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527 lines
24 KiB
527 lines
24 KiB
/*-========================================================================-_
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| - XDSP - |
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| Copyright (c) Microsoft Corporation. All rights reserved. |
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|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
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|PROJECT: XDSP MODEL: Unmanaged User-mode |
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|VERSION: 1.0 EXCEPT: No Exceptions |
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|CLASS: N / A MINREQ: WinXP, Xbox360 |
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|BASE: N / A DIALECT: MSC++ 14.00 |
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|>------------------------------------------------------------------------<|
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| DUTY: DSP functions with CPU extension specific optimizations |
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^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
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NOTES:
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1. Definition of terms:
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DSP: Digital Signal Processing.
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FFT: Fast Fourier Transform.
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2. All buffer parameters must be 16-byte aligned.
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3. All FFT functions support only FLOAT32 mono audio. */
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#pragma once
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//--------------<D-E-F-I-N-I-T-I-O-N-S>-------------------------------------//
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#include <windef.h> // general windows types
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#include <math.h> // trigonometric functions
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#if defined(_XBOX) // SIMD intrinsics
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#include <ppcintrinsics.h>
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#else
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#include <emmintrin.h>
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#endif
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//--------------<M-A-C-R-O-S>-----------------------------------------------//
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// assertion
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#if !defined(DSPASSERT)
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#if DBG
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#define DSPASSERT(exp) if (!(exp)) { OutputDebugStringA("XDSP ASSERT: " #exp ", {" __FUNCTION__ "}\n"); __debugbreak(); }
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#else
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#define DSPASSERT(exp) __assume(exp)
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#endif
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#endif
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// true if n is a power of 2
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#if !defined(ISPOWEROF2)
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#define ISPOWEROF2(n) ( ((n)&((n)-1)) == 0 && (n) != 0 )
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#endif
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//--------------<H-E-L-P-E-R-S>---------------------------------------------//
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namespace XDSP {
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#pragma warning(push)
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#pragma warning(disable: 4328 4640) // disable "indirection alignment of formal parameter", "construction of local static object is not thread-safe" compile warnings
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// Helper functions, used by the FFT functions.
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// The application need not call them directly.
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// primitive types
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typedef __m128 XVECTOR;
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typedef XVECTOR& XVECTORREF;
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// Parallel multiplication of four complex numbers, assuming
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// real and imaginary values are stored in separate vectors.
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__forceinline void vmulComplex (__out XVECTORREF rResult, __out XVECTORREF iResult, __in XVECTORREF r1, __in XVECTORREF i1, __in XVECTORREF r2, __in XVECTORREF i2)
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{
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// (r1, i1) * (r2, i2) = (r1r2 - i1i2, r1i2 + r2i1)
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XVECTOR vi1i2 = _mm_mul_ps(i1, i2);
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XVECTOR vr1r2 = _mm_mul_ps(r1, r2);
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XVECTOR vr1i2 = _mm_mul_ps(r1, i2);
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XVECTOR vr2i1 = _mm_mul_ps(r2, i1);
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rResult = _mm_sub_ps(vr1r2, vi1i2); // real: (r1*r2 - i1*i2)
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iResult = _mm_add_ps(vr1i2, vr2i1); // imaginary: (r1*i2 + r2*i1)
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}
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__forceinline void vmulComplex (__inout XVECTORREF r1, __inout XVECTORREF i1, __in XVECTORREF r2, __in XVECTORREF i2)
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{
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// (r1, i1) * (r2, i2) = (r1r2 - i1i2, r1i2 + r2i1)
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XVECTOR vi1i2 = _mm_mul_ps(i1, i2);
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XVECTOR vr1r2 = _mm_mul_ps(r1, r2);
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XVECTOR vr1i2 = _mm_mul_ps(r1, i2);
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XVECTOR vr2i1 = _mm_mul_ps(r2, i1);
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r1 = _mm_sub_ps(vr1r2, vi1i2); // real: (r1*r2 - i1*i2)
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i1 = _mm_add_ps(vr1i2, vr2i1); // imaginary: (r1*i2 + r2*i1)
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}
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// Radix-4 decimation-in-time FFT butterfly.
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// This version assumes that all four elements of the butterfly are
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// adjacent in a single vector.
