/* ////////////////////////////////////////////////////////////////////////////
-- Testing sormbr
*/
int main( int argc, char** argv )
{
TESTING_INIT();
real_Double_t gflops, gpu_perf, gpu_time, cpu_perf, cpu_time;
float Cnorm, error, dwork[1];
float c_neg_one = MAGMA_S_NEG_ONE;
magma_int_t ione = 1;
magma_int_t m, n, k, mi, ni, mm, nn, nq, size, info;
magma_int_t ISEED[4] = {0,0,0,1};
magma_int_t nb, ldc, lda, lwork, lwork_max;
float *C, *R, *A, *work, *tau, *tauq, *taup;
float *d, *e;
magma_int_t status = 0;
magma_opts opts;
opts.parse_opts( argc, argv );
// need slightly looser bound (60*eps instead of 30*eps) for some tests
opts.tolerance = max( 60., opts.tolerance );
float tol = opts.tolerance * lapackf77_slamch("E");
// test all combinations of input parameters
magma_vect_t vect [] = { MagmaQ, MagmaP };
magma_side_t side [] = { MagmaLeft, MagmaRight };
magma_trans_t trans[] = { MagmaTrans, MagmaNoTrans };
printf("%% M N K vect side trans CPU Gflop/s (sec) GPU Gflop/s (sec) ||R||_F / ||QC||_F\n");
printf("%%==============================================================================================\n");
for( int itest = 0; itest < opts.ntest; ++itest ) {
for( int ivect = 0; ivect < 2; ++ivect ) {
for( int iside = 0; iside < 2; ++iside ) {
for( int itran = 0; itran < 2; ++itran ) {
for( int iter = 0; iter < opts.niter; ++iter ) {
m = opts.msize[itest];
n = opts.nsize[itest];
k = opts.ksize[itest];
nb = magma_get_sgebrd_nb( m, n );
ldc = m;
// A is nq x k (vect=Q) or k x nq (vect=P)
// where nq=m (left) or nq=n (right)
nq = (side[iside] == MagmaLeft ? m : n );
mm = (vect[ivect] == MagmaQ ? nq : k );
nn = (vect[ivect] == MagmaQ ? k : nq);
lda = mm;
// MBR calls either MQR or MLQ in various ways
if ( vect[ivect] == MagmaQ ) {
if ( nq >= k ) {
gflops = FLOPS_SORMQR( m, n, k, side[iside] ) / 1e9;
}
else {
if ( side[iside] == MagmaLeft ) {
mi = m - 1;
ni = n;
}
else {
mi = m;
ni = n - 1;
}
gflops = FLOPS_SORMQR( mi, ni, nq-1, side[iside] ) / 1e9;
}
}
else {
if ( nq > k ) {
gflops = FLOPS_SORMLQ( m, n, k, side[iside] ) / 1e9;
}
else {
if ( side[iside] == MagmaLeft ) {
mi = m - 1;
ni = n;
}
else {
mi = m;
ni = n - 1;
}
gflops = FLOPS_SORMLQ( mi, ni, nq-1, side[iside] ) / 1e9;
}
}
// workspace for gebrd is (mm + nn)*nb
// workspace for unmbr is m*nb or n*nb, depending on side
lwork_max = max( (mm + nn)*nb, max( m*nb, n*nb ));
// this rounds it up slightly if needed to agree with lwork query below
lwork_max = int( real( magma_smake_lwork( lwork_max )));
TESTING_MALLOC_CPU( C, float, ldc*n );
TESTING_MALLOC_CPU( R, float, ldc*n );
TESTING_MALLOC_CPU( A, float, lda*nn );
TESTING_MALLOC_CPU( work, float, lwork_max );
TESTING_MALLOC_CPU( d, float, min(mm,nn) );
TESTING_MALLOC_CPU( e, float, min(mm,nn) );
TESTING_MALLOC_CPU( tauq, float, min(mm,nn) );
TESTING_MALLOC_CPU( taup, float, min(mm,nn) );
// C is full, m x n
size = ldc*n;
lapackf77_slarnv( &ione, ISEED, &size, C );
lapackf77_slacpy( "Full", &m, &n, C, &ldc, R, &ldc );
size = lda*nn;
lapackf77_slarnv( &ione, ISEED, &size, A );
// compute BRD factorization to get Householder vectors in A, tauq, taup
//lapackf77_sgebrd( &mm, &nn, A, &lda, d, e, tauq, taup, work, &lwork_max, &info );
magma_sgebrd( mm, nn, A, lda, d, e, tauq, taup, work, lwork_max, &info );
if (info != 0) {
