| Index: third_party/openmax_dl/dl/sp/src/omxSP_FFTFwd_RToCCS_S32_Sfs_s.S
|
| diff --git a/third_party/openmax_dl/dl/sp/src/omxSP_FFTFwd_RToCCS_S32_Sfs_s.S b/third_party/openmax_dl/dl/sp/src/omxSP_FFTFwd_RToCCS_S32_Sfs_s.S
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..a742162e6169d0df55ec836611b766fa6b38aacb
|
| --- /dev/null
|
| +++ b/third_party/openmax_dl/dl/sp/src/omxSP_FFTFwd_RToCCS_S32_Sfs_s.S
|
| @@ -0,0 +1,549 @@
|
| +@//
|
| +@// 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 file was originally licensed as follows. It has been
|
| +@// relicensed with permission from the copyright holders.
|
| +@//
|
| +
|
| +@//
|
| +@// File Name: omxSP_FFTFwd_RToCCS_S32_Sfs_s.s
|
| +@// OpenMAX DL: v1.0.2
|
| +@// Last Modified Revision: 7810
|
| +@// Last Modified Date: Thu, 04 Oct 2007
|
| +@//
|
| +@// (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
|
| +@//
|
| +@//
|
| +@//
|
| +@// Description:
|
| +@// Compute FFT for a real signal
|
| +@//
|
| +
|
| +
|
| +
|
| +@// Include standard headers
|
| +
|
| +#include "dl/api/armCOMM_s.h"
|
| +#include "dl/api/omxtypes_s.h"
|
| +
|
| +
|
| +@// Import symbols required from other files
|
| +@// (For example tables)
|
| +
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix8_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe
|
| +
|
| +@// Set debugging level
|
| +@//DEBUG_ON SETL {TRUE}
|
| +
|
| +
|
| +
|
| +@// Guarding implementation by the processor name
|
| +
|
| +
|
| +
|
| + @// Guarding implementation by the processor name
|
| +
|
| +@// Import symbols required from other files
|
| +@// (For example tables)
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe
|
| + .extern armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe
|
| +
|
| +
|
| +@//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 comple the FFT
|
| +#define count r8
|
| +#define x0r r4
|
| +#define x0i r5
|
| +#define diffMinusOne r2
|
| +#define subFFTSizeTmp r6
|
| +#define step r3
|
| +#define step1 r4
|
| +#define twStep r8
|
| +#define zero r9
|
| +#define pTwiddleTmp r5
|
| +#define t0 r10
|
| +
|
| +@// Neon registers
|
| +
|
| +#define dX0 d0.s32
|
| +#define dzero d1.s32
|
| +#define dZero d2.s32
|
| +#define dShift d3.s32
|
| +#define dX0r d2.s32
|
| +#define dX0i d3.s32
|
| +#define dX1r d4.s32
|
| +#define dX1i d5.s32
|
| +#define dT0 d6.s32
|
| +#define dT1 d7.s32
|
| +#define dT2 d8.s32
|
| +#define dT3 d9.s32
|
| +#define qT0 q5.s64
|
| +#define qT1 q6.s64
|
| +#define dW0r d14.s32
|
| +#define dW0i d15.s32
|
| +#define dW1r d16.s32
|
| +#define dW1i d17.s32
|
| +#define dY0r d14.s32
|
| +#define dY0i d15.s32
|
| +#define dY1r d16.s32
|
| +#define dY1i d17.s32
|
| +#define dY0rS64 d14.s64
|
| +#define dY0iS64 d15.s64
|
| +#define qT2 q9.s64
|
| +#define qT3 q10.s64
|
| +@// lastThreeelements
|
| +#define dX1 d3.s32
|
| +#define dW0 d4.s32
|
| +#define dW1 d5.s32
|
| +#define dY0 d10.s32
|
| +#define dY1 d11.s32
|
