/**
Purpose
-------
ZLAQPS computes a step of QR factorization with column pivoting
of a complex M-by-N matrix A by using Blas-3. It tries to factorize
NB columns from A starting from the row OFFSET+1, and updates all
of the matrix with Blas-3 xGEMM.
In some cases, due to catastrophic cancellations, it cannot
factorize NB columns. Hence, the actual number of factorized
columns is returned in KB.
Block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized.
Arguments
---------
@param[in]
m INTEGER
The number of rows of the matrix A. M >= 0.
@param[in]
n INTEGER
The number of columns of the matrix A. N >= 0
@param[in]
offset INTEGER
The number of rows of A that have been factorized in
previous steps.
@param[in]
nb INTEGER
The number of columns to factorize.
@param[out]
kb INTEGER
The number of columns actually factorized.
@param[in,out]
A COMPLEX_16 array, dimension (LDA,N)
On entry, the M-by-N matrix A.
On exit, block A(OFFSET+1:M,1:KB) is the triangular
factor obtained and block A(1:OFFSET,1:N) has been
accordingly pivoted, but no factorized.
The rest of the matrix, block A(OFFSET+1:M,KB+1:N) has
been updated.
@param[in]
lda INTEGER
The leading dimension of the array A. LDA >= max(1,M).
@param[in,out]
jpvt INTEGER array, dimension (N)
JPVT(I) = K <==> Column K of the full matrix A has been
permuted into position I in AP.
@param[out]
tau COMPLEX_16 array, dimension (KB)
The scalar factors of the elementary reflectors.
@param[in,out]
vn1 DOUBLE PRECISION array, dimension (N)
The vector with the partial column norms.
@param[in,out]
vn2 DOUBLE PRECISION array, dimension (N)
The vector with the exact column norms.
@param[in,out]
auxv COMPLEX_16 array, dimension (NB)
Auxiliar vector.
@param[in,out]
F COMPLEX_16 array, dimension (LDF,NB)
Matrix F' = L*Y'*A.
@param[in]
ldf INTEGER
The leading dimension of the array F. LDF >= max(1,N).
@ingroup magma_zgeqp3_aux
********************************************************************/
extern "C" magma_int_t
magma_zlaqps(
magma_int_t m, magma_int_t n, magma_int_t offset,
magma_int_t nb, magma_int_t *kb,
magmaDoubleComplex *A, magma_int_t lda,
magmaDoubleComplex_ptr dA, magma_int_t ldda,
magma_int_t *jpvt, magmaDoubleComplex *tau, double *vn1, double *vn2,
magmaDoubleComplex *auxv,
magmaDoubleComplex *F, magma_int_t ldf,
magmaDoubleComplex_ptr dF, magma_int_t lddf)
{
#define A(i, j) (A + (i) + (j)*(lda ))
#define dA(i, j) (dA + (i) + (j)*(ldda))
#define F(i, j) (F + (i) + (j)*(ldf ))
#define dF(i, j) (dF + (i) + (j)*(lddf))
magmaDoubleComplex c_zero = MAGMA_Z_MAKE( 0.,0.);
magmaDoubleComplex c_one = MAGMA_Z_MAKE( 1.,0.);
magmaDoubleComplex c_neg_one = MAGMA_Z_MAKE(-1.,0.);
magma_int_t ione = 1;
magma_int_t i__1, i__2;
double d__1;
magmaDoubleComplex z__1;
magma_int_t j, k, rk;
magmaDoubleComplex Akk;
magma_int_t pvt;
double temp, temp2, tol3z;
magma_int_t itemp;
magma_int_t lsticc;
magma_int_t lastrk;
lastrk = min( m, n + offset );
tol3z = magma_dsqrt( lapackf77_dlamch("Epsilon"));
magma_queue_t queue;
magma_device_t cdev;
magma_getdevice( &cdev );
magma_queue_create( cdev, &queue );
lsticc = 0;
k = 0;
while( k < nb && lsticc == 0 ) {
rk = offset + k;
/* Determine ith pivot column and swap if necessary */
// subtract 1 from Fortran idamax; pvt, k are 0-based.
i__1 = n-k;
pvt = k + blasf77_idamax( &i__1, &vn1[k], &ione ) - 1;
if (pvt != k) {
if (pvt >= nb) {
/* 1. Start copy from GPU */
magma_zgetmatrix_async( m - offset - nb, 1,
dA(offset + nb, pvt), ldda,
A (offset + nb, pvt), lda, queue );
}
/* F gets swapped so F must be sent at the end to GPU */
i__1 = k;
blasf77_zswap( &i__1, F(pvt,0), &ldf, F(k,0), &ldf );
itemp = jpvt[pvt];
jpvt[pvt] = jpvt[k];
jpvt[k] = itemp;
vn1[pvt] = vn1[k];
vn2[pvt] = vn2[k];
if (pvt < nb) {
/* no need of transfer if pivot is within the panel */
blasf77_zswap( &m, A(0, pvt), &ione, A(0, k), &ione );
}
else {
/* 1. Finish copy from GPU */
magma_queue_sync( queue );
/* 2. Swap as usual on CPU */
blasf77_zswap(&m, A(0, pvt), &ione, A(0, k), &ione);
/* 3. Restore the GPU */
magma_zsetmatrix_async( m - offset - nb, 1,
A (offset + nb, pvt), lda,
dA(offset + nb, pvt), ldda, queue );
}
}
/* Apply previous Householder reflectors to column K:
A(RK:M,K) := A(RK:M,K) - A(RK:M,1:K-1)*F(K,1:K-1)'.
Optimization: multiply with beta=0; wait for vector and subtract */
if (k > 0) {
#ifdef COMPLEX
for (j = 0; j < k; ++j) {
*F(k,j) = MAGMA_Z_CONJ( *F(k,j) );
}
#endif
i__1 = m - rk;
i__2 = k;
blasf77_zgemv( MagmaNoTransStr, &i__1, &i__2,
&c_neg_one, A(rk, 0), &lda,
F(k, 0), &ldf,
&c_one, A(rk, k), &ione );
#ifdef COMPLEX
for (j = 0; j < k; ++j) {
*F(k,j) = MAGMA_Z_CONJ( *F(k,j) );
}
#endif
}
/* Generate elementary reflector H(k). */
if (rk < m-1) {
i__1 = m - rk;
lapackf77_zlarfg( &i__1, A(rk, k), A(rk + 1, k), &ione, &tau[k] );
} else {
lapackf77_zlarfg( &ione, A(rk, k), A(rk, k), &ione, &tau[k] );
}
Akk = *A(rk, k);
*A(rk, k) = c_one;
/* Compute Kth column of F:
Compute F(K+1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) on the GPU */
if (k < n-1) {
i__1 = m - rk;
i__2 = n - k - 1;
/* Send the vector to the GPU */
magma_zsetmatrix( i__1, 1, A(rk, k), lda, dA(rk,k), ldda, queue );
/* Multiply on GPU */
// was CALL ZGEMV( 'Conjugate transpose', M-RK+1, N-K,
// TAU( K ), A( RK, K+1 ), LDA,
// A( RK, K ), 1,
// CZERO, F( K+1, K ), 1 )
magma_int_t i__3 = nb-k-1;
magma_int_t i__4 = i__2 - i__3;
magma_int_t i__5 = nb-k;
magma_zgemv( MagmaConjTrans, i__1 - i__5, i__2 - i__3,
tau[k], dA(rk +i__5, k+1+i__3), ldda,
dA(rk +i__5, k ), ione,
c_zero, dF(k+1+i__3, k ), ione, queue );
magma_zgetmatrix_async( i__2-i__3, 1,
dF(k + 1 +i__3, k), i__2,
F (k + 1 +i__3, k), i__2, queue );
blasf77_zgemv( MagmaConjTransStr, &i__1, &i__3,
&tau[k], A(rk, k+1), &lda,
A(rk, k ), &ione,
&c_zero, F(k+1, k ), &ione );
magma_queue_sync( queue );
blasf77_zgemv( MagmaConjTransStr, &i__5, &i__4,
&tau[k], A(rk, k+1+i__3), &lda,
A(rk, k ), &ione,
&c_one, F(k+1+i__3, k ), &ione );
}
/* Padding F(1:K,K) with zeros. */
for (j = 0; j < k; ++j) {
*F(j, k) = c_zero;
}
/* Incremental updating of F:
F(1:N,K) := F(1:N,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K). */
if (k > 0) {
i__1 = m - rk;
i__2 = k;
z__1 = MAGMA_Z_NEGATE( tau[k] );
blasf77_zgemv( MagmaConjTransStr, &i__1, &i__2,
&z__1, A(rk, 0), &lda,
A(rk, k), &ione,
&c_zero, auxv, &ione );
i__1 = k;
blasf77_zgemv( MagmaNoTransStr, &n, &i__1,
&c_one, F(0,0), &ldf,
auxv, &ione,
&c_one, F(0,k), &ione );
}
/* Optimization: On the last iteration start sending F back to the GPU */
/* Update the current row of A:
A(RK,K+1:N) := A(RK,K+1:N) - A(RK,1:K)*F(K+1:N,1:K)'. */
if (k < n-1) {
i__1 = n - k - 1;
i__2 = k + 1;
