inline static void
magma_zlarfxsym_v2(magma_int_t n,
magmaDoubleComplex *A, magma_int_t lda,
magmaDoubleComplex *V, magmaDoubleComplex *TAU,
magmaDoubleComplex *work)
{
/*
WORK (workspace) double complex array, dimension N
*/
magma_int_t ione = 1;
magmaDoubleComplex dtmp;
magmaDoubleComplex c_zero = MAGMA_Z_ZERO;
magmaDoubleComplex c_neg_one= MAGMA_Z_NEG_ONE;
magmaDoubleComplex c_half = MAGMA_Z_HALF;
/* X = AVtau */
blasf77_zhemv("L",&n, TAU, A, &lda, V, &ione, &c_zero, work, &ione);
/* compute dtmp= X'*V */
#if defined(PRECISION_z) || defined(PRECISION_c)
dtmp = c_zero;
for (magma_int_t j = 0; j < n ; j++)
dtmp = dtmp + MAGMA_Z_CNJG(work[j]) * V[j];
//cblas_zdotc_sub(n, work, ione, V, ione, &dtmp);
#else
dtmp = cblas_zdotc(n, work, ione, V, ione);
#endif
/* compute 1/2 X'*V*t = 1/2*dtmp*tau */
dtmp = -dtmp * c_half * (*TAU);
/* compute W=X-1/2VX'Vt = X - dtmp*V */
blasf77_zaxpy(&n, &dtmp, V, &ione, work, &ione);
/* performs the symmetric rank 2 operation A := alpha*x*y' + alpha*y*x' + A */
blasf77_zher2("L", &n, &c_neg_one, work, &ione, V, &ione, A, &lda);
}
extern "C" void
magma_zlarfxsym(magma_int_t N, magmaDoubleComplex *A, magma_int_t LDA, magmaDoubleComplex *V, magmaDoubleComplex *TAU) {
magma_int_t IONE=1;
magmaDoubleComplex dtmp;
magmaDoubleComplex Z_ZERO = MAGMA_Z_ZERO;
//magmaDoubleComplex Z_ONE = MAGMA_Z_ONE;
magmaDoubleComplex Z_MONE = MAGMA_Z_NEG_ONE;
magmaDoubleComplex Z_HALF = MAGMA_Z_HALF;
//magmaDoubleComplex WORK[N];
magmaDoubleComplex *WORK = (magmaDoubleComplex *) malloc( N * sizeof(magmaDoubleComplex) );
/* apply left and right on A(st:ed,st:ed)*/
//magma_zlarfxsym(len,A(st,st),LDX,V(st),TAU(st));
/* X = AVtau */
blasf77_zhemv("L",&N, TAU, A, &LDA, V, &IONE, &Z_ZERO, WORK, &IONE);
/* je calcul dtmp= X'*V */
#if defined(PRECISION_z) || defined(PRECISION_c)
dtmp = Z_ZERO;
for (magma_int_t j = 0; j < N ; j++)
dtmp = dtmp + MAGMA_Z_CNJG(WORK[j]) * V[j];
//cblas_zdotc_sub(N, WORK, IONE, V, IONE, &dtmp);
#else
dtmp = cblas_zdotc(N, WORK, IONE, V, IONE);
#endif
/* je calcul 1/2 X'*V*t = 1/2*dtmp*tau */
dtmp = -dtmp * Z_HALF * (*TAU);
/* je calcul W=X-1/2VX'Vt = X - dtmp*V */
/*
for (j = 0; j < N ; j++)
WORK[j] = WORK[j] + (dtmp*V[j]); */
blasf77_zaxpy(&N, &dtmp, V, &IONE, WORK, &IONE);
/* performs the symmetric rank 2 operation A := alpha*x*y' + alpha*y*x' + A */
blasf77_zher2("L",&N,&Z_MONE,WORK,&IONE,V,&IONE,A,&LDA);
magma_free_cpu(WORK);
}
// ----------------------------------------
int main( int argc, char** argv )
{
TESTING_INIT();
//real_Double_t t_m, t_c, t_f;
magma_int_t ione = 1;
magmaDoubleComplex *A, *B;
double diff, error;
magma_int_t ISEED[4] = {0,0,0,1};
magma_int_t m, n, k, size, maxn, ld;
magmaDoubleComplex x2_m, x2_c; // complex x for magma, cblas/fortran blas respectively
double x_m, x_c; // x for magma, cblas/fortran blas respectively
magma_opts opts;
parse_opts( argc, argv, &opts );
opts.tolerance = max( 100., opts.tolerance );
double tol = opts.tolerance * lapackf77_dlamch("E");
gTol = tol;
printf( "!! Calling these CBLAS and Fortran BLAS sometimes crashes (segfault), which !!\n"
"!! is why we use wrappers. It does not necesarily indicate a bug in MAGMA. !!\n"
"\n"
"Diff compares MAGMA wrapper to CBLAS and BLAS function; should be exactly 0.\n"
"Error compares MAGMA implementation to CBLAS and BLAS function; should be ~ machine epsilon.\n"
"\n" );
double total_diff = 0.;
double total_error = 0.;
int inc[] = { 1 }; //{ -2, -1, 1, 2 }; //{ 1 }; //{ -1, 1 };
int ninc = sizeof(inc)/sizeof(*inc);
for( int itest = 0; itest < opts.ntest; ++itest ) {
m = opts.msize[itest];
n = opts.nsize[itest];
k = opts.ksize[itest];
for( int iincx = 0; iincx < ninc; ++iincx ) {
magma_int_t incx = inc[iincx];
for( int iincy = 0; iincy < ninc; ++iincy ) {
magma_int_t incy = inc[iincy];
printf("=========================================================================\n");
printf( "m=%d, n=%d, k=%d, incx = %d, incy = %d\n",
(int) m, (int) n, (int) k, (int) incx, (int) incy );
printf( "Function MAGMA CBLAS BLAS Diff Error\n"
" msec msec msec\n" );
// allocate matrices
// over-allocate so they can be any combination of
// {m,n,k} * {abs(incx), abs(incy)} by
// {m,n,k} * {abs(incx), abs(incy)}
maxn = max( max( m, n ), k ) * max( abs(incx), abs(incy) );
ld = max( 1, maxn );
size = ld*maxn;
magma_zmalloc_pinned( &A, size ); assert( A != NULL );
magma_zmalloc_pinned( &B, size ); assert( B != NULL );
// initialize matrices
lapackf77_zlarnv( &ione, ISEED, &size, A );
lapackf77_zlarnv( &ione, ISEED, &size, B );
printf( "Level 1 BLAS ----------------------------------------------------------\n" );
// ----- test DZASUM
// get one-norm of column j of A
if ( incx > 0 && incx == incy ) { // positive, no incy
diff = 0;
error = 0;
for( int j = 0; j < k; ++j ) {
x_m = magma_cblas_dzasum( m, A(0,j), incx );
x_c = cblas_dzasum( m, A(0,j), incx );
diff += fabs( x_m - x_c );
x_c = blasf77_dzasum( &m, A(0,j), &incx );
error += fabs( (x_m - x_c) / (m*x_c) );
}
output( "dzasum", diff, error );
total_diff += diff;
total_error += error;
}
// ----- test DZNRM2
// get two-norm of column j of A
if ( incx > 0 && incx == incy ) { // positive, no incy
diff = 0;
error = 0;
for( int j = 0; j < k; ++j ) {
x_m = magma_cblas_dznrm2( m, A(0,j), incx );
x_c = cblas_dznrm2( m, A(0,j), incx );
diff += fabs( x_m - x_c );
x_c = blasf77_dznrm2( &m, A(0,j), &incx );
error += fabs( (x_m - x_c) / (m*x_c) );
}
output( "dznrm2", diff, error );
total_diff += diff;
total_error += error;
}
// ----- test ZDOTC
// dot columns, Aj^H Bj
diff = 0;
error = 0;
