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Motorola DSP96002 User Manual

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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.