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//
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// Compute the product of the complex input vector and the
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// 4-element DFT matrix:
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// | 1 1 1 1 | | (r1X,i1X) |
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// | 1 -j -1 j | | (r1Y,i1Y) |
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// | 1 -1 1 -1 | | (r1Z,i1Z) |
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// | 1 j -1 -j | | (r1W,i1W) |
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//
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// This matrix can be decomposed into two simpler ones to reduce the
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// number of additions needed. The decomposed matrices look like this:
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// | 1 0 1 0 | | 1 0 1 0 |
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// | 0 1 0 -j | | 1 0 -1 0 |
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// | 1 0 -1 0 | | 0 1 0 1 |
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// | 0 1 0 j | | 0 1 0 -1 |
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//
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// Combine as follows:
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// | 1 0 1 0 | | (r1X,i1X) | | (r1X + r1Z, i1X + i1Z) |
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// Temp = | 1 0 -1 0 | * | (r1Y,i1Y) | = | (r1X - r1Z, i1X - i1Z) |
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// | 0 1 0 1 | | (r1Z,i1Z) | | (r1Y + r1W, i1Y + i1W) |
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// | 0 1 0 -1 | | (r1W,i1W) | | (r1Y - r1W, i1Y - i1W) |
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//
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// | 1 0 1 0 | | (rTempX,iTempX) | | (rTempX + rTempZ, iTempX + iTempZ) |
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// Result = | 0 1 0 -j | * | (rTempY,iTempY) | = | (rTempY + iTempW, iTempY - rTempW) |
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// | 1 0 -1 0 | | (rTempZ,iTempZ) | | (rTempX - rTempZ, iTempX - iTempZ) |
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// | 0 1 0 j | | (rTempW,iTempW) | | (rTempY - iTempW, iTempY + rTempW) |
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__forceinline void ButterflyDIT4_1 (__inout XVECTORREF r1, __inout XVECTORREF i1)
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{
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// sign constants for radix-4 butterflies
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const static XVECTOR vDFT4SignBits1 = { 0.0f, -0.0f, 0.0f, -0.0f };
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const static XVECTOR vDFT4SignBits2 = { 0.0f, 0.0f, -0.0f, -0.0f };
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const static XVECTOR vDFT4SignBits3 = { 0.0f, -0.0f, -0.0f, 0.0f };
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// calculating Temp
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XVECTOR rTemp = _mm_add_ps( _mm_shuffle_ps(r1, r1, _MM_SHUFFLE(1, 1, 0, 0)), // [r1X| r1X|r1Y| r1Y] +
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_mm_xor_ps(_mm_shuffle_ps(r1, r1, _MM_SHUFFLE(3, 3, 2, 2)), vDFT4SignBits1) ); // [r1Z|-r1Z|r1W|-r1W]
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XVECTOR iTemp = _mm_add_ps( _mm_shuffle_ps(i1, i1, _MM_SHUFFLE(1, 1, 0, 0)), // [i1X| i1X|i1Y| i1Y] +
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_mm_xor_ps(_mm_shuffle_ps(i1, i1, _MM_SHUFFLE(3, 3, 2, 2)), vDFT4SignBits1) ); // [i1Z|-i1Z|i1W|-i1W]
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// calculating Result
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XVECTOR rZrWiZiW = _mm_shuffle_ps(rTemp, iTemp, _MM_SHUFFLE(3, 2, 3, 2)); // [rTempZ|rTempW|iTempZ|iTempW]
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XVECTOR rZiWrZiW = _mm_shuffle_ps(rZrWiZiW, rZrWiZiW, _MM_SHUFFLE(3, 0, 3, 0)); // [rTempZ|iTempW|rTempZ|iTempW]
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XVECTOR iZrWiZrW = _mm_shuffle_ps(rZrWiZiW, rZrWiZiW, _MM_SHUFFLE(1, 2, 1, 2)); // [rTempZ|iTempW|rTempZ|iTempW]
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r1 = _mm_add_ps( _mm_shuffle_ps(rTemp, rTemp, _MM_SHUFFLE(1, 0, 1, 0)), // [rTempX| rTempY| rTempX| rTempY] +
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_mm_xor_ps(rZiWrZiW, vDFT4SignBits2) ); // [rTempZ| iTempW|-rTempZ|-iTempW]
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i1 = _mm_add_ps( _mm_shuffle_ps(iTemp, iTemp, _MM_SHUFFLE(1, 0, 1, 0)), // [iTempX| iTempY| iTempX| iTempY] +
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_mm_xor_ps(iZrWiZrW, vDFT4SignBits3) ); // [iTempZ|-rTempW|-iTempZ| rTempW]
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}
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// Radix-4 decimation-in-time FFT butterfly.