| +#define dY2 d12.s32
|
| +#define dY3 d13.s32
|
| +
|
| + @// Allocate stack memory required by the function
|
| +
|
| + M_ALLOC4 diffOnStack, 4
|
| +
|
| + @// Write function header
|
| + M_START omxSP_FFTFwd_RToCCS_S32_Sfs,r11,d15
|
| +
|
| +@ Structure offsets for the FFTSpec
|
| + .set ARMsFFTSpec_N, 0
|
| + .set ARMsFFTSpec_pBitRev, 4
|
| + .set ARMsFFTSpec_pTwiddle, 8
|
| + .set ARMsFFTSpec_pBuf, 12
|
| +
|
| + @// Define stack arguments
|
| +
|
| + @// 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]
|
| +
|
| + @// N=1 Treat seperately
|
| + CMP N,#1
|
| + BGT sizeGreaterThanOne
|
| + VLD1 dX0[0],[pSrc]
|
| + RSB scale,scale,#0 @// to use VRSHL for right shift by a variable
|
| + MOV zero,#0
|
| + VMOV dShift[0],scale
|
| + VMOV dzero[0],zero
|
| + VRSHL dX0,dShift
|
| + VMOV dZero[0],zero
|
| + VST3 {dX0[0],dzero[0],dZero[0]},[pDst]
|
| +
|
| + B End
|
| +
|
| +
|
| +
|
| +sizeGreaterThanOne:
|
| + @// Do a N/2 point complex FFT including the scaling
|
| +
|
| + MOV N,N,ASR #1 @// N/2 point complex FFT
|
| +
|
| + CLZ order,N @// N = 2^order
|
| + RSB order,order,#31
|
| + MOV subFFTSize,#1
|
| + @//MOV subFFTNum,N
|
| +
|
| + CMP order,#3
|
| + BGT orderGreaterthan3 @// order > 3
|
| +
|
| + CMP order,#1
|
| + BGE orderGreaterthan0 @// order > 0
|
| + M_STR scale, diffOnStack,LT @// order = 0
|
| + VLD1 dX0,[pSrc]
|
| + VST1 dX0,[pOut]
|
| + MOV pSrc,pOut
|
| + MOV argDst,pDst
|
| + BLT FFTEnd
|
| +
|
| +orderGreaterthan0:
|
| + @// set the buffers appropriately for various orders
|
| + CMP order,#2
|
| + MOVEQ argDst,pDst
|
| + MOVNE argDst,pOut
|
| + MOVNE pOut,pDst @// Pass the first stage destination in RN5
|
| + MOV argTwiddle,pTwiddle
|
| +
|
| + SUBS diff,scale,order
|
| + M_STR diff,diffOnStack
|
| + MOVGT scale,order
|
| + @// Now scale <= order
|
| +
|
| + CMP order,#1
|
| + BGT orderGreaterthan1
|
| + SUBS scale,scale,#1
|
| + BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// order = 1
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe @// order = 1
|
| + B FFTEnd
|
| +
|
| +orderGreaterthan1:
|
| + CMP order,#2
|
| + MOV argScale,scale
|
| + BGT orderGreaterthan2
|
| + SUBS argScale,argScale,#1
|
| + BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// order =2
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe
|
| + SUBS argScale,argScale,#1
|
| + BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
|
| + B FFTEnd
|
| +
|
| +orderGreaterthan2:@// order =3
|
| + SUBS argScale,argScale,#1
|
| + BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_fs_OutOfPlace_unsafe
|
| + SUBS argScale,argScale,#1
|
| + BLGE armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe
|
| + SUBS argScale,argScale,#1
|
| + BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix2_ls_OutOfPlace_unsafe
|
| + BLLT armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
|
| + B FFTEnd
|
| +
|
| +
|
| +
|
| +orderGreaterthan3:
|
| + @// check scale = 0 or scale = order
