cantera/ext/lapack/dgetri.f

801 lines
No EOL
22 KiB
Fortran

SUBROUTINE DGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
*
* -- LAPACK routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* June 30, 1999
*
* .. Scalar Arguments ..
INTEGER INFO, LDA, LWORK, N
* ..
* .. Array Arguments ..
INTEGER IPIV( * )
DOUBLE PRECISION A( LDA, * ), WORK( * )
* ..
*
* Purpose
* =======
*
* DGETRI computes the inverse of a matrix using the LU factorization
* computed by DGETRF.
*
* This method inverts U and then computes inv(A) by solving the system
* inv(A)*L = inv(U) for inv(A).
*
* Arguments
* =========
*
* N (input) INTEGER
* The order of the matrix A. N >= 0.
*
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
* On entry, the factors L and U from the factorization
* A = P*L*U as computed by DGETRF.
* On exit, if INFO = 0, the inverse of the original matrix A.
*
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,N).
*
* IPIV (input) INTEGER array, dimension (N)
* The pivot indices from DGETRF; for 1<=i<=N, row i of the
* matrix was interchanged with row IPIV(i).
*
* WORK (workspace/output) DOUBLE PRECISION array, dimension (LWORK)
* On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
*
* LWORK (input) INTEGER
* The dimension of the array WORK. LWORK >= max(1,N).
* For optimal performance LWORK >= N*NB, where NB is
* the optimal blocksize returned by ILAENV.
*
* If LWORK = -1, then a workspace query is assumed; the routine
* only calculates the optimal size of the WORK array, returns
* this value as the first entry of the WORK array, and no error
* message related to LWORK is issued by XERBLA.
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* > 0: if INFO = i, U(i,i) is exactly zero; the matrix is
* singular and its inverse could not be computed.
*
* =====================================================================
*
* .. Parameters ..
DOUBLE PRECISION ZERO, ONE
PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
* ..
* .. Local Scalars ..
LOGICAL LQUERY
INTEGER I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,
$ NBMIN, NN
* ..
* .. External Functions ..
INTEGER ILAENV
EXTERNAL ILAENV
* ..
* .. External Subroutines ..
EXTERNAL DGEMM, DGEMV, DSWAP, DTRSM, DTRTRI, XERBLA
* ..
* .. Intrinsic Functions ..
INTRINSIC MAX, MIN
* ..
* .. Executable Statements ..
*
* Test the input parameters.
*
INFO = 0
NB = ILAENV( 1, 'DGETRI', ' ', N, -1, -1, -1 )
LWKOPT = N*NB
WORK( 1 ) = LWKOPT
LQUERY = ( LWORK.EQ.-1 )
IF( N.LT.0 ) THEN
INFO = -1
ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
INFO = -3
ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
INFO = -6
END IF
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'DGETRI', -INFO )
RETURN
ELSE IF( LQUERY ) THEN
RETURN
END IF
*
* Quick return if possible
*
IF( N.EQ.0 )
$ RETURN
*
* Form inv(U). If INFO > 0 from DTRTRI, then U is singular,
* and the inverse is not computed.
*
CALL DTRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )
IF( INFO.GT.0 )
$ RETURN
*
NBMIN = 2
LDWORK = N
IF( NB.GT.1 .AND. NB.LT.N ) THEN
IWS = MAX( LDWORK*NB, 1 )
IF( LWORK.LT.IWS ) THEN
NB = LWORK / LDWORK
NBMIN = MAX( 2, ILAENV( 2, 'DGETRI', ' ', N, -1, -1, -1 ) )
END IF
ELSE
IWS = N
END IF
*
* Solve the equation inv(A)*L = inv(U) for inv(A).
*
IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN
*
* Use unblocked code.
*
DO 20 J = N, 1, -1
*
* Copy current column of L to WORK and replace with zeros.
*
DO 10 I = J + 1, N
WORK( I ) = A( I, J )
A( I, J ) = ZERO
10 CONTINUE
*
* Compute current column of inv(A).
*
IF( J.LT.N )
$ CALL DGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),
$ LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )
20 CONTINUE
ELSE
*
* Use blocked code.
*
NN = ( ( N-1 ) / NB )*NB + 1
DO 50 J = NN, 1, -NB
JB = MIN( NB, N-J+1 )
*
* Copy current block column of L to WORK and replace with
* zeros.
*
DO 40 JJ = J, J + JB - 1
DO 30 I = JJ + 1, N
WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )
A( I, JJ ) = ZERO
30 CONTINUE
40 CONTINUE
*
* Compute current block column of inv(A).
