math.h

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// Copyright 2016 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
// Modified by Jeremy Retailleau.
 
#ifndef PXR_ARCH_MATH_H
#define PXR_ARCH_MATH_H
 
 
#include "./defines.h"
#include "./inttypes.h"
 
#if defined(ARCH_COMPILER_MSVC)
#include <intrin.h>
#endif
 
#include <cmath>
#if !defined(M_PI)
#define M_PI 3.14159265358979323846
#endif
 
namespace pxr {
 
#if defined (ARCH_CPU_INTEL) || defined (ARCH_CPU_ARM) || defined (doxygen)
 
#define ARCH_MIN_FLOAT_EPS_SQR      0.000244141F
 
inline long ArchSign(long val) {
    return (val > 0) - (val < 0);
}
 
inline uint32_t ArchFloatToBitPattern(float v) {
    union {
        float _float;
        uint32_t _uint;
    } value;
    value._float = v;
    return value._uint;
}
 
inline float ArchBitPatternToFloat(uint32_t v) {
    union {
        uint32_t _uint;
        float _float;
    } value;
    value._uint = v;
    return value._float;
}
 
inline uint64_t ArchDoubleToBitPattern(double v) {
    union {
        double _double;
        uint64_t _uint;
    } value;
    value._double = v;
    return value._uint;
}
 
inline double ArchBitPatternToDouble(uint64_t v) {
    union {
        uint64_t _uint;
        double _double;
    } value;
    value._uint = v;
    return value._double;
}
 
#else
#error Unknown system architecture.
#endif
 
#if defined(ARCH_OS_LINUX) || defined(doxygen)
 
inline void ArchSinCosf(float v, float *s, float *c) { sincosf(v, s, c); }
 
inline void ArchSinCos(double v, double *s, double *c) { sincos(v, s, c); }
 
#elif defined(ARCH_OS_DARWIN) || defined(ARCH_OS_WINDOWS)
 
inline void ArchSinCosf(float v, float *s, float *c) {
    *s = std::sin(v);
    *c = std::cos(v);  
}
inline void ArchSinCos(double v, double *s, double *c) {
    *s = std::sin(v);
    *c = std::cos(v);  
}
 
#else
#error Unknown architecture.
#endif
 
 
inline int
ArchCountTrailingZeros(uint64_t x)
{
#if defined(ARCH_COMPILER_GCC) || defined(ARCH_COMPILER_CLANG)
    return __builtin_ctzl(x);
#elif defined(ARCH_COMPILER_MSVC)
    unsigned long index;
    _BitScanForward64(&index, x);
    return index;
#else
    // Flip trailing zeros to 1s, and clear all other bits, then count.
    x = (x ^ (x - 1)) >> 1;
    int c = 0;
    for (; x; ++c) {
        x >>= 1;
    }
    return c;
#endif
}
 
}  // namespace pxr
 
#endif // PXR_ARCH_MATH_H