1 .text 2 .p2align 2 3 .global ia_eld_decoder_sbr_pre_twiddle 4 5 6 ia_eld_decoder_sbr_pre_twiddle: 7 8 9 10 STMFD sp!, {r4-r12, r14} 11 LDR r4, [r0, #0] @Xre = *pXre 12 MOV r3, #62 @Loop count 13 LDR r5, [r1, #0] @Xim = *pXim 14 15 LOOP: 16 LDR r6, [r2], #4 @Load and increment pointer *pTwiddles++ Lower - cosine , higher - sine 17 SUBS r3, r3, #1 @Decrement loop count by 1 18 19 SMULWB r8, r4, r6 @mult32x16in32(Xre, cosine) 20 LSL r8, r8, #1 @Left shift the multiplied value by 1 21 22 SMULWT r10, r5, r6 @mult32x16in32( Xim , sine) 23 24 ADD r12, r8, r10, LSL #1 @mac32x16in32_shl( mult32x16in32_shl(Xre, cosine) , mult32x16in32_shl( Xim , sine))@ 25 26 27 SMULWT r7, r4, r6 @mult32x16in32(Xre, sine) 28 LDR r4, [r0, #4] @Load next iteration value Xre = *pXre 29 30 SMULWB r9, r5, r6 @mult32x16in32(Xim, cosine) 31 STR r12, [r0], #4 @Store and increment pointer *pXre++ = re 32 33 LSL r9, r9, #1 @Left shift the multiplied value by 1 34 LDR r5, [r1, #4] @Load next iteration value Xim = *pXim 35 36 37 SUB r14, r9, r7, LSL #1 @sub32(mult32x16in32_shl(Xim, cosine) , mult32x16in32_shl(Xre, sine)) 38 39 STR r14, [r1], #4 @Store and increment pointer *pXim++ = im 40 41 BNE LOOP @Check r3 equals 0 and continue 42 43 EPILOUGE: 44 45 LDR r6, [r2], #4 46 47 SMULWB r8, r4, r6 48 LSL r8, r8, #1 49 50 SMULWT r10, r5, r6 51 52 ADD r12, r8, r10, LSL #1 53 54 55 SMULWB r9, r5, r6 56 LSL r9, r9, #1 57 58 SMULWT r7, r4, r6 59 60 SUB r14, r9, r7, LSL #1 61 62 STR r12, [r0], #4 63 STR r14, [r1], #4 64 65 END_LOOP: 66 67 LDMFD sp!, {r4-r12, pc} 68
