void bli_her2k_front( obj_t* alpha,
obj_t* a,
obj_t* b,
obj_t* beta,
obj_t* c,
herk_t* cntl )
{
obj_t alpha_conj;
obj_t c_local;
obj_t a_local;
obj_t bh_local;
obj_t b_local;
obj_t ah_local;
// Check parameters.
if ( bli_error_checking_is_enabled() )
bli_her2k_check( alpha, a, b, beta, c );
// If alpha is zero, scale by beta and return.
if ( bli_obj_equals( alpha, &BLIS_ZERO ) )
{
bli_scalm( beta, c );
return;
}
// Alias A, B, and C in case we need to apply transformations.
bli_obj_alias_to( *a, a_local );
bli_obj_alias_to( *b, b_local );
bli_obj_alias_to( *c, c_local );
bli_obj_set_as_root( c_local );
// For her2k, the first and second right-hand "B" operands are simply B'
// and A'.
bli_obj_alias_to( *b, bh_local );
bli_obj_induce_trans( bh_local );
bli_obj_toggle_conj( bh_local );
bli_obj_alias_to( *a, ah_local );
bli_obj_induce_trans( ah_local );
bli_obj_toggle_conj( ah_local );
// Initialize a conjugated copy of alpha.
bli_obj_scalar_init_detached_copy_of( bli_obj_datatype( *a ),
BLIS_CONJUGATE,
alpha,
&alpha_conj );
// An optimization: If C is row-stored, transpose the entire operation
// so as to allow the macro-kernel more favorable access patterns
// through C. (The effect of the transposition of A and A' is negligible
// because those operands are always packed to contiguous memory.)
if ( bli_obj_is_row_stored( c_local ) )
{
bli_obj_swap( a_local, bh_local );
bli_obj_swap( b_local, ah_local );
bli_obj_induce_trans( a_local );
bli_obj_induce_trans( bh_local );
bli_obj_induce_trans( b_local );
bli_obj_induce_trans( ah_local );
bli_obj_induce_trans( c_local );
}
#if 0
// Invoke the internal back-end.
bli_her2k_int( alpha,
&a_local,
&bh_local,
&alpha_conj,
&b_local,
&ah_local,
beta,
&c_local,
cntl );
#else
// Invoke herk twice, using beta only the first time.
bli_herk_int( alpha,
&a_local,
&bh_local,
beta,
&c_local,
cntl );
bli_herk_int( &alpha_conj,
&b_local,
&ah_local,
&BLIS_ONE,
&c_local,
cntl );
#endif
}
void bli_her2k_front( obj_t* alpha,
obj_t* a,
obj_t* b,
obj_t* beta,
obj_t* c,
gemm_t* cntl )
{
obj_t alpha_conj;
obj_t c_local;
obj_t a_local;
obj_t bh_local;
obj_t b_local;
obj_t ah_local;
// Check parameters.
if ( bli_error_checking_is_enabled() )
bli_her2k_check( alpha, a, b, beta, c );
// If alpha is zero, scale by beta, zero the imaginary components of
// the diagonal elements, and return.
if ( bli_obj_equals( alpha, &BLIS_ZERO ) )
{
bli_scalm( beta, c );
bli_setid( &BLIS_ZERO, c );
return;
}
// Alias A, B, and C in case we need to apply transformations.
bli_obj_alias_to( *a, a_local );
bli_obj_alias_to( *b, b_local );
bli_obj_alias_to( *c, c_local );
bli_obj_set_as_root( c_local );
// For her2k, the first and second right-hand "B" operands are simply B'
// and A'.
bli_obj_alias_to( *b, bh_local );
bli_obj_induce_trans( bh_local );
bli_obj_toggle_conj( bh_local );
bli_obj_alias_to( *a, ah_local );
bli_obj_induce_trans( ah_local );
bli_obj_toggle_conj( ah_local );
// Initialize a conjugated copy of alpha.
bli_obj_scalar_init_detached_copy_of( bli_obj_datatype( *a ),
BLIS_CONJUGATE,
alpha,
&alpha_conj );
// An optimization: If C is stored by rows and the micro-kernel prefers
// contiguous columns, or if C is stored by columns and the micro-kernel
// prefers contiguous rows, transpose the entire operation to allow the
// micro-kernel to access elements of C in its preferred manner.
if (
( bli_obj_is_row_stored( c_local ) &&
bli_func_prefers_contig_cols( bli_obj_datatype( c_local ),
bli_gemm_cntl_ukrs( cntl ) ) ) ||
( bli_obj_is_col_stored( c_local ) &&
bli_func_prefers_contig_rows( bli_obj_datatype( c_local ),
bli_gemm_cntl_ukrs( cntl ) ) )
)
{
bli_obj_swap( a_local, bh_local );
bli_obj_swap( b_local, ah_local );
bli_obj_induce_trans( a_local );
bli_obj_induce_trans( bh_local );
bli_obj_induce_trans( b_local );
bli_obj_induce_trans( ah_local );
bli_obj_induce_trans( c_local );
}
#if 0
// Invoke the internal back-end.
bli_her2k_int( alpha,
&a_local,
&bh_local,
&alpha_conj,
&b_local,
&ah_local,
beta,
&c_local,
cntl );
#else
// Invoke herk twice, using beta only the first time.
herk_thrinfo_t** infos = bli_create_herk_thrinfo_paths();
dim_t n_threads = thread_num_threads( infos[0] );
// Invoke the internal back-end.
bli_level3_thread_decorator( n_threads,
(level3_int_t) bli_herk_int,
alpha,
&a_local,
&bh_local,
beta,
&c_local,
(void*) cntl,
(void**) infos );
bli_level3_thread_decorator( n_threads,
(level3_int_t) bli_herk_int,
&alpha_conj,
&b_local,
&ah_local,
&BLIS_ONE,
&c_local,
(void*) cntl,
(void**) infos );
bli_herk_thrinfo_free_paths( infos, n_threads );
#endif
// The Hermitian rank-2k product was computed as A*B'+B*A', even for
// the diagonal elements. Mathematically, the imaginary components of
// diagonal elements of a Hermitian rank-2k product should always be
// zero. However, in practice, they sometimes accumulate meaningless
// non-zero values. To prevent this, we explicitly set those values
// to zero before returning.
bli_setid( &BLIS_ZERO, &c_local );
}
