📄 fft16_mac.s.list
字号:
0x00000224: 3a25 move.w -(a5),d5 ;d5 = ImX[im]
0x00000226: 48c5 ext.l d5
0x00000228: d685 add.l d5,d3 ;d3 = ImX[i] + ImX[im]
0x0000022a: e283 asr.l #1,d3 ;d3 = (ImX[i] + ImX[im]) / 2
0x0000022c: 3cc3 move.w d3,(a6)+ ;ReX[ip2] = d3
0x0000022e: 31836800 move.w d3,(a0,d6.l) ;ReX[ipm] = ReX[ip2]
0x00000232: 3824 move.w -(a4),d4 ;d4 = ReX[im]
0x00000234: 48c4 ext.l d4
0x00000236: 2e04 move.l d4,d7 ;d7 = ReX[im]
0x00000238: 3412 move.w (a2),d2 ;d2 = ReX[i]
0x0000023a: 48c2 ext.l d2
0x0000023c: 9882 sub.l d2,d4 ;d4 = ReX[im] - ReX[i]
0x0000023e: e284 asr.l #1,d4 ;d4 = (ReX[im] - ReX[i]) / 2
0x00000240: 33840800 move.w d4,(a1,d0.l) ;ImX[ip2] = d4
0x00000244: 4484 neg.l d4 ;d4 = -d4
0x00000246: 33846800 move.w d4,(a1,d6.l) ;ImX[ipm] = -ImX[ip2]
0x0000024a: d487 add.l d7,d2 ;d2 = ReX[i] + ReX[im]
0x0000024c: e282 asr.l #1,d2 ;d2 = (ReX[i] + ReX[im]) / 2
0x0000024e: 34c2 move.w d2,(a2)+ ;ReX[i] = d2
0x00000250: 3882 move.w d2,(a4) ;ReX[im] = ReX[i]
0x00000252: 9285 sub.l d5,d1 ;d1 = ImX[i] - ImX[im]
0x00000254: e281 asr.l #1,d1 ;d1 = (ImX[i] - ImX[im]) / 2
0x00000256: 36c1 move.w d1,(a3)+ ;ImX[i] = d1
0x00000258: 4481 neg.l d1 ;d1 = -d1
0x0000025a: 3a81 move.w d1,(a5) ;ImX[im]=-ImX[i];
0x0000025c: 5480 addq.l #2,d0 ;loop processing
0x0000025e: 5586 subq.l #2,d6
0x00000260: 0c8000000600 cmpi.l #1536,d0
0x00000266: 65b6 bcs.b adjust
0x00000268: 7000 moveq.l #0,d0
0x0000026a: 316902000600 move.w (512,a1),(1536,a0) ;ReX[n34]=ImX[n4];
0x00000270: 31510400 move.w (a1),(1024,a0) ;ReX[nd2]=ImX[0];
0x00000274: 33400600 move.w d0,(1536,a1) ;ImX[n34]=0;
0x00000278: 33400400 move.w d0,(1024,a1) ;ImX[nd2]=0;
0x0000027c: 33400200 move.w d0,(512,a1) ;ImX[n4]=0;
0x00000280: 3280 move.w d0,(a1) ;ImX[0]=0;
0x00000282: 2a7c00000400 movea.l #1024,a5 ;the last stage of FFT
0x00000288: 287c00000000 movea.l #TF_table,a4 ;a4 points to the first twiddle factor
0x0000028e: 2448 movea.l a0,a2 ;a0 points to ar0
0x00000290: 2649 movea.l a1,a3 ;a1 points to ai0
0x00000292: d5cd adda.l a5,a2 ;a2 points to br0
0x00000294: d7cd adda.l a5,a3 ;a3 points to bi0
0x00000296: 2c7c00000000 move.l #0,a6 ;counter for butterfly loop
fin_stage
0x0000029c: 201c move.l (a4)+,d0 ;wr -> MSW of d0
;wi -> LSW of d0
0x0000029e: 2812 move.l (a2),d4
0x000002a0: 3410 move.w (a0),d2
0x000002a2: 3e11 move.w (a1),d7
0x000002a4: 48c2 ext.l d2
0x000002a6: 48c7 ext.l d7
0x000002a8: a13c00000000 move.l #0,ACC
0x000002ae: aa9341c0 msacl.w d0.u,d4.u,(a3),d5 ;ar-br*wr -> ACC, bi -> MSW of d5
0x000002b2: aa000180 msac.w d0.l,d5.u ;ar-br*wr-bi*wi = xr -> ACC, ai -> MSW of d6
0x000002b6: a183 move.l ACC,d3
0x000002b8: d682 add.l d2,d3
0x000002ba: 48c3 ext.l d3
0x000002bc: e283 asr.l #1,d3
0x000002be: 30c3 move.w d3,(a0)+
0x000002c0: 9483 sub.l d3,d2 ;2*ar-xr = yr -> d2
0x000002c2: 34c2 move.w d2,(a2)+ ;yr -> memory
0x000002c4: a13c00000000 move.l #0,ACC ;ai -> ACC
0x000002ca: a8000280 mac.w d0.l,d4.u,<< ;ai+br*wi -> ACC, ar -> MSW of d2
0x000002ce: aa0003c0 msac.w d0.u,d5.u,<< ;ai+br*wi-bi*wr = xi -> ACC, br -> MSW of d4
0x000002d2: a183 move.l ACC,d3
0x000002d4: d687 add.l d7,d3