blasf77_zgemm( MagmaNoTransStr, MagmaConjTransStr, &ione, &i__1, &i__2,
&c_neg_one, A(rk, 0 ), &lda,
F(k+1,0 ), &ldf,
&c_one, A(rk, k+1), &lda );
}
/* Update partial column norms. */
if (rk < lastrk) {
for (j = k + 1; j < n; ++j) {
if (vn1[j] != 0.) {
/* NOTE: The following 4 lines follow from the analysis in
Lapack Working Note 176. */
temp = MAGMA_Z_ABS( *A(rk,j) ) / vn1[j];
temp = max( 0., ((1. + temp) * (1. - temp)) );
d__1 = vn1[j] / vn2[j];
temp2 = temp * (d__1 * d__1);
if (temp2 <= tol3z) {
vn2[j] = (double) lsticc;
lsticc = j;
} else {
vn1[j] *= magma_dsqrt(temp);
}
}
}
}
*A(rk, k) = Akk;
++k;
}
// leave k as the last column done
--k;
*kb = k + 1;
rk = offset + *kb - 1;
/* Apply the block reflector to the rest of the matrix:
A(OFFSET+KB+1:M,KB+1:N) := A(OFFSET+KB+1:M,KB+1:N) - A(OFFSET+KB+1:M,1:KB)*F(KB+1:N,1:KB)' */
if (*kb < min(n, m - offset)) {
i__1 = m - rk - 1;
i__2 = n - *kb;
/* Send F to the GPU */
magma_zsetmatrix( i__2, *kb,
F (*kb, 0), ldf,
dF(*kb, 0), i__2, queue );
magma_zgemm( MagmaNoTrans, MagmaConjTrans, i__1, i__2, *kb,
c_neg_one, dA(rk+1, 0 ), ldda,
dF(*kb, 0 ), i__2,
c_one, dA(rk+1, *kb), ldda, queue );
}
/* Recomputation of difficult columns. */
while( lsticc > 0 ) {
itemp = (magma_int_t)(vn2[lsticc] >= 0. ? floor(vn2[lsticc] + .5) : -floor(.5 - vn2[lsticc]));
i__1 = m - rk - 1;
if (lsticc <= nb) {
vn1[lsticc] = magma_cblas_dznrm2( i__1, A(rk+1,lsticc), ione );
}
else {
/* Where is the data, CPU or GPU ? */
double r1, r2;
r1 = magma_cblas_dznrm2( nb-k, A(rk+1,lsticc), ione );
r2 = magma_dznrm2( m-offset-nb, dA(offset + nb + 1, lsticc), ione, queue );
//vn1[lsticc] = magma_dznrm2( i__1, dA(rk + 1, lsticc), ione, queue );
vn1[lsticc] = magma_dsqrt(r1*r1 + r2*r2);
}
/* NOTE: The computation of VN1( LSTICC ) relies on the fact that
SNRM2 does not fail on vectors with norm below the value of SQRT(DLAMCH('S')) */
vn2[lsticc] = vn1[lsticc];
lsticc = itemp;
}
magma_queue_destroy( queue );
return MAGMA_SUCCESS;
} /* magma_zlaqps */
extern "C" magma_int_t
magma_zlaqps_gpu(magma_int_t m, magma_int_t n, magma_int_t offset,
magma_int_t nb, magma_int_t *kb,
magmaDoubleComplex *A, magma_int_t lda,
magma_int_t *jpvt, magmaDoubleComplex *tau,
double *vn1, double *vn2,
magmaDoubleComplex *auxv,
magmaDoubleComplex *F, magma_int_t ldf)
{
/* -- MAGMA (version 1.4.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
August 2013
Purpose
=======
ZLAQPS computes a step of QR factorization with column pivoting
of a complex M-by-N matrix A by using Blas-3. It tries to factorize
NB columns from A starting from the row OFFSET+1, and updates all
of the matrix with Blas-3 xGEMM.
In some cases, due to catastrophic cancellations, it cannot
factorize NB columns. Hence, the actual number of factorized
columns is returned in KB.
Block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized.
Arguments
=========
M (input) INTEGER
The number of rows of the matrix A. M >= 0.
N (input) INTEGER
The number of columns of the matrix A. N >= 0
OFFSET (input) INTEGER
The number of rows of A that have been factorized in
previous steps.
NB (input) INTEGER
The number of columns to factorize.
KB (output) INTEGER
The number of columns actually factorized.
A (input/output) COMPLEX*16 array, dimension (LDA,N)
On entry, the M-by-N matrix A.
On exit, block A(OFFSET+1:M,1:KB) is the triangular
factor obtained and block A(1:OFFSET,1:N) has been
accordingly pivoted, but no factorized.
The rest of the matrix, block A(OFFSET+1:M,KB+1:N) has
been updated.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,M).
JPVT (input/output) INTEGER array, dimension (N)
JPVT(I) = K <==> Column K of the full matrix A has been
permuted into position I in AP.
TAU (output) COMPLEX*16 array, dimension (KB)
The scalar factors of the elementary reflectors.
VN1 (input/output) DOUBLE PRECISION array, dimension (N)
The vector with the partial column norms.
VN2 (input/output) DOUBLE PRECISION array, dimension (N)
The vector with the exact column norms.
AUXV (input/output) COMPLEX*16 array, dimension (NB)
Auxiliar vector.
F (input/output) COMPLEX*16 array, dimension (LDF,NB)
Matrix F' = L*Y'*A.
LDF (input) INTEGER
The leading dimension of the array F. LDF >= max(1,N).
===================================================================== */
#define A(i, j) (A + (i) + (j)*(lda ))
#define F(i, j) (F + (i) + (j)*(ldf ))
magmaDoubleComplex c_zero = MAGMA_Z_MAKE( 0.,0.);
magmaDoubleComplex c_one = MAGMA_Z_MAKE( 1.,0.);
magmaDoubleComplex c_neg_one = MAGMA_Z_MAKE(-1.,0.);
magma_int_t ione = 1;
magma_int_t i__1, i__2;
//double d__1;
magmaDoubleComplex z__1;
//magma_int_t j;
magma_int_t k, rk;
//magmaDoubleComplex Akk;
magmaDoubleComplex *Aks;
magmaDoubleComplex tauk;
magma_int_t pvt;
//double temp, temp2;
double tol3z;
magma_int_t itemp;
double lsticc, *lsticcs;
magma_int_t lastrk;
magma_dmalloc( &lsticcs, 1+256*(n+255)/256 );
lastrk = min( m, n + offset );
tol3z = magma_dsqrt( lapackf77_dlamch("Epsilon"));
lsticc = 0;
k = 0;
magma_zmalloc( &Aks, nb );
while( k < nb && lsticc == 0 ) {
rk = offset + k;
/* Determine ith pivot column and swap if necessary */
// Fortran: pvt, k, idamax are all 1-based; subtract 1 from k.
// C: pvt, k, idamax are all 0-based; don't subtract 1.
pvt = k - 1 + magma_idamax( n-k, &vn1[k], ione );
if (pvt != k) {
/*if (pvt >= nb) {
// 1. Start copy from GPU
magma_zgetmatrix_async( m - offset - nb, 1,
dA(offset + nb, pvt), ldda,
A (offset + nb, pvt), lda, stream );
}*/
/* F gets swapped so F must be sent at the end to GPU */
i__1 = k;
/*if (pvt < nb){
// no need of transfer if pivot is within the panel
blasf77_zswap( &m, A(0, pvt), &ione, A(0, k), &ione );
}
else {
// 1. Finish copy from GPU
magma_queue_sync( stream );
// 2. Swap as usual on CPU
blasf77_zswap(&m, A(0, pvt), &ione, A(0, k), &ione);
// 3. Restore the GPU
magma_zsetmatrix_async( m - offset - nb, 1,
A (offset + nb, pvt), lda,
dA(offset + nb, pvt), ldda, stream);
}*/
magmablas_zswap( m, A(0, pvt), ione, A(0, k), ione );
//blasf77_zswap( &i__1, F(pvt,0), &ldf, F(k,0), &ldf );
magmablas_zswap( i__1, F(pvt, 0), ldf, F(k, 0), ldf);
itemp = jpvt[pvt];
jpvt[pvt] = jpvt[k];
jpvt[k] = itemp;
//vn1[pvt] = vn1[k];
//vn2[pvt] = vn2[k];
#if defined(PRECISION_d) || defined(PRECISION_z)
//magma_dswap( 1, &vn1[pvt], 1, &vn1[k], 1 );
//magma_dswap( 1, &vn2[pvt], 1, &vn2[k], 1 );
magma_dswap( 2, &vn1[pvt], n+offset, &vn1[k], n+offset );
#else
//magma_sswap( 1, &vn1[pvt], 1, &vn1[k], 1 );
//magma_sswap( 1, &vn2[pvt], 1, &vn2[k], 1 );
magma_sswap(2, &vn1[pvt], n+offset, &vn1[k], n+offset);
#endif
}
/* Apply previous Householder reflectors to column K:
A(RK:M,K) := A(RK:M,K) - A(RK:M,1:K-1)*F(K,1:K-1)'.
