'HEAD'  PUSH AND POP ROUTINES
C     EDIT DATE   10DEC78  21:04
C     SOURCE FILE PSHPOPFTM.FS
C     AUTHOR      F. T. MICKEY
C     CLUSTER     26
      'OUTFILE' PUSHFTM.FR
C     SUBROUTINE PUSH
C
C     SAVES THREE VALUES ON A LIFO STACK, TO BE RETRIEVED
C     LATER BY POP.  PARAMETERS FOR PUSH AND POP MUST BE
C     IN THE SAME ORDER.
C
      SUBROUTINE PUSH (A, B, C)
      'INCLUDE' PSHCOMFTM.IN,
      INTEGER A, B, C
      IF (PX .GT. PEND) CALL FATAL (45)
      PSTACK (PX) = A
      PSTACK (PX+1) = B
      PSTACK (PX+2) = C
      PX = PX + 3
      RETURN
      END
      'OUTFILE' POPFTM.FR
C     SUBROUTINE POP
C
C     RETRIEVES VALUES STACKED BY PUSH.
C
      SUBROUTINE POP (A, B, C)
      'INCLUDE' PSHCOMFTM.IN,
      INTEGER A, B, C
      PX = PX - 3
      IF (PX .LE. 0) CALL FATAL (46)
      A = PSTACK (PX)
      B = PSTACK (PX+1)
      C = PSTACK (PX+2)
      RETURN
      END