printf("magma_sgebrd returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
if ( vect[ivect] == MagmaQ ) {
tau = tauq;
} else {
tau = taup;
}
/* =====================================================================
Performs operation using LAPACK
=================================================================== */
cpu_time = magma_wtime();
lapackf77_sormbr( lapack_vect_const( vect[ivect] ),
lapack_side_const( side[iside] ),
lapack_trans_const( trans[itran] ),
&m, &n, &k,
A, &lda, tau, C, &ldc, work, &lwork_max, &info );
cpu_time = magma_wtime() - cpu_time;
cpu_perf = gflops / cpu_time;
if (info != 0) {
printf("lapackf77_sormbr returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
/* ====================================================================
Performs operation using MAGMA
=================================================================== */
// query for workspace size
lwork = -1;
magma_sormbr( vect[ivect], side[iside], trans[itran],
m, n, k,
A, lda, tau, R, ldc, work, lwork, &info );
if (info != 0) {
printf("magma_sormbr (lwork query) returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
lwork = (magma_int_t) MAGMA_S_REAL( work[0] );
if ( lwork < 0 || lwork > lwork_max ) {
printf("Warning: optimal lwork %d > allocated lwork_max %d\n", (int) lwork, (int) lwork_max );
lwork = lwork_max;
}
gpu_time = magma_wtime();
magma_sormbr( vect[ivect], side[iside], trans[itran],
m, n, k,
A, lda, tau, R, ldc, work, lwork, &info );
gpu_time = magma_wtime() - gpu_time;
gpu_perf = gflops / gpu_time;
if (info != 0) {
printf("magma_sormbr returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
/* =====================================================================
compute relative error |QC_magma - QC_lapack| / |QC_lapack|
=================================================================== */
size = ldc*n;
blasf77_saxpy( &size, &c_neg_one, C, &ione, R, &ione );
Cnorm = lapackf77_slange( "Fro", &m, &n, C, &ldc, dwork );
error = lapackf77_slange( "Fro", &m, &n, R, &ldc, dwork ) / (magma_ssqrt(m*n) * Cnorm);
printf( "%5d %5d %5d %c %4c %5c %7.2f (%7.2f) %7.2f (%7.2f) %8.2e %s\n",
(int) m, (int) n, (int) k,
lapacke_vect_const( vect[ivect] ),
lapacke_side_const( side[iside] ),
lapacke_trans_const( trans[itran] ),
cpu_perf, cpu_time, gpu_perf, gpu_time,
error, (error < tol ? "ok" : "failed") );
status += ! (error < tol);
TESTING_FREE_CPU( C );
TESTING_FREE_CPU( R );
TESTING_FREE_CPU( A );
TESTING_FREE_CPU( work );
TESTING_FREE_CPU( d );
TESTING_FREE_CPU( e );
TESTING_FREE_CPU( taup );
TESTING_FREE_CPU( tauq );
fflush( stdout );
}
if ( opts.niter > 1 ) {
printf( "\n" );
}
}}} // end ivect, iside, itran
printf( "\n" );
}
opts.cleanup();
TESTING_FINALIZE();
return status;
}
/**
Purpose
-------
SGEBRD reduces a general real M-by-N matrix A to upper or lower
bidiagonal form B by an orthogonal transformation: Q**H * A * P = B.
If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal.
Arguments
---------
@param[in]
m INTEGER
The number of rows in the matrix A. M >= 0.
@param[in]
n INTEGER
The number of columns in the matrix A. N >= 0.
@param[in,out]
A 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;
\n
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.
@param[in]
lda INTEGER
The leading dimension of the array A. LDA >= max(1,M).