*
IF( J+JB.LE.N )
$ CALL DGEMM( 'No transpose', 'No transpose', N, JB,
$ N-J-JB+1, -ONE, A( 1, J+JB ), LDA,
$ WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )
CALL DTRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,
$ ONE, WORK( J ), LDWORK, A( 1, J ), LDA )
50 CONTINUE
END IF
*
* Apply column interchanges.
*
DO 60 J = N - 1, 1, -1
JP = IPIV( J )
IF( JP.NE.J )
$ CALL DSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
60 CONTINUE
*
WORK( 1 ) = IWS
RETURN
*
* End of DGETRI
*
END
SUBROUTINE DTRTI2( UPLO, DIAG, N, A, LDA, INFO )
*
* -- LAPACK routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* February 29, 1992
*
* .. Scalar Arguments ..
CHARACTER DIAG, UPLO
INTEGER INFO, LDA, N
* ..
* .. Array Arguments ..
DOUBLE PRECISION A( LDA, * )
* ..
*
* Purpose
* =======
*
* DTRTI2 computes the inverse of a real upper or lower triangular
* matrix.
*
* This is the Level 2 BLAS version of the algorithm.
*
* Arguments
* =========
*
* UPLO (input) CHARACTER*1
* Specifies whether the matrix A is upper or lower triangular.
* = 'U': Upper triangular
* = 'L': Lower triangular
*
* DIAG (input) CHARACTER*1
* Specifies whether or not the matrix A is unit triangular.
* = 'N': Non-unit triangular
* = 'U': Unit triangular
*
* N (input) INTEGER
* The order of the matrix A. N >= 0.
*
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
* On entry, the triangular matrix A. If UPLO = 'U', the
* leading n by n upper triangular part of the array A contains
* the upper triangular matrix, and the strictly lower
* triangular part of A is not referenced. If UPLO = 'L', the
* leading n by n lower triangular part of the array A contains
* the lower triangular matrix, and the strictly upper
* triangular part of A is not referenced. If DIAG = 'U', the
* diagonal elements of A are also not referenced and are
* assumed to be 1.
*
* On exit, the (triangular) inverse of the original matrix, in
* the same storage format.
*
* 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
*
* =====================================================================
*
* .. Parameters ..
DOUBLE PRECISION ONE
PARAMETER ( ONE = 1.0D+0 )
* ..
* .. Local Scalars ..
LOGICAL NOUNIT, UPPER
INTEGER J
DOUBLE PRECISION AJJ
* ..
* .. External Functions ..
LOGICAL LSAME
EXTERNAL LSAME
* ..
* .. External Subroutines ..
EXTERNAL DSCAL, DTRMV, XERBLA
* ..
* .. Intrinsic Functions ..
INTRINSIC MAX
* ..
* .. Executable Statements ..
*
* Test the input parameters.
*
INFO = 0
UPPER = LSAME( UPLO, 'U' )
NOUNIT = LSAME( DIAG, 'N' )
IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
INFO = -1
ELSE IF( .NOT.NOUNIT .AND. .NOT.LSAME( DIAG, 'U' ) ) THEN
INFO = -2
ELSE IF( N.LT.0 ) THEN
INFO = -3
ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
INFO = -5
END IF
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'DTRTI2', -INFO )
RETURN
END IF
*
IF( UPPER ) THEN
*
* Compute inverse of upper triangular matrix.
*
DO 10 J = 1, N
IF( NOUNIT ) THEN
A( J, J ) = ONE / A( J, J )
AJJ = -A( J, J )
ELSE
AJJ = -ONE
END IF
*
* Compute elements 1:j-1 of j-th column.
*
CALL DTRMV( 'Upper', 'No transpose', DIAG, J-1, A, LDA,
$ A( 1, J ), 1 )
CALL DSCAL( J-1, AJJ, A( 1, J ), 1 )
10 CONTINUE
ELSE
*
* Compute inverse of lower triangular matrix.
*
DO 20 J = N, 1, -1
IF( NOUNIT ) THEN
A( J, J ) = ONE / A( J, J )
AJJ = -A( J, J )
ELSE
AJJ = -ONE
END IF
IF( J.LT.N ) THEN
*
* Compute elements j+1:n of j-th column.
*
CALL DTRMV( 'Lower', 'No transpose', DIAG, N-J,
$ A( J+1, J+1 ), LDA, A( J+1, J ), 1 )
CALL DSCAL( N-J, AJJ, A( J+1, J ), 1 )
END IF
20 CONTINUE
END IF
*
RETURN
*
* End of DTRTI2
*
END
SUBROUTINE DTRTRI( UPLO, DIAG, N, A, LDA, INFO )
*
* -- LAPACK routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* March 31, 1993
*
* .. Scalar Arguments ..