|
| + SUBS diff, scale, order @// scale > order
|
| + MOVGT scale,order
|
| + BGE specialScaleCase @// scale = 0 or scale = order
|
| + CMP scale,#0
|
| + BEQ specialScaleCase
|
| + B generalScaleCase
|
| +
|
| +specialScaleCase:@// scale = 0 or scale = order and order >= 2
|
| +
|
| + TST order, #2 @// Set input args to fft stages
|
| + MOVEQ argDst,pDst
|
| + MOVNE argDst,pOut
|
| + MOVNE pOut,pDst @// Pass the first stage destination in RN5
|
| + MOV argTwiddle,pTwiddle
|
| +
|
| + CMP diff,#0
|
| + M_STR diff, diffOnStack
|
| + BGE scaleEqualsOrder
|
| +
|
| + @//check for even or odd order
|
| + @// NOTE: The following combination of BL's would work fine eventhough the first
|
| + @// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside
|
| + @// armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ
|
| +
|
| + TST order,#0x00000001
|
| + BLEQ armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe
|
| + BLNE armSP_FFTFwd_CToC_SC32_Radix8_fs_OutOfPlace_unsafe
|
| +
|
| + CMP subFFTNum,#4
|
| + BLT FFTEnd
|
| +
|
| +
|
| +unscaledRadix4Loop:
|
| + BEQ lastStageUnscaledRadix4
|
| + BL armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe
|
| + CMP subFFTNum,#4
|
| + B unscaledRadix4Loop
|
| +
|
| +lastStageUnscaledRadix4:
|
| + BL armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
|
| + B FFTEnd
|
| +
|
| +
|
| +scaleEqualsOrder:
|
| + @//check for even or odd order
|
| + @// NOTE: The following combination of BL's would work fine eventhough the first
|
| + @// BL would corrupt the flags. This is because the end of the "grpZeroSetLoop" loop inside
|
| + @// armSP_FFTFwd_CToC_SC32_Radix4_fs_OutOfPlace_unsafe sets the Z flag to EQ
|
| +
|
| + TST order,#0x00000001
|
| + BLEQ armSP_FFTFwd_CToC_SC32_Sfs_Radix4_fs_OutOfPlace_unsafe
|
| + BLNE armSP_FFTFwd_CToC_SC32_Sfs_Radix8_fs_OutOfPlace_unsafe
|
| +
|
| + CMP subFFTNum,#4
|
| + BLT FFTEnd
|
| +
|
| +
|
| +scaledRadix4Loop:
|
| + BEQ lastStageScaledRadix4
|
| + BL armSP_FFTFwd_CToC_SC32_Sfs_Radix4_OutOfPlace_unsafe
|
| + CMP subFFTNum,#4
|
| + B scaledRadix4Loop
|
| +
|
| +lastStageScaledRadix4:
|
| + BL armSP_FFTFwd_CToC_SC32_Sfs_Radix4_ls_OutOfPlace_unsafe
|
| + B FFTEnd
|
| +
|
| +generalScaleCase:@// 0 < scale < order and order >= 2
|
| + @// Determine the correct destination buffer
|
| + SUB diff,order,scale
|
| + TST diff,#0x01
|
| + ADDEQ count, scale,diff,lsr #1 @// count = scale + (order - scale)/2
|
| + MOVNE count, order
|
| + TST count, #0x01 @// Is count even or odd ?
|
| +
|
| + MOVEQ argDst,pDst @// Set input args to fft stages
|
| + MOVNE argDst,pOut
|
| + MOVNE pOut,pDst @// Pass the first stage destination in RN5
|
| + MOV argTwiddle,pTwiddle
|
| +
|
| + M_STR diff, diffOnStack
|
| +
|
| + MOV argScale,scale @// Put scale in RN4 so as to save and restore
|
| + BL armSP_FFTFwd_CToC_SC32_Sfs_Radix2_fs_OutOfPlace_unsafe @// scaled first stage
|
| + SUBS argScale,argScale,#1
|
| +
|
| +scaledRadix2Loop:
|
