; SUBROUTINE FLINTP.MAC
; FLOATING POINT INTERPOLATION FUNCTION
; IF Y = F(X) AND FOR X1 AND X2 A CORRESPONDING
; Y1 AND Y2 ARE KNOWN, THEN GIVEN X0 BETWEEN
; X1 AND X2, Y0 WILL BE CALCULATED BY
; LINEAR INTERPOLATION.
; FORTRAN CALL:
;	Y0 = FLINTP(X1,X2,Y1,Y2,X0)
;
; DEFINE FLOATING REGISTERS:
AC0=%0
AC1=%1
AC2=%2
AC3=%3
	.TITLE	FLINTP
	.CSECT
	.GLOBL	FLINTP
; IF THE CONDITION OF THE FP STATUS REGISTER IS UNKNOWN
; THE FOLLOWING COMMANDS SHOULD BE THE FIRST TWO IN THE
; SUBROUTINE:
;	SETI
;	SETF
FLINTP:	LDF	@12(R5),AC3	;X0 IN AC3
	LDF	@4(R5),AC2	;X2 IN AC2
	SUBF	@2(R5),AC3	;X0-X1 IN AC3
	SUBF	@2(R5),AC2	;X2-X1 IN AC2
	DIVF	AC2,AC3		;(X0-X1)/(X2-X1) IN AC3
	LDF	@10(R5),AC1	;Y2 IN AC1
	LDF	@6(R5),AC0	;Y1 IN AC0
	SUBF	AC0,AC1		;Y2-Y1 IN AC1
	MULF	AC3,AC1		;(X0-X1)(Y2-Y1)/(X2-X1) IN AC1
	ADDF	AC1,AC0		;ANSWER IN AC0
	STF	AC0,-(SP)	;PUT IT ON STACK
	MOV	(SP)+,R0	;AND POP TO
	MOV	(SP)+,R1	;REGISTERS
	RTS	PC		;DONE
	.END