, real *, integer *), xerbla_( + char *, integer *); + extern integer ilaenv_(integer *, char *, char *, integer *, integer *, + integer *, integer *); + integer ldwrkx, ldwrky, 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 */ +/* ======= */ + +/* SGEBRD reduces a general real M-by-N matrix A to upper or lower */ +/* bidiagonal form B by an orthogonal transformation: Q**T * A * P = B. */ + +/* If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. */ + +/* Arguments */ +/* ========= */ + +/* M (input) INTEGER */ +/* The number of rows in the matrix A. M >= 0. */ + +/* N (input) INTEGER */ +/* The number of columns in the matrix A. N >= 0. */ + +/* A (input/output) REAL array, dimension (LDA,N) */ +/* On entry, the M-by-N general matrix to be reduced. */ +/* On exit, */ +/* if m >= n, the diagonal and the first superdiagonal are */ +/* overwritten with the upper bidiagonal matrix B; the */ +/* elements below the diagonal, with the array TAUQ, represent */ +/* the orthogonal matrix Q as a product of elementary */ +/* reflectors, and the elements above the first superdiagonal, */ +/* with the array TAUP, represent the orthogonal matrix P as */ +/* a product of elementary reflectors; */ +/* if m < n, the diagonal and the first subdiagonal are */ +/* overwritten with the lower bidiagonal matrix B; the */ +/* elements below the first subdiagonal, with the array TAUQ, */ +/* represent the orthogonal matrix Q as a product of */ +/* elementary reflectors, and the elements above the diagonal, */ +/* with the array TAUP, represent the orthogonal matrix P as */ +/* a product of elementary reflectors. */ +/* See Further Details. */ + +/* LDA (input) INTEGER */ +/* The leading dimension of the array A. LDA >= max(1,M). */ + +/* D (output) REAL array, dimension (min(M,N)) */ +/* The diagonal elements of the bidiagonal matrix B: */ +/* D(i) = A(i,i). */ + +/* E (output) REAL array, dimension (min(M,N)-1) */ +/* The off-diagonal elements of the bidiagonal matrix B: */ +/* if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; */ +/* if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. */ + +/* TAUQ (output) REAL array dimension (min(M,N)) */ +/* The scalar factors of the elementary reflectors which */ +/* represent the orthogonal matrix Q. See Further Details. */ + +/* TAUP (output) REAL array, dimension (min(M,N)) */ +/* The scalar factors of the elementary reflectors which */ +/* represent the orthogonal matrix P. See Further Details. */ + +/* WORK (workspace/output) REAL array, dimension (MAX(1,LWORK)) */ +/* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */ + +/* LWORK (input) INTEGER */ +/* The length of the array WORK. LWORK >= max(1,M,N). */ +/* For optimum performance LWORK >= (M+N)*NB, 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. */ + +/* Further Details */ +/* =============== */ + +/* The matrices Q and P are represented as products of elementary */ +/* reflectors: */ + +/* If m >= n, */ + +/* Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1) */ + +/* Each H(i) and G(i) has the form: */ + +/* H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' */ + +/* where tauq and taup are real scalars, and v and u are real vectors; */ +/* v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i); */ +/* u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n); */ +/* tauq is stored in TAUQ(i) and taup in TAUP(i). */ + +/* If m < n, */ + +/* Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m) */ + +/* Each H(i) and G(i) has the form: */ + +/* H(i) = I - tauq * v * v' and G(i) = I - taup * u * u' */ + +/* where tauq and taup are real scalars, and v and u are real vectors; */ +/* v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); */ +/* u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); */ +/* tauq is stored in TAUQ(i) and taup in TAUP(i). */ + +/* The contents of A on exit are illustrated by the following examples: */ + +/* m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): */ + +/* ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 ) */ +/* ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 ) */ +/* ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 ) */ +/* ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 ) */ +/* ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 ) */ +/* ( v1 v2 v3 v4 v5 ) */ + +/* where d and e denote diagonal and off-diagonal elements of B, vi */ +/* denotes an element of the vector defining H(i), and ui an element of */ +/* the vector defining G(i). */ + +/* ===================================================================== */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. External Functions .. */ +/* .. */ +/* .. Executable Statements .. */ + +/* Test the input parameters */ + + /* Parameter adjustments */ + a_dim1 = *lda; + a_offset = 1 + a_dim1; + a -= a_offset; + --d__; + --e; + --tauq; + --taup; + --work; + + /* Function Body */ + *info = 0; +/* Computing MAX */ + i__1 = 1, i__2 = ilaenv_(&c__1, "SGEBRD", " ", m, n, &c_n1, &c_n1); + nb = max(i__1,i__2); + lwkopt = (*m + *n) * nb; + work[1] = (real) lwkopt; + lquery = *lwork == -1; + if (*m < 0) { + *info = -1; + } else if (*n < 0) { + *info = -2; + } else if (*lda < max(1,*m)) { + *info = -4; + } else /* if(complicated condition) */ { +/* Computing MAX */ + i__1 = max(1,*m); + if (*lwork < max(i__1,*n) && ! lquery) { + *info = -10; + } + } + if (*info < 0) { + i__1 = -(*info); + xerbla_("SGEBRD", &i__1); + return 0; + } else if (lquery) { + return 0; + } + +/* Quick return if possible */ + + minmn = min(*m,*n); + if (minmn == 0) { + work[1] = 1.f; + return 0; + } + + ws = (real) max(*m,*n); + ldwrkx = *m; + ldwrky = *n; + + if (nb > 1 && nb < minmn) { + +/* Set the crossover point NX. */ + +/* Computing MAX */ + i__1 = nb, i__2 = ilaenv_(&c__3, "SGEBRD", " ", m, n, &c_n1, &c_n1); + nx = max(i__1,i__2); + +/* Determine when to switch from blocked to unblocked code. */ + + if (nx < minmn) { + ws = (real) ((*m + *n) * nb); + if ((real) (*lwork) < ws) { + +/* Not enough work space for the optimal NB, consider using */ +/* a smaller block size. */ + + nbmin = ilaenv_(&c__2, "SGEBRD", " ", m, n, &c_n1, &c_n1); + if (*lwork >= (*m + *n) * nbmin) { + nb = *lwork / (*m + *n); + } else { + nb = 1; + nx = minmn; + } + } + } + } else { + nx = minmn; + } + + i__1 = minmn - nx; + i__2 = nb; + for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) { + +/* Reduce rows and columns i:i+nb-1 to bidiagonal form and return */ +/* the matrices X and Y which are needed to update the unreduced */ +/* part of the matrix */ + + i__3 = *m - i__ + 1; + i__4 = *n - i__ + 1; + slabrd_(&i__3, &i__4, &nb, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[ + i__], &tauq[i__], &taup[i__], &work[1], &ldwrkx, &work[ldwrkx + * nb + 1], &ldwrky); + +/* Update the trailing submatrix A(i+nb:m,i+nb:n), using an update */ +/* of the form A := A - V*Y' - X*U' */ + + i__3 = *m - i__ - nb + 1; + i__4 = *n - i__ - nb + 1; + sgemm_("No transpose", "Transpose", &i__3, &i__4, &nb, &c_b21, &a[i__ + + nb + i__ * a_dim1], lda, &work[ldwrkx * nb + nb + 1], & + ldwrky, &c_b22, &a[i__ + nb + (i__ + nb) * a_dim1], lda); + i__3 = *m - i__ - nb + 1; + i__4 = *n - i__ - nb + 1; + sgemm_("No transpose", "No transpose", &i__3, &i__4, &nb, &c_b21, & + work[nb + 1], &ldwrkx, &a[i__ + (i__ + nb) * a_dim1], lda, & + c_b22, &a[i__ + nb + (i__ + nb) * a_dim1], lda); + +/* Copy diagonal and off-diagonal elements of B back into A */ + + if (*m >= *n) { + i__3 = i__ + nb - 1; + for (j = i__; j <= i__3; ++j) { + a[j + j * a_dim1] = d__[j]; + a[j + (j + 1) * a_dim1] = e[j]; +/* L10: */ + } + } else { + i__3 = i__ + nb - 1; + for (j = i__; j <= i__3; ++j) { + a[j + j * a_dim1] = d__[j]; + a[j + 1 + j * a_dim1] = e[j]; +/* L20: */ + } + } +/* L30: */ + } + +/* Use unblocked code to reduce the remainder of the matrix */ + + i__2 = *m - i__ + 1; + i__1 = *n - i__ + 1; + sgebd2_(&i__2, &i__1, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[i__], & + tauq[i__], &taup[i__], &work[1], &iinfo); + work[1] = ws; + return 0; + +/* End of SGEBRD */ + +} /* sgebrd_ */