DXRED(3)

SYNOPSIS
SUBROUTINE DXRED (X, IX, IERROR)

NAME
dxred - To provide double-precision floating-point arithmetic with an extended exponent range.

LIBRARY
SLATEC

CATEGORY
A3D

TYPE
DOUBLE PRECISION (XRED-S, DXRED-D)

KEYWORDS
EXTENDED-RANGE DOUBLE-PRECISION ARITHMETIC

AUTHOR
Lozier, Daniel W., (National Bureau of Standards) Smith, John M., (NBS and George Mason University)

DESCRIPTION
DOUBLE PRECISION X INTEGER IX IF RADIX**(-2L) .LE. (ABS(X),IX) .LE. RADIX**(2L) THEN DXRED TRANSFORMS (X,IX) SO THAT IX=0. IF (X,IX) IS OUTSIDE THE ABOVE RANGE, THEN DXRED TAKES NO ACTION. THIS SUBROUTINE IS USEFUL IF THE RESULTS OF EXTENDED-RANGE CALCULATIONS ARE TO BE USED IN SUBSEQUENT ORDINARY DOUBLE-PRECISION CALCULATIONS.

SEE ALSO
DXSET

REFERENCES
(NONE)

ROUTINES CALLED
(NONE)

COMMON BLOCKS
DXBLK2

REVISION HISTORY (YYMMDD)
820712 DATE WRITTEN
881020 Revised to meet SLATEC CML recommendations. (DWL and JMS)
901019 Revisions to prologue. (DWL and WRB)
901106 Changed all specific intrinsics to generic. (WRB) Corrected order of sections in prologue and added TYPE section. (WRB)
920127 Revised PURPOSE section of prologue. (DWL)