AAX_Denormal.h

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/*================================================================================================*/
/*
 *  Copyright 2014-2016, 2019, 2021, 2023 Avid Technology, Inc.
 *  All rights reserved.
 *  
 *  CONFIDENTIAL: this document contains confidential information of Avid. Do
 *  not disclose to any third party. Use of the information contained in this
 *  document is subject to an Avid SDK license.
 */
 
/*================================================================================================*/
#pragma once
 
#ifndef AAX_DENORMAL_H
#define AAX_DENORMAL_H
 
 
// AAX Includes
#include "AAX.h"
#include "AAX_PlatformOptimizationConstants.h"
 
 
#if ! defined( _TMS320C6X )
#include <limits>
#include <math.h>
#endif // ! defined( _TMS320C6X )
 
 
 
#if defined( _TMS320C6X )
 
// TODO: Currently noop on TI
#define AAX_SCOPE_COMPUTE_DENORMALS() do {} while(0)
#define AAX_SCOPE_DENORMALS_AS_ZERO() do {} while(0)
 
#elif ((defined _MSC_VER) || defined(WINDOWS_VERSION))
// Visual Studio
 
// Note: In Pro Tools 11 and higher for Windows, DAZ is turned on for all plug-in processing threads
 
// FIXME: These macros are currently noop on Windows because of compiler problems when intrin.h is included. Investigate using _controlfp(_DN_FLUSH, _MCW_DN) instead
#define AAX_SCOPE_COMPUTE_DENORMALS() do {} while(0)
#define AAX_SCOPE_DENORMALS_AS_ZERO() do {} while(0)
//#define AAX_SCOPE_COMPUTE_DENORMALS() AAX_StDenormalAsZeroFlagsOff computeDenormalFlagsScope ## __LINE__ ; do {} while (0)
//#define AAX_SCOPE_DENORMALS_AS_ZERO() AAX_StDenormalAsZeroFlagsOn denormalAsZeroFlagsScope ## __LINE__ ; do {} while (0)
//
//#include <Windows.h>
//#include <mmintrin.h>
//
//const unsigned gMXCSRFlags_DAZFZ = 0x00008040;
//
//struct AAX_StDenormalAsZeroFlagsOn
//{
//public:
//  AAX_StDenormalAsZeroFlagsOn()
//  : mSSESupported(IsProcessorFeaturePresent(PF_XMMI_INSTRUCTIONS_AVAILABLE))
//  {
//      if (mSSESupported) { set_flags(); }
//  }
//  
//  ~AAX_StDenormalAsZeroFlagsOn()
//  {
//      if (mSSESupported) { reset_flags(); }
//  }
//  
//private:
//  void set_flags()
//  {
//      mPrevFlags = _mm_getcsr();
//      unsigned newFlags = mPrevFlags | gMXCSRFlags_DAZFZ;
//      _mm_setcsr(newFlags);
//  }
//  
//  void reset_flags()
//  {
//      _mm_setcsr(mPrevFlags);
//  }
//  
//  unsigned mPrevFlags;
//  const bool mSSESupported;
//};
//
//struct AAX_StDenormalAsZeroFlagsOff
//{
//public:
//  AAX_StDenormalAsZeroFlagsOff()
//  : mSSESupported(IsProcessorFeaturePresent(PF_XMMI_INSTRUCTIONS_AVAILABLE))
//  {
//      if (mSSESupported) { set_flags(); }
//  }
//  
//  ~AAX_StDenormalAsZeroFlagsOff()
//  {
//      if (mSSESupported) { reset_flags(); }
//  }
//  
//private:
//  void set_flags()
//  {
//      mPrevFlags = _mm_getcsr();
//      unsigned newFlags = mPrevFlags & (~gMXCSRFlags_DAZFZ);
//      _mm_setcsr(newFlags);
//  }
//  
//  void reset_flags()
//  {
//      _mm_setcsr(mPrevFlags);
//  }
//  
//  unsigned mPrevFlags;
//  const bool mSSESupported;
//};
 
 
#elif defined(__linux__)
// Linux
 
// TODO: Currently noop on Linux
#define AAX_SCOPE_COMPUTE_DENORMALS() do {} while(0)
#define AAX_SCOPE_DENORMALS_AS_ZERO() do {} while(0)
 
#elif (defined (__GNUC__) || defined(MAC_VERSION))
// GCC / macOS
 
// Note: In Pro Tools 11 through Pro Tools 12.6 on macOS, DAZ is turned off for all plug-in processing threads
 