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// This version assumes that elements of the butterfly are
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// in different vectors, so that each vector in the input
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// contains elements from four different butterflies.
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// The four separate butterflies are processed in parallel.
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//
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// The calculations here are the same as the ones in the single-vector
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// radix-4 DFT, but instead of being done on a single vector (X,Y,Z,W)
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// they are done in parallel on sixteen independent complex values.
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// There is no interdependence between the vector elements:
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// | 1 0 1 0 | | (rIn0,iIn0) | | (rIn0 + rIn2, iIn0 + iIn2) |
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// | 1 0 -1 0 | * | (rIn1,iIn1) | = Temp = | (rIn0 - rIn2, iIn0 - iIn2) |
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// | 0 1 0 1 | | (rIn2,iIn2) | | (rIn1 + rIn3, iIn1 + iIn3) |
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// | 0 1 0 -1 | | (rIn3,iIn3) | | (rIn1 - rIn3, iIn1 - iIn3) |
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//
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// | 1 0 1 0 | | (rTemp0,iTemp0) | | (rTemp0 + rTemp2, iTemp0 + iTemp2) |
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// Result = | 0 1 0 -j | * | (rTemp1,iTemp1) | = | (rTemp1 + iTemp3, iTemp1 - rTemp3) |
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// | 1 0 -1 0 | | (rTemp2,iTemp2) | | (rTemp0 - rTemp2, iTemp0 - iTemp2) |
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// | 0 1 0 j | | (rTemp3,iTemp3) | | (rTemp1 - iTemp3, iTemp1 + rTemp3) |
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__forceinline void ButterflyDIT4_4 (__inout XVECTORREF r0,
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__inout XVECTORREF r1,
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__inout XVECTORREF r2,
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__inout XVECTORREF r3,
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__inout XVECTORREF i0,
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__inout XVECTORREF i1,
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__inout XVECTORREF i2,
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__inout XVECTORREF i3,
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__in_ecount(uStride*4) XVECTOR* __restrict pUnityTableReal,
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__in_ecount(uStride*4) XVECTOR* __restrict pUnityTableImaginary,
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const UINT32 uStride, const BOOL fLast)
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{
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DSPASSERT(pUnityTableReal != NULL);
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DSPASSERT(pUnityTableImaginary != NULL);
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DSPASSERT((UINT_PTR)pUnityTableReal % 16 == 0);
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DSPASSERT((UINT_PTR)pUnityTableImaginary % 16 == 0);
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DSPASSERT(ISPOWEROF2(uStride));
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XVECTOR rTemp0, rTemp1, rTemp2, rTemp3, rTemp4, rTemp5, rTemp6, rTemp7;
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XVECTOR iTemp0, iTemp1, iTemp2, iTemp3, iTemp4, iTemp5, iTemp6, iTemp7;
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// calculating Temp
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rTemp0 = _mm_add_ps(r0, r2); iTemp0 = _mm_add_ps(i0, i2);
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rTemp2 = _mm_add_ps(r1, r3); iTemp2 = _mm_add_ps(i1, i3);
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rTemp1 = _mm_sub_ps(r0, r2); iTemp1 = _mm_sub_ps(i0, i2);
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rTemp3 = _mm_sub_ps(r1, r3); iTemp3 = _mm_sub_ps(i1, i3);
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rTemp4 = _mm_add_ps(rTemp0, rTemp2); iTemp4 = _mm_add_ps(iTemp0, iTemp2);
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rTemp5 = _mm_add_ps(rTemp1, iTemp3); iTemp5 = _mm_sub_ps(iTemp1, rTemp3);
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rTemp6 = _mm_sub_ps(rTemp0, rTemp2); iTemp6 = _mm_sub_ps(iTemp0, iTemp2);
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rTemp7 = _mm_sub_ps(rTemp1, iTemp3); iTemp7 = _mm_add_ps(iTemp1, rTemp3);
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// calculating Result
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// vmulComplex(rTemp0, iTemp0, rTemp0, iTemp0, pUnityTableReal[0], pUnityTableImaginary[0]); // first one is always trivial
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vmulComplex(rTemp5, iTemp5, pUnityTableReal[uStride], pUnityTableImaginary[uStride]);
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vmulComplex(rTemp6, iTemp6, pUnityTableReal[uStride*2], pUnityTableImaginary[uStride*2]);
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vmulComplex(rTemp7, iTemp7, pUnityTableReal[uStride*3], pUnityTableImaginary[uStride*3]);
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if (fLast) {
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ButterflyDIT4_1(rTemp4, iTemp4);
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ButterflyDIT4_1(rTemp5, iTemp5);
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ButterflyDIT4_1(rTemp6, iTemp6);
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ButterflyDIT4_1(rTemp7, iTemp7);
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}
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r0 = rTemp4; i0 = iTemp4;
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r1 = rTemp5; i1 = iTemp5;
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r2 = rTemp6; i2 = iTemp6;
