BENCHMARK PROGRAMS
MOTOROLA
BENCHMARK PROGRAMS B - 25 ; 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:(r0)+,x1 y:(r4)-,y1 ;x1=b, y1=d, r4 ptr back to c
mpy x1,y0,B x:(r3)+,r7 ;A=bWr,
mac x0,y1,B x:(r3)+,r1 ;B=bWr+dWi=T1, get first index
sub B,A ;A=a-T1=c’, get second index
addl A,B A,x:(r1) ;B=a+T1=a’, PUT c’ to x:b
mpy y1,y0,A B,x:(r7) ;B=dWr, B=c PUT a’
mac -x1,x0,A y:(r4)+n4,B ;A=dWi-bWr=T2, B=c, r4 ptr to next c
sub B,A x:(r2)+,x0 y:(r6)+,y0 ;A=T2-c=d’,x0=next Wi, y0=next Wr
addl A,B A,y:(r1) ;B=T2+c=b’, update r4, A=next a, PUT d’
move x:(r0)+,A B,y:(r7) ;PUT b’, A=next a
move y:(r4)+,B ;B=next c
end_lastg endm
; Real input FFT based on Glenn Bergland algorithm
;
; Normal order input and normal order output.
; Since 56001 does not support Bergland addressing, extra instruction cycles are needed
; for converting Bergland order to normal order.It has been done in the last pass by
; looking at the bergtable.
; 'bergsincos' generates sin and cos table with size of points/4,COS in Y, SIN in X
; 'bergorder' generates table for address conversion, the size of twiddle factors is half
; of FFT output's
; 'rfft-56b' does FFT
;
; Normal order input and normal order output.
;
; Real input data are split into two parts, the first part is put in X, the second in Y.
; Real output data are in X, imaginary output data are in Y.
; The first real output is DC
; The first imaginary output is the Nyquist frequency.
; Note that only DC to Nyquist frequency range is calculated by this algorithm
; After twiddle factors and bergtable are generated, you may overwrite 'bergorder',
; 'norm2berg' by 'rfft-56b' for saving P memory.
;
;
Performance
;----------------------------------------------------------------
; Real input data points Clock cycle
; 64 1686
; 128 3846
; 256 8656
; 512 19296