for( int j = 0; j < k; ++j ) {
// MAGMA implementation, not just wrapper
x2_m = magma_cblas_zdotc( m, A(0,j), incx, B(0,j), incy );
// crashes on MKL 11.1.2, ILP64
#if ! defined( MAGMA_WITH_MKL )
#ifdef COMPLEX
cblas_zdotc_sub( m, A(0,j), incx, B(0,j), incy, &x2_c );
#else
x2_c = cblas_zdotc( m, A(0,j), incx, B(0,j), incy );
#endif
error += fabs( x2_m - x2_c ) / fabs( m*x2_c );
#endif
// crashes on MacOS 10.9
#if ! defined( __APPLE__ )
x2_c = blasf77_zdotc( &m, A(0,j), &incx, B(0,j), &incy );
error += fabs( x2_m - x2_c ) / fabs( m*x2_c );
#endif
}
output( "zdotc", diff, error );
total_diff += diff;
total_error += error;
total_error += error;
// ----- test ZDOTU
// dot columns, Aj^T * Bj
diff = 0;
error = 0;
for( int j = 0; j < k; ++j ) {
// MAGMA implementation, not just wrapper
x2_m = magma_cblas_zdotu( m, A(0,j), incx, B(0,j), incy );
// crashes on MKL 11.1.2, ILP64
#if ! defined( MAGMA_WITH_MKL )
#ifdef COMPLEX
cblas_zdotu_sub( m, A(0,j), incx, B(0,j), incy, &x2_c );
#else
x2_c = cblas_zdotu( m, A(0,j), incx, B(0,j), incy );
#endif
error += fabs( x2_m - x2_c ) / fabs( m*x2_c );
#endif
// crashes on MacOS 10.9
#if ! defined( __APPLE__ )
x2_c = blasf77_zdotu( &m, A(0,j), &incx, B(0,j), &incy );
error += fabs( x2_m - x2_c ) / fabs( m*x2_c );
#endif
}
output( "zdotu", diff, error );
total_diff += diff;
total_error += error;
// tell user about disabled functions
#if defined( MAGMA_WITH_MKL )
printf( "cblas_zdotc and cblas_zdotu disabled with MKL (segfaults)\n" );
#endif
#if defined( __APPLE__ )
printf( "blasf77_zdotc and blasf77_zdotu disabled on MacOS (segfaults)\n" );
#endif
// cleanup
magma_free_pinned( A );
magma_free_pinned( B );
fflush( stdout );
}}} // itest, incx, incy
// TODO use average error?
printf( "sum diffs = %8.2g, MAGMA wrapper compared to CBLAS and Fortran BLAS; should be exactly 0.\n"
"sum errors = %8.2e, MAGMA implementation compared to CBLAS and Fortran BLAS; should be ~ machine epsilon.\n\n",
total_diff, total_error );
if ( total_diff != 0. ) {
printf( "some tests failed diff == 0.; see above.\n" );
}
else {
printf( "all tests passed diff == 0.\n" );
}
TESTING_FINALIZE();
int status = (total_diff != 0.);
return status;
}
// ----------------------------------------
int main( int argc, char** argv )
{
TESTING_INIT();
//real_Double_t t_m, t_c, t_f;
magma_int_t ione = 1;
magmaDoubleComplex *A, *B;
double error_cblas, error_fblas, error_inline;
magma_int_t ISEED[4] = {0,0,0,1};
magma_int_t i, j, k, m, n, size, maxn, ld;
// complex x for magma, cblas, fortran, inline blas respectively
magmaDoubleComplex x2_m, x2_c, x2_f, x2_i;
// real x for magma, cblas, fortran, inline blas respectively
double x_m, x_c, x_f, x_i;
MAGMA_UNUSED( x_c );
MAGMA_UNUSED( x_f );
MAGMA_UNUSED( x2_c );
MAGMA_UNUSED( x2_f );
MAGMA_UNUSED( x2_m );
magma_opts opts;
opts.parse_opts( argc, argv );
opts.tolerance = max( 100., opts.tolerance );
double tol = opts.tolerance * lapackf77_dlamch("E");
gTol = tol;
magma_int_t inc[] = { -2, -1, 1, 2 }; //{ 1 }; //{ -1, 1 };
magma_int_t ninc = sizeof(inc)/sizeof(*inc);
magma_int_t maxinc = 0;
for( i=0; i < ninc; ++i ) {
maxinc = max( maxinc, abs(inc[i]) );
}
printf( "!! Calling these CBLAS and Fortran BLAS sometimes crashes (segfaults), which !!\n"
"!! is why we use wrappers. It does not necesarily indicate a bug in MAGMA. !!\n"
"!! If MAGMA_WITH_MKL or __APPLE__ are defined, known failures are skipped. !!\n"
"\n" );
// tell user about disabled functions
#ifndef HAVE_CBLAS
printf( "n/a: HAVE_CBLAS not defined, so no cblas functions tested.\n\n" );
#endif
#if defined(MAGMA_WITH_MKL)
printf( "n/a: cblas_zdotc, cblas_zdotu, blasf77_zdotc, and blasf77_zdotu are disabled with MKL, due to segfaults.\n\n" );
#endif
#if defined(__APPLE__)
printf( "n/a: blasf77_zdotc and blasf77_zdotu are disabled on MacOS, due to segfaults.\n\n" );
#endif
printf( "%% Error w.r.t. Error w.r.t. Error w.r.t.\n"
"%% M N K incx incy Function CBLAS Fortran BLAS inline\n"
"%%====================================================================================\n" );
for( int itest = 0; itest < opts.ntest; ++itest ) {
if ( itest > 0 ) {
printf( "%%----------------------------------------------------------------------\n" );
}
m = opts.msize[itest];
n = opts.nsize[itest];
k = opts.ksize[itest];
// allocate matrices
// over-allocate so they can be any combination of
// {m,n,k} * {abs(incx), abs(incy)} by
// {m,n,k} * {abs(incx), abs(incy)}
maxn = max( max( m, n ), k ) * maxinc;
ld = max( 1, maxn );
size = ld*maxn;
TESTING_MALLOC_CPU( A, magmaDoubleComplex, size );
TESTING_MALLOC_CPU( B, magmaDoubleComplex, size );
// initialize matrices
lapackf77_zlarnv( &ione, ISEED, &size, A );
lapackf77_zlarnv( &ione, ISEED, &size, B );
// ----- test DZASUM
for( int iincx = 0; iincx < ninc; ++iincx ) {
magma_int_t incx = inc[iincx];
for( int iincy = 0; iincy < ninc; ++iincy ) {
magma_int_t incy = inc[iincy];
// get one-norm of column j of A
if ( incx > 0 && incx == incy ) { // positive, no incy
error_cblas = 0;
error_fblas = 0;
error_inline = 0;
for( j=0; j < k; ++j ) {
x_m = magma_cblas_dzasum( m, A(0,j), incx );
#ifdef HAVE_CBLAS
x_c = cblas_dzasum( m, A(0,j), incx );
error_cblas = max( error_cblas, fabs(x_m - x_c) / fabs(m*x_c) );
#else
x_c = 0;
error_cblas = SKIPPED_FLAG;
#endif
x_f = blasf77_dzasum( &m, A(0,j), &incx );
error_fblas = max( error_fblas, fabs(x_m - x_f) / fabs(m*x_f) );
// inline implementation
x_i = 0;
for( i=0; i < m; ++i ) {
x_i += MAGMA_Z_ABS1( *A(i*incx,j) ); // |real(Aij)| + |imag(Aij)|
}
error_inline = max( error_inline, fabs(x_m - x_i) / fabs(m*x_i) );
