C
C             Parallel Sparse BLAS  version 2.2
C   (C) Copyright 2006/2007/2008
C                      Salvatore Filippone    University of Rome Tor Vergata
C                      Alfredo Buttari        University of Rome Tor Vergata
C
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C modification, are permitted provided that the following conditions
C are met:
C   1. Redistributions of source code must retain the above copyright
C      notice, this list of conditions and the following disclaimer.
C   2. Redistributions in binary form must reproduce the above copyright
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C   3. The name of the PSBLAS group or the names of its contributors may
C      not be used to endorse or promote products derived from this
C      software without specific written permission.
C
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C
C 
C     This routine compute only the casew with Unit diagonal ...
      SUBROUTINE DJADSV(UNITD,NROW,NG,A,KA,IA,JA,X,Y,IERROR)
      use psb_const_mod
      implicit none 
      real(psb_dpk_) A(*),X(*),Y(*)
      integer  IA(3,*),JA(*),KA(*),nrow,ng,i,j,k,ipg,ip2,ipx
      CHARACTER UNITD
      INTEGER   IERROR

      IERROR=0

      IF (UNITD.EQ.'U') THEN
        
        IF (NG.EQ.0) THEN
          DO I = 1, NROW
            Y(I) = X(I)
          ENDDO
        ENDIF

        DO IPG=1,NG
          DO I = IA(1,IPG),IA(1,IPG+1)-1
            Y(I) = X(I)
          END DO
*
*        LOOP ON COLUMNS
*        ---------------
*
          IP2 = IA(2,IPG)
          DO K = IP2, IA(3,IPG)-1
            IPX = IA(1,IPG)
            DO I = JA(K), JA(K+1)-1
              Y(IPX) = Y(IPX) - A(I)*Y(KA(I))
              IPX = IPX+1
            ENDDO
          ENDDO
*
*
*       LOOP ON ROWS
*       ---------------
*
          IPX = IA(1,IPG)
          DO K = IA(3,IPG), IA(2,IPG+1)-1
            DO I = JA(K), JA(K+1)-1
              Y(IPX) = Y(IPX) - A(I)*Y(KA(I))
            ENDDO
            IPX = IPX + 1
          ENDDO

****************************************
        END DO                  !END LOOP ON IPG=1,NG
****************************************
      ELSE
        WRITE(0,*) 'ERROR in DJADSV'
      ENDIF
      RETURN
      END