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Diffstat (limited to 'media/openmax_dl/dl/sp/src/armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe_s.S')
-rw-r--r-- | media/openmax_dl/dl/sp/src/armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe_s.S | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/media/openmax_dl/dl/sp/src/armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe_s.S b/media/openmax_dl/dl/sp/src/armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe_s.S new file mode 100644 index 0000000000..f375991f7d --- /dev/null +++ b/media/openmax_dl/dl/sp/src/armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe_s.S @@ -0,0 +1,294 @@ +@// +@// Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. +@// +@// Use of this source code is governed by a BSD-style license +@// that can be found in the LICENSE file in the root of the source +@// tree. An additional intellectual property rights grant can be found +@// in the file PATENTS. All contributing project authors may +@// be found in the AUTHORS file in the root of the source tree. +@// +@// This is a modification of +@// armSP_FFTInv_CCSToR_S32_preTwiddleRadix2_unsafe_s.s to support float +@// instead of SC32. +@// + +@// +@// Description: +@// Compute the "preTwiddleRadix2" stage prior to the call to the complexFFT +@// It does a Z(k) = Feven(k) + jW^(-k) FOdd(k); k=0,1,2,...N/2-1 computation +@// +@// + + +@// Include standard headers + +#include "dl/api/armCOMM_s.h" +#include "dl/api/omxtypes_s.h" + + +@// Import symbols required from other files +@// (For example tables) + + +@// Set debugging level +@//DEBUG_ON SETL {TRUE} + + + +@// Guarding implementation by the processor name + + + + @// Guarding implementation by the processor name + + + +@//Input Registers + +#define pSrc r0 +#define pDst r1 +#define pFFTSpec r2 +#define scale r3 + + +@// Output registers +#define result r0 + +@//Local Scratch Registers + +#define argTwiddle r1 +#define argDst r2 +#define argScale r4 +#define tmpOrder r4 +#define pTwiddle r4 +#define pOut r5 +#define subFFTSize r7 +#define subFFTNum r6 +#define N r6 +#define order r14 +#define diff r9 +@// Total num of radix stages required to complete the FFT +#define count r8 +#define x0r r4 +#define x0i r5 +#define diffMinusOne r2 +#define round r3 + +#define pOut1 r2 +#define size r7 +#define step r8 +#define step1 r9 +#define twStep r10 +#define pTwiddleTmp r11 +#define argTwiddle1 r12 +#define zero r14 + +@// Neon registers + +#define dX0 D0.F32 +#define dShift D1.F32 +#define dX1 D1.F32 +#define dY0 D2.F32 +#define dY1 D3.F32 +#define dX0r D0.F32 +#define dX0i D1.F32 +#define dX1r D2.F32 +#define dX1i D3.F32 +#define dW0r D4.F32 +#define dW0i D5.F32 +#define dW1r D6.F32 +#define dW1i D7.F32 +#define dT0 D8.F32 +#define dT1 D9.F32 +#define dT2 D10.F32 +#define dT3 D11.F32 +#define qT0 D12.F32 +#define qT1 D14.F32 +#define qT2 D16.F32 +#define qT3 D18.F32 +#define dY0r D4.F32 +#define dY0i D5.F32 +#define dY1r D6.F32 +#define dY1i D7.F32 + +#define dY2 D4.F32 +#define dY3 D5.F32 +#define dW0 D6.F32 +#define dW1 D7.F32 +#define dW0Tmp D10.F32 +#define dW1Neg D11.F32 + +#define half D13.F32 + +@ Structure offsets for the FFTSpec + .set ARMsFFTSpec_N, 0 + .set ARMsFFTSpec_pBitRev, 4 + .set ARMsFFTSpec_pTwiddle, 8 + .set ARMsFFTSpec_pBuf, 12 + + .MACRO FFTSTAGE scaled, inverse, name + + @// Read the size from structure and take log + LDR N, [pFFTSpec, #ARMsFFTSpec_N] + + @// Read