text: 
  /* Copyright (C) 1999-2022 by The D Language Foundation, All Rights Reserved
   * written by Walter Bright
   * https://www.digitalmars.com
   * Distributed under the Boost Software License, Version 1.0.
   * https://www.boost.org/LICENSE_1_0.txt
   * https://github.com/dlang/dmd/blob/master/src/dmd/root/ctfloat.h
   */
  
  #pragma once
  
  #include "longdouble.h"
  
  // Type used by the front-end for compile-time reals
  typedef longdouble real_t;
  
  #if IN_LLVM
  namespace llvm { class APFloat; }
  #endif
  
  // Compile-time floating-point helper
  struct CTFloat
  {
      static void yl2x(const real_t *x, const real_t *y, real_t *res);
      static void yl2xp1(const real_t *x, const real_t *y, real_t *res);
  
      static real_t sin(real_t x);
      static real_t cos(real_t x);
      static real_t tan(real_t x);
      static real_t sqrt(real_t x);
      static real_t fabs(real_t x);
      static real_t ldexp(real_t n, int exp);
  
      static real_t round(real_t x);
      static real_t floor(real_t x);
      static real_t ceil(real_t x);
      static real_t trunc(real_t x);
      static real_t log(real_t x);
      static real_t log2(real_t x);
      static real_t log10(real_t x);
      static real_t pow(real_t x, real_t y);
      static real_t exp(real_t x);
      static real_t expm1(real_t x);
      static real_t exp2(real_t x);
  
      static real_t fmin(real_t x, real_t y);
      static real_t fmax(real_t x, real_t y);
      static real_t copysign(real_t x, real_t s);
  
      static real_t fma(real_t x, real_t y, real_t z);
  
  #if IN_LLVM
      static real_t rint(real_t x);
      static real_t nearbyint(real_t x);
  
      // implemented in gen/ctfloat.cpp
      static void toAPFloat(real_t src, llvm::APFloat &dst);
      static real_t fromAPFloat(const llvm::APFloat &src);
  
      static bool isFloat32LiteralOutOfRange(const char *literal);
      static bool isFloat64LiteralOutOfRange(const char *literal);
  #endif
  
      static bool isIdentical(real_t a, real_t b);
      static bool isNaN(real_t r);
  #if !IN_LLVM
      static bool isSNaN(real_t r);
  #endif
      static bool isInfinity(real_t r);
  
      static real_t parse(const char *literal, bool *isOutOfRange = NULL);
      static int sprint(char *str, char fmt, real_t x);
  
      static size_t hash(real_t a);
  
      // Constant real values 0, 1, -1 and 0.5.
      static real_t zero;
      static real_t one;
      static real_t minusone;
      static real_t half;
  #if IN_LLVM
      static real_t nan;
      static real_t infinity;
  #endif
  
      static void initialize();
  };
  