| + BLGT armSP_FFTFwd_CToC_SC32_Sfs_Radix2_OutOfPlace_unsafe
|
| + SUBS argScale,argScale,#1 @// save and restore scale (RN4) in the scaled stages
|
| + BGT scaledRadix2Loop
|
| +
|
| +
|
| + M_LDR diff, diffOnStack
|
| + @//check for even or odd order
|
| + TST diff,#0x00000001
|
| + BEQ generalUnscaledRadix4Loop
|
| + B unscaledRadix2Loop
|
| +
|
| +generalUnscaledRadix4Loop:
|
| + CMP subFFTNum,#4
|
| + BEQ generalLastStageUnscaledRadix4
|
| + BL armSP_FFTFwd_CToC_SC32_Radix4_OutOfPlace_unsafe
|
| + B generalUnscaledRadix4Loop
|
| +
|
| +generalLastStageUnscaledRadix4:
|
| + BL armSP_FFTFwd_CToC_SC32_Radix4_ls_OutOfPlace_unsafe
|
| + B finalComplexToRealFixup
|
| +
|
| +
|
| +unscaledRadix2Loop:
|
| + CMP subFFTNum,#2
|
| + BEQ generalLastStageUnscaledRadix2
|
| + BL armSP_FFTFwd_CToC_SC32_Radix2_OutOfPlace_unsafe
|
| + B unscaledRadix2Loop
|
| +
|
| +generalLastStageUnscaledRadix2:
|
| + BL armSP_FFTFwd_CToC_SC32_Radix2_ls_OutOfPlace_unsafe
|
| + B finalComplexToRealFixup
|
| +
|
| +
|
| +FFTEnd:@// Does only the scaling
|
| +
|
| + M_LDR diff, diffOnStack
|
| + CMP diff,#0
|
| + BLE finalComplexToRealFixup
|
| +
|
| + RSB diff,diff,#0 @// to use VRSHL for right shift by a variable
|
| + VDUP dShift,diff
|
| +
|
| + @// save subFFTSize and use tmpsubfftsize in the folowwing loop
|
| + MOV subFFTSizeTmp,subFFTSize @// subFFTSizeTmp same reg as subFFTNum
|
| +
|
| +scaleFFTData:@// N = subFFTSize ; dataptr = pDst ; scale = diff
|
| + VLD1 {dX0},[pSrc] @// pSrc contains pDst pointer
|
| + SUBS subFFTSizeTmp,subFFTSizeTmp,#1
|
| + VRSHL dX0,dShift
|
| + VST1 {dX0},[pSrc]!
|
| +
|
| + BGT scaleFFTData
|
| +
|
| + SUB pSrc,pSrc,subFFTSize,LSL #3 @// reset pSrc for final fixup
|
| +
|
| + @// change the logic so that output after scaling is in pOut and not in pDst
|
| + @// finally store from pOut to pDst
|
| + @// change branch "End" to branch "finalComplexToRealFixup" in the above
|
| + @// chk the code below for multiplication by j factor
|
| +
|
| +finalComplexToRealFixup:
|
| +
|
| +
|
| + @// F(0) = 1/2[Z(0) + Z'(0)] - j [Z(0) - Z'(0)]
|
| + @// 1/2[(a+jb) + (a-jb)] - j [(a+jb) - (a-jb)]
|
| + @// 1/2[2a+j0] - j [0+j2b]
|
| + @// (a+b, 0)
|
| +
|
| + @// F(N/2) = 1/2[Z(0) + Z'(0)] + j [Z(0) - Z'(0)]
|
| + @// 1/2[(a+jb) + (a-jb)] + j [(a+jb) - (a-jb)]
|
| + @// 1/2[2a+j0] + j [0+j2b]
|
| + @// (a-b, 0)
|
| +
|
| + @// F(0) and F(N/2)
|
| + VLD2 {dX0r[0],dX0i[0]},[pSrc]!
|
| + MOV zero,#0
|
| + VMOV dX0r[1],zero
|
| + MOV step,subFFTSize,LSL #3 @// step = N/2 * 8 bytes
|
| + VMOV dX0i[1],zero
|
| + SUB twStep,step,subFFTSize,LSL #1 @// twStep = 3N/8 * 8 bytes pointing to W^1
|
| +
|
| + VADD dY0r,dX0r,dX0i @// F(0) = ((Z0.r+Z0.i) , 0)
|
| + MOV step1,subFFTSize,LSL #2 @// step1 = N/2 * 4 bytes
|
| + VSUB dY0i,dX0r,dX0i @// F(N/2) = ((Z0.r-Z0.i) , 0)
|
| + SUBS subFFTSize,subFFTSize,#2
|
| +
|
| + VST1 dY0r,[argDst],step
|
| + ADD pTwiddleTmp,argTwiddle,#8 @// W^2
|
| + VST1 dY0i,[argDst]!