@param[out]
d real array, dimension (min(M,N))
The diagonal elements of the bidiagonal matrix B:
D(i) = A(i,i).
@param[out]
e 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.
@param[out]
tauq REAL array dimension (min(M,N))
The scalar factors of the elementary reflectors which
represent the orthogonal matrix Q. See Further Details.
@param[out]
taup REAL array, dimension (min(M,N))
The scalar factors of the elementary reflectors which
represent the orthogonal matrix P. See Further Details.
@param[out]
work (workspace) REAL array, dimension (MAX(1,LWORK))
On exit, if INFO = 0, WORK[0] returns the optimal LWORK.
@param[in]
lwork INTEGER
The length of the array WORK. LWORK >= (M+N)*NB, where NB
is the optimal blocksize.
\n
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.
@param[out]
info 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:
@verbatim
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 )
@endverbatim
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).
@ingroup magma_sgesvd_comp
********************************************************************/
extern "C" magma_int_t
magma_sgebrd(
magma_int_t m, magma_int_t n,
float *A, magma_int_t lda, float *d, float *e,
float *tauq, float *taup,
float *work, magma_int_t lwork,
magma_int_t *info)
{
#define A(i, j) (A + (j)*lda + (i))
#define dA(i, j) (dA + (j)*ldda + (i))
float c_neg_one = MAGMA_S_NEG_ONE;
float c_one = MAGMA_S_ONE;
float *dA, *dwork;
magma_int_t ncol, nrow, jmax, nb, ldda;
magma_int_t i, j, nx;
magma_int_t iinfo;
magma_int_t minmn;
magma_int_t ldwrkx, ldwrky, lwkopt;
magma_int_t lquery;
nb = magma_get_sgebrd_nb(n);
ldda = m;
lwkopt = (m + n) * nb;
work[0] = MAGMA_S_MAKE( lwkopt, 0. );
lquery = (lwork == -1);
/* Check arguments */
*info = 0;
if (m < 0) {
*info = -1;
} else if (n < 0) {
*info = -2;
} else if (lda < max(1,m)) {
*info = -4;
} else if (lwork < lwkopt && (! lquery) ) {
*info = -10;
}
if (*info < 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
else if (lquery)
return *info;
/* Quick return if possible */
minmn = min(m,n);
if (minmn == 0) {
work[0] = c_one;
return *info;
}
if (MAGMA_SUCCESS != magma_smalloc( &dA, n*ldda + (m + n)*nb )) {
fprintf (stderr, "!!!! device memory allocation error in sgebrd\n" );
*info = MAGMA_ERR_DEVICE_ALLOC;
return *info;
}
dwork = dA + n*ldda;
ldwrkx = m;
ldwrky = n;
/* Set the block/unblock crossover point NX. */
nx = 128;
/* Copy the matrix to the GPU */
if (minmn - nx >= 1) {
magma_ssetmatrix( m, n, A, lda, dA, ldda );
}
for (i=0; i < (minmn - nx); i += nb) {
/* 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 */
nrow = m - i;
ncol = n - i;
/* Get the current panel (no need for the 1st iteration) */
if ( i > 0 ) {
magma_sgetmatrix( nrow, nb, dA(i, i), ldda, A( i, i), lda );
magma_sgetmatrix( nb, ncol - nb,
dA(i, i+nb), ldda,
A( i, i+nb), lda );
}
magma_slabrd_gpu(nrow, ncol, nb,
A(i, i), lda, dA(i, i), ldda,
d+i, e+i, tauq+i, taup+i,
work, ldwrkx, dwork, ldwrkx, // x, dx
work+(ldwrkx*nb), ldwrky, dwork+(ldwrkx*nb), ldwrky); // y, dy
/* Update the trailing submatrix A(i+nb:m,i+nb:n), using an update