Optimization: multiply with beta=0; wait for vector and subtract */
if (k > 0) {
/*#if (defined(PRECISION_c) || defined(PRECISION_z))
for (j = 0; j < k; ++j){
*F(k,j) = MAGMA_Z_CNJG( *F(k,j) );
}
#endif*/
//#define RIGHT_UPDATE
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, A(offset+nb, 0), lda,
F(k, 0), ldf,
c_one, A(offset+nb, k), ione );
#else
i__1 = m - rk;
i__2 = k;
/*blasf77_zgemv( MagmaNoTransStr, &i__1, &i__2,
&c_neg_one, A(rk, 0), &lda,
F(k, 0), &ldf,
&c_one, A(rk, k), &ione );*/
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, A(rk, 0), lda,
F(k, 0), ldf,
c_one, A(rk, k), ione );
#endif
/*#if (defined(PRECISION_c) || defined(PRECISION_z))
for (j = 0; j < k; ++j) {
*F(k,j) = MAGMA_Z_CNJG( *F(k,j) );
}
#endif*/
}
/* Generate elementary reflector H(k). */
magma_zlarfg_gpu(m-rk, A(rk, k), A(rk + 1, k), &tau[k], &vn1[k], &Aks[k]);
//Akk = *A(rk, k);
//*A(rk, k) = c_one;
//magma_zgetvector( 1, &Aks[k], 1, &Akk, 1 );
/* needed to avoid the race condition */
if (k == 0) magma_zsetvector( 1, &c_one, 1, A(rk, k), 1 );
else magma_zcopymatrix( 1, 1, A(offset, 0), 1, A(rk, k), 1 );
/* Compute Kth column of F:
Compute F(K+1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) on the GPU */
if (k < n-1 || k > 0) magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
if (k < n-1) {
i__1 = m - rk;
i__2 = n - k - 1;
/* Send the vector to the GPU */
//magma_zsetmatrix( i__1, 1, A(rk, k), lda, dA(rk,k), ldda );
/* Multiply on GPU */
// was CALL ZGEMV( 'Conjugate transpose', M-RK+1, N-K,
// TAU( K ), A( RK, K+1 ), LDA,
// A( RK, K ), 1,
// CZERO, F( K+1, K ), 1 )
//magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
magma_zgemv( MagmaConjTrans, m-rk, n-k-1,
tauk, A( rk, k+1 ), lda,
A( rk, k ), 1,
c_zero, F( k+1, k ), 1 );
//magma_zscal( m-rk, tau[k], F( k+1, k), 1 );
//magma_int_t i__3 = nb-k-1;
//magma_int_t i__4 = i__2 - i__3;
//magma_int_t i__5 = nb-k;
//magma_zgemv( MagmaConjTrans, i__1 - i__5, i__2 - i__3,
// tau[k], dA(rk +i__5, k+1+i__3), ldda,
// dA(rk +i__5, k ), ione,
// c_zero, dF(k+1+i__3, k ), ione );
//magma_zgetmatrix_async( i__2-i__3, 1,
// dF(k + 1 +i__3, k), i__2,
// F (k + 1 +i__3, k), i__2, stream );
//blasf77_zgemv( MagmaConjTransStr, &i__1, &i__3,
// &tau[k], A(rk, k+1), &lda,
// A(rk, k ), &ione,
// &c_zero, F(k+1, k ), &ione );
//magma_queue_sync( stream );
//blasf77_zgemv( MagmaConjTransStr, &i__5, &i__4,
// &tau[k], A(rk, k+1+i__3), &lda,
// A(rk, k ), &ione,
// &c_one, F(k+1+i__3, k ), &ione );
}
/* Padding F(1:K,K) with zeros.
for (j = 0; j <= k; ++j) {
magma_zsetvector( 1, &c_zero, 1, F(j, k), 1 );
}*/
/* Incremental updating of F:
F(1:N,K) := F(1:N,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K).
F(1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K)
:= tau(K)(A(RK:M,K+1:N)' - F(1:N,1:K-1)*A(RK:M,1:K-1)') A(RK:M,K)
so, F is (updated A)*V */
//if (k > 0 && k<n-1) {
if (k > 0) {
//magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
z__1 = MAGMA_Z_NEGATE( tauk );
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, A(offset+nb, 0), lda,
A(offset+nb, k), ione,
c_zero, auxv, ione );
i__1 = k;
magma_zgemv( MagmaNoTrans, n-k-1, i__1,
c_one, F(k+1,0), ldf,
auxv, ione,
c_one, F(k+1,k), ione );
#else
i__1 = m - rk;
i__2 = k;
//blasf77_zgemv( MagmaConjTransStr, &i__1, &i__2,
// &z__1, A(rk, 0), &lda,
// A(rk, k), &ione,
// &c_zero, auxv, &ione );
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, A(rk, 0), lda,
A(rk, k), ione,
c_zero, auxv, ione );
//i__1 = k;
//blasf77_zgemv( MagmaNoTransStr, &n, &i__1,
// &c_one, F(0,0), &ldf,
// auxv, &ione,
// &c_one, F(0,k), &ione );
/*magma_zgemv( MagmaNoTrans, n, i__1,
c_one, F(0,0), ldf,
auxv, ione,
c_one, F(0,k), ione );*/
/* I think we only need stricly lower-triangular part :) */
magma_zgemv( MagmaNoTrans, n-k-1, i__2,
c_one, F(k+1,0), ldf,
auxv, ione,
c_one, F(k+1,k), ione );
#endif
}
/* Optimization: On the last iteration start sending F back to the GPU */
/* Update the current row of A:
A(RK,K+1:N) := A(RK,K+1:N) - A(RK,1:K)*F(K+1:N,1:K)'. */
if (k < n-1) {
i__1 = n - k - 1;
i__2 = k + 1;
//blasf77_zgemm( MagmaNoTransStr, MagmaConjTransStr, &ione, &i__1, &i__2,
// &c_neg_one, A(rk, 0 ), &lda,
// F(k+1,0 ), &ldf,
// &c_one, A(rk, k+1), &lda );
#ifdef RIGHT_UPDATE
/* right-looking update of rows, */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, nb-k, i__1, ione,
c_neg_one, A(rk, k ), lda,
F(k+1, k ), ldf,
c_one, A(rk, k+1), lda );
#else
/* left-looking update of rows, *
* since F=A'v with original A, so no right-looking */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, ione, i__1, i__2,
c_neg_one, A(rk, 0 ), lda,
F(k+1,0 ), ldf,
c_one, A(rk, k+1), lda );
#endif
}
/* Update partial column norms. */
if (rk < min(m, n+offset)-1 ) {
magmablas_dznrm2_row_check_adjust(n-k-1, tol3z, &vn1[k+1], &vn2[k+1], A(rk,k+1), lda, lsticcs);
magma_device_sync();
#if defined(PRECISION_d) || defined(PRECISION_z)
magma_dgetvector( 1, &lsticcs[0], 1, &lsticc, 1 );
#else
magma_sgetvector( 1, &lsticcs[0], 1, &lsticc, 1 );
#endif
}
/*if (rk < lastrk) {
for (j = k + 1; j < n; ++j) {
if (vn1[j] != 0.) {
// NOTE: The following 4 lines follow from the analysis in
// Lapack Working Note 176.
temp = MAGMA_Z_ABS( *A(rk,j) ) / vn1[j];
temp = max( 0., ((1. + temp) * (1. - temp)) );
d__1 = vn1[j] / vn2[j];
temp2 = temp * (d__1 * d__1);
if (temp2 <= tol3z) {
vn2[j] = (double) lsticc;
lsticc = j;
} else {
vn1[j] *= magma_dsqrt(temp);
}
}
}
}*/
//*A(rk, k) = Akk;
//magma_zsetvector( 1, &Akk, 1, A(rk, k), 1 );
//magma_zswap( 1, &Aks[k], 1, A(rk, k), 1 );
++k;
}
magma_zcopymatrix( 1, k, Aks, 1, A(offset, 0), lda+1 );
// leave k as the last column done
--k;
*kb = k + 1;
rk = offset + *kb - 1;
/* Apply the block reflector to the rest of the matrix:
A(OFFSET+KB+1:M,KB+1:N) := A(OFFSET+KB+1:M,KB+1:N) - A(OFFSET+KB+1:M,1:KB)*F(KB+1:N,1:KB)' */
if (*kb < min(n, m - offset)) {
i__1 = m - rk - 1;
i__2 = n - *kb;
/* Send F to the GPU
magma_zsetmatrix( i__2, *kb,
F (*kb, 0), ldf,
dF(*kb, 0), i__2 );*/
magma_zgemm( MagmaNoTrans, MagmaConjTrans, i__1, i__2, *kb,
c_neg_one, A(rk+1, 0 ), lda,
F(*kb, 0 ), ldf,
c_one, A(rk+1, *kb), lda );
}
/* Recomputation of difficult columns. */
if( lsticc > 0 ) {
printf( " -- recompute dnorms --\n" );
magmablas_dznrm2_check(m-rk-1, n-*kb, A(rk+1,*kb), lda,
&vn1[*kb], lsticcs);
#if defined(PRECISION_d) || defined(PRECISION_z)
magma_dcopymatrix( n-*kb, 1, &vn1[*kb], *kb, &vn2[*kb], *kb);
#else
magma_scopymatrix( n-*kb, 1, &vn1[*kb], *kb, &vn2[*kb], *kb);
#endif
/*while( lsticc > 0 ) {
itemp = (magma_int_t)(vn2[lsticc] >= 0. ? floor(vn2[lsticc] + .5) : -floor(.5 - vn2[lsticc]));
i__1 = m - rk - 1;
if (lsticc <= nb)
vn1[lsticc] = cblas_dznrm2(i__1, A(rk + 1, lsticc), ione);
else {
// Where is the data, CPU or GPU ?
double r1, r2;
r1 = cblas_dznrm2(nb-k, A(rk + 1, lsticc), ione);
r2 = magma_dznrm2(m-offset-nb, dA(offset + nb + 1, lsticc), ione);
vn1[lsticc] = magma_dsqrt(r1*r1+r2*r2);
}
// NOTE: The computation of VN1( LSTICC ) relies on the fact that
// SNRM2 does not fail on vectors with norm below the value of SQRT(DLAMCH('S'))
vn2[lsticc] = vn1[lsticc];
lsticc = itemp;*/
}
magma_free(Aks);
magma_free(lsticcs);
return MAGMA_SUCCESS;
} /* magma_zlaqps */
extern "C" magma_int_t
magma_zlahr2_m(
magma_int_t n, magma_int_t k, magma_int_t nb,
magmaDoubleComplex *A, magma_int_t lda,
magmaDoubleComplex *tau,
magmaDoubleComplex *T, magma_int_t ldt,
magmaDoubleComplex *Y, magma_int_t ldy,
struct zgehrd_data* data )
{
/* -- MAGMA (version 1.4.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
August 2013
Purpose
=======
ZLAHR2 reduces the first NB columns of a complex general n-BY-(n-k+1)
matrix A so that elements below the k-th subdiagonal are zero. The
reduction is performed by an orthogonal similarity transformation
Q' * A * Q. The routine returns the matrices V and T which determine
Q as a block reflector I - V*T*V', and also the matrix Y = A * V.
(Note this is different than LAPACK, which computes Y = A * V * T.)
This is an auxiliary routine called by ZGEHRD.
Arguments
=========
N (input) INTEGER
The order of the matrix A.
K (input) INTEGER
The offset for the reduction. Elements below the k-th
subdiagonal in the first NB columns are reduced to zero.
K < N.
NB (input) INTEGER
The number of columns to be reduced.
