C Copyright(C) 1999-2020 National Technology & Engineering Solutions
C of Sandia, LLC (NTESS).  Under the terms of Contract DE-NA0003525 with
C NTESS, the U.S. Government retains certain rights in this software.
C
C See packages/seacas/LICENSE for details

C=======================================================================
      SUBROUTINE MPMUL4(N,MASK,ARR1,ARR2,ARR3,ARR4,MAT,RES1,RES2,RES3,
     *                  RES4)
      DIMENSION ARR1(*),ARR2(*),ARR3(*),ARR4(*),RES1(*),
     *          RES2(*),RES3(*),RES4(*),MAT(4,4)
      REAL MAT
      include 'izbit.inc'

      IF (MASK.EQ.0) THEN
         RETURN

      END IF

      DO 3160 I = 1,N
         IF (IAND(MASK,IZBIT(I)).NE.0) THEN
           RES1(I) = MAT(1,1)*ARR1(I) + MAT(2,1)*ARR2(I) +
     *       MAT(3,1)*ARR3(I) + MAT(4,1)*ARR4(I)
           RES2(I) = MAT(1,2)*ARR1(I) + MAT(2,2)*ARR2(I) +
     *       MAT(3,2)*ARR3(I) + MAT(4,2)*ARR4(I)
           RES3(I) = MAT(1,3)*ARR1(I) + MAT(2,3)*ARR2(I) +
     *       MAT(3,3)*ARR3(I) + MAT(4,3)*ARR4(I)
           RES4(I) = MAT(1,4)*ARR1(I) + MAT(2,4)*ARR2(I) +
     *       MAT(3,4)*ARR3(I) + MAT(4,4)*ARR4(I)
         END IF

 3160 CONTINUE
      RETURN

      END