//printf( "dzasum xm %.8e, xc %.8e, xf %.8e, xi %.8e\n", x_m, x_c, x_f, x_i );
}
output( "dzasum", m, n, k, incx, incy, error_cblas, error_fblas, error_inline );
}
}
}
printf( "\n" );
// ----- test DZNRM2
// get two-norm of column j of A
for( int iincx = 0; iincx < ninc; ++iincx ) {
magma_int_t incx = inc[iincx];
for( int iincy = 0; iincy < ninc; ++iincy ) {
magma_int_t incy = inc[iincy];
if ( incx > 0 && incx == incy ) { // positive, no incy
error_cblas = 0;
error_fblas = 0;
error_inline = 0;
for( j=0; j < k; ++j ) {
x_m = magma_cblas_dznrm2( m, A(0,j), incx );
#ifdef HAVE_CBLAS
x_c = cblas_dznrm2( m, A(0,j), incx );
error_cblas = max( error_cblas, fabs(x_m - x_c) / fabs(m*x_c) );
#else
x_c = 0;
error_cblas = SKIPPED_FLAG;
#endif
x_f = blasf77_dznrm2( &m, A(0,j), &incx );
error_fblas = max( error_fblas, fabs(x_m - x_f) / fabs(m*x_f) );
// inline implementation (poor -- doesn't scale)
x_i = 0;
for( i=0; i < m; ++i ) {
x_i += real( *A(i*incx,j) ) * real( *A(i*incx,j) )
+ imag( *A(i*incx,j) ) * imag( *A(i*incx,j) );
// same: real( conj( *A(i*incx,j) ) * *A(i*incx,j) );
}
x_i = sqrt( x_i );
error_inline = max( error_inline, fabs(x_m - x_i) / fabs(m*x_i) );
//printf( "dznrm2 xm %.8e, xc %.8e, xf %.8e, xi %.8e\n", x_m, x_c, x_f, x_i );
}
output( "dznrm2", m, n, k, incx, incy, error_cblas, error_fblas, error_inline );
}
}
}
printf( "\n" );
// ----- test ZDOTC
// dot columns, Aj^H Bj
for( int iincx = 0; iincx < ninc; ++iincx ) {
magma_int_t incx = inc[iincx];
for( int iincy = 0; iincy < ninc; ++iincy ) {
magma_int_t incy = inc[iincy];
error_cblas = 0;
error_fblas = 0;
error_inline = 0;
for( j=0; j < k; ++j ) {
// MAGMA implementation, not just wrapper
x2_m = magma_cblas_zdotc( m, A(0,j), incx, B(0,j), incy );
// crashes with MKL 11.1.2, ILP64
#if defined(HAVE_CBLAS) && ! defined(MAGMA_WITH_MKL)
#ifdef COMPLEX
cblas_zdotc_sub( m, A(0,j), incx, B(0,j), incy, &x2_c );
#else
x2_c = cblas_zdotc( m, A(0,j), incx, B(0,j), incy );
#endif
error_cblas = max( error_cblas, fabs(x2_m - x2_c) / fabs(m*x2_c) );
#else
x2_c = MAGMA_Z_ZERO;
error_cblas = SKIPPED_FLAG;
#endif
// crashes with MKL 11.2.3 and MacOS 10.9
#if (! defined(COMPLEX) || ! defined(MAGMA_WITH_MKL)) && ! defined(__APPLE__)
x2_f = blasf77_zdotc( &m, A(0,j), &incx, B(0,j), &incy );
error_fblas = max( error_fblas, fabs(x2_m - x2_f) / fabs(m*x2_f) );
#else
x2_f = MAGMA_Z_ZERO;
error_fblas = SKIPPED_FLAG;
#endif
// inline implementation
x2_i = MAGMA_Z_ZERO;
magma_int_t A_offset = (incx > 0 ? 0 : (-n + 1)*incx);
magma_int_t B_offset = (incy > 0 ? 0 : (-n + 1)*incy);
for( i=0; i < m; ++i ) {
x2_i += conj( *A(A_offset + i*incx,j) ) * *B(B_offset + i*incy,j);
}
error_inline = max( error_inline, fabs(x2_m - x2_i) / fabs(m*x2_i) );
//printf( "zdotc xm %.8e + %.8ei, xc %.8e + %.8ei, xf %.8e + %.8ei, xi %.8e + %.8ei\n",
// real(x2_m), imag(x2_m),
// real(x2_c), imag(x2_c),
// real(x2_f), imag(x2_f),
// real(x2_i), imag(x2_i) );
}
output( "zdotc", m, n, k, incx, incy, error_cblas, error_fblas, error_inline );
}
}
printf( "\n" );
// ----- test ZDOTU
// dot columns, Aj^T * Bj
for( int iincx = 0; iincx < ninc; ++iincx ) {
magma_int_t incx = inc[iincx];
for( int iincy = 0; iincy < ninc; ++iincy ) {
magma_int_t incy = inc[iincy];
error_cblas = 0;
error_fblas = 0;
error_inline = 0;
for( j=0; j < k; ++j ) {
// MAGMA implementation, not just wrapper
x2_m = magma_cblas_zdotu( m, A(0,j), incx, B(0,j), incy );
// crashes with MKL 11.1.2, ILP64
#if defined(HAVE_CBLAS) && ! defined(MAGMA_WITH_MKL)
#ifdef COMPLEX
cblas_zdotu_sub( m, A(0,j), incx, B(0,j), incy, &x2_c );
#else
x2_c = cblas_zdotu( m, A(0,j), incx, B(0,j), incy );
#endif
error_cblas = max( error_cblas, fabs(x2_m - x2_c) / fabs(m*x2_c) );
#else
x2_c = MAGMA_Z_ZERO;
error_cblas = SKIPPED_FLAG;
#endif
// crashes with MKL 11.2.3 and MacOS 10.9
#if (! defined(COMPLEX) || ! defined(MAGMA_WITH_MKL)) && ! defined(__APPLE__)
x2_f = blasf77_zdotu( &m, A(0,j), &incx, B(0,j), &incy );
error_fblas = max( error_fblas, fabs(x2_m - x2_f) / fabs(m*x2_f) );
#else
x2_f = MAGMA_Z_ZERO;
error_fblas = SKIPPED_FLAG;
#endif
// inline implementation
x2_i = MAGMA_Z_ZERO;
magma_int_t A_offset = (incx > 0 ? 0 : (-n + 1)*incx);
magma_int_t B_offset = (incy > 0 ? 0 : (-n + 1)*incy);
for( i=0; i < m; ++i ) {
x2_i += *A(A_offset + i*incx,j) * *B(B_offset + i*incy,j);
}
error_inline = max( error_inline, fabs(x2_m - x2_i) / fabs(m*x2_i) );
//printf( "zdotu xm %.8e + %.8ei, xc %.8e + %.8ei, xf %.8e + %.8ei, xi %.8e + %.8ei\n",
// real(x2_m), imag(x2_m),
// real(x2_c), imag(x2_c),
// real(x2_f), imag(x2_f),
// real(x2_i), imag(x2_i) );
}
output( "zdotu", m, n, k, incx, incy, error_cblas, error_fblas, error_inline );
}
}
// cleanup
TESTING_FREE_CPU( A );
TESTING_FREE_CPU( B );
fflush( stdout );
} // itest, incx, incy
opts.cleanup();
TESTING_FINALIZE();
return gStatus;
}
extern "C" magma_int_t
magma_zlatrd2(char uplo, magma_int_t n, magma_int_t nb,
magmaDoubleComplex *a, magma_int_t lda,
double *e, magmaDoubleComplex *tau,
magmaDoubleComplex *w, magma_int_t ldw,
magmaDoubleComplex *da, magma_int_t ldda,
magmaDoubleComplex *dw, magma_int_t lddw,
magmaDoubleComplex *dwork, magma_int_t ldwork)
{
/* -- MAGMA (version 1.4.0) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
August 2013
Purpose
=======
ZLATRD2 reduces NB rows and columns of a complex Hermitian matrix A to
Hermitian tridiagonal form by an orthogonal similarity
transformation Q' * A * Q, and returns the matrices V and W which are
needed to apply the transformation to the unreduced part of A.
