ZLAUU2 (3lapack)

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 ZLAUU2( UPLO, N, A, LDA, INFO )

      CHARACTER      UPLO

      INTEGER        INFO, LDA, N

      COMPLEX*16     A( LDA, * )

PURPOSE

  ZLAUU2 computes 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.

  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*16 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