of the form A := A - V*Y' - X*U' */
nrow = m - i - nb;
ncol = n - i - nb;
// Send Y back to the GPU
magma_ssetmatrix( nrow, nb, work + nb, ldwrkx, dwork + nb, ldwrkx );
magma_ssetmatrix( ncol, nb,
work + (ldwrkx+1)*nb, ldwrky,
dwork + (ldwrkx+1)*nb, ldwrky );
magma_sgemm( MagmaNoTrans, MagmaConjTrans,
nrow, ncol, nb,
c_neg_one, dA(i+nb, i ), ldda,
dwork+(ldwrkx+1)*nb, ldwrky,
c_one, dA(i+nb, i+nb), ldda);
magma_sgemm( MagmaNoTrans, MagmaNoTrans,
nrow, ncol, nb,
c_neg_one, dwork+nb, ldwrkx,
dA( i, i+nb ), ldda,
c_one, dA( i+nb, i+nb ), ldda);
/* Copy diagonal and off-diagonal elements of B back into A */
if (m >= n) {
jmax = i + nb;
for (j = i; j < jmax; ++j) {
*A(j, j ) = MAGMA_S_MAKE( d[j], 0. );
*A(j, j+1) = MAGMA_S_MAKE( e[j], 0. );
}
} else {
jmax = i + nb;
for (j = i; j < jmax; ++j) {
*A(j, j ) = MAGMA_S_MAKE( d[j], 0. );
*A(j+1, j ) = MAGMA_S_MAKE( e[j], 0. );
}
}
}
/* Use unblocked code to reduce the remainder of the matrix */
nrow = m - i;
ncol = n - i;
if ( 0 < minmn - nx ) {
magma_sgetmatrix( nrow, ncol, dA(i, i), ldda, A(i, i), lda );
}
lapackf77_sgebrd( &nrow, &ncol,
A(i, i), &lda, d+i, e+i,
tauq+i, taup+i, work, &lwork, &iinfo);
work[0] = MAGMA_S_MAKE( lwkopt, 0. );
magma_free( dA );
return *info;
} /* magma_sgebrd */
/* ////////////////////////////////////////////////////////////////////////////
-- Return nb for gesvd based on m
*/
magma_int_t magma_get_sgesvd_nb( magma_int_t m )
{
return magma_get_sgebrd_nb( m );
}
magma_int_t magmaf_get_sgebrd_nb( magma_int_t *m )
{
return magma_get_sgebrd_nb( *m );
}
/***************************************************************************//**
Purpose
-------
SORMBR multiplies by Q or P as part of the SVD decomposition.
If VECT = MagmaQ, SORMBR overwrites the general real M-by-N matrix C with
SIDE = MagmaLeft SIDE = MagmaRight
TRANS = MagmaNoTrans: Q*C C*Q
TRANS = MagmaTrans: Q**H*C C*Q**H
If VECT = MagmaP, SORMBR overwrites the general real M-by-N matrix C with
SIDE = MagmaLeft SIDE = MagmaRight
TRANS = MagmaNoTrans: P*C C*P
TRANS = MagmaTrans: P**H*C C*P**H
Here Q and P**H are the orthogonal matrices determined by SGEBRD when
reducing A real matrix A to bidiagonal form: A = Q*B * P**H. Q
and P**H are defined as products of elementary reflectors H(i) and
G(i) respectively.
Let nq = m if SIDE = MagmaLeft and nq = n if SIDE = MagmaRight. Thus nq is the
order of the orthogonal matrix Q or P**H that is applied.
If VECT = MagmaQ, A is assumed to have been an NQ-by-K matrix:
if nq >= k, Q = H(1) H(2) . . . H(k);
if nq < k, Q = H(1) H(2) . . . H(nq-1).
If VECT = MagmaP, A is assumed to have been A K-by-NQ matrix:
if k < nq, P = G(1) G(2) . . . G(k);
if k >= nq, P = G(1) G(2) . . . G(nq-1).
Arguments
---------
@param[in]
vect magma_vect_t
- = MagmaQ: apply Q or Q**H;
- = MagmaP: apply P or P**H.
@param[in]
side magma_side_t
- = MagmaLeft: apply Q, Q**H, P or P**H from the Left;
- = MagmaRight: apply Q, Q**H, P or P**H from the Right.
@param[in]
trans magma_trans_t
- = MagmaNoTrans: No transpose, apply Q or P;
- = MagmaTrans: Conjugate transpose, apply Q**H or P**H.