If UPLO = 'U', ZLATRD reduces the last NB rows and columns of a
matrix, of which the upper triangle is supplied;
if UPLO = 'L', ZLATRD reduces the first NB rows and columns of a
matrix, of which the lower triangle is supplied.
This is an auxiliary routine called by ZHETRD2_GPU. It uses an
accelerated HEMV that needs extra memory.
Arguments
=========
UPLO (input) CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored:
= 'U': Upper triangular
= 'L': Lower triangular
N (input) INTEGER
The order of the matrix A.
NB (input) INTEGER
The number of rows and columns to be reduced.
A (input/output) COMPLEX_16 array, dimension (LDA,N)
On entry, the Hermitian matrix A. If UPLO = 'U', the leading
n-by-n upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = 'L', the
leading n-by-n lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit:
if UPLO = 'U', the last NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements above the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors;
if UPLO = 'L', the first NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements below the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors.
See Further Details.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= (1,N).
E (output) COMPLEX_16 array, dimension (N-1)
If UPLO = 'U', E(n-nb:n-1) contains the superdiagonal
elements of the last NB columns of the reduced matrix;
if UPLO = 'L', E(1:nb) contains the subdiagonal elements of
the first NB columns of the reduced matrix.
TAU (output) COMPLEX_16 array, dimension (N-1)
The scalar factors of the elementary reflectors, stored in
TAU(n-nb:n-1) if UPLO = 'U', and in TAU(1:nb) if UPLO = 'L'.
See Further Details.
W (output) COMPLEX_16 array, dimension (LDW,NB)
The n-by-nb matrix W required to update the unreduced part
of A.
LDW (input) INTEGER
The leading dimension of the array W. LDW >= max(1,N).
Further Details
===============
If UPLO = 'U', the matrix Q is represented as a product of elementary
reflectors
Q = H(n) H(n-1) . . . H(n-nb+1).
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(i:n) = 0 and v(i-1) = 1; v(1:i-1) is stored on exit in A(1:i-1,i),
and tau in TAU(i-1).
If UPLO = 'L', the matrix Q is represented as a product of 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) = 0 and v(i+1) = 1; v(i+1:n) is stored on exit in A(i+1:n,i),
and tau in TAU(i).
The elements of the vectors v together form the n-by-nb matrix V
which is needed, with W, to apply the transformation to the unreduced
part of the matrix, using a Hermitian rank-2k update of the form:
A := A - V*W' - W*V'.
The contents of A on exit are illustrated by the following examples
with n = 5 and nb = 2:
if UPLO = 'U': if UPLO = 'L':
( a a a v4 v5 ) ( d )
( a a v4 v5 ) ( 1 d )
( a 1 v5 ) ( v1 1 a )
( d 1 ) ( v1 v2 a a )
( d ) ( v1 v2 a a a )
where d denotes a diagonal element of the reduced matrix, a denotes
an element of the original matrix that is unchanged, and vi denotes
an element of the vector defining H(i).
===================================================================== */
char uplo_[2] = {uplo, 0};
magma_int_t i;
magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magmaDoubleComplex c_one = MAGMA_Z_ONE;
magmaDoubleComplex c_zero = MAGMA_Z_ZERO;
magmaDoubleComplex value = MAGMA_Z_ZERO;
magma_int_t ione = 1;
magma_int_t i_n, i_1, iw;
magmaDoubleComplex alpha;
magmaDoubleComplex *f;
if (n <= 0) {
return 0;
}
magma_queue_t stream;
magma_queue_create( &stream );
magma_zmalloc_cpu( &f, n );
assert( f != NULL ); // TODO return error, or allocate outside zlatrd
if (lapackf77_lsame(uplo_, "U")) {
/* Reduce last NB columns of upper triangle */
for (i = n-1; i >= n - nb ; --i) {
i_1 = i + 1;
i_n = n - i - 1;
iw = i - n + nb;
if (i < n-1) {
/* Update A(1:i,i) */
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, W(i, iw+1), &ldw);
#endif
blasf77_zgemv("No transpose", &i_1, &i_n, &c_neg_one, A(0, i+1), &lda,
W(i, iw+1), &ldw, &c_one, A(0, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, W(i, iw+1), &ldw);
lapackf77_zlacgv(&i_n, A(i, i+1), &ldw);
#endif
blasf77_zgemv("No transpose", &i_1, &i_n, &c_neg_one, W(0, iw+1), &ldw,
A(i, i+1), &lda, &c_one, A(0, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, A(i, i+1), &ldw);
#endif
}
if (i > 0) {
/* Generate elementary reflector H(i) to annihilate A(1:i-2,i) */
alpha = *A(i-1, i);
lapackf77_zlarfg(&i, &alpha, A(0, i), &ione, &tau[i - 1]);
e[i-1] = MAGMA_Z_REAL( alpha );
MAGMA_Z_SET2REAL(*A(i-1, i), 1.);
/* Compute W(1:i-1,i) */
// 1. Send the block reflector A(0:n-i-1,i) to the GPU
magma_zsetvector( i, A(0, i), 1, dA(0, i), 1 );
#if (GPUSHMEM < 200)
magma_zhemv(MagmaUpper, i, c_one, dA(0, 0), ldda,
dA(0, i), ione, c_zero, dW(0, iw), ione);
#else
magmablas_zhemv2(MagmaUpper, i, c_one, dA(0, 0), ldda,
dA(0, i), ione, c_zero, dW(0, iw), ione,
dwork, ldwork);
#endif
// 2. Start putting the result back (asynchronously)
magma_zgetmatrix_async( i, 1,
dW(0, iw), lddw,
W(0, iw) /*test*/, ldw, stream );
if (i < n-1) {
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, W(0, iw+1), &ldw,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
}
// 3. Here is where we need it // TODO find the right place
magma_queue_sync( stream );
if (i < n-1) {
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, A(0, i+1), &lda,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, A(0, i+1), &lda,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, W(0, iw+1), &ldw,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
}
blasf77_zscal(&i, &tau[i - 1], W(0, iw), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i, W(0,iw), ione, A(0,i), ione, &value );
#else
value = cblas_zdotc( i, W(0,iw), ione, A(0,i), ione );
#endif
alpha = tau[i - 1] * -0.5f * value;