other structure parameters + LDR pTwiddle, [pFFTSpec, #ARMsFFTSpec_pTwiddle] + LDR pOut, [pFFTSpec, #ARMsFFTSpec_pBuf] + + VMOV half, 0.5 + + + MOV size,N,ASR #1 @// preserve the contents of N + MOV step,N,LSL #2 @// step = N/2 * 8 bytes + + + @// Z(k) = 1/2 {[F(k) + F'(N/2-k)] +j*W^(-k) [F(k) - F'(N/2-k)]} + @// Note: W^(k) is stored as negated value and also need to + @// conjugate the values from the table + + @// Z(0) : no need of twiddle multiply + @// Z(0) = 1/2 { [F(0) + F'(N/2)] +j [F(0) - F'(N/2)] } + + VLD1 dX0,[pSrc],step + ADD pOut1,pOut,step @// pOut1 = pOut+ N/2*8 bytes + + VLD1 dX1,[pSrc]! + @// twStep = 3N/8 * 8 bytes pointing to W^1 + SUB twStep,step,size,LSL #1 + + MOV step1,size,LSL #2 @// step1 = N/4 * 8 = N/2*4 bytes + SUB step1,step1,#8 @// (N/4-1)*8 bytes + + VADD dY0,dX0,dX1 @// [b+d | a+c] + VSUB dY1,dX0,dX1 @// [b-d | a-c] + VMUL dY0, dY0, half[0] + VMUL dY1, dY1, half[0] + + @// dY0= [a-c | a+c] ;dY1= [b-d | b+d] + VZIP dY0,dY1 + + VSUB dX0,dY0,dY1 + SUBS size,size,#2 + VADD dX1,dY0,dY1 + + SUB pSrc,pSrc,step + + VST1 dX0[0],[pOut1]! + ADD pTwiddleTmp,pTwiddle,#8 @// W^2 + VST1 dX1[1],[pOut1]! + ADD argTwiddle1,pTwiddle,twStep @// W^1 + + + BLT decrementScale\name + BEQ lastElement\name + + + @// Z(k) = 1/2[F(k) + F'(N/2-k)] +j*W^(-k) [F(k) - F'(N/2-k)] + @// Note: W^k is stored as negative values in the table and also + @// need to conjugate the values from the table. + @// + @// Process 4 elements at a time. E.g: Z(1),Z(2) and Z(N/2-2),Z(N/2-1) + @// since both of them require F(1),F(2) and F(N/2-2),F(N/2-1) + + + SUB step,step,#24 +evenOddButterflyLoop\name : + + + VLD1 dW0r,[argTwiddle1],step1 + VLD1 dW1r,[argTwiddle1]! + + VLD2 {dX0r,dX0i},[pSrc],step + SUB argTwiddle1,argTwiddle1,step1 + VLD2 {dX1r,dX1i},[pSrc]! + + SUB step1,step1,#8 @// (N/4-2)*8 bytes + VLD1 dW0i,[pTwiddleTmp],step1 + VLD1 dW1i,[pTwiddleTmp]! + SUB pSrc,pSrc,step + + SUB pTwiddleTmp,pTwiddleTmp,step1 + VREV64 dX1r,dX1r + VREV64 dX1i,dX1i + SUBS size,size,#4 + + + VSUB dT2,dX0r,dX1r @// a-c + VADD dT3,dX0i,dX1i @// b+d + VADD dT0,dX0r,dX1r @// a+c + VSUB dT1,dX0i,dX1i @// b-d + SUB step1,step1,#8 + + VMUL dT2, dT2, half[0] + VMUL dT3, dT3, half[0] + + VMUL dT0, dT0, half[0] + VMUL dT1, dT1, half[0] + + VZIP dW1r,dW1i + VZIP dW0r,dW0i + + + VMUL dX1r,dW1r,dT2 + VMUL dX1i,dW1r,dT3 + VMUL dX0r,dW0r,dT2 + VMUL dX0i,dW0r,dT3 + + VMLS dX1r,dW1i,dT3 + VMLA dX1i,dW1i,dT2 + + VMLA dX0r,dW0i,dT3 + VMLS dX0i,dW0i,dT2 + + + VADD dY1r,dT0,dX1i @// F(N/2 -1) + VSUB dY1i,dX1r,dT1 + + VREV64 dY1r,dY1r + VREV64 dY1i,dY1i + + + VADD dY0r,dT0,dX0i @// F(1) + VSUB dY0i,dT1,dX0r + + + VST2 {dY0r,dY0i},[pOut1],step + VST2 {dY1r,dY1i},[pOut1]! + SUB pOut1,pOut1,step + SUB step,step,#32 @// (N/2-4)*8 bytes + + + BGT evenOddButterflyLoop\name + + + @// set both the ptrs to the last element + SUB pSrc,pSrc,#8 + SUB pOut1,pOut1,#8 + + @// Last element can be expanded as follows + @// 1/2[Z(k) + Z'(k)] - j w^-k [Z(k) - Z'(k)] (since W^k is stored as + @// -ve) + @// 1/2[(a+jb) + (a-jb)] - j w^-k [(a+jb) - (a-jb)] + @// 1/2[2a+j0] - j (c-jd) [0+j2b] + @// (a+bc, -bd) + @// Since (c,d) = (0,1) for the last element, result is just (a,-b) + +lastElement\name : + VLD1 dX0r,[pSrc] + + VST1 dX0r[0],[pOut1]! + VNEG dX0r,dX0r + VST1 dX0r[1],[pOut1] + + + +decrementScale\name : + + .endm + + M_START armSP_FFTInv_CCSToR_F32_preTwiddleRadix2_unsafe,r4 + + FFTSTAGE "FALSE","TRUE",Inv + M_END + + .end |