A (input/output) COMPLEX_16 array, dimension (LDA,N-K+1)
On entry, the n-by-(n-k+1) general matrix A.
On exit, the elements on and above the k-th subdiagonal in
the first NB columns are overwritten with the corresponding
elements of the reduced matrix; the elements below the k-th
subdiagonal, with the array TAU, represent the matrix Q as a
product of elementary reflectors. The other columns of A are
unchanged. See Further Details.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
TAU (output) COMPLEX_16 array, dimension (NB)
The scalar factors of the elementary reflectors. See Further
Details.
T (output) COMPLEX_16 array, dimension (LDT,NB)
The upper triangular matrix T.
LDT (input) INTEGER
The leading dimension of the array T. LDT >= NB.
Y (output) COMPLEX_16 array, dimension (LDY,NB)
The n-by-nb matrix Y.
LDY (input) INTEGER
The leading dimension of the array Y. LDY >= N.
dA (input/output) COMPLEX_16 array on the GPU, dimension (LDA,N-K+1)
On entry, the n-by-(n-k+1) general matrix A.
On exit, the elements in rows K:N of the first NB columns are
overwritten with the matrix Y.
DV (output) COMPLEX_16 array on the GPU, dimension (N, NB)
On exit this contains the Householder vectors of the transformation.
Further Details
===============
The matrix Q is represented as a product of nb elementary reflectors
Q = H(1) H(2) . . . H(nb).
Each H(i) has the form
H(i) = I - tau * v * v'
where tau is a complex scalar, and v is a complex vector with
v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in
A(i+k+1:n,i), and tau in TAU(i).
The elements of the vectors v together form the (n-k+1)-by-nb matrix
V which is needed, with T and Y, to apply the transformation to the
unreduced part of the matrix, using an update of the form:
A := (I - V*T*V') * (A - Y*T*V').
The contents of A on exit are illustrated by the following example
with n = 7, k = 3 and nb = 2:
( a a a a a )
( a a a a a )
( a a a a a )
( h h a a a )
( v1 h a a a )
( v1 v2 a a a )
( v1 v2 a a a )
where "a" denotes an element of the original matrix A, h denotes a
modified element of the upper Hessenberg matrix H, and vi denotes an
element of the vector defining H(i).
This implementation follows the hybrid algorithm and notations described in
S. Tomov and J. Dongarra, "Accelerating the reduction to upper Hessenberg
form through hybrid GPU-based computing," University of Tennessee Computer
Science Technical Report, UT-CS-09-642 (also LAPACK Working Note 219),
May 24, 2009.
===================================================================== */
#define A( i, j ) ( A + (i) + (j)*lda)
#define Y( i, j ) ( Y + (i) + (j)*ldy)
#define T( i, j ) ( T + (i) + (j)*ldt)
#define dA( d, i, j ) (data->A [d] + (i) + (j)*ldda)
#define dTi( d ) (data->Ti[d])
#define dV( d, i, j ) (data->V [d] + (i) + (j)*ldv )
#define dVd( d, i, j ) (data->Vd[d] + (i) + (j)*ldvd)
#define dY( d, i, j ) (data->Y [d] + (i) + (j)*ldda)
magmaDoubleComplex c_zero = MAGMA_Z_ZERO;
magmaDoubleComplex c_one = MAGMA_Z_ONE;
magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magmaDoubleComplex tmp;
magma_int_t ngpu = data->ngpu;
magma_int_t ldda = data->ldda;
magma_int_t ldv = data->ldv;
magma_int_t ldvd = data->ldvd;
magma_int_t ione = 1;
magma_int_t d, dki1, dn, nblocks, gblock, lblock, lgid;
magma_int_t n_k_i_1, n_k;
magmaDoubleComplex scale;
magma_int_t i;
magmaDoubleComplex ei = MAGMA_Z_ZERO;
magma_int_t info_data = 0;
magma_int_t *info = &info_data;
if (n < 0) {
*info = -1;
} else if (k < 0 || k >= n) {
*info = -2;
} else if (nb < 1 || nb > n) {
*info = -3;
} else if (lda < max(1,n)) {
*info = -5;
} else if (ldt < nb) {
*info = -8;
} else if (ldy < max(1,n)) {
*info = -10;
}
if (*info != 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
// adjust from 1-based indexing
k -= 1;
// Function Body
if (n <= 1)
return 0;
// zero out current top block of V on all GPUs
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magmablasSetKernelStream( data->streams[d] );
magmablas_zlaset( MagmaUpperLower, nb, nb, dV(d,k,0), ldv );
}
// set all Y=0
lapackf77_zlaset( "Full", &n, &nb, &c_zero, &c_zero, Y, &ldy );
for (i = 0; i < nb; ++i) {
n_k_i_1 = n - k - i - 1;
n_k = n - k;
if (i > 0) {
// Finish applying I - V * T * V' on right
tmp = MAGMA_Z_NEGATE( tau[i-1] );
blasf77_zaxpy( &n_k, &tmp, Y(k,i-1), &ione, A(k,i), &ione );
// Apply I - V * T' * V' to this column (call it b) from the
// left, using the last column of T as workspace, w.
//
// Let V = ( V1 ) and b = ( b1 ) (first i-1 rows)
// ( V2 ) ( b2 )
// where V1 is unit lower triangular
// w := b1 = A(k+1:k+i, i)
blasf77_zcopy( &i,
A(k+1,i), &ione,
T(0,nb-1), &ione );
// w := V1' * b1 = VA(k+1:k+i, 0:i-1)' * w
blasf77_ztrmv( "Lower", "Conj", "Unit", &i,
A(k+1,0), &lda,
T(0,nb-1), &ione );
// w := w + V2'*b2 = w + VA(k+i+1:n-1, 0:i-1)' * A(k+i+1:n-1, i)
blasf77_zgemv( "Conj", &n_k_i_1, &i,
&c_one, A(k+i+1,0), &lda,
A(k+i+1,i), &ione,
&c_one, T(0,nb-1), &ione );
// w := T'*w = T(0:i-1, 0:i-1)' * w
blasf77_ztrmv( "Upper", "Conj", "Non-unit", &i,
T(0,0), &ldt,
T(0,nb-1), &ione );
// b2 := b2 - V2*w = A(k+i+1:n-1, i) - VA(k+i+1:n-1, 0:i-1) * w
blasf77_zgemv( "No trans", &n_k_i_1, &i,
&c_neg_one, A(k+i+1,0), &lda,
T(0,nb-1), &ione,
&c_one, A(k+i+1,i), &ione );
// w := V1*w = VA(k+1:k+i, 0:i-1) * w
blasf77_ztrmv( "Lower", "No trans", "Unit", &i,
A(k+1,0), &lda,
T(0,nb-1), &ione );
// b1 := b1 - w = A(k+1:k+i-1, i) - w
blasf77_zaxpy( &i,
&c_neg_one, T(0,nb-1), &ione,
A(k+1,i), &ione );
// Restore diagonal element, saved below during previous iteration
*A(k+i,i-1) = ei;
}
// Generate the elementary reflector H(i) to annihilate A(k+i+1:n-1,i)
lapackf77_zlarfg( &n_k_i_1,
A(k+i+1,i),
A(k+i+2,i), &ione, &tau[i] );
// Save diagonal element and set to one, to simplify multiplying by V
ei = *A(k+i+1,i);
*A(k+i+1,i) = c_one;
// compute yi = A vi = sum_g A{d} vi{d}
nblocks = (n-1) / nb / ngpu + 1;
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magmablasSetKernelStream( data->streams[d] );
// dV(k+i+1:n-1, i) = VA(k+i:n, i)
magma_zsetvector_async( n_k_i_1,
A(k+i+1,i), 1,
dV(d, k+i+1, i), 1, data->streams[d] );
// copy column of dV -> dVd, using block cyclic distribution.
// This assumes V and Vd have been padded so that
// a 2D matrix copy doesn't access them out-of-bounds
gblock = k / nb;
lblock = gblock / ngpu;
lgid = gblock % ngpu;
if ( d < lgid ) {
lblock += 1;
}
// treat V as (nb*ngpu) x nblock matrix, and Vd as nb x nblock matrix
magmablas_zlacpy( 'F', nb, nblocks-lblock,
dV (d, d*nb + lblock*nb*ngpu, i), nb*ngpu,
dVd(d, 0 + lblock*nb , i), nb );
// convert global indices (k) to local indices (dk)
magma_indices_1D_bcyclic( nb, ngpu, d, k+i+1, n, &dki1, &dn );
// dY(k:n, i) = dA(k:n, k+i+1:n) * dV(k+i+1:n, i)
// skip if matrix is empty
// each GPU copies to different temporary vector in Y,
// which are summed in separate loop below
if ( dn-dki1 > 0 ) {
magma_zgemv( 'N', n-k, dn-dki1,
c_one, dA (d, k , dki1), ldda,
dVd(d, dki1, i), 1,
c_zero, dY (d, k , i), 1 );
// copy vector to host, storing in column nb+d of Y
// as temporary space (Y has >= nb+ngpu columns)
magma_zgetvector_async( n-k,
dY(d, k, i), 1,
Y(k, nb+d), 1, data->streams[d] );
}
}
// while GPU is doing above Ag*v...
// Compute T(0:i,i) = [ -tau T V' vi ]
// [ tau ]
// T(0:i-1, i) = -tau VA(k+i+1:n-1, 0:i-1)' VA(k+i+1:n-1, i)
scale = MAGMA_Z_NEGATE( tau[i] );
blasf77_zgemv( "Conj", &n_k_i_1, &i,
&scale, A(k+i+1,0), &lda,
A(k+i+1,i), &ione,
&c_zero, T(0,i), &ione );
// T(0:i-1, i) = T(0:i-1, 0:i-1) * T(0:i-1, i)
blasf77_ztrmv( "Upper", "No trans", "Non-unit", &i,
T(0,0), &ldt,
T(0,i), &ione );
*T(i,i) = tau[i];
// apply reflectors to next column, A(i+1), on right only.
