Mercurial > hg > pub > prymula > com
diff DPF-Prymula-audioplugins/dpf/distrho/extra/ScopedDenormalDisable.hpp @ 3:84e66ea83026
DPF-Prymula-audioplugins-0.231015-2
author | prymula <prymula76@outlook.com> |
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date | Mon, 16 Oct 2023 21:53:34 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DPF-Prymula-audioplugins/dpf/distrho/extra/ScopedDenormalDisable.hpp Mon Oct 16 21:53:34 2023 +0200 @@ -0,0 +1,112 @@ +/* + * DISTRHO Plugin Framework (DPF) + * Copyright (C) 2012-2023 Filipe Coelho <falktx@falktx.com> + * + * Permission to use, copy, modify, and/or distribute this software for any purpose with + * or without fee is hereby granted, provided that the above copyright notice and this + * permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD + * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN + * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER + * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef DISTRHO_SCOPED_DENORMAL_DISABLE_HPP_INCLUDED +#define DISTRHO_SCOPED_DENORMAL_DISABLE_HPP_INCLUDED + +#include "../DistrhoUtils.hpp" + +#ifdef __SSE2_MATH__ +# include <xmmintrin.h> +#endif + +START_NAMESPACE_DISTRHO + +// -------------------------------------------------------------------------------------------------------------------- +// ScopedDenormalDisable class definition + +/** + ScopedDenormalDisable is a handy class for disabling denormal numbers during a function scope. + Denormal numbers can happen in IIR or other types of filters, they are often very slow. + + Use this class with care! Messing up with the global state is bound to make some hosts unhappy. + */ +class ScopedDenormalDisable { +public: + /* + * Constructor. + * Current cpu flags will saved, then denormals-as-zero and flush-to-zero set on top. + */ + inline ScopedDenormalDisable() noexcept; + + /* + * Destructor. + * CPU flags will be restored to the value obtained in the constructor. + */ + inline ~ScopedDenormalDisable() noexcept + { + setFlags(oldflags); + } + +private: + #if defined(__SSE2_MATH__) + typedef uint cpuflags_t; + #elif defined(__aarch64__) + typedef uint64_t cpuflags_t; + #elif defined(__arm__) && !defined(__SOFTFP__) + typedef uint32_t cpuflags_t; + #else + typedef char cpuflags_t; + #endif + + // retrieved on constructor, reset to it on destructor + cpuflags_t oldflags; + + // helper function to set cpu flags + inline void setFlags(cpuflags_t flags) noexcept; + + DISTRHO_DECLARE_NON_COPYABLE(ScopedDenormalDisable) + DISTRHO_PREVENT_HEAP_ALLOCATION +}; + +// -------------------------------------------------------------------------------------------------------------------- +// ScopedDenormalDisable class implementation + +inline ScopedDenormalDisable::ScopedDenormalDisable() noexcept + : oldflags(0) +{ + #if defined(__SSE2_MATH__) + oldflags = _mm_getcsr(); + setFlags(oldflags | 0x8040); + #elif defined(__aarch64__) + __asm__ __volatile__("mrs %0, fpcr" : "=r" (oldflags)); + setFlags(oldflags | 0x1000000); + __asm__ __volatile__("isb"); + #elif defined(__arm__) && !defined(__SOFTFP__) + __asm__ __volatile__("vmrs %0, fpscr" : "=r" (oldflags)); + setFlags(oldflags | 0x1000000); + #endif +} + +inline void ScopedDenormalDisable::setFlags(const cpuflags_t flags) noexcept +{ + #if defined(__SSE2_MATH__) + _mm_setcsr(flags); + #elif defined(__aarch64__) + __asm__ __volatile__("msr fpcr, %0" :: "r" (flags)); + #elif defined(__arm__) && !defined(__SOFTFP__) + __asm__ __volatile__("vmsr fpscr, %0" :: "r" (flags)); + #else + // unused + (void)flags; + #endif +} + +// -------------------------------------------------------------------------------------------------------------------- + +END_NAMESPACE_DISTRHO + +#endif // DISTRHO_SCOPED_DENORMAL_DISABLE_HPP_INCLUDED