void LUNMedium
( const AbstractDistMatrix<F>& UPre, AbstractDistMatrix<F>& XPre,
bool checkIfSingular )
{
DEBUG_CSE
const Int m = XPre.Height();
const Int bsize = Blocksize();
const Grid& g = UPre.Grid();
DistMatrixReadProxy<F,F,MC,MR> UProx( UPre );
DistMatrixReadWriteProxy<F,F,MC,MR> XProx( XPre );
auto& U = UProx.GetLocked();
auto& X = XProx.Get();
DistMatrix<F,MC, STAR> U01_MC_STAR(g);
DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
DistMatrix<F,MR, STAR> X1Trans_MR_STAR(g);
const Int kLast = LastOffset( m, bsize );
Int k=kLast, kOld=m;
while( true )
{
const bool in2x2 = ( k>0 && U.Get(k,k-1) != F(0) );
if( in2x2 )
--k;
const Int nb = kOld-k;
const Range<Int> ind0( 0, k ),
ind1( k, k+nb );
auto U01 = U( ind0, ind1 );
auto U11 = U( ind1, ind1 );
auto X0 = X( ind0, ALL );
auto X1 = X( ind1, ALL );
U11_STAR_STAR = U11; // U11[* ,* ] <- U11[MC,MR]
X1Trans_MR_STAR.AlignWith( X0 );
Transpose( X1, X1Trans_MR_STAR );
// X1^T[MR,* ] := X1^T[MR,* ] U11^-T[* ,* ]
// = (U11^-1[* ,* ] X1[* ,MR])^T
LocalQuasiTrsm
( RIGHT, UPPER, TRANSPOSE,
F(1), U11_STAR_STAR, X1Trans_MR_STAR, checkIfSingular );
Transpose( X1Trans_MR_STAR, X1 );
U01_MC_STAR.AlignWith( X0 );
U01_MC_STAR = U01; // U01[MC,* ] <- U01[MC,MR]
// X0[MC,MR] -= U01[MC,* ] X1[* ,MR]
LocalGemm
( NORMAL, TRANSPOSE, F(-1), U01_MC_STAR, X1Trans_MR_STAR, F(1), X0 );
if( k == 0 )
break;
kOld = k;
k -= Min(bsize,k);
}
}
void LLNMedium
( const AbstractDistMatrix<F>& LPre,
AbstractDistMatrix<F>& XPre,
bool checkIfSingular )
{
DEBUG_CSE
const Int m = XPre.Height();
const Int bsize = Blocksize();
const Grid& g = LPre.Grid();
DistMatrixReadProxy<F,F,MC,MR> LProx( LPre );
DistMatrixReadWriteProxy<F,F,MC,MR> XProx( XPre );
auto& L = LProx.GetLocked();
auto& X = XProx.Get();
DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
DistMatrix<F,MC, STAR> L21_MC_STAR(g);
DistMatrix<F,MR, STAR> X1Trans_MR_STAR(g);
for( Int k=0; k<m; k+=bsize )
{
const Int nbProp = Min(bsize,m-k);
const bool in2x2 = ( k+nbProp<m && L.Get(k+nbProp-1,k+nbProp) != F(0) );
const Int nb = ( in2x2 ? nbProp+1 : nbProp );
const Range<Int> ind1( k, k+nb ),
ind2( k+nb, m );
auto L11 = L( ind1, ind1 );
auto L21 = L( ind2, ind1 );
auto X1 = X( ind1, ALL );
auto X2 = X( ind2, ALL );
L11_STAR_STAR = L11; // L11[* ,* ] <- L11[MC,MR]
X1Trans_MR_STAR.AlignWith( X2 );
Transpose( X1, X1Trans_MR_STAR );
// X1^T[MR,* ] := X1^T[MR,* ] L11^-T[* ,* ]
// = (L11^-1[* ,* ] X1[* ,MR])^T
LocalQuasiTrsm
( RIGHT, LOWER, TRANSPOSE,
F(1), L11_STAR_STAR, X1Trans_MR_STAR, checkIfSingular );
Transpose( X1Trans_MR_STAR, X1 );
L21_MC_STAR.AlignWith( X2 );
L21_MC_STAR = L21; // L21[MC,* ] <- L21[MC,MR]
// X2[MC,MR] -= L21[MC,* ] X1[* ,MR]
LocalGemm
( NORMAL, TRANSPOSE, F(-1), L21_MC_STAR, X1Trans_MR_STAR, F(1), X2 );
}