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r3 = rTemp7; i3 = iTemp7;
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}
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//--------------<F-U-N-C-T-I-O-N-S>-----------------------------------------//
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////
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// DESCRIPTION:
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// 4-sample FFT.
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//
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// PARAMETERS:
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// pReal - [inout] real components, must have at least uCount elements
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// pImaginary - [inout] imaginary components, must have at least uCount elements
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// uCount - [in] number of FFT iterations
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//
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// RETURN VALUE:
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// void
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////
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__forceinline void FFT4 (__inout_ecount(uCount) XVECTOR* __restrict pReal, __inout_ecount(uCount) XVECTOR* __restrict pImaginary, const UINT32 uCount=1)
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{
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DSPASSERT(pReal != NULL);
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DSPASSERT(pImaginary != NULL);
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DSPASSERT((UINT_PTR)pReal % 16 == 0);
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DSPASSERT((UINT_PTR)pImaginary % 16 == 0);
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DSPASSERT(ISPOWEROF2(uCount));
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for (UINT32 uIndex=0; uIndex<uCount; ++uIndex) {
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ButterflyDIT4_1(pReal[uIndex], pImaginary[uIndex]);
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}
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}
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////
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// DESCRIPTION:
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// 8-sample FFT.
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//
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// PARAMETERS:
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// pReal - [inout] real components, must have at least uCount*2 elements
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// pImaginary - [inout] imaginary components, must have at least uCount*2 elements
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// uCount - [in] number of FFT iterations
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//
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// RETURN VALUE:
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// void
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////
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__forceinline void FFT8 (__inout_ecount(uCount*2) XVECTOR* __restrict pReal, __inout_ecount(uCount*2) XVECTOR* __restrict pImaginary, const UINT32 uCount=1)
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{
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DSPASSERT(pReal != NULL);
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DSPASSERT(pImaginary != NULL);
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DSPASSERT((UINT_PTR)pReal % 16 == 0);
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DSPASSERT((UINT_PTR)pImaginary % 16 == 0);
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DSPASSERT(ISPOWEROF2(uCount));
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static XVECTOR wr1 = { 1.0f, 0.707168f, 0.0f, -0.707168f };
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static XVECTOR wi1 = { 0.0f, -0.707168f, -1.0f, -0.707168f };
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static XVECTOR wr2 = { -1.0f, -0.707168f, 0.0f, 0.707168f };
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static XVECTOR wi2 = { 0.0f, 0.707168f, 1.0f, 0.707168f };
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for (UINT32 uIndex=0; uIndex<uCount; ++uIndex) {
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XVECTOR* __restrict pR = pReal + uIndex*2;
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XVECTOR* __restrict pI = pImaginary + uIndex*2;
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XVECTOR oddsR = _mm_shuffle_ps(pR[0], pR[1], _MM_SHUFFLE(3, 1, 3, 1));
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XVECTOR evensR = _mm_shuffle_ps(pR[0], pR[1], _MM_SHUFFLE(2, 0, 2, 0));
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XVECTOR oddsI = _mm_shuffle_ps(pI[0], pI[1], _MM_SHUFFLE(3, 1, 3, 1));
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XVECTOR evensI = _mm_shuffle_ps(pI[0], pI[1], _MM_SHUFFLE(2, 0, 2, 0));
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ButterflyDIT4_1(oddsR, oddsI);
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ButterflyDIT4_1(evensR, evensI);
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XVECTOR r, i;
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vmulComplex(r, i, oddsR, oddsI, wr1, wi1);
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pR[0] = _mm_add_ps(evensR, r);
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pI[0] = _mm_add_ps(evensI, i);
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vmulComplex(r, i, oddsR, oddsI, wr2, wi2);
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pR[1] = _mm_add_ps(evensR, r);
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pI[1] = _mm_add_ps(evensI, i);
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}
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}
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////
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// DESCRIPTION:
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// 16-sample FFT.
