FLA_Error FLA_Axpy_sync_circular( FLA_Obj alpha, FLA_Obj X, FLA_Obj B )
{
FLA_Obj XL, XR, X0, X1, X2;
FLA_Obj BL, BR, B0, B1, B2;
int n_stages = FLA_omp_get_num_stages();
int stage_width = FLA_omp_compute_stage_width( X );
int thread_num = omp_get_thread_num();
int n_done = 0;
int b, i;
// Start thread i on the ith panel partition of B.
FLA_Part_1x2( X, &XL, &XR, stage_width*thread_num, FLA_LEFT );
FLA_Part_1x2( B, &BL, &BR, stage_width*thread_num, FLA_LEFT );
while ( n_done++ < n_stages ){
// The last lockable partition may be smaller than the others.
b = min( FLA_Obj_width( XR ), stage_width );
FLA_Repart_1x2_to_1x3( XL, /**/ XR, &X0, /**/ &X1, &X2,
b, FLA_RIGHT );
FLA_Repart_1x2_to_1x3( BL, /**/ BR, &B0, /**/ &B1, &B2,
b, FLA_RIGHT );
/*------------------------------------------------------------*/
// Get the index of the current partition.
i = FLA_Obj_width(XL)/stage_width;
// Acquire lock[i] (the lock for X1 and B1).
omp_set_lock( &fla_omp_lock[i] );
// B1 := alpha * X1 + B1
FLA_Axpy_external( alpha, X1, B1 );
// Release lock[i] (the lock for X1 and B1).
omp_unset_lock( &fla_omp_lock[i] );
/*------------------------------------------------------------*/
FLA_Cont_with_1x3_to_1x2( &XL, /**/ &XR, X0, X1, /**/ X2,
FLA_LEFT );
FLA_Cont_with_1x3_to_1x2( &BL, /**/ &BR, B0, B1, /**/ B2,
FLA_LEFT );
// If this thread reaches the last partition, wrap back around to
// the first partition for the next iteration.
if( FLA_Obj_width( XL ) == FLA_Obj_width( X ) )
{
FLA_Part_1x2( X, &XL, &XR, 0, FLA_LEFT );
FLA_Part_1x2( B, &BL, &BR, 0, FLA_LEFT );
}
}
return FLA_SUCCESS;
}
FLA_Error FLA_Axpy_sync_pipeline( FLA_Obj alpha, FLA_Obj X, FLA_Obj B )
{
FLA_Obj XL, XR, X0, X1, X2;
FLA_Obj BL, BR, B0, B1, B2;
int b, i, nb_alg;
FLA_Part_1x2( X, &XL, &XR, 0, FLA_LEFT );
FLA_Part_1x2( B, &BL, &BR, 0, FLA_LEFT );
// Compute the width of one lockable partition.
nb_alg = FLA_omp_compute_stage_width( X );
while ( FLA_Obj_width( XL ) < FLA_Obj_width( X ) ){
b = min( FLA_Obj_width( XR ), nb_alg );
FLA_Repart_1x2_to_1x3( XL, /**/ XR, &X0, /**/ &X1, &X2,
b, FLA_RIGHT );
FLA_Repart_1x2_to_1x3( BL, /**/ BR, &B0, /**/ &B1, &B2,
b, FLA_RIGHT );
/*------------------------------------------------------------*/
// Get the index of the current partition.
i = FLA_Obj_width(XL)/nb_alg;
// Acquire lock[i] (the lock for X1 and B1).
omp_set_lock( &fla_omp_lock[i] );
// B1 := alpha * X1 + B1
FLA_Axpy_external( alpha, X1, B1 );
// Release lock[i] (the lock for X1 and B1).
omp_unset_lock( &fla_omp_lock[i] );
/*------------------------------------------------------------*/
FLA_Cont_with_1x3_to_1x2( &XL, /**/ &XR, X0, X1, /**/ X2,
FLA_LEFT );
FLA_Cont_with_1x3_to_1x2( &BL, /**/ &BR, B0, B1, /**/ B2,
FLA_LEFT );
}
return FLA_SUCCESS;
}