@param[in]
m INTEGER
The number of rows of the matrix C. M >= 0.
@param[in]
n INTEGER
The number of columns of the matrix C. N >= 0.
@param[in]
k INTEGER
If VECT = MagmaQ, the number of columns in the original
matrix reduced by SGEBRD.
If VECT = MagmaP, the number of rows in the original
matrix reduced by SGEBRD.
K >= 0.
@param[in]
A REAL array, dimension
(LDA,min(nq,K)) if VECT = MagmaQ
(LDA,nq) if VECT = MagmaP
The vectors which define the elementary reflectors H(i) and
G(i), whose products determine the matrices Q and P, as
returned by SGEBRD.
@param[in]
lda INTEGER
The leading dimension of the array A.
If VECT = MagmaQ, LDA >= max(1,nq);
if VECT = MagmaP, LDA >= max(1,min(nq,K)).
@param[in]
tau REAL array, dimension (min(nq,K))
TAU(i) must contain the scalar factor of the elementary
reflector H(i) or G(i) which determines Q or P, as returned
by SGEBRD in the array argument TAUQ or TAUP.
@param[in,out]
C REAL array, dimension (LDC,N)
On entry, the M-by-N matrix C.
On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q
or P*C or P**H*C or C*P or C*P**H.
@param[in]
ldc INTEGER
The leading dimension of the array C. LDC >= max(1,M).
@param[out]
work (workspace) REAL array, dimension (MAX(1,LWORK))
On exit, if INFO = 0, WORK[0] returns the optimal LWORK.
@param[in]
lwork INTEGER
The dimension of the array WORK.
If SIDE = MagmaLeft, LWORK >= max(1,N);
if SIDE = MagmaRight, LWORK >= max(1,M);
if N = 0 or M = 0, LWORK >= 1.
For optimum performance
if SIDE = MagmaLeft, LWORK >= max(1,N*NB);
if SIDE = MagmaRight, LWORK >= max(1,M*NB),
where NB is the optimal blocksize. (NB = 0 if M = 0 or N = 0.)
\n
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.
@param[out]
info INTEGER
- = 0: successful exit
- < 0: if INFO = -i, the i-th argument had an illegal value
@ingroup magma_unmbr
*******************************************************************************/
extern "C" magma_int_t
magma_sormbr(
magma_vect_t vect, magma_side_t side, magma_trans_t trans,
magma_int_t m, magma_int_t n, magma_int_t k,
float *A, magma_int_t lda,
float *tau,
float *C, magma_int_t ldc,
float *work, magma_int_t lwork,
magma_int_t *info)
{
#define A(i,j) (A + (i) + (j)*lda)
#define C(i,j) (C + (i) + (j)*ldc)
magma_int_t i1, i2, nb, mi, ni, nq, nq_1, minwrk, iinfo, lwkopt;
magma_int_t left, notran, applyq, lquery;
magma_trans_t transt;
MAGMA_UNUSED( nq_1 ); // used only in version 1
*info = 0;
applyq = (vect == MagmaQ);
left = (side == MagmaLeft);
notran = (trans == MagmaNoTrans);
lquery = (lwork == -1);
/* NQ is the order of Q or P and MINWRK (previously "nw") is the minimum dimension of WORK */
if (left) {
nq = m;
minwrk = n;
}
else {
nq = n;
minwrk = m;
}
if (m == 0 || n == 0) {
minwrk = 0;
}
/* check arguments */
if (! applyq && vect != MagmaP) {
*info = -1;
}
else if (! left && side != MagmaRight) {
*info = -2;
}
else if (! notran && trans != MagmaTrans) {
*info = -3;
}
else if (m < 0) {
*info = -4;
}
else if (n < 0) {
*info = -5;
}
else if (k < 0) {
*info = -6;
}
else if ( ( applyq && lda < max(1,nq) ) ||
( ! applyq && lda < max(1,min(nq,k)) ) ) {
*info = -8;
}
else if (ldc < max(1,m)) {
*info = -11;
}
else if (lwork < max(1,minwrk) && ! lquery) {
*info = -13;
}
if (*info == 0) {
if (minwrk > 0) {
// TODO have get_sormqr_nb and get_sormlq_nb routines? see original LAPACK sormbr.