blasf77_zaxpy(&i, &alpha, A(0, i), &ione,
W(0, iw), &ione);
}
}
}
else {
/* Reduce first NB columns of lower triangle */
for (i = 0; i < nb; ++i) {
/* Update A(i:n,i) */
i_n = n - i;
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(i, 0), &ldw);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(i, 0), &lda,
W(i, 0), &ldw, &c_one, A(i, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(i, 0), &ldw);
lapackf77_zlacgv(&i, A(i ,0), &lda);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(i, 0), &ldw,
A(i, 0), &lda, &c_one, A(i, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, A(i, 0), &lda);
#endif
if (i < n-1) {
/* Generate elementary reflector H(i) to annihilate A(i+2:n,i) */
i_n = n - i - 1;
alpha = *A(i+1, i);
lapackf77_zlarfg(&i_n, &alpha, A(min(i+2,n-1), i), &ione, &tau[i]);
e[i] = MAGMA_Z_REAL( alpha );
MAGMA_Z_SET2REAL(*A(i+1, i), 1.);
/* Compute W(i+1:n,i) */
// 1. Send the block reflector A(i+1:n,i) to the GPU
magma_zsetvector( i_n, A(i+1, i), 1, dA(i+1, i), 1 );
#if (GPUSHMEM < 200)
magma_zhemv(MagmaLower, i_n, c_one, dA(i+1, i+1), ldda, dA(i+1, i), ione, c_zero,
dW(i+1, i), ione);
#else
magmablas_zhemv2('L', i_n, c_one, dA(i+1, i+1), ldda, dA(i+1, i), ione, c_zero,
dW(i+1, i), ione,
dwork, ldwork);
#endif
// 2. Start putting the result back (asynchronously)
magma_zgetmatrix_async( i_n, 1,
dW(i+1, i), lddw,
W(i+1, i), ldw, stream );
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, W(i+1, 0), &ldw,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(i+1, 0), &lda,
W(0, i), &ione, &c_zero, f, &ione);
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, A(i+1, 0), &lda,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
// 3. Here is where we need it
magma_queue_sync( stream );
if (i!=0)
blasf77_zaxpy(&i_n, &c_one, f, &ione, W(i+1, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(i+1, 0), &ldw,
W(0, i), &ione, &c_one, W(i+1, i), &ione);
blasf77_zscal(&i_n, &tau[i], W(i+1,i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i_n, W(i+1,i), ione, A(i+1,i), ione, &value );
#else
value = cblas_zdotc( i_n, W(i+1,i), ione, A(i+1,i), ione );
#endif
alpha = tau[i] * -0.5f * value;
blasf77_zaxpy(&i_n, &alpha, A(i+1, i), &ione, W(i+1,i), &ione);
}
}
}
magma_free_cpu(f);
magma_queue_destroy( stream );
return 0;
} /* zlatrd */
/**
Purpose
-------
ZLATRD2 reduces NB rows and columns of a complex Hermitian matrix A to
Hermitian tridiagonal form by an orthogonal similarity
transformation Q' * A * Q, and returns the matrices V and W which are
needed to apply the transformation to the unreduced part of A.
If UPLO = MagmaUpper, ZLATRD reduces the last NB rows and columns of a
matrix, of which the upper triangle is supplied;
if UPLO = MagmaLower, ZLATRD reduces the first NB rows and columns of a
matrix, of which the lower triangle is supplied.
This is an auxiliary routine called by ZHETRD2_GPU. It uses an
accelerated HEMV that needs extra memory.
Arguments
---------
@param[in]
uplo magma_uplo_t
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored:
- = MagmaUpper: Upper triangular
- = MagmaLower: Lower triangular
@param[in]
n INTEGER
The order of the matrix A.
@param[in]
nb INTEGER
The number of rows and columns to be reduced.
@param[in,out]
A COMPLEX_16 array, dimension (LDA,N)
On entry, the Hermitian matrix A. If UPLO = MagmaUpper, the leading
n-by-n upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = MagmaLower, the
leading n-by-n lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit:
- if UPLO = MagmaUpper, the last NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements above the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors;
- if UPLO = MagmaLower, the first NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements below the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors.
See Further Details.
@param[in]
lda INTEGER
The leading dimension of the array A. LDA >= (1,N).
@param[out]
e COMPLEX_16 array, dimension (N-1)
If UPLO = MagmaUpper, E(n-nb:n-1) contains the superdiagonal
elements of the last NB columns of the reduced matrix;
if UPLO = MagmaLower, E(1:nb) contains the subdiagonal elements of
the first NB columns of the reduced matrix.
@param[out]
tau COMPLEX_16 array, dimension (N-1)
The scalar factors of the elementary reflectors, stored in
TAU(n-nb:n-1) if UPLO = MagmaUpper, and in TAU(1:nb) if UPLO = MagmaLower.
See Further Details.
@param[out]
W COMPLEX_16 array, dimension (LDW,NB)
The n-by-nb matrix W required to update the unreduced part
of A.
@param[in]
ldw INTEGER
The leading dimension of the array W. LDW >= max(1,N).
Further Details
---------------
If UPLO = MagmaUpper, the matrix Q is represented as a product of elementary
reflectors
Q = H(n) H(n-1) . . . H(n-nb+1).
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(i:n) = 0 and v(i-1) = 1; v(1:i-1) is stored on exit in A(1:i-1,i),
and tau in TAU(i-1).
If UPLO = MagmaLower, the matrix Q is represented as a product of 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) = 0 and v(i+1) = 1; v(i+1:n) is stored on exit in A(i+1:n,i),
and tau in TAU(i).
The elements of the vectors v together form the n-by-nb matrix V
which is needed, with W, to apply the transformation to the unreduced
part of the matrix, using a Hermitian rank-2k update of the form:
A := A - V*W' - W*V'.
The contents of A on exit are illustrated by the following examples
with n = 5 and nb = 2:
if UPLO = MagmaUpper: if UPLO = MagmaLower:
( a a a v4 v5 ) ( d )
( a a v4 v5 ) ( 1 d )
( a 1 v5 ) ( v1 1 a )
( d 1 ) ( v1 v2 a a )
( d ) ( v1 v2 a a a )
where d denotes a diagonal element of the reduced matrix, a denotes
an element of the original matrix that is unchanged, and vi denotes
an element of the vector defining H(i).
