PLASMA  2.8.0
PLASMA - Parallel Linear Algebra for Scalable Multi-core Architectures
int CORE_dttqrt ( int  M,
int  N,
int  IB,
double *  A1,
int  LDA1,
double *  A2,
int  LDA2,
double *  T,
int  LDT,
double *  TAU,
double *  WORK 
)

CORE_dttqrt computes a QR factorization of a rectangular matrix formed by coupling a complex N-by-N upper triangular tile A1 on top of a complex M-by-N upper trapezoidal tile A2:

| A1 | = Q * R | A2 |

The tile Q is represented as a product of elementary reflectors

Q = H(1) H(2) . . . H(k), where k = min(M,N).

Each H(i) has the form

H(i) = I - tau * v * v'

where tau is a complex scalar, and v is a complex vector with v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A2(1:m,i), and tau in TAU(i).

Parameters
[in]MThe number of rows of the tile A2. M >= 0.
[in]NThe number of columns of the tile A1 and A2. N >= 0.
[in]IBThe inner-blocking size. IB >= 0.
[in,out]A1On entry, the N-by-N tile A1. On exit, the elements on and above the diagonal of the array contain the N-by-N upper trapezoidal tile R; the elements below the diagonal are not referenced.
[in]LDA1The leading dimension of the array A1. LDA1 >= max(1,N).
[in,out]A2On entry, the M-by-N upper triangular tile A2. On exit, the elements on and above the diagonal of the array with the array TAU, represent the unitary tile Q as a product of elementary reflectors (see Further Details).
[in]LDA2The leading dimension of the array A2. LDA2 >= max(1,M).
[out]TThe IB-by-N triangular factor T of the block reflector. T is upper triangular by block (economic storage); The rest of the array is not referenced.
[in]LDTThe leading dimension of the array T. LDT >= IB.
[out]TAUThe scalar factors of the elementary reflectors (see Further Details).
[in,out]WORK
Returns
Return values
PLASMA_SUCCESSsuccessful exit
<0if -i, the i-th argument had an illegal value