Motorola DSP96002 User Manual
Page 578
MOTOROLA
DSP96002 USER’S MANUAL
B-59
divloop_fast not
d0
d8.l,d3.l
lsl
d2,d0
lsr
d2,d0
d1.m,d2.l
tst
d2
neg
d0
ifmi
divdone
The final quotient is destroyed in the generation of the remainder. This program calculates only the number
of quotient bits required and has variable execution time.
Signed 32 Bit Integer
Remainder of d0 = d0 rem d1, d0 >= d1
abs
d1
d0.l,d2.l
abs
d2
d0.l,d1.m
cmp
d1,d2
d2.l,d2.m
jlo
divdone
bfind
d2,d0
bfind
d1,d2
d0.h,d0.l
move
d2.h,d2.l
sub
d0,d2
d2.m,d0.l
inc
d2
d2.l,d2.h
lsl
d2,d1
d2.l,d2.h
do
d2.l,remloop_fast
cmp
d1,d0
sub
d1,d0
ifhs
rol
d0
remloop_fastlsr
d2,d0
d1.m,d2.l
tst
d2
neg
d0
ifmi
divdone
B.1.33
Graphics Accept/Reject Of Polygons
In graphics applications, checks are made to determine if objects are within a viewing window. Initial
checks are made to see if the object can be trivially accepted or trivially rejected. If the object can not be
trivially accepted/rejected, then a clipping algorithm is used.
The following code segments perform the trivial accept/reject of a point, line or 4 point polygon within a
cube.
B.1.33.1
One Point Accept/Reject
This determines if the point (x,y,z) is within a three-dimensional view cube. If the point is within the cube,
the A (accept) bit of the CCR will be set. Single point accept/reject for plotting is useful for plotting of sto-
chastic images such as fractals.