@ingroup magma_zheev_aux
********************************************************************/
extern "C" magma_int_t
magma_zlatrd2(magma_uplo_t uplo, magma_int_t n, magma_int_t nb,
magmaDoubleComplex *A, magma_int_t lda,
double *e, magmaDoubleComplex *tau,
magmaDoubleComplex *W, magma_int_t ldw,
magmaDoubleComplex *dA, magma_int_t ldda,
magmaDoubleComplex *dW, magma_int_t lddw,
magmaDoubleComplex *dwork, magma_int_t ldwork)
{
#define A(i, j) (A + (j)*lda + (i))
#define W(i, j) (W + (j)*ldw + (i))
#define dA(i, j) (dA + (j)*ldda + (i))
#define dW(i, j) (dW + (j)*lddw + (i))
magma_int_t i;
magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magmaDoubleComplex c_one = MAGMA_Z_ONE;
magmaDoubleComplex c_zero = MAGMA_Z_ZERO;
magmaDoubleComplex value = MAGMA_Z_ZERO;
magma_int_t ione = 1;
magma_int_t i_n, i_1, iw;
magmaDoubleComplex alpha;
magmaDoubleComplex *f;
if (n <= 0) {
return 0;
}
magma_queue_t stream;
magma_queue_create( &stream );
magma_zmalloc_cpu( &f, n );
assert( f != NULL ); // TODO return error, or allocate outside zlatrd
if (uplo == MagmaUpper) {
/* Reduce last NB columns of upper triangle */
for (i = n-1; i >= n - nb; --i) {
i_1 = i + 1;
i_n = n - i - 1;
iw = i - n + nb;
if (i < n-1) {
/* Update A(1:i,i) */
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, W(i, iw+1), &ldw);
#endif
blasf77_zgemv("No transpose", &i_1, &i_n, &c_neg_one, A(0, i+1), &lda,
W(i, iw+1), &ldw, &c_one, A(0, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, W(i, iw+1), &ldw);
lapackf77_zlacgv(&i_n, A(i, i+1), &ldw);
#endif
blasf77_zgemv("No transpose", &i_1, &i_n, &c_neg_one, W(0, iw+1), &ldw,
A(i, i+1), &lda, &c_one, A(0, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_n, A(i, i+1), &ldw);
#endif
}
if (i > 0) {
/* Generate elementary reflector H(i) to annihilate A(1:i-2,i) */
alpha = *A(i-1, i);
lapackf77_zlarfg(&i, &alpha, A(0, i), &ione, &tau[i - 1]);
e[i-1] = MAGMA_Z_REAL( alpha );
*A(i-1,i) = MAGMA_Z_MAKE( 1, 0 );
/* Compute W(1:i-1,i) */
// 1. Send the block reflector A(0:n-i-1,i) to the GPU
magma_zsetvector( i, A(0, i), 1, dA(0, i), 1 );
//#if (GPUSHMEM < 200)
//magma_zhemv(MagmaUpper, i, c_one, dA(0, 0), ldda,
// dA(0, i), ione, c_zero, dW(0, iw), ione);
//#else
magmablas_zhemv_work(MagmaUpper, i, c_one, dA(0, 0), ldda,
dA(0, i), ione, c_zero, dW(0, iw), ione,
dwork, ldwork);
//#endif
// 2. Start putting the result back (asynchronously)
magma_zgetmatrix_async( i, 1,
dW(0, iw), lddw,
W(0, iw) /*test*/, ldw, stream );
if (i < n-1) {
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, W(0, iw+1), &ldw,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
}
// 3. Here is where we need it // TODO find the right place
magma_queue_sync( stream );
if (i < n-1) {
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, A(0, i+1), &lda,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, A(0, i+1), &lda,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, W(0, iw+1), &ldw,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
}
blasf77_zscal(&i, &tau[i - 1], W(0, iw), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i, W(0,iw), ione, A(0,i), ione, &value );
#else
value = cblas_zdotc( i, W(0,iw), ione, A(0,i), ione );
#endif
alpha = tau[i - 1] * -0.5f * value;
blasf77_zaxpy(&i, &alpha, A(0, i), &ione,
W(0, iw), &ione);
}
}
}
else {
/* Reduce first NB columns of lower triangle */
for (i = 0; i < nb; ++i) {
/* Update A(i:n,i) */
i_n = n - i;
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(i, 0), &ldw);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(i, 0), &lda,
W(i, 0), &ldw, &c_one, A(i, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(i, 0), &ldw);
lapackf77_zlacgv(&i, A(i, 0), &lda);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(i, 0), &ldw,
A(i, 0), &lda, &c_one, A(i, i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, A(i, 0), &lda);
#endif
if (i < n-1) {
/* Generate elementary reflector H(i) to annihilate A(i+2:n,i) */
i_n = n - i - 1;
alpha = *A(i+1, i);
lapackf77_zlarfg(&i_n, &alpha, A(min(i+2,n-1), i), &ione, &tau[i]);
e[i] = MAGMA_Z_REAL( alpha );
*A(i+1,i) = MAGMA_Z_MAKE( 1, 0 );
/* Compute W(i+1:n,i) */
// 1. Send the block reflector A(i+1:n,i) to the GPU
magma_zsetvector( i_n, A(i+1, i), 1, dA(i+1, i), 1 );
//#if (GPUSHMEM < 200)
//magma_zhemv(MagmaLower, i_n, c_one, dA(i+1, i+1), ldda, dA(i+1, i), ione, c_zero,
// dW(i+1, i), ione);
//#else
magmablas_zhemv_work(MagmaLower, i_n, c_one, dA(i+1, i+1), ldda, dA(i+1, i), ione, c_zero,
dW(i+1, i), ione,
dwork, ldwork);
//#endif
// 2. Start putting the result back (asynchronously)
magma_zgetmatrix_async( i_n, 1,
dW(i+1, i), lddw,
W(i+1, i), ldw, stream );
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, W(i+1, 0), &ldw,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(i+1, 0), &lda,
W(0, i), &ione, &c_zero, f, &ione);
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, A(i+1, 0), &lda,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
// 3. Here is where we need it
magma_queue_sync( stream );
if (i != 0)
blasf77_zaxpy(&i_n, &c_one, f, &ione, W(i+1, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(i+1, 0), &ldw,
W(0, i), &ione, &c_one, W(i+1, i), &ione);
blasf77_zscal(&i_n, &tau[i], W(i+1,i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i_n, W(i+1,i), ione, A(i+1,i), ione, &value );
#else
value = cblas_zdotc( i_n, W(i+1,i), ione, A(i+1,i), ione );
#endif
alpha = tau[i] * -0.5f * value;
blasf77_zaxpy(&i_n, &alpha, A(i+1, i), &ione, W(i+1,i), &ione);
}
}
}
magma_free_cpu(f);
magma_queue_destroy( stream );
return 0;
} /* magma_zlatrd */
extern "C" double
magma_zlatrd_mgpu(magma_int_t num_gpus, char uplo,
magma_int_t n0, magma_int_t n, magma_int_t nb, magma_int_t nb0,
magmaDoubleComplex *a, magma_int_t lda,
double *e, magmaDoubleComplex *tau,
magmaDoubleComplex *w, magma_int_t ldw,
magmaDoubleComplex **da, magma_int_t ldda, magma_int_t offset,
magmaDoubleComplex **dw, magma_int_t lddw,
magmaDoubleComplex *dwork[MagmaMaxGPUs], magma_int_t ldwork,
magma_int_t k,
magmaDoubleComplex *dx[MagmaMaxGPUs], magmaDoubleComplex *dy[MagmaMaxGPUs],
magmaDoubleComplex *work,
magma_queue_t stream[][10],
double *times)
{
/* -- MAGMA (version 1.4.1) --
Univ. of Tennessee, Knoxville
Univ. of California, Berkeley
Univ. of Colorado, Denver
December 2013
Purpose
=======
ZLATRD reduces NB rows and columns of a complex Hermitian matrix A to
Hermitian tridiagonal form by an orthogonal similarity
transformation Q' * A * Q, and returns the matrices V and W which are
needed to apply the transformation to the unreduced part of A.
