C
C
C-----------------------------------------------------------------------------
C
C	FUNCTION:	G C D I
C
C	AUTHOR:		Jan H. Belgraver
C
C	DATE:		29-NOV-83
C
C	VERSION:	V1.0
C
C	MODIFIED BY:	
C
C	PURPOSE:	Computes the Greatest Common Divisor of two integers.
C
C	DESCRIPTION:	Step 1
C			Subtract the 2nd number (I2) as many times as possible
C			from the 1st one (I1) and save remainder using FORTRAN
C			function MOD. 
C			Step 2
C			Test if remainder is equal to zero, if so GCD = I2.
C			If not replace I1 with I2 and I2 with remainder and 
C			proceed with step 1.
C			Repeat both steps until remainder becomes zero.
C
C	CALL:		result = GCDI (I1, I2)
C
C	ARGUMENTS:	NAME		DESCRIPTOIN
C	    I		I1	Integer value	(INTEGER*4)
C	    I		I2	Integer value	(INTEGER*4)
C	    O		result	Contains GCD	(INTEGER*4)
C
C	CALLS TO:	MOD
C
C-----------------------------------------------------------------------------
C
C

C
C
	INTEGER*4	FUNCTION	G C D I	( I1, I2 )
C
C
	INTEGER*4	I1, I2, IREST


10	IREST	= MOD	(I1, I2)
	IF	(IREST .EQ. 0)	GOTO	20
	I1	= I2
	I2	= IREST
	GOTO	10

20	GCDI	= IABS	(I2)

	RETURN
	END