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//
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// PARAMETERS:
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// pReal - [inout] real components, must have at least uCount*4 elements
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// pImaginary - [inout] imaginary components, must have at least uCount*4 elements
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// uCount - [in] number of FFT iterations
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//
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// RETURN VALUE:
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// void
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////
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__forceinline void FFT16 (__inout_ecount(uCount*4) XVECTOR* __restrict pReal, __inout_ecount(uCount*4) XVECTOR* __restrict pImaginary, const UINT32 uCount=1)
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{
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DSPASSERT(pReal != NULL);
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DSPASSERT(pImaginary != NULL);
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DSPASSERT((UINT_PTR)pReal % 16 == 0);
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DSPASSERT((UINT_PTR)pImaginary % 16 == 0);
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DSPASSERT(ISPOWEROF2(uCount));
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XVECTOR aUnityTableReal[4] = { 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.92387950f, 0.70710677f, 0.38268343f, 1.0f, 0.70710677f, -4.3711388e-008f, -0.70710677f, 1.0f, 0.38268343f, -0.70710677f, -0.92387950f };
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XVECTOR aUnityTableImaginary[4] = { -0.0f, -0.0f, -0.0f, -0.0f, -0.0f, -0.38268343f, -0.70710677f, -0.92387950f, -0.0f, -0.70710677f, -1.0f, -0.70710677f, -0.0f, -0.92387950f, -0.70710677f, 0.38268343f };
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for (UINT32 uIndex=0; uIndex<uCount; ++uIndex) {
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ButterflyDIT4_4(pReal[uIndex*4],
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pReal[uIndex*4 + 1],
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pReal[uIndex*4 + 2],
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pReal[uIndex*4 + 3],
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pImaginary[uIndex*4],
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pImaginary[uIndex*4 + 1],
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pImaginary[uIndex*4 + 2],
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pImaginary[uIndex*4 + 3],
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aUnityTableReal,
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aUnityTableImaginary,
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1, TRUE);
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}
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}
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////
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// DESCRIPTION:
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// 2^N-sample FFT.
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//
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// REMARKS:
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// For FFTs length 16 and below, call FFT16(), FFT8(), or FFT4().
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//
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// PARAMETERS:
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// pReal - [inout] real components, must have at least (uLength*uCount)/4 elements
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// pImaginary - [inout] imaginary components, must have at least (uLength*uCount)/4 elements
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// pUnityTable - [in] unity table, must have at least uLength*uCount elements, see FFTInitializeUnityTable()
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// uLength - [in] FFT length in samples, must be a power of 2 > 16
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// uCount - [in] number of FFT iterations
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//
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// RETURN VALUE:
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// void
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////
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inline void FFT (__inout_ecount((uLength*uCount)/4) XVECTOR* __restrict pReal, __inout_ecount((uLength*uCount)/4) XVECTOR* __restrict pImaginary, __in_ecount(uLength*uCount) XVECTOR* __restrict pUnityTable, const UINT32 uLength, const UINT32 uCount=1)
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{
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DSPASSERT(pReal != NULL);
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DSPASSERT(pImaginary != NULL);
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DSPASSERT(pUnityTable != NULL);
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DSPASSERT((UINT_PTR)pReal % 16 == 0);
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DSPASSERT((UINT_PTR)pImaginary % 16 == 0);
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DSPASSERT((UINT_PTR)pUnityTable % 16 == 0);
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DSPASSERT(uLength > 16);
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DSPASSERT(ISPOWEROF2(uLength));
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DSPASSERT(ISPOWEROF2(uCount));
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XVECTOR* __restrict pUnityTableReal = pUnityTable;
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XVECTOR* __restrict pUnityTableImaginary = pUnityTable + (uLength>>2);
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const UINT32 uTotal = uCount * uLength;
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const UINT32 uTotal_vectors = uTotal >> 2;
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const UINT32 uStage_vectors = uLength >> 2;
