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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck * |
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* Copyright (C) 2005 - 2016 Christian Schoenebeck * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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|
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#ifndef __RT_MATH_H__ |
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#define __RT_MATH_H__ |
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|
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#include <math.h> |
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#include <stdint.h> |
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#include "global_private.h" |
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|
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/// Needed for calculating frequency ratio used to pitch a sample |
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#define TWELVEHUNDREDTH_ROOT_OF_TWO 1.000577789506555 |
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|
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enum implementation_t { |
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CPP, |
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ASM_X86_MMX_SSE |
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}; |
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|
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/** @brief Real Time Math Base Class |
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* |
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* Math functions for real time operation. This base class contains all |
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* non-template methods. |
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*/ |
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class RTMathBase { |
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public: |
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/** |
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* Highly accurate time stamp. |
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*/ |
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typedef uint32_t time_stamp_t; |
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|
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/** |
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* We read the processor's cycle count register as a reference |
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* for the real time. These are of course only abstract values |
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* with arbitrary time entity, but that's not a problem as long |
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* as we calculate relatively. |
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*/ |
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static time_stamp_t CreateTimeStamp(); |
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|
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/** |
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* Calculates the frequency ratio for a pitch value given in cents |
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* (assuming equal tempered scale of course, divided into 12 |
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* semitones per octave and 100 cents per semitone). |
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* |
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* Note: CONFIG_MAX_PITCH (defined in config.h) has to be defined to an |
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* appropriate value, otherwise the behavior of this function is |
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* undefined, but most probably if CONFIG_MAX_PITCH is too small, the |
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* application will crash due to segmentation fault here. |
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* |
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* @param cents - pitch value in cents (+1200 cents means +1 octave) |
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* @returns frequency ratio (e.g. +2.0 for +1 octave) |
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*/ |
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inline static double CentsToFreqRatio(double Cents) { |
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int index_int = (int) (Cents); // integer index |
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float index_fract = Cents - index_int; // fractional part of index |
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return pCentsToFreqTable[index_int] + index_fract * (pCentsToFreqTable[index_int+1] - pCentsToFreqTable[index_int]); |
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} |
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|
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/** |
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* Slower version of CentsToFreqRatio, for big values. |
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* |
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* @param cents - pitch value in cents (+1200 cents means +1 octave) |
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* @returns frequency ratio (e.g. +2.0 for +1 octave) |
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*/ |
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static double CentsToFreqRatioUnlimited(double Cents) { |
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int octaves = int(Cents / 1200); |
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double x = CentsToFreqRatio(Cents - octaves * 1200); |
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return octaves < 0 ? x / (1 << -octaves) : x * (1 << octaves); |
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} |
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|
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/** |
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* Inverse function to CentsToFreqRatio(). This function is a bit |
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* slow, so it should not be called too frequently. |
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*/ |
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static double FreqRatioToCents(double FreqRatio) { |
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return log(FreqRatio) / log(TWELVEHUNDREDTH_ROOT_OF_TWO); |
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} |
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|
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/** |
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* Calculates the line ratio value representation (linear scale) |
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* of the @a decibel value provided (exponential scale). |
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* |
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* The context of audio acoustic sound pressure levels is assumed, and |
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* hence the field version of the dB unit is used here (which uses a |
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* linear factor of 20). This function is a bit slow, so it should |
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* not be called too frequently. |
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* |
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* @param decibel - sound pressure level in dB |
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* @returns linear ratio of the supplied dB value |
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*/ |
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static float DecibelToLinRatio(float decibel) { |
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return powf(10.f, decibel / 20.f); |
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} |
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|
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/** |
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* Calculates the relatively summed average of a set of values. |
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* |
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* @param current - the current avaerage value of all previously summed values |
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* @param sample - new value to be applied as summed average to the existing values |
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* @param n - amount of sample values applied so far |
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* @returns new average value of all summed values (including the new @a sample) |
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*/ |
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inline static float RelativeSummedAvg(float current, float sample, int n) { |
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return current + (sample - current) / float(n); |
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} |
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|
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private: |
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static float* pCentsToFreqTable; |
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|
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static float* InitCentsToFreqTable(); |