#define AAX_SCOPE_COMPUTE_DENORMALS() AAX_StDenormalAsZeroFlagsOff computeDenormalFlagsScope ## __LINE__ ; do {} while (0)
#define AAX_SCOPE_DENORMALS_AS_ZERO() AAX_StDenormalAsZeroFlagsOn denormalAsZeroFlagsScope ## __LINE__ ; do {} while (0)
 
#include <fenv.h>
struct AAX_StDenormalAsZeroFlagsOn
{
public:
    AAX_StDenormalAsZeroFlagsOn() { set_flags(); }
    ~AAX_StDenormalAsZeroFlagsOn() { reset_flags(); }
    
private:
#if !defined(__arm64__)
    void set_flags() { fegetenv(&mPrevFlags); fesetenv(FE_DFL_DISABLE_SSE_DENORMS_ENV); }
#else
    void set_flags() { fegetenv(&mPrevFlags); fesetenv(FE_DFL_DISABLE_DENORMS_ENV); }
#endif
    void reset_flags() { fesetenv(&mPrevFlags); }
    fenv_t mPrevFlags;
};
struct AAX_StDenormalAsZeroFlagsOff
{
public:
    AAX_StDenormalAsZeroFlagsOff() { set_flags(); }
    ~AAX_StDenormalAsZeroFlagsOff() { reset_flags(); }
    
private:
    void set_flags() { fegetenv(&mPrevFlags); fesetenv(FE_DFL_ENV); } // assuming that FE_DFL_ENV are the flags that we want here
    void reset_flags() { fesetenv(&mPrevFlags); }
    fenv_t mPrevFlags;
};
 
 
 
#else
 
#error AAX_SCOPE_COMPUTE_DENORMALS is not defined for this compiler
#error AAX_SCOPE_DENORMALS_AS_ZERO is not defined for this compiler
 
// Just for Doxygen
#define AAX_SCOPE_COMPUTE_DENORMALS() do {} while(0)
#define AAX_SCOPE_DENORMALS_AS_ZERO() do {} while(0)
 
#endif // End compiler selection for AAX_SCOPE_COMPUTE_DENORMALS / AAX_SCOPE_DENORMALS_AS_ZERO definition
 
 
 
 
namespace AAX
{
    const double cDenormalAvoidanceOffset=3.0e-34;
    const float cFloatDenormalAvoidanceOffset=3.0e-20f; //This number is emprically derived with minimal trial and error.
 
#if ! defined( _TMS320C6X )
    static const float cMinimumNormalFloat = std::numeric_limits<float>::min();
#endif
    
    inline void DeDenormal(double &iValue)
    {
#if defined(WINDOWS_VERSION) || defined(MAC_VERSION) || defined(LINUX_VERSION)
        if(iValue < cDenormalAvoidanceOffset && iValue > -cDenormalAvoidanceOffset) iValue=0.0;
#endif
    }
    
    inline void DeDenormal(float &iValue)
    {
#if defined(WINDOWS_VERSION) || defined(MAC_VERSION) || defined(LINUX_VERSION)
        if(iValue < cFloatDenormalAvoidanceOffset && iValue > -cFloatDenormalAvoidanceOffset) iValue=0.0f;
#endif 
    }
    
#if AAX_CPP11_SUPPORT
    inline float DeDenormal(float &&iValue)
    {
#if defined(WINDOWS_VERSION) || defined(MAC_VERSION) || defined(LINUX_VERSION)
        return (iValue < cFloatDenormalAvoidanceOffset && iValue > -cFloatDenormalAvoidanceOffset) ? 0.f : iValue;
#endif
    }
#endif // AAX_CPP11_SUPPORT
    
    inline void DeDenormalFine(float &iValue)
    {
#if ! defined( _TMS320C6X )
        if(iValue < cMinimumNormalFloat && iValue > -cMinimumNormalFloat) iValue=0.0f;
#endif
    }
    
    inline void FilterDenormals(float* inSamples, int32_t inLength)
    {
        //TODO: Implement optimized versions for TI and SSE
#if ! defined( _TMS320C6X ) // Not yet implemented for TI
        for( int32_t i = 0; i < inLength; ++i )
        {
            float curFloat = *inSamples;
            if( fabsf(curFloat) < cMinimumNormalFloat )
                curFloat = 0.0f;
            *(inSamples++) = curFloat;
        }
#endif
    }
 
} // namespace AAX
 
#endif // AAX_QUANTIZE_H