1 @// 2 @// Copyright (c) 2013 The WebRTC project authors. All Rights Reserved. 3 @// 4 @// Use of this source code is governed by a BSD-style license 5 @// that can be found in the LICENSE file in the root of the source 6 @// tree. An additional intellectual property rights grant can be found 7 @// in the file PATENTS. All contributing project authors may 8 @// be found in the AUTHORS file in the root of the source tree. 9 @// 10 @// This is a modification of armSP_FFT_CToC_SC32_Radix2_fs_unsafe_s.S 11 @// to support float instead of SC32. 12 @// 13 14 @// 15 @// Description: 16 @// Compute the first stage of a Radix 2 DIT in-order out-of-place FFT 17 @// stage for a N point complex signal. 18 @// 19 @// 20 21 22 @// Include standard headers 23 24 #include "dl/api/arm/armCOMM_s.h" 25 #include "dl/api/arm/omxtypes_s.h" 26 27 28 @// Import symbols required from other files 29 @// (For example tables) 30 31 32 33 34 @// Set debugging level 35 @//DEBUG_ON SETL {TRUE} 36 37 38 39 @// Guarding implementation by the processor name 40 41 42 43 @// Guarding implementation by the processor name 44 45 46 @//Input Registers 47 48 #define pSrc r0 49 #define pDst r2 50 #define pTwiddle r1 51 #define pPingPongBuf r5 52 #define subFFTNum r6 53 #define subFFTSize r7 54 55 56 @//Output Registers 57 58 59 @//Local Scratch Registers 60 61 #define pointStep r3 62 #define outPointStep r3 63 #define grpSize r4 64 #define setCount r4 65 #define step r8 66 #define dstStep r8 67 68 @// Neon Registers 69 70 #define dX0 D0.F32 71 #define dX1 D1.F32 72 #define dY0 D2.F32 73 #define dY1 D3.F32 74 75 76 .MACRO FFTSTAGE scaled, inverse, name 77 78 @// Define stack arguments 79 80 81 @// update subFFTSize and subFFTNum into RN6 and RN7 for the next stage 82 83 84 MOV subFFTSize,#2 85 LSR grpSize,subFFTNum,#1 86 MOV subFFTNum,grpSize 87 88 89 @// pT0+1 increments pT0 by 8 bytes 90 @// pT0+pointStep = increment of 8*pointStep bytes = 4*grpSize bytes 91 @// Note: outPointStep = pointStep for firststage 92 @// Note: setCount = grpSize/2 (reuse the updated grpSize for setCount) 93 94 MOV pointStep,grpSize,LSL #3 95 RSB step,pointStep,#8 96 97 98 @// Loop on the sets for grp zero 99 100 grpZeroSetLoop\name : 101 102 VLD1 dX0,[pSrc],pointStep 103 VLD1 dX1,[pSrc],step @// step = -pointStep + 8 104 SUBS setCount,setCount,#1 105 106 VADD dY0,dX0,dX1 107 VSUB dY1,dX0,dX1 108 109 VST1 dY0,[pDst],outPointStep 110 @// dstStep = step = -pointStep + 8 111 VST1 dY1,[pDst],dstStep 112 113 BGT grpZeroSetLoop\name 114 115 116 @// reset pSrc to pDst for the next stage 117 SUB pSrc,pDst,pointStep @// pDst -= 2*grpSize 118 MOV pDst,pPingPongBuf 119 120 .endm 121 122 123 124 M_START armSP_FFTFwd_CToC_FC32_Radix2_fs_OutOfPlace_unsafe,r4 125 FFTSTAGE "FALSE","FALSE",fwd 126 M_END 127 128 129 130 M_START armSP_FFTInv_CToC_FC32_Radix2_fs_OutOfPlace_unsafe,r4 131 FFTSTAGE "FALSE","TRUE",inv 132 M_END 133 134 .end 135