|
| + ADD argTwiddle,argTwiddle,twStep @// W^1
|
| +
|
| + VDUP dzero,zero
|
| + SUB argDst,argDst,step
|
| +
|
| + BLT End
|
| + BEQ lastElement
|
| + SUB step,step,#24
|
| + SUB step1,step1,#8 @// (N/4-1)*8 bytes
|
| +
|
| + @// F(k) = 1/2[Z(k) + Z'(N/2-k)] -j*W^(k) [Z(k) - Z'(N/2-k)]
|
| + @// Note: W^k is stored as negative values in the table
|
| + @// Process 4 elements at a time. E.g: F(1),F(2) and F(N/2-2),F(N/2-1) since both of them
|
| + @// require Z(1),Z(2) and Z(N/2-2),Z(N/2-1)
|
| +
|
| +
|
| +evenOddButterflyLoop:
|
| +
|
| +
|
| + VLD1 dW0r,[argTwiddle],step1
|
| + VLD1 dW1r,[argTwiddle]!
|
| +
|
| + VLD2 {dX0r,dX0i},[pSrc],step
|
| + SUB argTwiddle,argTwiddle,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 subFFTSize,subFFTSize,#4
|
| +
|
| +
|
| +
|
| + VSUB dT2,dX0r,dX1r @// a-c
|
| + SUB step1,step1,#8
|
| + VADD dT3,dX0i,dX1i @// b+d
|
| + VADD dT0,dX0r,dX1r @// a+c
|
| + VSUB dT1,dX0i,dX1i @// b-d
|
| + VHADD dT0,dT0,dzero
|
| + VHADD dT1,dT1,dzero
|
| +
|
| + VZIP dW1r,dW1i
|
| + vzip dW0r,dW0i
|
| +
|
| +
|
| + VMULL qT0,dW1r,dT2
|
| + VMLAL qT0,dW1i,dT3
|
| + VMULL qT1,dW1r,dT3
|
| + VMLSL qT1,dW1i,dT2
|
| +
|
| + VMULL qT2,dW0r,dT2
|
| + VMLSL qT2,dW0i,dT3
|
| + VMULL qT3,dW0r,dT3
|
| + VMLAL qT3,dW0i,dT2
|
| +
|
| +
|
| + VRSHRN dX1r,qT0,#32
|
| + VRSHRN dX1i,qT1,#32
|
| +
|
| + VSUB dY1r,dT0,dX1i @// F(N/2 -1)
|
| + VADD dY1i,dT1,dX1r
|
| + VNEG dY1i,dY1i
|
| +
|
| + VREV64 dY1r,dY1r
|
| + VREV64 dY1i,dY1i
|
| +
|
| +
|
| + VRSHRN dX0r,qT2,#32
|
| + VRSHRN dX0i,qT3,#32
|
| +
|
| +
|
| + VSUB dY0r,dT0,dX0i @// F(1)
|
| + VADD dY0i,dT1,dX0r
|
| +
|
| +
|
| + VST2 {dY0r,dY0i},[argDst],step
|
| + VST2 {dY1r,dY1i},[argDst]!
|
| + SUB argDst,argDst,step
|
| + SUB step,step,#32 @// (N/2-4)*8 bytes
|
| +
|
| +
|
| + BGT evenOddButterflyLoop
|
| +
|
| + SUB pSrc,pSrc,#8 @// set both the ptrs to the last element
|
| + SUB argDst,argDst,#8
|
| +
|
| +
|
| +
|
| + @// Last element can be expanded as follows
|
| + @// 1/2[Z(k) + Z'(k)] + j w^k [Z(k) - Z'(k)]
|
| + @// 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:
|
| + VLD1 dX0r,[pSrc]
|
| +
|
| + VST1 dX0r[0],[argDst]!
|
| + VNEG dX0r,dX0r
|
| + VST1 dX0r[1],[argDst]!
|
| +
|
| +
|
| +
|
| +
|
| +
|
| +
|
| +End:
|
| + @// Set return value
|
| + MOV result, #OMX_Sts_NoErr
|
| +
|
| + @// Write function tail
|
| + M_END
|
| +
|
| + .end
|
| +
|
|
|