int ATL_potrf(const enum ATLAS_ORDER Order, const enum ATLAS_UPLO Uplo,
const int N, TYPE *A, const int lda0)
{
int ierr=0;
size_t lda = lda0;
if (N)
{
if (Order == AtlasColMajor)
{
if (Uplo == AtlasUpper) ierr = ATL_potrfU(N, A, lda);
else ierr = ATL_potrfL(N, A, lda);
}
else
{
#ifdef TREAL
if (Uplo == AtlasUpper) ierr = ATL_potrfL(N, A, lda);
else ierr = ATL_potrfU(N, A, lda);
#else
if (Uplo == AtlasUpper) ierr = Mjoin(PATL,potrfRU)(N, A, lda);
else ierr = Mjoin(PATL,potrfRL)(N, A, lda);
#endif
}
}
return(ierr);
}
int ATL_potrfU(const int N, TYPE *A, const int lda)
{
TYPE *An, *Ac;
int Nleft, Nright, ierr;
const size_t lda2 = lda SHIFT;
#ifdef TREAL
#define ONE ATL_rone
#else
static const TYPE ONE[2] = {ATL_rone, ATL_rzero};
#endif
#ifdef TREAL
if (N > 4)
#else
if (N > 1)
#endif
{
Nleft = N >> 1;
#ifdef NB
if (Nleft > NB<<1) Nleft = ATL_MulByNB(ATL_DivByNB(Nleft));
#endif
Nright = N - Nleft;
ierr = ATL_potrfU(Nleft, A, lda);
if (!ierr)
{
Ac = A + lda2 * Nleft;
An = Ac + (Nleft SHIFT);
cblas_trsm(CblasColMajor, CblasLeft, CblasUpper, llt_trans,
CblasNonUnit, Nleft, Nright, ONE, A, lda, Ac, lda);
llt_syrk(CblasColMajor, CblasUpper, llt_trans, Nright, Nleft,
ATL_rnone, Ac, lda, ATL_rone, An, lda);
ierr = ATL_potrfU(Nright, An, lda);
if (ierr) return(ierr+Nleft);
}
else return(ierr);
}
