Motorola DSP56000, 24-Bit Digital Signal Processor manual Benchmark Programs

BENCHMARK PROGRAMS

lua	(r0)+n0,r1	;r1 ptr to next group b
move	r1,r5	;r5 ptr to next group d

;Intermediate Passes -- W(n) < 1

;A---\ /---A’= Re[ A + jC + (B - jD)W(k) ] = A+BWr+DWi=A+T1

;B----\__/----B’= Im[ A + jC - (B - jD)W(k) ] = C+DWr-BWi=T2+C

;C----/ \----C’= Re[ A + jC - (B - jD)W(k) ] = A-(BWr+DWi)=A-T1

;D---/ \---D’= Im[-A - jC - (B - jD)W(k) ] = -C+DWr-BWi=T2-C

;______________________________

move	x:(r2)+,x0		y:(r6)+,y0	;x0=Wi, y0=Wr
move	x:(r1)-,x1		y:(r5),y1	;x1=b,y1=d
move	x:(r1),B			;for pointer reason
do	n0,end_bfly			;n0 bfly in this group
mpy	-x1,x0,B B,x:(r1)			;B=-bWi, PUT c’ to x:b
mac	y0,y1,B y:(r4),A			;B=dWr-bWi=T2, A=c
sub	A,B			;B=T2-c=d’
addl	B,A x:(r1)+,B B,x:(r5)+			;A=T2+c=b’, PUT d’
mpy	-x1,y0,B x:(r0),A A,y:(r4)+			;B=-bWr, A=a, PUT b’ to y:c
mac	-x0,y1,B x:(r1)-,x1			;B=-bWr-dWi=-T1, x1=next b
sub	B,A			;A=a+T1=a’
addl	A,B A,x:(r0)+ y:(r5),y1			;B=a-T1=c’, y1=next d, PUT a’
end_bfly
move	B,x:(r1)+			;PUT last b’
end_group
move	#idata,r0			;r0 = ptr to a
end_pass
;the last pass converts bergland order to normal order by calling bergtable
move	r7,r2			;r2 points to real twiddle
move	r2,r6			;r6 points to imag twiddle
move	r0,r4			r4 points to c
move	#bergtable,r3			;r3=pointer of bergland table
move	#(points/4)-1,n2			;n2=group per pass -1
move	x:(r3)+,r7			;get first index
move	x:(r3)+,r1			;get second index
move	#2,n4
; first group in the last pass
move	x:(r0)+,A		y:(r4)+,B	;A=a, B=c
sub	B,A	x:(r0)+,x0 y:(r6)+,y0		;A=a-c=c’,x0=b, y0=Wr for next bfly
addl	A,B	A,x:(r1) y:(r4),A		;B=a+c=a’, A=d,PUT c’ to x:b
sub	x0,A	B,x:(r7)		;A=d-b=d’,PUT a’ to x
move	y:(r4)+,B			;B=d
add	x0,B	A,y:(r1)		;B=d+b=b’, A=next a,PUT d’
move	x:(r0)+,A B,y:(r7)			;A=next a, PUT b’
move	x:(r2)+,x0 y:(r4)+,B			;x0=Wi,B=next c
do	n2,end_lastg			;rest groups in the last pass

B - 24 BENCHMARK PROGRAMS MOTOROLA