// one axpy will be required to finish this, in the next iteration above
if ( i > 0 && i+1 < nb ) {
// Update next column, A(k:n,i+1), applying Q on right.
// One axpy will be required to finish this, in the next iteration
// above, after yi is computed.
// This updates one more row than LAPACK does (row k),
// making block above panel an even multiple of nb.
// Use last column of T as workspace, w.
magma_int_t i1 = i+1;
// If complex, conjugate row of V, and undo afterwards
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv( &i1, A(k+i1,0), &lda );
#endif
// w = T(0:i, 0:i+1) * VA(k+i+1, 0:i+1)'
// T is now rectangular, so we use gemv instead of trmv as in lapack.
blasf77_zgemv( "No trans", &i, &i1,
&c_one, T(0,0), &ldt,
A(k+i1,0), &lda,
&c_zero, T(0,nb-1), &ione );
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv( &i1, A(k+i1,0), &lda );
#endif
// A(k:n, i+1) -= Y(k:n, 0:i) * w
blasf77_zgemv( "No trans", &n_k, &i,
&c_neg_one, Y(k,0), &ldy,
T(0,nb-1), &ione,
&c_one, A(k,i1), &ione );
}
// yi = sum_g yi{d}
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magma_queue_sync( data->streams[d] );
magma_indices_1D_bcyclic( nb, ngpu, d, k+i+1, n, &dki1, &dn );
if ( dn-dki1 > 0 ) {
// yi = yi + yi{d}
blasf77_zaxpy( &n_k, &c_one, Y(k,nb+d), &ione, Y(k,i), &ione );
}
}
}
// Restore diagonal element
*A(k+nb,nb-1) = ei;
// compute Y = Am V = sum_g Am{d} V{d} --- top part, Y(0:k-1,:)
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magmablasSetKernelStream( data->streams[d] );
// convert global indices (k) to local indices (dk)
magma_indices_1D_bcyclic( nb, ngpu, d, k+1, n, &dki1, &dn );
// dY(0:k, :) = dA(0:k, k+i+1:n-1) * dV(k+i+1:n-1, :)
// skip if matrix is empty
// each GPU copies to different temporary block in Y,
// which are summed in separate loop below
if ( dn-dki1 > 0 ) {
magma_zgemm( 'N', 'N', k, nb, dn-dki1,
c_one, dA (d, 0 , dki1), ldda,
dVd(d, dki1, 0), ldvd,
c_zero, dY (d, 0 , 0), ldda );
// copy result to host, storing in columns [nb + nb*d : nb + nb*(d+1)] of Y
// as temporary space (Y has nb + nb*ngpu columns)
magma_zgetmatrix_async( k, nb,
dY(d, 0, 0), ldda,
Y(0,nb+nb*d), ldy, data->streams[d] );
}
}
// Y = sum_g Y{d}
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magma_queue_sync( 0 );
magma_indices_1D_bcyclic( nb, ngpu, d, k+1, n, &dki1, &dn );
if ( dn-dki1 > 0 ) {
// Y = Y + Am V
for( i = 0; i < nb; ++i ) {
blasf77_zaxpy( &k, &c_one, Y(0,nb+nb*d+i), &ione, Y(0,i), &ione );
}
}
}
// copy Y and T matrices to GPUs
for( d = 0; d < ngpu; ++d ) {
magma_setdevice( d );
magma_zsetmatrix_async( n, nb, Y, ldy, dY(d, 0, 0), ldda, data->streams[d] );
magma_zsetmatrix_async( nb, nb, T, nb, dTi(d), nb, data->streams[d] );
}
return 0;
} // magma_zlahr2
/**
@deprecated
Purpose
-------
ZLAQPS computes a step of QR factorization with column pivoting
of a complex M-by-N matrix A by using Blas-3. It tries to factorize
NB columns from A starting from the row OFFSET+1, and updates all
of the matrix with Blas-3 xGEMM.
In some cases, due to catastrophic cancellations, it cannot
factorize NB columns. Hence, the actual number of factorized
columns is returned in KB.
Block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized.
Arguments
---------
@param[in]
m INTEGER
The number of rows of the matrix A. M >= 0.
@param[in]
n INTEGER
The number of columns of the matrix A. N >= 0
@param[in]
offset INTEGER
The number of rows of A that have been factorized in
previous steps.
@param[in]
nb INTEGER
The number of columns to factorize.
@param[out]
kb INTEGER
The number of columns actually factorized.
@param[in,out]
dA COMPLEX_16 array, dimension (LDDA,N), on the GPU.
On entry, the M-by-N matrix A.
On exit, block A(OFFSET+1:M,1:KB) is the triangular
factor obtained and block A(1:OFFSET,1:N) has been
accordingly pivoted, but no factorized.
The rest of the matrix, block A(OFFSET+1:M,KB+1:N) has
been updated.
@param[in]
ldda INTEGER
The leading dimension of the array A. LDDA >= max(1,M).
@param[in,out]
jpvt INTEGER array, dimension (N)
JPVT(I) = K <==> Column K of the full matrix A has been
permuted into position I in AP.
@param[out]
tau COMPLEX_16 array, dimension (KB)
The scalar factors of the elementary reflectors.
@param[in,out]
vn1 DOUBLE PRECISION array, dimension (N)
The vector with the partial column norms.
@param[in,out]
vn2 DOUBLE PRECISION array, dimension (N)
The vector with the exact column norms.
@param[in,out]
dauxv COMPLEX_16 array, dimension (NB), on the GPU
Auxiliary vector.
@param[in,out]
dF COMPLEX_16 array, dimension (LDDF,NB), on the GPU
Matrix F' = L*Y'*A.
@param[in]
lddf INTEGER
The leading dimension of the array F. LDDF >= max(1,N).
@ingroup magma_zgeqp3_aux
********************************************************************/
extern "C" magma_int_t
magma_zlaqps_gpu(
magma_int_t m, magma_int_t n, magma_int_t offset,
magma_int_t nb, magma_int_t *kb,
magmaDoubleComplex_ptr dA, magma_int_t ldda,
magma_int_t *jpvt, magmaDoubleComplex *tau,
double *vn1, double *vn2,
magmaDoubleComplex_ptr dauxv,
magmaDoubleComplex_ptr dF, magma_int_t lddf)
{
#define dA(i, j) (dA + (i) + (j)*(ldda))
#define dF(i, j) (dF + (i) + (j)*(lddf))
magmaDoubleComplex c_zero = MAGMA_Z_MAKE( 0.,0.);
magmaDoubleComplex c_one = MAGMA_Z_MAKE( 1.,0.);
magmaDoubleComplex c_neg_one = MAGMA_Z_MAKE(-1.,0.);
magma_int_t ione = 1;
magma_int_t i__1, i__2;
//double d__1;
magmaDoubleComplex z__1;
//magma_int_t j;
magma_int_t k, rk;
//magmaDoubleComplex Akk;
magmaDoubleComplex_ptr dAks;
magmaDoubleComplex tauk = MAGMA_Z_ZERO;
magma_int_t pvt;
//double temp, temp2;
double tol3z;
magma_int_t itemp;
double lsticc;
magmaDouble_ptr dlsticcs;
magma_dmalloc( &dlsticcs, 1+256*(n+255)/256 );
//lastrk = min( m, n + offset );
tol3z = magma_dsqrt( lapackf77_dlamch("Epsilon"));
lsticc = 0;
k = 0;
magma_zmalloc( &dAks, nb );
while( k < nb && lsticc == 0 ) {
rk = offset + k;
/* Determine ith pivot column and swap if necessary */
// subtract 1 from Fortran/CUBLAS idamax; pvt, k are 0-based.
pvt = k + magma_idamax( n-k, &vn1[k], ione ) - 1;
if (pvt != k) {
/*if (pvt >= nb) {
// 1. Start copy from GPU
magma_zgetmatrix_async( m - offset - nb, 1,
dA(offset + nb, pvt), ldda,
A (offset + nb, pvt), lda, stream );
}*/
/* F gets swapped so F must be sent at the end to GPU */
i__1 = k;
/*if (pvt < nb) {
// no need of transfer if pivot is within the panel
blasf77_zswap( &m, A(0, pvt), &ione, A(0, k), &ione );
}
else {
// 1. Finish copy from GPU
magma_queue_sync( stream );
// 2. Swap as usual on CPU
blasf77_zswap(&m, A(0, pvt), &ione, A(0, k), &ione);
// 3. Restore the GPU
magma_zsetmatrix_async( m - offset - nb, 1,
A (offset + nb, pvt), lda,
dA(offset + nb, pvt), ldda, stream);
}*/
magmablas_zswap( m, dA(0, pvt), ione, dA(0, k), ione );
//blasf77_zswap( &i__1, F(pvt,0), &ldf, F(k,0), &ldf );
magmablas_zswap( i__1, dF(pvt, 0), lddf, dF(k, 0), lddf);
itemp = jpvt[pvt];
jpvt[pvt] = jpvt[k];
jpvt[k] = itemp;
//vn1[pvt] = vn1[k];
//vn2[pvt] = vn2[k];
#if defined(PRECISION_d) || defined(PRECISION_z)
//magma_dswap( 1, &vn1[pvt], 1, &vn1[k], 1 );
//magma_dswap( 1, &vn2[pvt], 1, &vn2[k], 1 );
magma_dswap( 2, &vn1[pvt], n+offset, &vn1[k], n+offset );
#else
//magma_sswap( 1, &vn1[pvt], 1, &vn1[k], 1 );
//magma_sswap( 1, &vn2[pvt], 1, &vn2[k], 1 );
magma_sswap(2, &vn1[pvt], n+offset, &vn1[k], n+offset);
#endif
}
/* Apply previous Householder reflectors to column K:
A(RK:M,K) := A(RK:M,K) - A(RK:M,1:K-1)*F(K,1:K-1)'.
