lsame.f

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*> \brief \b LSAME
*
*  =========== DOCUMENTATION ===========
*
* Online html documentation available at
*            http://www.netlib.org/lapack/explore-html/
*
*  Definition:
*  ===========
*
*      LOGICAL FUNCTION LSAME( CA, CB )
*
*     .. Scalar Arguments ..
*      CHARACTER          CA, CB
*     ..
*
*
*> \par Purpose:
*  =============
*>
*> \verbatim
*>
*> LSAME returns .TRUE. if CA is the same letter as CB regardless of
*> case.
*> \endverbatim
*
*  Arguments:
*  ==========
*
*> \param[in] CA
*> \param[in] CB
*> \verbatim
*>          CA and CB specify the single characters to be compared.
*> \endverbatim
*
*  Authors:
*  ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \ingroup lsame
*
*  =====================================================================
      LOGICAL FUNCTION lsame( CA, CB )
*
*  -- LAPACK auxiliary routine --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      CHARACTER          ca, cb
*     ..
*
* =====================================================================
*
*     .. Intrinsic Functions ..
      INTRINSIC          ichar
*     ..
*     .. Local Scalars ..
      INTEGER            inta, intb, zcode
*     ..
*     .. Executable Statements ..
*
*     Test if the characters are equal
*
      lsame = ca.EQ.cb
      IF( lsame )
     $   RETURN
*
*     Now test for equivalence if both characters are alphabetic.
*
      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.
*
      inta = ichar( ca )
      intb = ichar( cb )
*
      IF( zcode.EQ.90 .OR. zcode.EQ.122 ) THEN
*
*        ASCII is assumed - ZCODE is the ASCII code of either lower or
*        upper case 'Z'.
*
         IF( inta.GE.97 .AND. inta.LE.122 ) inta = inta - 32
         IF( intb.GE.97 .AND. intb.LE.122 ) intb = intb - 32
*
      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'.
*
         IF( inta.GE.129 .AND. inta.LE.137 .OR.
     $       inta.GE.145 .AND. inta.LE.153 .OR.
     $       inta.GE.162 .AND. inta.LE.169 ) inta = inta + 64
         IF( intb.GE.129 .AND. intb.LE.137 .OR.
     $       intb.GE.145 .AND. intb.LE.153 .OR.
     $       intb.GE.162 .AND. intb.LE.169 ) intb = intb + 64
*
      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'.
*
         IF( inta.GE.225 .AND. inta.LE.250 ) inta = inta - 32
         IF( intb.GE.225 .AND. intb.LE.250 ) intb = intb - 32
      END IF
      lsame = inta.EQ.intb
*
*     RETURN
*
*     End of LSAME
*
      END