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const UINT32 uStride = uStage_vectors >> 2; // stride between butterfly elements
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const UINT32 uSkip = uStage_vectors - uStride;
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for (UINT32 uIndex=0; uIndex<(uTotal_vectors>>2); ++uIndex) {
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UINT32 n = (uIndex/uStride) * (uStride + uSkip) + (uIndex % uStride);
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ButterflyDIT4_4(pReal[n],
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pReal[n + uStride],
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pReal[n + uStride*2],
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pReal[n + uStride*3],
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pImaginary[n ],
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pImaginary[n + uStride],
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pImaginary[n + uStride*2],
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pImaginary[n + uStride*3],
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pUnityTableReal + n % uStage_vectors,
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pUnityTableImaginary + n % uStage_vectors,
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uStride, FALSE);
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}
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if (uLength > 16*4) {
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FFT(pReal, pImaginary, pUnityTable+(uLength>>1), uLength>>2, uCount*4);
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} else if (uLength == 16*4) {
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FFT16(pReal, pImaginary, uCount*4);
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} else if (uLength == 8*4) {
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FFT8(pReal, pImaginary, uCount*4);
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} else if (uLength == 4*4) {
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FFT4(pReal, pImaginary, uCount*4);
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}
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}
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//--------------------------------------------------------------------------//
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////
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// DESCRIPTION:
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// Initializes unity roots lookup table used by FFT functions.
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// Once initialized, the table need not be initialized again unless a
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// different FFT length is desired.
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//
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// REMARKS:
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// The unity tables of FFT length 16 and below are hard coded into the
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// respective FFT functions and so need not be initialized.
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//
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// PARAMETERS:
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// pUnityTable - [out] unity table, receives unity roots lookup table, must have at least uLength XVECTORs
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// uLength - [in] FFT length in samples, must be a power of 2 > 16
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//
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// RETURN VALUE:
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// void
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////
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inline void FFTInitializeUnityTable (__out_bcount(uLength*sizeof(XVECTOR)) FLOAT32* __restrict pUnityTable, UINT32 uLength)
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{
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DSPASSERT(pUnityTable != NULL);
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DSPASSERT(uLength > 16);
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DSPASSERT(ISPOWEROF2(uLength));
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// initialize unity table for recursive FFT lengths: uLength, uLength/4, uLength/16... > 16
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do {
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FLOAT32 flStep = 6.283185307f / uLength; // 2PI / FFT length
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uLength >>= 2;
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// pUnityTable[0 to uLength*4-1] contains real components for current FFT length
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// pUnityTable[uLength*4 to uLength*8-1] contains imaginary components for current FFT length
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for (UINT32 i=0; i<4; ++i) {
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for (UINT32 j=0; j<uLength; ++j) {
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UINT32 uIndex = (i*uLength) + j;
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pUnityTable[uIndex] = cosf(FLOAT32(i)*FLOAT32(j)*flStep); // real component
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pUnityTable[uIndex + uLength*4] = -sinf(FLOAT32(i)*FLOAT32(j)*flStep); // imaginary component
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}
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}
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pUnityTable += uLength*8;
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} while (uLength > 16);
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}
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////
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// DESCRIPTION:
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// The FFT functions generate output in bit reversed order.
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// Use this function to re-arrange them into order of increasing frequency.