If UPLO = 'U', ZLATRD reduces the last NB rows and columns of a
matrix, of which the upper triangle is supplied;
if UPLO = 'L', ZLATRD reduces the first NB rows and columns of a
matrix, of which the lower triangle is supplied.
This is an auxiliary routine called by ZHETRD.
Arguments
=========
UPLO (input) CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored:
= 'U': Upper triangular
= 'L': Lower triangular
N (input) INTEGER
The order of the matrix A.
NB (input) INTEGER
The number of rows and columns to be reduced.
A (input/output) COMPLEX_16 array, dimension (LDA,N)
On entry, the Hermitian matrix A. If UPLO = 'U', the leading
n-by-n upper triangular part of A contains the upper
triangular part of the matrix A, and the strictly lower
triangular part of A is not referenced. If UPLO = 'L', the
leading n-by-n lower triangular part of A contains the lower
triangular part of the matrix A, and the strictly upper
triangular part of A is not referenced.
On exit:
if UPLO = 'U', the last NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements above the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors;
if UPLO = 'L', the first NB columns have been reduced to
tridiagonal form, with the diagonal elements overwriting
the diagonal elements of A; the elements below the diagonal
with the array TAU, represent the orthogonal matrix Q as a
product of elementary reflectors.
See Further Details.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= (1,N).
E (output) COMPLEX_16 array, dimension (N-1)
If UPLO = 'U', E(n-nb:n-1) contains the superdiagonal
elements of the last NB columns of the reduced matrix;
if UPLO = 'L', E(1:nb) contains the subdiagonal elements of
the first NB columns of the reduced matrix.
TAU (output) COMPLEX_16 array, dimension (N-1)
The scalar factors of the elementary reflectors, stored in
TAU(n-nb:n-1) if UPLO = 'U', and in TAU(1:nb) if UPLO = 'L'.
See Further Details.
W (output) COMPLEX_16 array, dimension (LDW,NB)
The n-by-nb matrix W required to update the unreduced part
of A.
LDW (input) INTEGER
The leading dimension of the array W. LDW >= max(1,N).
Further Details
===============
If UPLO = 'U', the matrix Q is represented as a product of elementary
reflectors
Q = H(n) H(n-1) . . . H(n-nb+1).
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(i:n) = 0 and v(i-1) = 1; v(1:i-1) is stored on exit in A(1:i-1,i),
and tau in TAU(i-1).
If UPLO = 'L', the matrix Q is represented as a product of 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) = 0 and v(i+1) = 1; v(i+1:n) is stored on exit in A(i+1:n,i),
and tau in TAU(i).
The elements of the vectors v together form the n-by-nb matrix V
which is needed, with W, to apply the transformation to the unreduced
part of the matrix, using a Hermitian rank-2k update of the form:
A := A - V*W' - W*V'.
The contents of A on exit are illustrated by the following examples
with n = 5 and nb = 2:
if UPLO = 'U': if UPLO = 'L':
( a a a v4 v5 ) ( d )
( a a v4 v5 ) ( 1 d )
( a 1 v5 ) ( v1 1 a )
( d 1 ) ( v1 v2 a a )
( d ) ( v1 v2 a a a )
where d denotes a diagonal element of the reduced matrix, a denotes
an element of the original matrix that is unchanged, and vi denotes
an element of the vector defining H(i).
===================================================================== */
char uplo_[2] = {uplo, 0};
double mv_time = 0.0;
magma_int_t i;
#ifndef MAGMABLAS_ZHEMV_MGPU
magma_int_t loffset = nb0*((offset/nb0)/num_gpus);
#endif
magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magmaDoubleComplex c_one = MAGMA_Z_ONE;
magmaDoubleComplex c_zero = MAGMA_Z_ZERO;
magmaDoubleComplex value = MAGMA_Z_ZERO;
magma_int_t id, idw, i_one = 1;
//magma_int_t kk;
magma_int_t ione = 1;
magma_int_t i_n, i_1, iw;
magmaDoubleComplex alpha;
magmaDoubleComplex *dx2[MagmaMaxGPUs];
magmaDoubleComplex *f = (magmaDoubleComplex *)malloc(n*sizeof(magmaDoubleComplex ));
if (n <= 0) {
return 0;
}
//#define PROFILE_SYMV
#ifdef PROFILE_SYMV
magma_event_t start, stop;
float etime;
magma_timestr_t cpu_start, cpu_end;
magma_setdevice(0);
magma_event_create( &start );
magma_event_create( &stop );
#endif
if (lapackf77_lsame(uplo_, "U")) {
/* Reduce last NB columns of upper triangle */
for (i = n-1; i >= n - nb ; --i) {
i_1 = i + 1;
i_n = n - i - 1;
iw = i - n + nb;
if (i < n-1) {
/* Update A(1:i,i) */
magmaDoubleComplex wii = *W(i, iw+1);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_one, &wii, &ldw);
#endif
wii = -wii;
blasf77_zaxpy(&i_1, &wii, A(0, i+1), &i_one, A(0, i), &ione);
wii = *A(i, i+1);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_one, &wii, &ldw);
#endif
wii = -wii;
blasf77_zaxpy(&i_1, &wii, W(0, iw+1), &i_one, A(0, i), &ione);
}
if (i > 0) {
/* Generate elementary reflector H(i) to annihilate A(1:i-2,i) */
alpha = *A(i-1, i);
lapackf77_zlarfg(&i, &alpha, A(0, i), &ione, &tau[i - 1]);
e[i-1] = MAGMA_Z_REAL( alpha );
*A(i-1,i) = MAGMA_Z_MAKE( 1, 0 );
for( id=0; id<num_gpus; id++ ) {
magma_setdevice(id);
dx2[id] = dW1(id, 0, iw);
magma_zsetvector_async( n, A(0,i), 1, dW1(id, 0, iw), 1, stream[id][0]);
#ifndef MAGMABLAS_ZHEMV_MGPU
magma_zsetvector_async( i, A(0,i), 1, dx[id], 1, stream[id][0] );
#endif
}
magmablas_zhemv_mgpu(num_gpus, k, 'U', i, nb0, c_one, da, ldda, 0,
dx2, ione, c_zero, dy, ione, dwork, ldwork,
work, W(0, iw), stream );
if (i < n-1) {
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, W(0, iw+1), &ldw,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
}
/* overlap update */
if( i < n-1 && i-1 >= n - nb )
{
magma_int_t im1_1 = i_1 - 1;
magma_int_t im1 = i-1;
/* Update A(1:i,i) */
#if defined(PRECISION_z) || defined(PRECISION_c)
magma_int_t im1_n = i_n + 1;
lapackf77_zlacgv(&im1_n, W(im1, iw+1), &ldw);
#endif