// TODO make them dependent on m, n, and k?
nb = magma_get_sgebrd_nb( m, n );
lwkopt = max(1, minwrk*nb);
}
else {
lwkopt = 1;
}
work[0] = magma_smake_lwork( lwkopt );
}
if (*info != 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
else if (lquery) {
return *info;
}
/* Quick return if possible */
if (m == 0 || n == 0) {
return *info;
}
if (applyq) {
/* Apply Q */
if (nq >= k) {
/* Q was determined by a call to SGEBRD with nq >= k */
#if VERSION == 1
lapackf77_sormqr( lapack_side_const(side), lapack_trans_const(trans),
&m, &n, &k, A, &lda, tau, C, &ldc, work, &lwork, &iinfo);
#else
magma_sormqr( side, trans,
m, n, k, A, lda, tau, C, ldc, work, lwork, &iinfo);
#endif
}
else if (nq > 1) {
/* Q was determined by a call to SGEBRD with nq < k */
if (left) {
mi = m - 1;
ni = n;
i1 = 1;
i2 = 0;
}
else {
mi = m;
ni = n - 1;
i1 = 0;
i2 = 1;
}
#if VERSION == 1
nq_1 = nq - 1;
lapackf77_sormqr( lapack_side_const(side), lapack_trans_const(trans),
&mi, &ni, &nq_1, A(1,0), &lda, tau, C(i1,i2), &ldc, work, &lwork, &iinfo);
#else
magma_sormqr( side, trans,
mi, ni, nq-1, A(1,0), lda, tau, C(i1,i2), ldc, work, lwork, &iinfo);
#endif
}
}
else {
/* Apply P */
if (notran) {
transt = MagmaTrans;
}
else {
transt = MagmaNoTrans;
}
if (nq > k) {
/* P was determined by a call to SGEBRD with nq > k */
#if VERSION == 1
lapackf77_sormlq( lapack_side_const(side), lapack_trans_const(transt),
&m, &n, &k, A, &lda, tau, C, &ldc, work, &lwork, &iinfo);
#else
magma_sormlq( side, transt,
m, n, k, A, lda, tau, C, ldc, work, lwork, &iinfo);
#endif
}
else if (nq > 1) {
/* P was determined by a call to SGEBRD with nq <= k */
if (left) {
mi = m - 1;
ni = n;
i1 = 1;
i2 = 0;
}
else {
mi = m;
ni = n - 1;
i1 = 0;
i2 = 1;
}
#if VERSION == 1
nq_1 = nq - 1;
lapackf77_sormlq( lapack_side_const(side), lapack_trans_const(transt),
&mi, &ni, &nq_1, A(0,1), &lda, tau, C(i1,i2), &ldc, work, &lwork, &iinfo);
#else
magma_sormlq( side, transt,
mi, ni, nq-1, A(0,1), lda, tau, C(i1,i2), ldc, work, lwork, &iinfo);
#endif
}
}
work[0] = magma_smake_lwork( lwkopt );
return *info;
} /* magma_sormbr */
extern "C" magma_int_t
magma_sgebrd(magma_int_t m, magma_int_t n,
float *a, magma_int_t lda, float *d, float *e,
float *tauq, float *taup,
float *work, magma_int_t lwork,
magma_int_t *info)
{
/* -- MAGMA (version 1.3.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
November 2012
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[0] returns the optimal LWORK.
LWORK (input) INTEGER
The length of the array WORK. 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).
