```      SUBROUTINE SGECON( NORM, N, A, LDA, ANORM, RCOND, WORK, IWORK,
\$                   INFO )
*
*  -- LAPACK routine (version 3.1) --
*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
*     November 2006
*
*     Modified to call SLACN2 in place of SLACON, 7 Feb 03, SJH.
*
*     .. Scalar Arguments ..
CHARACTER          NORM
INTEGER            INFO, LDA, N
REAL               ANORM, RCOND
*     ..
*     .. Array Arguments ..
INTEGER            IWORK( * )
REAL               A( LDA, * ), WORK( * )
*     ..
*
*  Purpose
*  =======
*
*  SGECON estimates the reciprocal of the condition number of a general
*  real matrix A, in either the 1-norm or the infinity-norm, using
*  the LU factorization computed by SGETRF.
*
*  An estimate is obtained for norm(inv(A)), and the reciprocal of the
*  condition number is computed as
*     RCOND = 1 / ( norm(A) * norm(inv(A)) ).
*
*  Arguments
*  =========
*
*  NORM    (input) CHARACTER*1
*          Specifies whether the 1-norm condition number or the
*          infinity-norm condition number is required:
*          = '1' or 'O':  1-norm;
*          = 'I':         Infinity-norm.
*
*  N       (input) INTEGER
*          The order of the matrix A.  N >= 0.
*
*  A       (input) REAL array, dimension (LDA,N)
*          The factors L and U from the factorization A = P*L*U
*          as computed by SGETRF.
*
*  LDA     (input) INTEGER
*          The leading dimension of the array A.  LDA >= max(1,N).
*
*  ANORM   (input) REAL
*          If NORM = '1' or 'O', the 1-norm of the original matrix A.
*          If NORM = 'I', the infinity-norm of the original matrix A.
*
*  RCOND   (output) REAL
*          The reciprocal of the condition number of the matrix A,
*          computed as RCOND = 1/(norm(A) * norm(inv(A))).
*
*  WORK    (workspace) REAL array, dimension (4*N)
*
*  IWORK   (workspace) INTEGER array, dimension (N)
*
*  INFO    (output) INTEGER
*          = 0:  successful exit
*          < 0:  if INFO = -i, the i-th argument had an illegal value
*
*  =====================================================================
*
*     .. Parameters ..
REAL               ONE, ZERO
PARAMETER          ( ONE = 1.0E+0, ZERO = 0.0E+0 )
*     ..
*     .. Local Scalars ..
LOGICAL            ONENRM
CHARACTER          NORMIN
INTEGER            IX, KASE, KASE1
REAL               AINVNM, SCALE, SL, SMLNUM, SU
*     ..
*     .. Local Arrays ..
INTEGER            ISAVE( 3 )
*     ..
*     .. External Functions ..
LOGICAL            LSAME
INTEGER            ISAMAX
REAL               SLAMCH
EXTERNAL           LSAME, ISAMAX, SLAMCH
*     ..
*     .. External Subroutines ..
EXTERNAL           SLACN2, SLATRS, SRSCL, XERBLA
*     ..
*     .. Intrinsic Functions ..
INTRINSIC          ABS, MAX
*     ..
*     .. Executable Statements ..
*
*     Test the input parameters.
*
INFO = 0
ONENRM = NORM.EQ.'1' .OR. LSAME( NORM, 'O' )
IF( .NOT.ONENRM .AND. .NOT.LSAME( NORM, 'I' ) ) THEN
INFO = -1
ELSE IF( N.LT.0 ) THEN
INFO = -2
ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
INFO = -4
ELSE IF( ANORM.LT.ZERO ) THEN
INFO = -5
END IF
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'SGECON', -INFO )
RETURN
END IF
*
*     Quick return if possible
*
RCOND = ZERO
IF( N.EQ.0 ) THEN
RCOND = ONE
RETURN
ELSE IF( ANORM.EQ.ZERO ) THEN
RETURN
END IF
*
SMLNUM = SLAMCH( 'Safe minimum' )
*
*     Estimate the norm of inv(A).
*
AINVNM = ZERO
NORMIN = 'N'
IF( ONENRM ) THEN
KASE1 = 1
ELSE
KASE1 = 2
END IF
KASE = 0
10 CONTINUE
CALL SLACN2( N, WORK( N+1 ), WORK, IWORK, AINVNM, KASE, ISAVE )
IF( KASE.NE.0 ) THEN
IF( KASE.EQ.KASE1 ) THEN
*
*           Multiply by inv(L).
*
CALL SLATRS( 'Lower', 'No transpose', 'Unit', NORMIN, N, A,
\$                   LDA, WORK, SL, WORK( 2*N+1 ), INFO )
*
*           Multiply by inv(U).
*
CALL SLATRS( 'Upper', 'No transpose', 'Non-unit', NORMIN, N,
\$                   A, LDA, WORK, SU, WORK( 3*N+1 ), INFO )
ELSE
*
*           Multiply by inv(U').
*
CALL SLATRS( 'Upper', 'Transpose', 'Non-unit', NORMIN, N, A,
\$                   LDA, WORK, SU, WORK( 3*N+1 ), INFO )
*
*           Multiply by inv(L').
*
CALL SLATRS( 'Lower', 'Transpose', 'Unit', NORMIN, N, A,
\$                   LDA, WORK, SL, WORK( 2*N+1 ), INFO )
END IF
*
*        Divide X by 1/(SL*SU) if doing so will not cause overflow.
*
SCALE = SL*SU
NORMIN = 'Y'
IF( SCALE.NE.ONE ) THEN
IX = ISAMAX( N, WORK, 1 )
IF( SCALE.LT.ABS( WORK( IX ) )*SMLNUM .OR. SCALE.EQ.ZERO )
\$         GO TO 20
CALL SRSCL( N, SCALE, WORK, 1 )
END IF
GO TO 10
END IF
*
*     Compute the estimate of the reciprocal condition number.
*
IF( AINVNM.NE.ZERO )
\$   RCOND = ( ONE / AINVNM ) / ANORM
*
20 CONTINUE
RETURN
*
*     End of SGECON
*
END

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