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//
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// PARAMETERS:
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// pOutput - [out] output buffer, receives samples in order of increasing frequency, must have at least (1<<uLog2Length) elements
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// pInput - [in] input buffer, samples in bit reversed order as generated by FFT functions, must have at least (1<<uLog2Length) elements
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// uLog2Length - [in] LOG (base 2) of FFT length in samples, must be > 0
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//
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// RETURN VALUE:
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// void
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////
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inline void FFTUnswizzle (__out_ecount(1<<uLog2Length) FLOAT32* __restrict pOutput, __in_ecount(1<<uLog2Length) const FLOAT32* __restrict pInput, UINT32 uLog2Length)
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{
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DSPASSERT(pOutput != NULL);
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DSPASSERT(pInput != NULL);
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DSPASSERT(uLog2Length > 0);
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UINT32 uLength = UINT32(1 << uLog2Length);
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if ((uLog2Length & 0x1) == 0) {
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// even powers of two
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for (UINT32 uIndex=0; uIndex<uLength; ++uIndex) {
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UINT32 n = uIndex;
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n = ( (n & 0xcccccccc) >> 2 ) | ( (n & 0x33333333) << 2 );
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n = ( (n & 0xf0f0f0f0) >> 4 ) | ( (n & 0x0f0f0f0f) << 4 );
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n = ( (n & 0xff00ff00) >> 8 ) | ( (n & 0x00ff00ff) << 8 );
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n = ( (n & 0xffff0000) >> 16 ) | ( (n & 0x0000ffff) << 16 );
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n >>= (32 - uLog2Length);
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pOutput[n] = pInput[uIndex];
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}
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} else {
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// odd powers of two
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for (UINT32 uIndex=0; uIndex<uLength; ++uIndex) {
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UINT32 n = (uIndex>>3);
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n = ( (n & 0xcccccccc) >> 2 ) | ( (n & 0x33333333) << 2 );
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n = ( (n & 0xf0f0f0f0) >> 4 ) | ( (n & 0x0f0f0f0f) << 4 );
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n = ( (n & 0xff00ff00) >> 8 ) | ( (n & 0x00ff00ff) << 8 );
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n = ( (n & 0xffff0000) >> 16 ) | ( (n & 0x0000ffff) << 16 );
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n >>= (32 - (uLog2Length-3));
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n |= ((uIndex & 0x7) << (uLog2Length - 3));
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pOutput[n] = pInput[uIndex];
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}
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}
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}
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|
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////
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|
// DESCRIPTION:
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|
// Convert complex components to polar form.
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|
//
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|
// PARAMETERS:
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|
// pOutput - [out] output buffer, receives samples in polar form, must have at least uLength/4 elements
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|
// pInputReal - [in] input buffer (real components), must have at least uLength/4 elements
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// pInputImaginary - [in] input buffer (imaginary components), must have at least uLength/4 elements
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|
// uLength - [in] FFT length in samples, must be a power of 2 >= 4
|
|
//
|
|
// RETURN VALUE:
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|
// void
|
|
////
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inline void FFTPolar (__out_ecount(uLength/4) XVECTOR* __restrict pOutput, __in_ecount(uLength/4) const XVECTOR* __restrict pInputReal, __in_ecount(uLength/4) const XVECTOR* __restrict pInputImaginary, UINT32 uLength)
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|
{
|
|
DSPASSERT(pOutput != NULL);
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|
DSPASSERT(pInputReal != NULL);
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|
DSPASSERT(pInputImaginary != NULL);
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|
DSPASSERT(uLength >= 4);
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|
DSPASSERT(ISPOWEROF2(uLength));
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|
|
|
FLOAT32 flOneOverLength = 1.0f / uLength;
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|
|
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|
// result = sqrtf((real/uLength)^2 + (imaginary/uLength)^2) * 2
|
|
XVECTOR vOneOverLength = _mm_set_ps1(flOneOverLength);
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|
|
|
for (UINT32 uIndex=0; uIndex<(uLength>>2); ++uIndex) {
|
|
XVECTOR vReal = _mm_mul_ps(pInputReal[uIndex], vOneOverLength);
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|
XVECTOR vImaginary = _mm_mul_ps(pInputImaginary[uIndex], vOneOverLength);
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|
XVECTOR vRR = _mm_mul_ps(vReal, vReal);
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|
XVECTOR vII = _mm_mul_ps(vImaginary, vImaginary);
|
|
XVECTOR vRRplusII = _mm_add_ps(vRR, vII);
|
|
XVECTOR vTotal = _mm_sqrt_ps(vRRplusII);
|
|
pOutput[uIndex] = _mm_add_ps(vTotal, vTotal);
|
|
}
|
|
}
|
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|
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|
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#pragma warning(pop)
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|
}; // namespace XDSP
|
|
//---------------------------------<-EOF->----------------------------------//
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