/**
Purpose
-------
ZPOTRI computes the inverse of a real symmetric positive definite
matrix A using the Cholesky factorization A = U**T*U or A = L*L**T
computed by ZPOTRF.
Arguments
---------
@param[in]
uplo magma_uplo_t
- = MagmaUpper: Upper triangle of A is stored;
- = MagmaLower: Lower triangle of A is stored.
@param[in]
n INTEGER
The order of the matrix A. N >= 0.
@param[in,out]
A COMPLEX_16 array, dimension (LDA,N)
On entry, the triangular factor U or L from the Cholesky
factorization A = U**T*U or A = L*L**T, as computed by
ZPOTRF.
On exit, the upper or lower triangle of the (symmetric)
inverse of A, overwriting the input factor U or L.
@param[in]
lda INTEGER
The leading dimension of the array A. LDA >= max(1,N).
@param[out]
info INTEGER
- = 0: successful exit
- < 0: if INFO = -i, the i-th argument had an illegal value
- > 0: if INFO = i, the (i,i) element of the factor U or L is
zero, and the inverse could not be computed.
@ingroup magma_zposv_comp
********************************************************************/
extern "C" magma_int_t
magma_zpotri(magma_uplo_t uplo, magma_int_t n,
magmaDoubleComplex *A, magma_int_t lda, magma_int_t *info)
{
/* Local variables */
*info = 0;
if ((uplo != MagmaUpper) && (uplo != MagmaLower))
*info = -1;
else if (n < 0)
*info = -2;
else if (lda < max(1,n))
*info = -4;
if (*info != 0) {
magma_xerbla( __func__, -(*info) );
return *info;
}
/* Quick return if possible */
if ( n == 0 )
return *info;
/* Invert the triangular Cholesky factor U or L */
magma_ztrtri( uplo, MagmaNonUnit, n, A, lda, info );
if ( *info == 0 ) {
/* Form inv(U) * inv(U)**T or inv(L)**T * inv(L) */
magma_zlauum( uplo, n, A, lda, info );
}
return *info;
} /* magma_zpotri */
/* ////////////////////////////////////////////////////////////////////////////
-- Testing ztrtri
*/
int main( int argc, char** argv)
{
TESTING_INIT();
real_Double_t gflops, gpu_perf, gpu_time, cpu_perf, cpu_time;
magmaDoubleComplex *h_A, *h_R;
magmaDoubleComplex c_neg_one = MAGMA_Z_NEG_ONE;
magma_int_t N, n2, lda, info;
magma_int_t ione = 1;
magma_int_t ISEED[4] = {0,0,0,1};
double Anorm, error, work[1];
magma_int_t status = 0;
magma_opts opts;
opts.parse_opts( argc, argv );
opts.lapack |= opts.check; // check (-c) implies lapack (-l)
double tol = opts.tolerance * lapackf77_dlamch("E");
printf("%% uplo = %s\n", lapack_uplo_const(opts.uplo) );
printf("%% N CPU Gflop/s (sec) GPU Gflop/s (sec) ||R||_F / ||A||_F\n");
printf("%%================================================================\n");
for( int itest = 0; itest < opts.ntest; ++itest ) {
for( int iter = 0; iter < opts.niter; ++iter ) {
N = opts.nsize[itest];
lda = N;
n2 = lda*N;
gflops = FLOPS_ZTRTRI( N ) / 1e9;
TESTING_MALLOC_CPU( h_A, magmaDoubleComplex, n2 );
TESTING_MALLOC_PIN( h_R, magmaDoubleComplex, n2 );
/* ====================================================================
Initialize the matrix
=================================================================== */
lapackf77_zlarnv( &ione, ISEED, &n2, h_A );
magma_zmake_hpd( N, h_A, lda );
lapackf77_zlacpy( MagmaFullStr, &N, &N, h_A, &lda, h_R, &lda );
/* ====================================================================
Performs operation using MAGMA
=================================================================== */
if ( opts.warmup ) {
magma_zpotrf( opts.uplo, N, h_R, lda, &info );
magma_ztrtri( opts.uplo, opts.diag, N, h_R, lda, &info );
lapackf77_zlacpy( MagmaFullStr, &N, &N, h_A, &lda, h_R, &lda );
}
/* factorize matrix */
magma_zpotrf( opts.uplo, N, h_R, lda, &info );
// check for exact singularity
//h_R[ 10 + 10*lda ] = MAGMA_Z_ZERO;
gpu_time = magma_wtime();
magma_ztrtri( opts.uplo, opts.diag, N, h_R, lda, &info );
gpu_time = magma_wtime() - gpu_time;
gpu_perf = gflops / gpu_time;
if (info != 0) {
printf("magma_ztrtri returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
/* =====================================================================
Performs operation using LAPACK
=================================================================== */
if ( opts.lapack ) {
lapackf77_zpotrf( lapack_uplo_const(opts.uplo), &N, h_A, &lda, &info );
cpu_time = magma_wtime();
lapackf77_ztrtri( lapack_uplo_const(opts.uplo), lapack_diag_const(opts.diag), &N, h_A, &lda, &info );
cpu_time = magma_wtime() - cpu_time;
cpu_perf = gflops / cpu_time;
if (info != 0) {
printf("lapackf77_ztrtri returned error %d: %s.\n",
(int) info, magma_strerror( info ));
}
/* =====================================================================
Check the result compared to LAPACK
=================================================================== */
blasf77_zaxpy(&n2, &c_neg_one, h_A, &ione, h_R, &ione);
Anorm = lapackf77_zlantr("f", lapack_uplo_const(opts.uplo), MagmaNonUnitStr, &N, &N, h_A, &lda, work);
error = lapackf77_zlantr("f", lapack_uplo_const(opts.uplo), MagmaNonUnitStr, &N, &N, h_R, &lda, work) / Anorm;
bool okay = (error < tol);
status += ! okay;
printf("%5d %7.2f (%7.2f) %7.2f (%7.2f) %8.2e %s\n",
(int) N, cpu_perf, cpu_time, gpu_perf, gpu_time,
error, (okay ? "ok" : "failed") );
}
else {
printf("%5d --- ( --- ) %7.2f (%7.2f) ---\n",
(int) N, gpu_perf, gpu_time );
}
TESTING_FREE_CPU( h_A );
TESTING_FREE_PIN( h_R );
fflush( stdout );
}
if ( opts.niter > 1 ) {
printf( "\n" );
}
}
opts.cleanup();
TESTING_FINALIZE();
return status;
}