0x000002d6: 48c3 ext.l d3
0x000002d8: e283 asr.l #1,d3
0x000002da: 32c3 move.w d3,(a1)+ ;xi -> memory
0x000002dc: 9e83 sub.l d3,d7 ;2*ai-xi = yi -> d6
0x000002de: 36c7 move.w d7,(a3)+ ;yi -> memory
0x000002e0: ddfc00000002 adda.l #2,a6
0x000002e6: bdcd cmpa.l a5,a6
0x000002e8: 65b2 bcs.b fin_stage ;end of butterfly loop
0x000002ea: a93c00000000 move.l #0x00000000,MACSR
0x000002f0: 4cd77fff movem.l (a7),d0-d7/a0-a6
0x000002f4: 4fef0048 lea +72(a7),a7
0x000002f8: 4e75 rts
;******************************************************************************
;Inversed Real FFT
;******************************************************************************
;Upon entry, REX[ ] and IMX[ ] contain the real and imaginary parts of the
;frequency domain running from index 0 to 512. The remaining samples in
;REX[ ] and IMX[ ] are ignored.
;Upon return, REX[ ] contains the real time domain.
;******************************************************************************
_inv_fft16_mac
;make frequency domain symmetrical
;Corresponding C code:
;n=smpl_num;
;for (i=((n>>1)+1);i<n;i++){
; ReX[i]=ReX[n-i];
; ImX[i]=-ImX[n-i];
;}
0x000002fa: 7200 moveq.l #0,d1 ;make frequency domain
0x000002fc: 4cef03000004 movem.l (4,a7),a0-a1 ;symmetrical
0x00000302: 45e80400 lea (1024,a0),a2
0x00000306: 47e90400 lea (1024,a1),a3
0x0000030a: 41e80402 lea (1026,a0),a0
0x0000030e: 43e90402 lea (1026,a1),a1
movneg
0x00000312: 30e2 move.w -(a2),(a0)+ ;ReX[i]=ReX[n-i];
0x00000314: 3023 move.w -(a3),d0
0x00000316: 4480 neg.l d0
0x00000318: 32c0 move.w d0,(a1)+ ;ImX[i]=-ImX[n-i];
0x0000031a: 5281 addq.l #1,d1 ;loop processing
0x0000031c: 0c81000001ff cmp.l #511,d1
0x00000322: 65ee bcs.b movneg
;add real and imaginary parts together
;Corresponding C code:
;for (i=0;i<n;i++){
; ReX[i]=ReX[i]+ImX[i];
;}
0x00000324: 7000 moveq.l #0,d0 ;add real and imaginary parts
0x00000326: 4cef03000004 movem.l (4,a7),a0-a1 ;together
sum
0x0000032c: 3210 move.w (a0),d1 ;d1 = ReX[i]
0x0000032e: 48c1 ext.l d1
0x00000330: 3419 move.w (a1)+,d2 ;d2 = ImX[i]
0x00000332: 48c2 ext.l d2
0x00000334: d282 add.l d2,d1 ;d1 = ReX[i] + ImX[i]
0x00000336: 30c1 move.w d1,(a0)+ ;ReX[i] = d1
0x00000338: 5280 addq.l #1,d0 ;loop processing
0x0000033a: 0c8000000400 cmp.l #1024,d0
0x00000340: 65ea bcs.b sum
0x00000342: 2f2f000c move.l (12,a7),-(a7) ;calculate forward real FFT
0x00000346: 2f2f000c move.l (12,a7),-(a7)
0x0000034a: 2f2f000c move.l (12,a7),-(a7)
0x0000034e: 4eb90000004e jsr _fft16_mac
0x00000354: dffc0000000c add.l #12,a7
;add real and imaginary parts together
;Corresponding C code:
;for (i=0;i<n;i++){
; ReX[i]=(ReX[i]+ImX[i])/n;
;}
0x0000035a: 7000 moveq.l #0,d0 ;add real and imaginary parts
0x0000035c: 4cef03000004 movem.l (4,a7),a0-a1 ;together
norm
0x00000362: 3210 move.w (a0),d1 ;d1 = ReX[i]
0x00000364: 3419 move.w (a1)+,d2 ;d2 = ImX[i]
0x00000366: d282 add.l d2,d1 ;d1 = ReX[i] + ImX[i]
0x00000368: 30c1 move.w d1,(a0)+ ;ReX[i] = d1
0x0000036a: 5280 addq.l #1,d0 ;loop processing
0x0000036c: 0c8000000400 cmp.l #1024,d0
0x00000372: 65ee bcs.b norm
0x00000374: 4e75 rts
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