SUBROUTINE DESC_CONVERT( DESC_IN, DESC_OUT, INFO )

*

• .. Array Arguments .. INTEGER DESC_IN( * ), DESC_OUT( * ), INFO
• .. *
• Purpose

  ---

  *
• Converts descriptors from one type to another if they are compatible. *
• Supports *ONLY* an output descriptor type of 1D_horizontal (type
• number 501) or 1D_vertical (number 502).
• Supports only one-dimensional 1xP input grids if descriptor_in is 2D. *
• Arguments

  ---

  *
• DESC_IN: (input) input descriptor *
• DESC_OUT: (output) output descriptor (required to be 1D_horizontal
• in this release). *
• INFO: (output) return code *

  ---

  *
• .. Parameters .. INTEGER BLOCK_CYCLIC_2D, CSRC_, CTXT_, DLEN_, DT_, $ LLD_, MB_, M_, NB_, N_, RSRC_ PARAMETER ( BLOCK_CYCLIC_2D = 1, DLEN_ = 9, DT_ = 1, $ CTXT_ = 2, M_ = 3, N_ = 4, MB_ = 5, NB_ = 6, $ RSRC_ = 7, CSRC_ = 8, LLD_ = 9 )
• .. *
• .. Local Scalars .. INTEGER DESC_TYPE, DESC_TYPE_IN, ICTXT INTEGER CSRC, RSRC, MB, NB, LLDA INTEGER M, N, NPROW, NPCOL, IDUM1, IDUM2 *
• .. External routines ..
• EXTERNAL BLACS_GRIDINFO
• ..
• .. Executable Statements .. *

  INFO = 0 *

  DESC_TYPE_IN = DESC_IN( 1 ) *

  IF( DESC_TYPE_IN .EQ. BLOCK_CYCLIC_2D ) THEN

  ICTXT = DESC_IN( CTXT_ ) RSRC = DESC_IN( RSRC_ ) CSRC = DESC_IN( CSRC_ ) MB = DESC_IN( MB_ ) NB = DESC_IN( NB_ ) LLDA = DESC_IN( LLD_ ) M = DESC_IN( M_ ) N = DESC_IN( N_ ) CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, IDUM1, IDUM2 ) ELSEIF ( DESC_TYPE_IN .EQ. 502 ) THEN

  ICTXT = DESC_IN( 2 ) RSRC = DESC_IN( 5 ) CSRC = 1 MB = DESC_IN( 4 ) NB = 1 LLDA = DESC_IN( 6 ) M = DESC_IN( 3 ) N = 1 NPROW = 0 NPCOL = 1 ELSEIF ( DESC_TYPE_IN .EQ. 501 ) THEN

  ICTXT = DESC_IN( 2 ) RSRC = 1 CSRC = DESC_IN( 5 ) MB = 1 NB = DESC_IN( 4 ) LLDA = DESC_IN( 6 ) M = 1 N = DESC_IN( 3 ) NPROW = 1 NPCOL = 0 ENDIF

  *

  DESC_TYPE = DESC_OUT( 1 ) *

  IF( DESC_TYPE .EQ. 501 ) THEN

  IF( NPROW .NE. 1 )THEN

  INFO = -1 RETURN ENDIF DESC_OUT( 2 ) = ICTXT DESC_OUT( 5 ) = CSRC DESC_OUT( 4 ) = NB DESC_OUT( 6 ) = LLDA DESC_OUT( 3 ) = N ELSEIF( DESC_TYPE .EQ. 502 ) THEN

  IF( NPCOL .NE. 1 )THEN

  INFO = -1 RETURN ENDIF DESC_OUT( 2 ) = ICTXT DESC_OUT( 5 ) = RSRC DESC_OUT( 4 ) = MB DESC_OUT( 6 ) = LLDA DESC_OUT( 3 ) = M ENDIF *

  RETURN *

• End of DESC_CONVERT *

  END