blasf77_zgemv("No transpose", &im1_1, &i_n, &c_neg_one, A(0, i+1), &lda,
W(im1, iw+1), &ldw, &c_one, A(0, i-1), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&im1_n, W(im1, iw+1), &ldw);
lapackf77_zlacgv(&im1_n, A(im1, i +1), &lda);
#endif
blasf77_zgemv("No transpose", &im1_1, &i_n, &c_neg_one, W(0, iw+1), &ldw,
A(im1, i+1), &lda, &c_one, A(0, i-1), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&im1_n, A(im1, i+1), &lda);
#endif
}
// 3. Here is where we need it // TODO find the right place
magmablas_zhemv_sync(num_gpus, k, i, work, W(0, iw), stream );
if (i < n-1) {
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, A(0, i+1), &lda,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
blasf77_zgemv(MagmaConjTransStr, &i, &i_n, &c_one, A(0, i+1), &lda,
A(0, i), &ione, &c_zero, W(i+1, iw), &ione);
blasf77_zgemv("No transpose", &i, &i_n, &c_neg_one, W(0, iw+1), &ldw,
W(i+1, iw), &ione, &c_one, W(0, iw), &ione);
}
blasf77_zscal(&i, &tau[i - 1], W(0, iw), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i, W(0,iw), ione, A(0,i), ione, &value );
#else
value = cblas_zdotc( i, W(0,iw), ione, A(0,i), ione );
#endif
alpha = tau[i - 1] * -.5f * value;
blasf77_zaxpy(&i, &alpha, A(0, i), &ione, W(0, iw), &ione);
for( id=0; id<num_gpus; id++ ) {
magma_setdevice(id);
if( k > 1 ) {
magma_zsetvector_async( n, W(0,iw), 1, dW(id, 0, iw), 1, stream[id][1] );
} else {
magma_zsetvector_async( n, W(0,iw), 1, dW(id, 0, iw), 1, stream[id][0] );
}
}
}
}
} else {
/* Reduce first NB columns of lower triangle */
for (i = 0; i < nb; ++i) {
/* Update A(i:n,i) */
i_n = n - i;
idw = ((offset+i)/nb)%num_gpus;
if( i > 0 ) {
trace_cpu_start( 0, "gemv", "gemv" );
magmaDoubleComplex wii = *W(i, i-1);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_one, &wii, &ldw);
#endif
wii = -wii;
blasf77_zaxpy( &i_n, &wii, A(i, i-1), &ione, A(i, i), &ione);
wii = *A(i, i-1);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i_one, &wii, &lda);
#endif
wii = -wii;
blasf77_zaxpy( &i_n, &wii, W(i, i-1), &ione, A(i, i), &ione);
}
if (i < n-1) {
/* Generate elementary reflector H(i) to annihilate A(i+2:n,i) */
i_n = n - i - 1;
trace_cpu_start( 0, "larfg", "larfg" );
alpha = *A(i+1, i);
#ifdef PROFILE_SYMV
cpu_start = get_current_time();
#endif
lapackf77_zlarfg(&i_n, &alpha, A(min(i+2,n-1), i), &ione, &tau[i]);
#ifdef PROFILE_SYMV
cpu_end = get_current_time();
times[0] += GetTimerValue(cpu_start,cpu_end)/1000.0;
#endif
e[i] = MAGMA_Z_REAL( alpha );
*A(i+1,i) = MAGMA_Z_MAKE( 1, 0 );
trace_cpu_end( 0 );
/* Compute W(i+1:n,i) */
// 1. Send the block reflector A(i+1:n,i) to the GPU
//trace_gpu_start( idw, 0, "comm", "comm1" );
#ifndef MAGMABLAS_ZHEMV_MGPU
magma_setdevice(idw);
magma_zsetvector( i_n, A(i+1,i), 1, dA(idw, i+1, i), 1 );
#endif
for( id=0; id<num_gpus; id++ ) {
magma_setdevice(id);
trace_gpu_start( id, 0, "comm", "comm" );
#ifdef MAGMABLAS_ZHEMV_MGPU
dx2[id] = dW1(id, 0, i)-offset;
#else
dx2[id] = dx[id];
magma_zsetvector( i_n, A(i+1,i), 1, dx[id], 1 );
#endif
magma_zsetvector_async( n, A(0,i), 1, dW1(id, 0, i), 1, stream[id][0] );
trace_gpu_end( id, 0 );
}
/* mat-vec on multiple GPUs */
#ifdef PROFILE_SYMV
magma_setdevice(0);
magma_event_record(start, stream[0][0]);
#endif
magmablas_zhemv_mgpu(num_gpus, k, 'L', i_n, nb0, c_one, da, ldda, offset+i+1,
dx2, ione, c_zero, dy, ione, dwork, ldwork,
work, W(i+1,i), stream );
#ifdef PROFILE_SYMV
magma_setdevice(0);
magma_event_record(stop, stream[0][0]);
#endif
trace_cpu_start( 0, "gemv", "gemv" );
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, W(i+1, 0), &ldw,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(i+1, 0), &lda,
W(0, i), &ione, &c_zero, f, &ione);
blasf77_zgemv(MagmaConjTransStr, &i_n, &i, &c_one, A(i+1, 0), &lda,
A(i+1, i), &ione, &c_zero, W(0, i), &ione);
trace_cpu_end( 0 );
/* overlap update */
if( i > 0 && i+1 < n )
{
magma_int_t ip1 = i+1;
trace_cpu_start( 0, "gemv", "gemv" );
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(ip1, 0), &ldw);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, A(ip1, 0), &lda,
W(ip1, 0), &ldw, &c_one, A(ip1, ip1), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, W(ip1, 0), &ldw);
lapackf77_zlacgv(&i, A(ip1 ,0), &lda);
#endif
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(ip1, 0), &ldw,
A(ip1, 0), &lda, &c_one, A(ip1, ip1), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
lapackf77_zlacgv(&i, A(ip1, 0), &lda);
#endif
trace_cpu_end( 0 );
}
/* synchronize */
magmablas_zhemv_sync(num_gpus, k, i_n, work, W(i+1,i), stream );
#ifdef PROFILE_SYMV
cudaEventElapsedTime(&etime, start, stop);
mv_time += (etime/1000.0);
times[1+(i_n/(n0/10))] += (etime/1000.0);
#endif
trace_cpu_start( 0, "axpy", "axpy" );
if (i!=0)
blasf77_zaxpy(&i_n, &c_one, f, &ione, W(i+1, i), &ione);
blasf77_zgemv("No transpose", &i_n, &i, &c_neg_one, W(i+1, 0), &ldw,
W(0, i), &ione, &c_one, W(i+1, i), &ione);
blasf77_zscal(&i_n, &tau[i], W(i+1,i), &ione);
#if defined(PRECISION_z) || defined(PRECISION_c)
cblas_zdotc_sub( i_n, W(i+1,i), ione, A(i+1,i), ione, &value );
#else
value = cblas_zdotc( i_n, W(i+1,i), ione, A(i+1,i), ione );
#endif
alpha = tau[i]* -.5f * value;
blasf77_zaxpy(&i_n, &alpha, A(i+1, i), &ione, W(i+1,i), &ione);
trace_cpu_end( 0 );
for( id=0; id<num_gpus; id++ ) {
magma_setdevice(id);
if( k > 1 ) {
magma_zsetvector_async( n, W(0,i), 1, dW(id, 0, i), 1, stream[id][1] );
} else {
magma_zsetvector_async( n, W(0,i), 1, dW(id, 0, i), 1, stream[id][0] );
}
}
}
}
}
#ifdef PROFILE_SYMV
magma_setdevice(0);
magma_event_destory( start );
magma_event_destory( stop );
#endif
for( id=0; id<num_gpus; id++ ) {
magma_setdevice(id);
if( k > 1) magma_queue_sync(stream[id][1]);
}
free(f);
return mv_time;
} /* zlatrd_ */
