Motorola DSP96002 User Manual page 672

; d4.h
; d5.h
;
;
;
; Alters Program Control Registers
; pc
;
;
; Version 1.0
; Latest Revision - 01-Aug-88
;
section
emsk equ
eden equ
grsmsk equ
grmsk equ
smsk equ
bit
onemsk equ
inum equ
imsk equ
qnane equ
qnanmh equ
qnanml equ
maxnum equ
;
sdptest
;
; Clear ER portion of status register
;
andi
;
; Check for Maximum and Minimum Exponents
;
move
move
move
and
cmp
jeq
move
and
cmp
jeq
tst
jeq
tst
jeq
jmp
;
; Check if Addend 0 is Infinity
;
_mant1 move
MOTOROLA
d4.l
d5.l
d6.l
d7.l
sr
ieeeadd
$7ff ; exponent mask
$1 ; denorm exponent
$700 ; GRS (guard-round-sticky) bits mask
$fffffe00 ; GR (guard-round) bits mask
$ffffff00 ; mask to clear bits to right of the sticky
$1ff ; mask to set bits to right of the round bit
$100 ; increment number
$7fffffff ; infinity mask
$7ff ; quiet NaN exponent
$7fffffff ; quiet NaN mantissa high
$ffffffff ; quiet NaN mantissa low
$fffff800 ; low part of maximum number
; double precision add subroutine
#0,er
#0,d6.l
d0.h,d4.l
#emsk,d7.l
d7,d4 d0.m,d2.l
d7,d4 d1.m,d3.l
_mant1
d1.h,d5.l
d7,d5 #1,d6.l
d7,d5 #0,d2.m
_mant2
d4 #0,d6.l
_mant3
d5 #1,d6.l
_mant4
_nadd
#imsk,d7.l ; get infinity mask
DSP96002 USER'S MANUAL
; addend 0 flag
; get exp0
; get exponent mask
; delete tags, get m0.h
; check max exp, get m1.h
; jump if exp0 = max exp
; get exp1
; delete tags, a1 flag
; check max exp, sticky=0
; jump if exp1 = max exp
; check min exp, a0 flag
; jump if exp0 = min exp
; check min exp, a1 flag
; jump if exp1 = min exp
; jump to normalized add
B-153