Optimization: multiply with beta=0; wait for vector and subtract */
if (k > 0) {
/*#if (defined(PRECISION_c) || defined(PRECISION_z))
for (j = 0; j < k; ++j) {
*F(k,j) = MAGMA_Z_CNJG( *F(k,j) );
}
#endif*/
//#define RIGHT_UPDATE
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, A(offset+nb, 0), lda,
F(k, 0), ldf,
c_one, A(offset+nb, k), ione );
#else
i__1 = m - rk;
i__2 = k;
/*blasf77_zgemv( MagmaNoTransStr, &i__1, &i__2,
&c_neg_one, A(rk, 0), &lda,
F(k, 0), &ldf,
&c_one, A(rk, k), &ione ); */
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, dA(rk, 0), ldda,
dF(k, 0), lddf,
c_one, dA(rk, k), ione );
#endif
/*#if (defined(PRECISION_c) || defined(PRECISION_z))
for (j = 0; j < k; ++j) {
*F(k,j) = MAGMA_Z_CNJG( *F(k,j) );
}
#endif*/
}
/* Generate elementary reflector H(k). */
magma_zlarfg_gpu( m-rk, dA(rk, k), dA(rk + 1, k), &tau[k], &vn1[k], &dAks[k]);
//Akk = *A(rk, k);
//*A(rk, k) = c_one;
//magma_zgetvector( 1, &dAks[k], 1, &Akk, 1 );
/* needed to avoid the race condition */
if (k == 0) magma_zsetvector( 1, &c_one, 1, dA(rk, k), 1 );
else magma_zcopymatrix( 1, 1, dA(offset, 0), 1, dA(rk, k), 1 );
/* Compute Kth column of F:
Compute F(K+1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) on the GPU */
if (k < n-1 || k > 0) magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
if (k < n-1) {
i__1 = m - rk;
i__2 = n - k - 1;
/* Send the vector to the GPU */
//magma_zsetmatrix( i__1, 1, A(rk, k), lda, dA(rk,k), ldda );
/* Multiply on GPU */
// was CALL ZGEMV( 'Conjugate transpose', M-RK+1, N-K,
// TAU( K ), A( RK, K+1 ), LDA,
// A( RK, K ), 1,
// CZERO, F( K+1, K ), 1 )
//magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
magma_zgemv( MagmaConjTrans, m-rk, n-k-1,
tauk, dA( rk, k+1 ), ldda,
dA( rk, k ), 1,
c_zero, dF( k+1, k ), 1 );
//magma_zscal( m-rk, tau[k], F( k+1, k), 1 );
//magma_int_t i__3 = nb-k-1;
//magma_int_t i__4 = i__2 - i__3;
//magma_int_t i__5 = nb-k;
//magma_zgemv( MagmaConjTrans, i__1 - i__5, i__2 - i__3,
// tau[k], dA(rk +i__5, k+1+i__3), ldda,
// dA(rk +i__5, k ), ione,
// c_zero, dF(k+1+i__3, k ), ione );
//magma_zgetmatrix_async( i__2-i__3, 1,
// dF(k + 1 +i__3, k), i__2,
// F (k + 1 +i__3, k), i__2, stream );
//blasf77_zgemv( MagmaConjTransStr, &i__1, &i__3,
// &tau[k], A(rk, k+1), &lda,
// A(rk, k ), &ione,
// &c_zero, F(k+1, k ), &ione );
//magma_queue_sync( stream );
//blasf77_zgemv( MagmaConjTransStr, &i__5, &i__4,
// &tau[k], A(rk, k+1+i__3), &lda,
// A(rk, k ), &ione,
// &c_one, F(k+1+i__3, k ), &ione );
}
/* Padding F(1:K,K) with zeros.
for (j = 0; j <= k; ++j) {
magma_zsetvector( 1, &c_zero, 1, F(j, k), 1 );
}*/
/* Incremental updating of F:
F(1:N,K) := F(1:N,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K).
F(1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K)
:= tau(K)(A(RK:M,K+1:N)' - F(1:N,1:K-1)*A(RK:M,1:K-1)') A(RK:M,K)
so, F is (updated A)*V */
//if (k > 0 && k < n-1) {
if (k > 0) {
//magma_zgetvector( 1, &tau[k], 1, &tauk, 1 );
z__1 = MAGMA_Z_NEGATE( tauk );
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, dA(offset+nb, 0), lda,
dA(offset+nb, k), ione,
c_zero, dauxv, ione );
i__1 = k;
magma_zgemv( MagmaNoTrans, n-k-1, i__1,
c_one, F(k+1,0), ldf,
dauxv, ione,
c_one, F(k+1,k), ione );
#else
i__1 = m - rk;
i__2 = k;
//blasf77_zgemv( MagmaConjTransStr, &i__1, &i__2,
// &z__1, A(rk, 0), &lda,
// A(rk, k), &ione,
// &c_zero, auxv, &ione );
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, dA(rk, 0), ldda,
dA(rk, k), ione,
c_zero, dauxv, ione );
//i__1 = k;
//blasf77_zgemv( MagmaNoTransStr, &n, &i__1,
// &c_one, F(0,0), &ldf,
// auxv, &ione,
// &c_one, F(0,k), &ione );
/*magma_zgemv( MagmaNoTrans, n, i__1,
c_one, F(0,0), ldf,
auxv, ione,
c_one, F(0,k), ione ); */
/* I think we only need stricly lower-triangular part :) */
magma_zgemv( MagmaNoTrans, n-k-1, i__2,
c_one, dF(k+1,0), lddf,
dauxv, ione,
c_one, dF(k+1,k), ione );
#endif
}
/* Optimization: On the last iteration start sending F back to the GPU */
/* Update the current row of A:
A(RK,K+1:N) := A(RK,K+1:N) - A(RK,1:K)*F(K+1:N,1:K)'. */
if (k < n-1) {
i__1 = n - k - 1;
i__2 = k + 1;
//blasf77_zgemm( MagmaNoTransStr, MagmaConjTransStr, &ione, &i__1, &i__2,
// &c_neg_one, A(rk, 0 ), &lda,
// F(k+1,0 ), &ldf,
// &c_one, A(rk, k+1), &lda );
#ifdef RIGHT_UPDATE
/* right-looking update of rows, */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, nb-k, i__1, ione,
c_neg_one, dA(rk, k ), ldda,
dF(k+1, k ), lddf,
c_one, dA(rk, k+1), ldda );
#else
/* left-looking update of rows, *
* since F=A'v with original A, so no right-looking */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, ione, i__1, i__2,
c_neg_one, dA(rk, 0 ), ldda,
dF(k+1,0 ), lddf,
c_one, dA(rk, k+1), ldda );
#endif
}
/* Update partial column norms. */
if (rk < min(m, n+offset)-1 ) {
magmablas_dznrm2_row_check_adjust(n-k-1, tol3z, &vn1[k+1], &vn2[k+1], dA(rk,k+1), ldda, dlsticcs);
magma_device_sync();
#if defined(PRECISION_d) || defined(PRECISION_z)
magma_dgetvector( 1, &dlsticcs[0], 1, &lsticc, 1 );
#else
magma_sgetvector( 1, &dlsticcs[0], 1, &lsticc, 1 );
#endif
}
/*if (rk < lastrk) {
for (j = k + 1; j < n; ++j) {
if (vn1[j] != 0.) {
// NOTE: The following 4 lines follow from the analysis in
// Lapack Working Note 176.
temp = MAGMA_Z_ABS( *A(rk,j) ) / vn1[j];
temp = max( 0., ((1. + temp) * (1. - temp)) );
d__1 = vn1[j] / vn2[j];
temp2 = temp * (d__1 * d__1);
if (temp2 <= tol3z) {
vn2[j] = (double) lsticc;
lsticc = j;
} else {
vn1[j] *= magma_dsqrt(temp);
}
}
}
}*/
//*A(rk, k) = Akk;
//magma_zsetvector( 1, &Akk, 1, A(rk, k), 1 );
//magma_zswap( 1, &dAks[k], 1, A(rk, k), 1 );
++k;
}
magma_zcopymatrix( 1, k, dAks, 1, dA(offset, 0), ldda+1 );
// leave k as the last column done
--k;
*kb = k + 1;
rk = offset + *kb - 1;
/* Apply the block reflector to the rest of the matrix:
A(OFFSET+KB+1:M,KB+1:N) := A(OFFSET+KB+1:M,KB+1:N) - A(OFFSET+KB+1:M,1:KB)*F(KB+1:N,1:KB)' */
if (*kb < min(n, m - offset)) {
i__1 = m - rk - 1;
i__2 = n - *kb;
/* Send F to the GPU
magma_zsetmatrix( i__2, *kb,
F (*kb, 0), ldf,
dF(*kb, 0), i__2 ); */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, i__1, i__2, *kb,
c_neg_one, dA(rk+1, 0 ), ldda,
dF(*kb, 0 ), lddf,
c_one, dA(rk+1, *kb), ldda );
}
/* Recomputation of difficult columns. */
if ( lsticc > 0 ) {
// printf( " -- recompute dnorms --\n" );
magmablas_dznrm2_check( m-rk-1, n-*kb, dA(rk+1,*kb), ldda,
&vn1[*kb], dlsticcs );
magma_dcopymatrix( n-*kb, 1, &vn1[*kb], *kb, &vn2[*kb], *kb );
/*while( lsticc > 0 ) {
itemp = (magma_int_t)(vn2[lsticc] >= 0. ? floor(vn2[lsticc] + .5) : -floor(.5 - vn2[lsticc]));
i__1 = m - rk - 1;
if (lsticc <= nb)
vn1[lsticc] = magma_cblas_dznrm2( i__1, A(rk+1,lsticc), ione );
else {
// Where is the data, CPU or GPU ?
double r1, r2;
r1 = magma_cblas_dznrm2( nb-k, A(rk+1,lsticc), ione );
r2 = magma_dznrm2(m-offset-nb, dA(offset + nb + 1, lsticc), ione);
vn1[lsticc] = magma_dsqrt(r1*r1+r2*r2);
}
// NOTE: The computation of VN1( LSTICC ) relies on the fact that
// SNRM2 does not fail on vectors with norm below the value of SQRT(DLAMCH('S'))
vn2[lsticc] = vn1[lsticc];
lsticc = itemp; */
}
magma_free(dAks);
magma_free(dlsticcs);
return MAGMA_SUCCESS;
} /* magma_zlaqps */
/**
@deprecated
Purpose
-------
ZLAQPS computes a step of QR factorization with column pivoting
of a complex M-by-N matrix A by using Blas-3. It tries to factorize
NB columns from A starting from the row OFFSET+1, and updates all
of the matrix with Blas-3 xGEMM.
