User's Manual

iAPX2Bb MACRO ASSEMBLER
LOC OBJ
COCA O'9EO
ooce D9Cl
DOCE D96EFC
0001 D9FC
0003 8946FC
0006 D9bEFC
0009 D9CA
DaDa 08E2
DODD BB46FE
OOEO D9FD
00E2 D9FO
00E4 C9
ODES DEE1
OOE7 Dcca
00E9 C3
NUMERIC PROGRAMMING EXAMPLES
Calculate the value of 10**ax
LINE SOURCE
5.
-Fchs
60
n.
st( 1)
61
fIldcw
word
ptr
6. f'rndint
63
mav word ptr
6'
fidew wOl'd
ptr
65
Fxch
st(2)
66
hub
st, st(2)
67
mov
ax, Cbp-2J
68 flscale
6.
f'2xml
70
l ... v.
71 fsubl'
7. flmul st. steOl
73
rot
7.
75
get_power _10
endp
76
77 code
ends
78
en.
[bp-4J
[bp-4], ax
[bp-4J
12: 11: 08 09/25/83 PAGE
I COPV power value in base two
Set new control word value
TOS = I: -inf < I <= X. I is an int~g~r
I R~5tor~ original rounding control
I TOS .. X. 91(U "" -1.0. 51(2) '" I
TOS. F - .. X-I: a < .. TOS < 1. a
Restore power of ten
TOS ... F/2: a < .. TOS < 0.5
TOS '" 2**(F/21 - 1. 0
I Restore stack
J Form 2**(F/2)
Form 2**F
j OK to leave fmul running
A8SEMBL V COMPLETE,
NO WARNINGS,
NO ERRORS
iAPX28b MACRO ASSEMBLER
Det~rmin~ TOS r~gist~r cont~nts
12: 12: 13 09/25/83 PAGE
SERtES-I11 iAPX28b MACRO ASSEMBLER XI08 ASSEMBLV OF MODULE TOS_STATUS
OBJECT
MODULE PLACED IN : F3: TOS8T. OBJ
ASSEMBLER
INVOKED BV: ASM28b.86: F3: T09ST. AP2
LaC
OBJ
0000
0000 09E5
0002 9BDFEO
0005 8AC4
0007 250740
OOOA COEC03
0000 OAC4
OOOF B400
0011 C3
LINE
SOURCE
1 +1 $title("D~t~rmine TOS register contents")
2
3 This subr.outine will return a value from 0-15 in AX corres,ponding
4 to the contents of 80287 T09. All re!listlH's are transparent and no
5 errors are possible The return value corresponds to c3,c2,cl.cO
6 of FXAM instruction.
7
8 tos_status
•
10
11
12
13
I.
15
16
17
18
,.
20
21
22
23
2.
25
26
27
28
2.
30
stack
code
code
pub lic
fxam
fstsw
mov
an.
,hr
mov
ret
stacks8g 6
se!lment
proc
a.
OIl. ah
al,4007h
ah,3
OIl. ah
ah.O
endp
ends
end
) Allocate space on the stack
pub 1 ic
) Get register contents status
) Get status
Put bit 10-8 into bits 2-0
Mask out bits c3,c2.c1.cO
) Put bit c3 into bit 11
J Put c3 into bit 3
I Clear return value
ASSEMBLV COMPLETE, NO WARNINGS, NO ERRORS
Fi!!~lrA 4-~~ Flnllting-Point to ASCII Conversion Routine (Cont'd.l
Function. Partitioning
Three separate modules implement the conversion. Most of the work of the conversion is done in the
module
FLOATING_TO_ASCII. The other modules are provided separately, because they have a
more general use.
One of them, GET_POWER_IO, is also used by the ASCII to floating-point conver-
sion routine. The other small module, TOS_STATUS, will identify what, if anything, is in the top of
the numeric register stack.
4-14