CHARACTER DIAG, UPLO
INTEGER INFO, LDA, N
* ..
* .. Array Arguments ..
DOUBLE PRECISION A( LDA, * )
* ..
*
* Purpose
* =======
*
* DTRTRI computes the inverse of a real upper or lower triangular
* matrix A.
*
* This is the Level 3 BLAS version of the algorithm.
*
* Arguments
* =========
*
* UPLO (input) CHARACTER*1
* = 'U': A is upper triangular;
* = 'L': A is lower triangular.
*
* DIAG (input) CHARACTER*1
* = 'N': A is non-unit triangular;
* = 'U': A is unit triangular.
*
* N (input) INTEGER
* The order of the matrix A. N >= 0.
*
* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
* On entry, the triangular matrix A. If UPLO = 'U', the
* leading N-by-N upper triangular part of the array A contains
* the upper triangular matrix, and the strictly lower
* triangular part of A is not referenced. If UPLO = 'L', the
* leading N-by-N lower triangular part of the array A contains
* the lower triangular matrix, and the strictly upper
* triangular part of A is not referenced. If DIAG = 'U', the
* diagonal elements of A are also not referenced and are
* assumed to be 1.
* On exit, the (triangular) inverse of the original matrix, in
* the same storage format.
*
* LDA (input) INTEGER
* The leading dimension of the array A. LDA >= max(1,N).
*
* INFO (output) INTEGER
* = 0: successful exit
* < 0: if INFO = -i, the i-th argument had an illegal value
* > 0: if INFO = i, A(i,i) is exactly zero. The triangular
* matrix is singular and its inverse can not be computed.
*
* =====================================================================
*
* .. Parameters ..
DOUBLE PRECISION ONE, ZERO
PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 )
* ..
* .. Local Scalars ..
LOGICAL NOUNIT, UPPER
INTEGER J, JB, NB, NN
* ..
* .. External Functions ..
LOGICAL LSAME
INTEGER ILAENV
EXTERNAL LSAME, ILAENV
* ..
* .. External Subroutines ..
EXTERNAL DTRMM, DTRSM, DTRTI2, XERBLA
* ..
* .. Intrinsic Functions ..
INTRINSIC MAX, MIN
* ..
* .. Executable Statements ..
*
* Test the input parameters.
*
INFO = 0
UPPER = LSAME( UPLO, 'U' )
NOUNIT = LSAME( DIAG, 'N' )
IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
INFO = -1
ELSE IF( .NOT.NOUNIT .AND. .NOT.LSAME( DIAG, 'U' ) ) THEN
INFO = -2
ELSE IF( N.LT.0 ) THEN
INFO = -3
ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
INFO = -5
END IF
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'DTRTRI', -INFO )
RETURN
END IF
*
* Quick return if possible
*
IF( N.EQ.0 )
$ RETURN
*
* Check for singularity if non-unit.
*
IF( NOUNIT ) THEN
DO 10 INFO = 1, N
IF( A( INFO, INFO ).EQ.ZERO )
$ RETURN
10 CONTINUE
INFO = 0
END IF
*
* Determine the block size for this environment.
*
NB = ILAENV( 1, 'DTRTRI', UPLO // DIAG, N, -1, -1, -1 )
IF( NB.LE.1 .OR. NB.GE.N ) THEN
*
* Use unblocked code
*
CALL DTRTI2( UPLO, DIAG, N, A, LDA, INFO )
ELSE
*
* Use blocked code
*
IF( UPPER ) THEN
*
* Compute inverse of upper triangular matrix
*
DO 20 J = 1, N, NB
JB = MIN( NB, N-J+1 )
*
* Compute rows 1:j-1 of current block column
*
CALL DTRMM( 'Left', 'Upper', 'No transpose', DIAG, J-1,
$ JB, ONE, A, LDA, A( 1, J ), LDA )
CALL DTRSM( 'Right', 'Upper', 'No transpose', DIAG, J-1,
$ JB, -ONE, A( J, J ), LDA, A( 1, J ), LDA )
*
* Compute inverse of current diagonal block
*
CALL DTRTI2( 'Upper', DIAG, JB, A( J, J ), LDA, INFO )
20 CONTINUE
ELSE
*
* Compute inverse of lower triangular matrix
*
NN = ( ( N-1 ) / NB )*NB + 1
DO 30 J = NN, 1, -NB
JB = MIN( NB, N-J+1 )
IF( J+JB.LE.N ) THEN
*
* Compute rows j+jb:n of current block column
*
CALL DTRMM( 'Left', 'Lower', 'No transpose', DIAG,
$ N-J-JB+1, JB, ONE, A( J+JB, J+JB ), LDA,
$ A( J+JB, J ), LDA )
CALL DTRSM( 'Right', 'Lower', 'No transpose', DIAG,
$ N-J-JB+1, JB, -ONE, A( J, J ), LDA,
$ A( J+JB, J ), LDA )
END IF
*
* Compute inverse of current diagonal block
*
CALL DTRTI2( 'Lower', DIAG, JB, A( J, J ), LDA, INFO )
30 CONTINUE
END IF
END IF
*
RETURN
*
* End of DTRTRI
*
END
INTEGER FUNCTION IEEECK( ISPEC, ZERO, ONE )
*
* -- LAPACK auxiliary routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* June 30, 1998
*
* .. Scalar Arguments ..