In some cases, due to catastrophic cancellations, it cannot
factorize NB columns. Hence, the actual number of factorized
columns is returned in KB.
Block A(1:OFFSET,1:N) is accordingly pivoted, but not factorized.
Arguments
---------
@param[in]
m INTEGER
The number of rows of the matrix A. M >= 0.
@param[in]
n INTEGER
The number of columns of the matrix A. N >= 0
@param[in]
offset INTEGER
The number of rows of A that have been factorized in
previous steps.
@param[in]
nb INTEGER
The number of columns to factorize.
@param[out]
kb INTEGER
The number of columns actually factorized.
@param[in,out]
dA COMPLEX_16 array, dimension (LDDA,N), on the GPU.
On entry, the M-by-N matrix A.
On exit, block A(OFFSET+1:M,1:KB) is the triangular
factor obtained and block A(1:OFFSET,1:N) has been
accordingly pivoted, but no factorized.
The rest of the matrix, block A(OFFSET+1:M,KB+1:N) has
been updated.
@param[in]
ldda INTEGER
The leading dimension of the array A. LDDA >= max(1,M).
@param[in,out]
jpvt INTEGER array, dimension (N)
JPVT(I) = K <==> Column K of the full matrix A has been
permuted into position I in AP.
@param[out]
tau COMPLEX_16 array, dimension (KB)
The scalar factors of the elementary reflectors.
@param[in,out]
vn1 DOUBLE PRECISION array, dimension (N)
The vector with the partial column norms.
@param[in,out]
vn2 DOUBLE PRECISION array, dimension (N)
The vector with the exact column norms.
@param[in,out]
dauxv COMPLEX_16 array, dimension (NB), on the GPU
Auxiliary vector.
@param[in,out]
dF COMPLEX_16 array, dimension (LDDF,NB), on the GPU
Matrix F' = L*Y'*A.
@param[in]
lddf INTEGER
The leading dimension of the array F. LDDF >= max(1,N).
@ingroup magma_zgeqp3_aux
********************************************************************/
extern "C" magma_int_t
magma_zlaqps_gpu(
magma_int_t m, magma_int_t n, magma_int_t offset,
magma_int_t nb, magma_int_t *kb,
magmaDoubleComplex_ptr dA, magma_int_t ldda,
magma_int_t *jpvt, magmaDoubleComplex *tau,
double *vn1, double *vn2,
magmaDoubleComplex_ptr dauxv,
magmaDoubleComplex_ptr dF, magma_int_t lddf)
{
#define dA(i, j) (dA + (i) + (j)*(ldda))
#define dF(i, j) (dF + (i) + (j)*(lddf))
magmaDoubleComplex c_zero = MAGMA_Z_MAKE( 0.,0.);
magmaDoubleComplex c_one = MAGMA_Z_MAKE( 1.,0.);
magmaDoubleComplex c_neg_one = MAGMA_Z_MAKE(-1.,0.);
magma_int_t ione = 1;
magma_int_t i__1, i__2;
magmaDoubleComplex z__1;
magma_int_t k, rk;
magmaDoubleComplex_ptr dAks;
magmaDoubleComplex tauk = MAGMA_Z_ZERO;
magma_int_t pvt;
double tol3z;
magma_int_t itemp;
double lsticc;
magmaDouble_ptr dlsticcs;
magma_dmalloc( &dlsticcs, 1+256*(n+255)/256 );
tol3z = magma_dsqrt( lapackf77_dlamch("Epsilon"));
lsticc = 0;
k = 0;
magma_zmalloc( &dAks, nb );
magma_queue_t queue;
magma_device_t cdev;
magma_getdevice( &cdev );
magma_queue_create( cdev, &queue );
while( k < nb && lsticc == 0 ) {
rk = offset + k;
/* Determine ith pivot column and swap if necessary */
// subtract 1 from Fortran/CUBLAS idamax; pvt, k are 0-based.
pvt = k + magma_idamax( n-k, &vn1[k], ione, queue ) - 1;
if (pvt != k) {
/* F gets swapped so F must be sent at the end to GPU */
i__1 = k;
magmablas_zswap( m, dA(0, pvt), ione, dA(0, k), ione, queue );
magmablas_zswap( i__1, dF(pvt, 0), lddf, dF(k, 0), lddf, queue );
itemp = jpvt[pvt];
jpvt[pvt] = jpvt[k];
jpvt[k] = itemp;
magma_dswap( 2, &vn1[pvt], n+offset, &vn1[k], n+offset, queue );
}
/* Apply previous Householder reflectors to column K:
A(RK:M,K) := A(RK:M,K) - A(RK:M,1:K-1)*F(K,1:K-1)'.
Optimization: multiply with beta=0; wait for vector and subtract */
if (k > 0) {
//#define RIGHT_UPDATE
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, A(offset+nb, 0), lda,
F(k, 0), ldf,
c_one, A(offset+nb, k), ione, queue );
#else
i__1 = m - rk;
i__2 = k;
magma_zgemv( MagmaNoTrans, i__1, i__2,
c_neg_one, dA(rk, 0), ldda,
dF(k, 0), lddf,
c_one, dA(rk, k), ione, queue );
#endif
}
/* Generate elementary reflector H(k). */
magma_zlarfg_gpu( m-rk, dA(rk, k), dA(rk + 1, k), &tau[k], &vn1[k], &dAks[k], queue );
/* needed to avoid the race condition */
if (k == 0) magma_zsetvector( 1, &c_one, 1, dA(rk, k), 1, queue );
else magma_zcopymatrix( 1, 1, dA(offset, 0), 1, dA(rk, k), 1, queue );
/* Compute Kth column of F:
Compute F(K+1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) on the GPU */
if (k < n-1 || k > 0) magma_zgetvector( 1, &tau[k], 1, &tauk, 1, queue );
if (k < n-1) {
i__1 = m - rk;
i__2 = n - k - 1;
/* Multiply on GPU */
magma_zgemv( MagmaConjTrans, m-rk, n-k-1,
tauk, dA( rk, k+1 ), ldda,
dA( rk, k ), 1,
c_zero, dF( k+1, k ), 1, queue );
}
/* Incremental updating of F:
F(1:N,K) := F(1:N,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K).
F(1:N,K) := tau(K)*A(RK:M,K+1:N)'*A(RK:M,K) - tau(K)*F(1:N,1:K-1)*A(RK:M,1:K-1)'*A(RK:M,K)
:= tau(K)(A(RK:M,K+1:N)' - F(1:N,1:K-1)*A(RK:M,1:K-1)') A(RK:M,K)
so, F is (updated A)*V */
if (k > 0) {
z__1 = MAGMA_Z_NEGATE( tauk );
#ifdef RIGHT_UPDATE
i__1 = m - offset - nb;
i__2 = k;
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, dA(offset+nb, 0), lda,
dA(offset+nb, k), ione,
c_zero, dauxv, ione, queue );
i__1 = k;
magma_zgemv( MagmaNoTrans, n-k-1, i__1,
c_one, F(k+1,0), ldf,
dauxv, ione,
c_one, F(k+1,k), ione, queue );
#else
i__1 = m - rk;
i__2 = k;
magma_zgemv( MagmaConjTrans, i__1, i__2,
z__1, dA(rk, 0), ldda,
dA(rk, k), ione,
c_zero, dauxv, ione, queue );
/* I think we only need stricly lower-triangular part :) */
magma_zgemv( MagmaNoTrans, n-k-1, i__2,
c_one, dF(k+1,0), lddf,
dauxv, ione,
c_one, dF(k+1,k), ione, queue );
#endif
}
/* Optimization: On the last iteration start sending F back to the GPU */
/* Update the current row of A:
A(RK,K+1:N) := A(RK,K+1:N) - A(RK,1:K)*F(K+1:N,1:K)'. */
if (k < n-1) {
i__1 = n - k - 1;
i__2 = k + 1;
#ifdef RIGHT_UPDATE
/* right-looking update of rows, */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, nb-k, i__1, ione,
c_neg_one, dA(rk, k ), ldda,
dF(k+1, k ), lddf,
c_one, dA(rk, k+1), ldda, queue );
#else
/* left-looking update of rows, *
* since F=A'v with original A, so no right-looking */
magma_zgemm( MagmaNoTrans, MagmaConjTrans, ione, i__1, i__2,
c_neg_one, dA(rk, 0 ), ldda,
dF(k+1,0 ), lddf,
c_one, dA(rk, k+1), ldda, queue );
#endif
}
/* Update partial column norms. */
if (rk < min(m, n+offset)-1 ) {
magmablas_dznrm2_row_check_adjust( n-k-1, tol3z, &vn1[k+1], &vn2[k+1],
dA(rk,k+1), ldda, dlsticcs, queue );
//magma_device_sync();
magma_dgetvector( 1, &dlsticcs[0], 1, &lsticc, 1, queue );
}
++k;
}
magma_zcopymatrix( 1, k, dAks, 1, dA(offset, 0), ldda+1, queue );
// leave k as the last column done
--k;
*kb = k + 1;
rk = offset + *kb - 1;
/* Apply the block reflector to the rest of the matrix:
A(OFFSET+KB+1:M,KB+1:N) := A(OFFSET+KB+1:M,KB+1:N) - A(OFFSET+KB+1:M,1:KB)*F(KB+1:N,1:KB)' */
if (*kb < min(n, m - offset)) {
i__1 = m - rk - 1;
i__2 = n - *kb;
magma_zgemm( MagmaNoTrans, MagmaConjTrans, i__1, i__2, *kb,
c_neg_one, dA(rk+1, 0 ), ldda,
dF(*kb, 0 ), lddf,
c_one, dA(rk+1, *kb), ldda, queue );
}
/* Recomputation of difficult columns. */
if ( lsticc > 0 ) {
// printf( " -- recompute dnorms --\n" );
magmablas_dznrm2_check( m-rk-1, n-*kb, dA(rk+1,*kb), ldda,
&vn1[*kb], dlsticcs, queue );
magma_dcopymatrix( n-*kb, 1, &vn1[*kb], *kb, &vn2[*kb], *kb, queue );
}
magma_free( dAks );
magma_free( dlsticcs );
magma_queue_destroy( queue );
return MAGMA_SUCCESS;
} /* magma_zlaqps */
extern "C" magma_int_t
magma_zlahr2(magma_int_t n, magma_int_t k, magma_int_t nb,
cuDoubleComplex *da, cuDoubleComplex *dv,
cuDoubleComplex *a, magma_int_t lda,
cuDoubleComplex *tau, cuDoubleComplex *t, magma_int_t ldt,
cuDoubleComplex *y, magma_int_t ldy)
{
/* -- MAGMA auxiliary routine (version 1.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
November 2012
Purpose
=======
ZLAHR2 reduces the first NB columns of a complex general n-BY-(n-k+1)
matrix A so that elements below the k-th subdiagonal are zero. The
reduction is performed by an orthogonal similarity transformation
Q' * A * Q. The routine returns the matrices V and T which determine
Q as a block reflector I - V*T*V', and also the matrix Y = A * V.