===================================================================== */
float c_neg_one = MAGMA_S_NEG_ONE;
float c_one = MAGMA_S_ONE;
float *da, *dwork;
magma_int_t ncol, nrow, jmax, nb, ldda;
magma_int_t i, j, nx;
magma_int_t iinfo;
magma_int_t minmn;
magma_int_t ldwrkx, ldwrky, lwkopt;
magma_int_t lquery;
nb = magma_get_sgebrd_nb(n);
ldda = m;
lwkopt = (m + n) * nb;
work[0] = MAGMA_S_MAKE( lwkopt, 0. );
lquery = (lwork == -1);
/* Check arguments */
*info = 0;
if (m < 0) {
*info = -1;
} else if (n < 0) {
*info = -2;
} else if (lda < max(1,m)) {
*info = -4;
} else if (lwork < lwkopt && (! lquery) ) {
*info = -10;
}
if (*info < 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
else if (lquery)
return *info;
/* Quick return if possible */
minmn = min(m,n);
if (minmn == 0) {
work[0] = c_one;
return *info;
}
if (MAGMA_SUCCESS != magma_smalloc( &da, n*ldda + (m + n)*nb )) {
fprintf (stderr, "!!!! device memory allocation error in sgebrd\n" );
*info = MAGMA_ERR_DEVICE_ALLOC;
return *info;
}
dwork = da + (n)*ldda;
ldwrkx = m;
ldwrky = n;
/* Set the block/unblock crossover point NX. */
nx = 128;
/* Copy the matrix to the GPU */
if (minmn - nx >= 1) {
magma_ssetmatrix( m, n, a, lda, da, ldda );
}
for (i=0; i< (minmn - nx); i += nb) {
/* 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 */
nrow = m - i;
ncol = n - i;
/* Get the current panel (no need for the 1st iteration) */
if ( i > 0 ) {
magma_sgetmatrix( nrow, nb, dA(i, i), ldda, A( i, i), lda );
magma_sgetmatrix( nb, ncol - nb,
dA(i, i+nb), ldda,
A( i, i+nb), lda );
}
magma_slabrd_gpu(nrow, ncol, nb,
A(i, i), lda, dA(i, i), ldda,
d+i, e+i, tauq+i, taup+i,
work, ldwrkx, dwork, ldwrkx, // x, dx
work+(ldwrkx*nb), ldwrky, dwork+(ldwrkx*nb), ldwrky); // y, dy
/* Update the trailing submatrix A(i+nb:m,i+nb:n), using an update
of the form A := A - V*Y' - X*U' */
nrow = m - i - nb;
ncol = n - i - nb;
// Send Y back to the GPU
magma_ssetmatrix( nrow, nb, work + nb, ldwrkx, dwork + nb, ldwrkx );
magma_ssetmatrix( ncol, nb,
work + (ldwrkx+1)*nb, ldwrky,
dwork + (ldwrkx+1)*nb, ldwrky );
magma_sgemm( MagmaNoTrans, MagmaTrans,
nrow, ncol, nb,
c_neg_one, dA(i+nb, i ), ldda,
dwork+(ldwrkx+1)*nb, ldwrky,
c_one, dA(i+nb, i+nb), ldda);
magma_sgemm( MagmaNoTrans, MagmaNoTrans,
nrow, ncol, nb,
c_neg_one, dwork+nb, ldwrkx,
dA( i, i+nb ), ldda,
c_one, dA( i+nb, i+nb ), ldda);
/* Copy diagonal and off-diagonal elements of B back into A */
if (m >= n) {
jmax = i + nb;
for (j = i; j < jmax; ++j) {
*A(j, j ) = MAGMA_S_MAKE( d[j], 0. );
*A(j, j+1) = MAGMA_S_MAKE( e[j], 0. );
}
} else {
jmax = i + nb;
for (j = i; j < jmax; ++j) {
*A(j, j ) = MAGMA_S_MAKE( d[j], 0. );
*A(j+1, j ) = MAGMA_S_MAKE( e[j], 0. );
}
}
}
/* Use unblocked code to reduce the remainder of the matrix */
nrow = m - i;
ncol = n - i;
if ( 0 < minmn - nx ) {
magma_sgetmatrix( nrow, ncol, dA(i, i), ldda, A(i, i), lda );
}
lapackf77_sgebrd( &nrow, &ncol,
A(i, i), &lda, d+i, e+i,
tauq+i, taup+i, work, &lwork, &iinfo);
work[0] = MAGMA_S_MAKE( lwkopt, 0. );
magma_free( da );
return *info;
} /* sgebrd */