INTEGER ISPEC
REAL ONE, ZERO
* ..
*
* Purpose
* =======
*
* IEEECK is called from the ILAENV to verify that Infinity and
* possibly NaN arithmetic is safe (i.e. will not trap).
*
* Arguments
* =========
*
* ISPEC (input) INTEGER
* Specifies whether to test just for inifinity arithmetic
* or whether to test for infinity and NaN arithmetic.
* = 0: Verify infinity arithmetic only.
* = 1: Verify infinity and NaN arithmetic.
*
* ZERO (input) REAL
* Must contain the value 0.0
* This is passed to prevent the compiler from optimizing
* away this code.
*
* ONE (input) REAL
* Must contain the value 1.0
* This is passed to prevent the compiler from optimizing
* away this code.
*
* RETURN VALUE: INTEGER
* = 0: Arithmetic failed to produce the correct answers
* = 1: Arithmetic produced the correct answers
*
* .. Local Scalars ..
REAL NAN1, NAN2, NAN3, NAN4, NAN5, NAN6, NEGINF,
$ NEGZRO, NEWZRO, POSINF
* ..
* .. Executable Statements ..
IEEECK = 1
*
POSINF = ONE / ZERO
IF( POSINF.LE.ONE ) THEN
IEEECK = 0
RETURN
END IF
*
NEGINF = -ONE / ZERO
IF( NEGINF.GE.ZERO ) THEN
IEEECK = 0
RETURN
END IF
*
NEGZRO = ONE / ( NEGINF+ONE )
IF( NEGZRO.NE.ZERO ) THEN
IEEECK = 0
RETURN
END IF
*
NEGINF = ONE / NEGZRO
IF( NEGINF.GE.ZERO ) THEN
IEEECK = 0
RETURN
END IF
*
NEWZRO = NEGZRO + ZERO
IF( NEWZRO.NE.ZERO ) THEN
IEEECK = 0
RETURN
END IF
*
POSINF = ONE / NEWZRO
IF( POSINF.LE.ONE ) THEN
IEEECK = 0
RETURN
END IF
*
NEGINF = NEGINF*POSINF
IF( NEGINF.GE.ZERO ) THEN
IEEECK = 0
RETURN
END IF
*
POSINF = POSINF*POSINF
IF( POSINF.LE.ONE ) THEN
IEEECK = 0
RETURN
END IF
*
*
*
*
* Return if we were only asked to check infinity arithmetic
*
IF( ISPEC.EQ.0 )
$ RETURN
*
NAN1 = POSINF + NEGINF
*
NAN2 = POSINF / NEGINF
*
NAN3 = POSINF / POSINF
*
NAN4 = POSINF*ZERO
*
NAN5 = NEGINF*NEGZRO
*
NAN6 = NAN5*0.0
*
IF( NAN1.EQ.NAN1 ) THEN
IEEECK = 0
RETURN
END IF
*
IF( NAN2.EQ.NAN2 ) THEN
IEEECK = 0
RETURN
END IF
*
IF( NAN3.EQ.NAN3 ) THEN
IEEECK = 0
RETURN
END IF
*
IF( NAN4.EQ.NAN4 ) THEN
IEEECK = 0
RETURN
END IF
*
IF( NAN5.EQ.NAN5 ) THEN
IEEECK = 0
RETURN
END IF
*
IF( NAN6.EQ.NAN6 ) THEN
IEEECK = 0
RETURN
END IF
*
RETURN
END
c END
c LOGICAL FUNCTION LSAME( CA, CB )
*
* -- LAPACK auxiliary routine (version 3.0) --
* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
* Courant Institute, Argonne National Lab, and Rice University
* September 30, 1994
*
* .. Scalar Arguments ..
c CHARACTER CA, CB
* ..