This is an auxiliary routine called by ZGEHRD.
Arguments
=========
N (input) INTEGER
The order of the matrix A.
K (input) INTEGER
The offset for the reduction. Elements below the k-th
subdiagonal in the first NB columns are reduced to zero.
K < N.
NB (input) INTEGER
The number of columns to be reduced.
DA (input/output) COMPLEX_16 array on the GPU, dimension (LDA,N-K+1)
On entry, the n-by-(n-k+1) general matrix A.
On exit, the elements on and above the k-th subdiagonal in
the first NB columns are overwritten with the corresponding
elements of the reduced matrix; the elements below the k-th
subdiagonal, with the array TAU, represent the matrix Q as a
product of elementary reflectors. The other columns of A are
unchanged. See Further Details.
DV (output) COMPLEX_16 array on the GPU, dimension (N, NB)
On exit this contains the Householder vectors of the transformation.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
TAU (output) COMPLEX_16 array, dimension (NB)
The scalar factors of the elementary reflectors. See Further
Details.
T (output) COMPLEX_16 array, dimension (LDT,NB)
The upper triangular matrix T.
LDT (input) INTEGER
The leading dimension of the array T. LDT >= NB.
Y (output) COMPLEX_16 array, dimension (LDY,NB)
The n-by-nb matrix Y.
LDY (input) INTEGER
The leading dimension of the array Y. LDY >= N.
Further Details
===============
The matrix Q is represented as a product of nb elementary reflectors
Q = H(1) H(2) . . . H(nb).
Each H(i) has the form
H(i) = I - tau * v * v'
where tau is a complex scalar, and v is a complex vector with
v(1:i+k-1) = 0, v(i+k) = 1; v(i+k+1:n) is stored on exit in
A(i+k+1:n,i), and tau in TAU(i).
The elements of the vectors v together form the (n-k+1)-by-nb matrix
V which is needed, with T and Y, to apply the transformation to the
unreduced part of the matrix, using an update of the form:
A := (I - V*T*V') * (A - Y*T*V').
The contents of A on exit are illustrated by the following example
with n = 7, k = 3 and nb = 2:
( a a a a a )
( a a a a a )
( a a a a a )
( h h a a a )
( v1 h a a a )
( v1 v2 a a a )
( v1 v2 a a a )
where a denotes an element of the original matrix A, h denotes a
modified element of the upper Hessenberg matrix H, and vi denotes an
element of the vector defining H(i).
This implementation follows the hybrid algorithm and notations described in
S. Tomov and J. Dongarra, "Accelerating the reduction to upper Hessenberg
form through hybrid GPU-based computing," University of Tennessee Computer
Science Technical Report, UT-CS-09-642 (also LAPACK Working Note 219),
May 24, 2009.
===================================================================== */
cuDoubleComplex c_zero = MAGMA_Z_ZERO;
cuDoubleComplex c_one = MAGMA_Z_ONE;
cuDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magma_int_t ldda = lda;
magma_int_t c__1 = 1;
magma_int_t a_dim1, a_offset, t_dim1, t_offset, y_dim1, y_offset, i__2, i__3;
cuDoubleComplex d__1;
magma_int_t i__;
cuDoubleComplex ei;
--tau;
a_dim1 = lda;
a_offset = 1 + a_dim1;
a -= a_offset;
t_dim1 = ldt;
t_offset = 1 + t_dim1;
t -= t_offset;
y_dim1 = ldy;
y_offset = 1 + y_dim1;
y -= y_offset;
/* Function Body */
if (n <= 1)
return 0;
for (i__ = 1; i__ <= nb; ++i__) {
if (i__ > 1) {
/* Update A(K+1:N,I); Update I-th column of A - Y * V' */
i__2 = n - k + 1;
i__3 = i__ - 1;
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i__3, &a[k+i__-1+a_dim1], &lda);
#endif
blasf77_zcopy(&i__3, &a[k+i__-1+a_dim1], &lda, &t[nb*t_dim1+1], &c__1);
blasf77_ztrmv("u","n","n",&i__3,&t[t_offset], &ldt, &t[nb*t_dim1+1], &c__1);
blasf77_zgemv("NO TRANSPOSE", &i__2, &i__3, &c_neg_one, &y[k + y_dim1],
&ldy, &t[nb*t_dim1+1], &c__1, &c_one, &a[k+i__*a_dim1],&c__1);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i__3, &a[k+i__-1+a_dim1], &lda);
#endif
/* Apply I - V * T' * V' to this column (call it b) from the
left, using the last column of T as workspace
Let V = ( V1 ) and b = ( b1 ) (first I-1 rows)
( V2 ) ( b2 )
where V1 is unit lower triangular
w := V1' * b1 */
i__2 = i__ - 1;
blasf77_zcopy(&i__2, &a[k+1+i__*a_dim1], &c__1, &t[nb*t_dim1+1], &c__1);
blasf77_ztrmv("Lower", MagmaConjTransStr, "UNIT", &i__2,
&a[k + 1 + a_dim1], &lda, &t[nb * t_dim1 + 1], &c__1);
/* w := w + V2'*b2 */
i__2 = n - k - i__ + 1;
i__3 = i__ - 1;
blasf77_zgemv(MagmaConjTransStr, &i__2, &i__3, &c_one,
&a[k + i__ + a_dim1], &lda, &a[k+i__+i__*a_dim1], &c__1,
&c_one, &t[nb*t_dim1+1], &c__1);
/* w := T'*w */
i__2 = i__ - 1;
blasf77_ztrmv("U", MagmaConjTransStr, "N", &i__2, &t[t_offset], &ldt,
&t[nb*t_dim1+1], &c__1);
/* b2 := b2 - V2*w */
i__2 = n - k - i__ + 1;
i__3 = i__ - 1;
blasf77_zgemv("N", &i__2, &i__3, &c_neg_one, &a[k + i__ + a_dim1], &lda,
&t[nb*t_dim1+1], &c__1, &c_one, &a[k+i__+i__*a_dim1], &c__1);
/* b1 := b1 - V1*w */
i__2 = i__ - 1;
blasf77_ztrmv("L","N","U",&i__2,&a[k+1+a_dim1],&lda,&t[nb*t_dim1+1],&c__1);
blasf77_zaxpy(&i__2, &c_neg_one, &t[nb * t_dim1 + 1], &c__1,
&a[k + 1 + i__ * a_dim1], &c__1);
a[k + i__ - 1 + (i__ - 1) * a_dim1] = ei;
}
/* Generate the elementary reflector H(I) to annihilate A(K+I+1:N,I) */
i__2 = n - k - i__ + 1;
i__3 = k + i__ + 1;
lapackf77_zlarfg(&i__2, &a[k + i__ + i__ * a_dim1],
&a[min(i__3,n) + i__ * a_dim1], &c__1, &tau[i__]);
ei = a[k + i__ + i__ * a_dim1];
a[k + i__ + i__ * a_dim1] = c_one;
/* Compute Y(K+1:N,I) */
i__2 = n - k;
i__3 = n - k - i__ + 1;
magma_zsetvector( i__3,
&a[k + i__ + i__*a_dim1], 1,
dv+(i__-1)*(ldda+1), 1 );
magma_zgemv(MagmaNoTrans, i__2+1, i__3, c_one,
da -1 + k + i__ * ldda, ldda,
dv+(i__-1)*(ldda+1), c__1, c_zero,
da-1 + k + (i__-1)*ldda, c__1);
i__2 = n - k - i__ + 1;
i__3 = i__ - 1;
blasf77_zgemv(MagmaConjTransStr, &i__2, &i__3, &c_one,
&a[k + i__ + a_dim1], &lda, &a[k+i__+i__*a_dim1], &c__1,
&c_zero, &t[i__*t_dim1+1], &c__1);
/* Compute T(1:I,I) */
i__2 = i__ - 1;
d__1 = MAGMA_Z_NEGATE( tau[i__] );
blasf77_zscal(&i__2, &d__1, &t[i__ * t_dim1 + 1], &c__1);
blasf77_ztrmv("U","N","N", &i__2, &t[t_offset], &ldt, &t[i__*t_dim1+1], &c__1);
t[i__ + i__ * t_dim1] = tau[i__];
magma_zgetvector( n - k + 1,
da-1+ k+(i__-1)*ldda, 1,
y+ k + i__*y_dim1, 1 );
}
a[k + nb + nb * a_dim1] = ei;
return 0;
} /* magma_zlahr2 */
