denormal_disabler.h | Explore in Territory

/*
 * Copyright (C) 2011, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
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 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DENORMAL_DISABLER_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DENORMAL_DISABLER_H_

#include <float.h>
#include "build/build_config.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"

namespace blink {

// Deal with denormals. They can very seriously impact performance on x86.

// Define HAVE_DENORMAL if we support flushing denormals to zero.

#if BUILDFLAG(IS_WIN) && defined(COMPILER_MSVC)
// Windows compiled using MSVC with SSE2
#define HAVE_DENORMAL …
#endif

#if defined(COMPILER_GCC) && defined(ARCH_CPU_X86_FAMILY)
// X86 chips can flush denormals
#define HAVE_DENORMAL …
#endif

#if defined(ARCH_CPU_ARM_FAMILY)
#define HAVE_DENORMAL …
#endif

#if defined(HAVE_DENORMAL)
class DenormalDisabler { … };

#else
// FIXME: add implementations for other architectures and compilers
class DenormalDisabler {
  STACK_ALLOCATED();

 public:
  DenormalDisabler() {}

  // Assume the worst case that other architectures and compilers
  // need to flush denormals to zero manually.
  static inline float FlushDenormalFloatToZero(float f) {
    return (fabs(f) < FLT_MIN) ? 0.0f : f;
  }
};

#endif

}  // namespace blink

#undef HAVE_DENORMAL
#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DENORMAL_DISABLER_H_
chromium/third_party/blink/renderer/platform/audio/denormal_disabler.h
