📄 fft_1024.asm
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// 5 m = c*g (1) | D1 = D0, o:p = k+:-l | write w | abcNefgqOP stuv// 6 D0 = addr(d), m = c*g (2) | | write v | abMnef qop stu// 7 l = b*f (1) | u:w = p+:-s | write u | abMnef qo tU W// 8 jump, l = b*f (2) | t:v = o+:-q | write t | a mne TuVw// J5 is the input/output buffer.J15 = 4;; // J15 = number of radix-4 stages remainingK14 = K14 - K31; R8 = 0x6341;; // R8 = permutation control for multiply by -jif nkle; do, R8 = 0x2705; K3 = J6;; // R8 = permutation control for multiply by j; K3 = fft_configK6 = K31 + 12;; // K6 = twiddles table size (for current stage)R9 = [K3+0];; // R9 = twiddles(0), equals scale_factorKB3 = K3;; // KB3, KL3 = circular buffer of twiddles for current stageKL3 = K6;; // 'step' is the distance between butterfly inputs; equal to 4 in stage 2.J1 = J31 + -4;; // J1 = -stepK1 = K31 + -4;; // K1 = -stepJ3 = J31 + 12;; // J3 = step*3J2 = J3 + 4;; // J2 = step*3 + 4J8 = J31 + 1;; // J8 = step/4J6 = J31 + 64;; // J6 = N/step/4#if 1 // This code for stage two can be disabled and the function will still // be correct. However, it will run slower.//stage 2 begins here//-------------------LC1 = J6; J0 = J5 + J3;; // J0 = input and output address of first butterfly (points to fourth point) J4 = J0 + 4;; // J4 and K4 point to safe place where trash is written on first two loop iterations K4 = J4;; // (Correct data is written to this address in the third iteration).align_code 4;bfly_loop2: //-- Read data and twiddles ------------- //-- Multiply --------------------- //-- Radix-4 butterflies ------------------------- //-- Write data ---- R07:06 = Q[J0+=J1]; R21:20=CB Q[K3+=4]; R18= MR1:0, MR1:0 += R1 ** R9(CR); SR15:14 = R05:04+R07:06, SR23:22 = R05:04-R07:06;; R05:04 = Q[J0+=J1]; R13:12=CB Q[K3+=4]; R17= MR1:0, MR1:0 += R0 ** R9(CR);; R03:02 = Q[J0+=J1]; R11:10=CB Q[K3+=4]; R16= MR1:0, MR1:0 += R7 ** R21(CR);; R01:00 = Q[J0+=J2]; R07= MR1:0, MR1:0 += R6 ** R20(CR); R23:20 = permute (R23:22, -R23:22, R8); K2 = K4 - 4;; K4 = J4; R06= MR1:0, MR1:0 += R5 ** R13(CR); SR17:16 = R17:16+R19:18, SR19:18 = R17:16-R19:18; Q[K2+=K1] = R31:30;; J4 = J0; R05= MR1:0, MR1:0 += R4 ** R12(CR); Q[K2+=K1] = R29:28;; J0 = J0 + J3; R04= MR1:0, MR1:0 += R3 ** R11(CR); SR27:26 = R19:18+R21:20, SR31:30 = R19:18-R21:20; Q[K2+=K1] = R27:26;;.align_code 4;if nlc1e, jump bfly_loop2; R19= MR1:0, MR1:0 += R2 ** R10(CR); SR25:24 = R17:16+R15:14, SR29:28 = R17:16-R15:14; Q[K2+=0 ] = R25:24;;//-- Advance to next stage ------------------ //-- Butterfly loop epilogue ------------------------------------------------------------------------------ R18= MR1:0, MR1:0 += R1 ** R9(CR); SR15:14 = R05:04+R07:06, SR23:22 = R05:04-R07:06; K0 = J4;;K3 = K3 + K6; R17= MR1:0, MR1:0 += R0 ** R9(CR);;K6 = K31 + 48; R16= MR1:0, MR1:0 += R0 ** R9(CR);;KB3 = K3; R23:20 = permute (R23:22, -R23:22, R8); K2 = K4 - 4;;KL3 = K6; SR17:16 = R17:16+R19:18, SR19:18 = R17:16-R19:18; Q[K2+=K1] = R31:30;;J1 = J31 + -16; Q[K2+=K1] = R29:28;;J3 = J31 + 48; SR27:26 = R19:18+R21:20, SR31:30 = R19:18-R21:20; Q[K2+=K1] = R27:26;;J2 = J3 + 4; SR25:24 = R17:16+R15:14, SR29:28 = R17:16-R15:14; Q[K2+=0 ] = R25:24;;J8 = J31 + 4; K2 = K0 - 4;;J6 = J31 + 16; Q[K2+=K1] = R31:30;; Q[K2+=K1] = R29:28;; Q[K2+=K1] = R27:26;; Q[K2+=0 ] = R25:24;;K1 = K31 + -16; j15 = J15 - 1;;#endif// --------------------------------------------------------------------------//stages 3-5 begin here//---------------------stage_loop:LC1 = J6; J0 = J5 + J3;; // J0 = input and output address of first butterfly (points to fourth point)LC0 = J8; J4 = J0 + 4;; // J4 and K4 point to safe place where trash is written on first two loop iterations K4 = J4;; // (Correct data is written to this address in the third iteration).align_code 4;group_loop:bfly_loop: //-- Read data and twiddles ------------- //-- Multiply --------------------- //-- Radix-4 butterflies ------------------------- //-- Write data ---- R07:06 = Q[J0+=J1]; R21:20=CB Q[K3+=4]; R18= MR1:0, MR1:0 += R1 ** R9(CR); SR15:14 = R05:04+R07:06, SR23:22 = R05:04-R07:06;; R05:04 = Q[J0+=J1]; R13:12=CB Q[K3+=4]; R17= MR1:0, MR1:0 += R0 ** R9(CR);; R03:02 = Q[J0+=J1]; R11:10=CB Q[K3+=4]; R16= MR1:0, MR1:0 += R7 ** R21(CR);; R01:00 = Q[J0+=J2]; R07= MR1:0, MR1:0 += R6 ** R20(CR); R23:20 = permute (R23:22, -R23:22, R8); K2 = K4 - 4;; K4 = J4; R06= MR1:0, MR1:0 += R5 ** R13(CR); SR17:16 = R17:16+R19:18, SR19:18 = R17:16-R19:18; Q[K2+=K1] = R31:30;; J4 = J0; R05= MR1:0, MR1:0 += R4 ** R12(CR); Q[K2+=K1] = R29:28;; R04= MR1:0, MR1:0 += R3 ** R11(CR); SR27:26 = R19:18+R21:20, SR31:30 = R19:18-R21:20; Q[K2+=K1] = R27:26;;.align_code 4;if nlc0e, jump bfly_loop; R19= MR1:0, MR1:0 += R2 ** R10(CR); SR25:24 = R17:16+R15:14, SR29:28 = R17:16-R15:14; Q[K2+=0 ] = R25:24;;.align_code 4;if nlc1e, jump group_loop; J0 = J0 + J3; LC0 = J8;;//-- Advance to next stage ------------------ //-- Butterfly loop epilogue ------------------------------------------------------------------------------ R18= MR1:0, MR1:0 += R1 ** R9(CR); SR15:14 = R05:04+R07:06, SR23:22 = R05:04-R07:06; K0 = J4;;K3 = K3 + K6; R17= MR1:0, MR1:0 += R0 ** R9(CR);;K6 = K6 + K6; R16= MR1:0, MR1:0 += R0 ** R9(CR);;K6 = K6 + K6;;KB3 = K3; R23:20 = permute (R23:22, -R23:22, R8); K2 = K4 - 4;;KL3 = K6; SR17:16 = R17:16+R19:18, SR19:18 = R17:16-R19:18; Q[K2+=K1] = R31:30;;J1 = J1 + J1; Q[K2+=K1] = R29:28;;J1 = J1 + J1; SR27:26 = R19:18+R21:20, SR31:30 = R19:18-R21:20; Q[K2+=K1] = R27:26;;J3 = J3 + J3; SR25:24 = R17:16+R15:14, SR29:28 = R17:16-R15:14; Q[K2+=0 ] = R25:24;;J3 = J3 + J3; K2 = K0 - 4;;J2 = J3 + 4; Q[K2+=K1] = R31:30;;J8 = J8 + J8; Q[K2+=K1] = R29:28;;J8 = J8 + J8; Q[K2+=K1] = R27:26;;J6 = lshiftr J6; Q[K2+=0 ] = R25:24;;J6 = lshiftr J6; K1 = K1 + K1;;j15 = J15 - 1; K1 = K1 + K1;;.align_code 4;if njeq, jump stage_loop;;// -------------------------------------------------------------------------- // Restore R24..31 from stack... XR31:28 = Q[J27 + 0x4]; YR31:28 = Q[K27 + 0x4];; XR27:24 = Q[J27 + 0x8]; YR27:24 = Q[K27 + 0x8];;.align_code 4; cjmp (abs); J27 = J27 + 8; K27 = K27 + 8;;_fft_1024.end:/***** EOF***/⌨️ 快捷键说明
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