*
* Purpose
* =======
*
* LSAME returns .TRUE. if CA is the same letter as CB regardless of
* case.
*
* Arguments
* =========
*
* CA (input) CHARACTER*1
* CB (input) CHARACTER*1
* CA and CB specify the single characters to be compared.
*
* =====================================================================
*
* .. Intrinsic Functions ..
c INTRINSIC ICHAR
* ..
* .. Local Scalars ..
c INTEGER INTA, INTB, ZCODE
* ..
* .. Executable Statements ..
*
* Test if the characters are equal
*
c LSAME = CA.EQ.CB
c IF( LSAME )
c $ RETURN
*
* Now test for equivalence if both characters are alphabetic.
*
c ZCODE = ICHAR( 'Z' )
*
* Use 'Z' rather than 'A' so that ASCII can be detected on Prime
* machines, on which ICHAR returns a value with bit 8 set.
* ICHAR('A') on Prime machines returns 193 which is the same as
* ICHAR('A') on an EBCDIC machine.
*
c INTA = ICHAR( CA )
c INTB = ICHAR( CB )
*
c IF( ZCODE.EQ.90 .OR. ZCODE.EQ.122 ) THEN
*
* ASCII is assumed - ZCODE is the ASCII code of either lower or
* upper case 'Z'.
*
c IF( INTA.GE.97 .AND. INTA.LE.122 ) INTA = INTA - 32
c IF( INTB.GE.97 .AND. INTB.LE.122 ) INTB = INTB - 32
*
c ELSE IF( ZCODE.EQ.233 .OR. ZCODE.EQ.169 ) THEN
*
* EBCDIC is assumed - ZCODE is the EBCDIC code of either lower or
* upper case 'Z'.
*
c IF( INTA.GE.129 .AND. INTA.LE.137 .OR.
c $ INTA.GE.145 .AND. INTA.LE.153 .OR.
c $ INTA.GE.162 .AND. INTA.LE.169 ) INTA = INTA + 64
c IF( INTB.GE.129 .AND. INTB.LE.137 .OR.
c $ INTB.GE.145 .AND. INTB.LE.153 .OR.
c $ INTB.GE.162 .AND. INTB.LE.169 ) INTB = INTB + 64
*
c ELSE IF( ZCODE.EQ.218 .OR. ZCODE.EQ.250 ) THEN
*
* ASCII is assumed, on Prime machines - ZCODE is the ASCII code
* plus 128 of either lower or upper case 'Z'.
*
c IF( INTA.GE.225 .AND. INTA.LE.250 ) INTA = INTA - 32
c IF( INTB.GE.225 .AND. INTB.LE.250 ) INTB = INTB - 32
c END IF
c LSAME = INTA.EQ.INTB
*
* RETURN
*
* End of LSAME
*
c END
c$$$ SUBROUTINE XERBLA( SRNAME, INFO )
c$$$*
c$$$* -- LAPACK auxiliary routine (version 3.0) --
c$$$* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
c$$$* Courant Institute, Argonne National Lab, and Rice University
c$$$* September 30, 1994
c$$$*
c$$$* .. Scalar Arguments ..
c$$$ CHARACTER*6 SRNAME
c$$$ INTEGER INFO
c$$$* ..
c$$$*
c$$$* Purpose
c$$$* =======
c$$$*
c$$$* XERBLA is an error handler for the LAPACK routines.
c$$$* It is called by an LAPACK routine if an input parameter has an
c$$$* invalid value. A message is printed and execution stops.
c$$$*
c$$$* Installers may consider modifying the STOP statement in order to
c$$$* call system-specific exception-handling facilities.
c$$$*
c$$$* Arguments
c$$$* =========
c$$$*
c$$$* SRNAME (input) CHARACTER*6
c$$$* The name of the routine which called XERBLA.
c$$$*
c$$$* INFO (input) INTEGER
c$$$* The position of the invalid parameter in the parameter list
c$$$* of the calling routine.
c$$$*
c$$$* =====================================================================
c$$$*
c$$$* .. Executable Statements ..
c$$$*
c$$$ WRITE( *, FMT = 9999 )SRNAME, INFO
c$$$*
c$$$ STOP
c$$$*
c$$$ 9999 FORMAT( ' ** On entry to ', A6, ' parameter number ', I2, ' had ',
c$$$ $ 'an illegal value' )
c$$$*
c$$$* End of XERBLA
c$$$*
c$$$ END