SLATEC Routines --- XRED ---

*DECK XRED
      SUBROUTINE XRED (X, IX, IERROR)
C***BEGIN PROLOGUE  XRED
C***PURPOSE  To provide single-precision floating-point arithmetic
C            with an extended exponent range.
C***LIBRARY   SLATEC
C***CATEGORY  A3D
C***TYPE      SINGLE PRECISION (XRED-S, DXRED-D)
C***KEYWORDS  EXTENDED-RANGE SINGLE-PRECISION ARITHMETIC
C***AUTHOR  Lozier, Daniel W., (National Bureau of Standards)
C           Smith, John M., (NBS and George Mason University)
C***DESCRIPTION
C     REAL X
C     INTEGER IX
C
C                  IF
C                  RADIX**(-2L) .LE. (ABS(X),IX) .LE. RADIX**(2L)
C                  THEN XRED TRANSFORMS (X,IX) SO THAT IX=0.
C                  IF (X,IX) IS OUTSIDE THE ABOVE RANGE,
C                  THEN XRED TAKES NO ACTION.
C                  THIS SUBROUTINE IS USEFUL IF THE
C                  RESULTS OF EXTENDED-RANGE CALCULATIONS
C                  ARE TO BE USED IN SUBSEQUENT ORDINARY
C                  SINGLE-PRECISION CALCULATIONS.
C
C***SEE ALSO  XSET
C***REFERENCES  (NONE)
C***ROUTINES CALLED  (NONE)
C***COMMON BLOCKS    XBLK2
C***REVISION HISTORY  (YYMMDD)
C   820712  DATE WRITTEN
C   881020  Revised to meet SLATEC CML recommendations.  (DWL and JMS)
C   901019  Revisions to prologue.  (DWL and WRB)
C   901106  Changed all specific intrinsics to generic.  (WRB)
C           Corrected order of sections in prologue and added TYPE
C           section.  (WRB)
C   920127  Revised PURPOSE section of prologue.  (DWL)
C***END PROLOGUE  XRED