Intel 80287, 80286 manual Intel Programming Numeric Applications, ·7. Sample ASM286 Program

intel" PROGRAMMING NUMERIC APPLICATIONS

"iAPX286 MACRO ASSEMBLER EXAMPLE_ASM286_PROGRAM

SERIES-I I I iAPX286 MACRO ASSEMBLER X10B ASSEMBLY OF MODULE EXAMPLE_ASM286_PROGRAM OBJECT MODULE PLACED IN : F6: 287EXP, OBJ

ASSEMBLER INVOKED BY: ASM286.86: F6: 287EXP. SRC XREF

LOC OBJ LINE SOURCE

1name example_ASM28b_pT'ogram

2Define initialization routine

3extl'n init287: faT'

4

SAllocate 'space foT' data

6 data se!Jment T'W public

0000	3E03	7	control_287		dw	033eh
0002	????	8	n - of	- ,	dU/	?
0004	( 100	9	,_array		dd	100 dup (1)
	????????
	)
0194 ????????		10	sum_squaT'es		d d	?
0198	????????	11	sum_indexes		dd	?
019C	????????	12	sum	,	dd	?
		13	data	ends
		14

15; Allocate CPU stack spaclt

16stack stackseg 400

			17	; Begi"n
			Ie		code
			19	code	segment	eT'	public
			20		assume	ds:	data. 55: stack. es: nothing
0000			21	start:	mov	ax. data
0000	B8----		22
0003	8ED8		23		mov	ds. ax
0005	B8----	R	24		mov	ax. stack
0008	8EDO		25			ss. ax
OOOA BCFEFF		R	26			sp. sta.ckstsrt stack

'Z7

28Assume x_array and "_of_x are initialized

29this pprogram zeroes n_of_lC

			30	Prepare the 80287 or its emulator.
			31
OOOD 9AOOOO----		E	32		call	init287
0012	D92EOOOO	R	33		fldclll	control_287
			34	j Clear	three	reg isters to hold	running	sums
			35
0016	D9EE		36		fldz
0018	D9EE		37		fld z
001A	D9EE		38		fld z
			39	Setup CX as loop counter imd
			40
			41	SI as index to x_array
001C	8BOE0200	R	42		mov	c lC. n - of -,
0020	F7E9		43		imul
0022 8BFO'			44		mov	si. ax
			45	; Sl now contains index of last element + 1
			46
			47	; Loop thru lC_array. accumulat.ing ~ums
0024			48	sum_next:
0024	83EE04		49		sub	si. type x_array	backup	one	element
0027	D9840400	R	50		fld	x_array[siJ	push it	on	the stac k
002B	DCC3		51		fadd	st(3)' st	add into sum of x
002D	D9CO		52		fld	st	duplicate x		on top
002F	DCC8		53		fmul	st . st	square	it
0031	DEC2		54		faddp	st(2). st	add into sum of (index+x)
			55				and discard
0033	FFOE0200	R	56		dec		reduce index for next iteration
0037	E2EB		57		loop			; continue
			58	; Pop running sums into memory
			59
0039			60	pop_results:
0039	D91E9401		61		fstp	sum_squares
003D	D91E9801		Qc.		.tc.t.!"I	sum indexes
0041	D91E9COl	R	63		fstp
0045 9B			64		fwai t
			65
			66	Etc.
			67
			68
			69	code	ends	start
			70		end

Figure 2·7. Sample ASM286 Program

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