blob: 323eb8319dacacaebeea91f785eca602fc6d59c3 [file] [log] [blame]
@// 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_FFT_CToC_SC32_Radix2_fs_unsafe_s.S
@// to support float instead of SC32.
@// Description:
@// Compute the first stage of a Radix 2 DIT in-order out-of-place FFT
@// stage for a N point complex 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)
@// Set debugging level
@// Guarding implementation by the processor name
@// Guarding implementation by the processor name
@//Input Registers
#define pSrc r0
#define pDst r2
#define pTwiddle r1
#define pPingPongBuf r5
#define subFFTNum r6
#define subFFTSize r7
@//Output Registers
@//Local Scratch Registers
#define pointStep r3
#define outPointStep r3
#define grpSize r4
#define setCount r4
#define step r8
#define dstStep r8
@// Neon Registers
#define dX0 D0.F32
#define dX1 D1.F32
#define dY0 D2.F32
#define dY1 D3.F32
.MACRO FFTSTAGE scaled, inverse, name
@// Define stack arguments
@// update subFFTSize and subFFTNum into RN6 and RN7 for the next stage
MOV subFFTSize,#2
LSR grpSize,subFFTNum,#1
MOV subFFTNum,grpSize
@// pT0+1 increments pT0 by 8 bytes
@// pT0+pointStep = increment of 8*pointStep bytes = 4*grpSize bytes
@// Note: outPointStep = pointStep for firststage
@// Note: setCount = grpSize/2 (reuse the updated grpSize for setCount)
MOV pointStep,grpSize,LSL #3
RSB step,pointStep,#8
@// Loop on the sets for grp zero
grpZeroSetLoop\name :
VLD1 dX0,[pSrc],pointStep
VLD1 dX1,[pSrc],step @// step = -pointStep + 8
SUBS setCount,setCount,#1
VADD dY0,dX0,dX1
VSUB dY1,dX0,dX1
VST1 dY0,[pDst],outPointStep
@// dstStep = step = -pointStep + 8
VST1 dY1,[pDst],dstStep
BGT grpZeroSetLoop\name
@// reset pSrc to pDst for the next stage
SUB pSrc,pDst,pointStep @// pDst -= 2*grpSize
MOV pDst,pPingPongBuf
M_START armSP_FFTFwd_CToC_FC32_Radix2_fs_OutOfPlace_unsafe,r4
M_START armSP_FFTInv_CToC_FC32_Radix2_fs_OutOfPlace_unsafe,r4