}
void LLNLarge
( const AbstractDistMatrix<F>& LPre,
AbstractDistMatrix<F>& XPre,
bool checkIfSingular )
{
DEBUG_CSE
const Int m = XPre.Height();
const Int bsize = Blocksize();
const Grid& g = LPre.Grid();
DistMatrixReadProxy<F,F,MC,MR> LProx( LPre );
DistMatrixReadWriteProxy<F,F,MC,MR> XProx( XPre );
auto& L = LProx.GetLocked();
auto& X = XProx.Get();
DistMatrix<F,STAR,STAR> L11_STAR_STAR(g);
DistMatrix<F,MC, STAR> L21_MC_STAR(g);
DistMatrix<F,STAR,MR > X1_STAR_MR(g);
DistMatrix<F,STAR,VR > X1_STAR_VR(g);
for( Int k=0; k<m; k+=bsize )
{
const Int nbProp = Min(bsize,m-k);
const bool in2x2 = ( k+nbProp<m && L.Get(k+nbProp-1,k+nbProp) != F(0) );
const Int nb = ( in2x2 ? nbProp+1 : nbProp );
const Range<Int> ind1( k, k+nb ),
ind2( k+nb, m );
auto L11 = L( ind1, ind1 );
auto L21 = L( ind2, ind1 );
auto X1 = X( ind1, ALL );
auto X2 = X( ind2, ALL );
// X1[* ,VR] := L11^-1[* ,* ] X1[* ,VR]
L11_STAR_STAR = L11;
X1_STAR_VR = X1;
LocalQuasiTrsm
( LEFT, LOWER, NORMAL, F(1), L11_STAR_STAR, X1_STAR_VR,
checkIfSingular );
X1_STAR_MR.AlignWith( X2 );
X1_STAR_MR = X1_STAR_VR; // X1[* ,MR] <- X1[* ,VR]
X1 = X1_STAR_MR; // X1[MC,MR] <- X1[* ,MR]
L21_MC_STAR.AlignWith( X2 );
L21_MC_STAR = L21; // L21[MC,* ] <- L21[MC,MR]
// X2[MC,MR] -= L21[MC,* ] X1[* ,MR]
LocalGemm( NORMAL, NORMAL, F(-1), L21_MC_STAR, X1_STAR_MR, F(1), X2 );
}
}
void LUNLarge
( const ElementalMatrix<F>& UPre,
ElementalMatrix<F>& XPre,
bool checkIfSingular )
{
DEBUG_CSE
const Int m = XPre.Height();
const Int bsize = Blocksize();
const Grid& g = UPre.Grid();
DistMatrixReadProxy<F,F,MC,MR> UProx( UPre );
DistMatrixReadWriteProxy<F,F,MC,MR> XProx( XPre );
auto& U = UProx.GetLocked();
auto& X = XProx.Get();
DistMatrix<F,MC, STAR> U01_MC_STAR(g);
DistMatrix<F,STAR,STAR> U11_STAR_STAR(g);
DistMatrix<F,STAR,MR > X1_STAR_MR(g);
DistMatrix<F,STAR,VR > X1_STAR_VR(g);
const Int kLast = LastOffset( m, bsize );
Int k=kLast, kOld=m;
while( true )
{
const bool in2x2 = ( k>0 && U.Get(k,k-1) != F(0) );
if( in2x2 )
--k;
const Int nb = kOld-k;
const Range<Int> ind0( 0, k ),
ind1( k, k+nb );
auto U01 = U( ind0, ind1 );
auto U11 = U( ind1, ind1 );
auto X0 = X( ind0, ALL );
auto X1 = X( ind1, ALL );
U11_STAR_STAR = U11; // U11[* ,* ] <- U11[MC,MR]
X1_STAR_VR = X1; // X1[* ,VR] <- X1[MC,MR]
// X1[* ,VR] := U11^-1[* ,* ] X1[* ,VR]
LocalQuasiTrsm
( LEFT, UPPER, NORMAL, F(1), U11_STAR_STAR, X1_STAR_VR,
checkIfSingular );
X1_STAR_MR.AlignWith( X0 );
X1_STAR_MR = X1_STAR_VR; // X1[* ,MR] <- X1[* ,VR]
X1 = X1_STAR_MR; // X1[MC,MR] <- X1[* ,MR]
U01_MC_STAR.AlignWith( X0 );
U01_MC_STAR = U01; // U01[MC,* ] <- U01[MC,MR]
// X0[MC,MR] -= U01[MC,* ] X1[* ,MR]
LocalGemm( NORMAL, NORMAL, F(-1), U01_MC_STAR, X1_STAR_MR, F(1), X0 );
if( k == 0 )
break;
kOld = k;
k -= Min(bsize,k);
}
}
