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# clauu2

```
NAME
CLAUU2 - compute the product U * U' or L' * L, where the
triangular factor U or L is stored in the upper or lower
triangular part of the array A

SYNOPSIS
SUBROUTINE CLAUU2( UPLO, N, A, LDA, INFO )

CHARACTER      UPLO

INTEGER        INFO, LDA, N

COMPLEX        A( LDA, * )

PURPOSE
CLAUU2 computes the product U * U' or L' * L, where the tri-
angular factor U or L is stored in the upper or lower tri-
angular part of the array A.

If UPLO = 'U' or 'u' then the upper triangle of the result
is stored, overwriting the factor U in A.
If UPLO = 'L' or 'l' then the lower triangle of the result
is stored, overwriting the factor L in A.

This is the unblocked form of the algorithm, calling Level 2
BLAS.

ARGUMENTS
UPLO    (input) CHARACTER*1
Specifies whether the triangular factor stored in
the array A is upper or lower triangular:
= 'U':  Upper triangular
= 'L':  Lower triangular

N       (input) INTEGER
The order of the triangular factor U or L.  N >= 0.

A       (input/output) COMPLEX array, dimension (LDA,N)
On entry, the triangular factor U or L.  On exit, if
UPLO = 'U', the upper triangle of A is overwritten
with the upper triangle of the product U * U'; if
UPLO = 'L', the lower triangle of A is overwritten
with the lower triangle of the product L' * L.

LDA     (input) INTEGER
The leading dimension of the array A.  LDA >=
max(1,N).

INFO    (output) INTEGER
= 0: successful exit
< 0: if INFO = -k, the k-th argument had an illegal

value
```