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}; |
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|
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/** @brief Real Time Math |
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* |
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* This is a template which provides customized methods for the desired low |
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* level implementation. The ASM_X86_MMX_SSE implementation of each method |
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* for example doesn't use 387 FPU instruction. This is needed for MMX |
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* algorithms which do not allow mixed MMX and 387 instructions. |
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*/ |
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template<implementation_t IMPL = CPP> |
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class __RTMath : public RTMathBase { |
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public: |
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// conversion using truncate |
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inline static int Int(const float a) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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int ret; |
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asm ( |
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"cvttss2si %1, %0 # convert to int\n\t" |
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: "=r" (ret) |
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: "m" (a) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (int) a; |
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} |
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} |
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} |
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|
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//for doubles and everything else except floats |
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template<class T_a> inline static int Int(const T_a a) { |
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return (int) a; |
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} |
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|
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inline static float Float(const int a) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"cvtsi2ss %1, %%xmm0 # convert to float\n\t" |
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"movss %%xmm0,%0 # output\n\t" |
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: "=m" (ret) |
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: "r" (a) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (float) a; |
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} |
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} |
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} |
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|
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#if 0 |
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//for everything except ints |
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template<class T_a> inline static float Float(T_a a) { |
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return (float) a; |
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} |
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#endif |
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|
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inline static float Sum(const float& a, const float& b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"addss %2, %%xmm0 # a + b\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (a + b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Sum(const T_a a, const T_b b) { |
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return (a + b); |
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} |
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|
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inline static float Sub(const float& a, const float& b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"subss %2, %%xmm0 # a - b\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (a - b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Sub(const T_a a, const T_b b) { |
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return (a - b); |
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} |
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|
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inline static float Mul(const float a, const float b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"mulss %2, %%xmm0 # a * b\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (a * b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Mul(const T_a a, const T_b b) { |
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return (a * b); |
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} |
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|
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inline static float Div(const float a, const float b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"divss %2, %%xmm0 # a / b\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return (a / b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Div(const T_a a, const T_b b) { |
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return (a / b); |
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} |
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|
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inline static float Min(const float a, const float b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"minss %2, %%xmm0 # Minimum(a, b)\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return std::min(a, b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Min(const T_a a, const T_b b) { |
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return (b < a) ? b : a; |
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} |
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|
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inline static float Max(const float a, const float b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"maxss %2, %%xmm0 # Maximum(a, b)\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return std::max(a, b); |
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} |
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} |
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} |
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|
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template<class T_a, class T_b> inline static T_a Max(const T_a a, const T_b b) { |
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return (b > a) ? b : a; |
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} |
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|
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inline static float Fmodf(const float &a, const float &b) { |
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switch (IMPL) { |
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#if CONFIG_ASM && ARCH_X86 |
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case ASM_X86_MMX_SSE: { |
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float ret; |
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asm ( |
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"movss %1, %%xmm0 # load a\n\t" |
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"movss %2, %%xmm1 # load b\n\t" |
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"movss %%xmm0,%%xmm2\n\t" |
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"divss %%xmm1, %%xmm2 # xmm2 = a / b\n\t" |
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"cvttss2si %%xmm2, %%ecx #convert to int\n\t" |
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"cvtsi2ss %%ecx, %%xmm2 #convert back to float\n\t" |
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"mulss %%xmm1, %%xmm2 # xmm2 = b * int(a/b)\n\t" |
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"subss %%xmm2, %%xmm0 #sub a\n\t" |
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"movss %%xmm0, %0 # output\n\t" |
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: "=m" (ret) |
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: "m" (a), "m" (b) |
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: "%ecx" |
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); |
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return ret; |
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} |
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#endif // CONFIG_ASM && ARCH_X86 |
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default: { |
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return fmodf(a, b); |
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} |
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} |
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} |
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}; |
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|
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/// convenience typedef for using the default implementation (which is CPP) |
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typedef __RTMath<> RTMath; |
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|
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#endif // __RT_MATH_H__ |