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
*> \verbatim
*>          CA is CHARACTER*1
*> \endverbatim
*>
*> \param[in] CB
*> \verbatim
*>          CB is CHARACTER*1
*>          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 aux_blas
*
*  =====================================================================
      LOGICAL FUNCTION lsame(CA,CB)
*
*  -- Reference BLAS level1 routine --
*  -- Reference BLAS 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
*     ..
*
*     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