text: //=========================================================================
  // Copyright (C) 2018 The C++ Component Model(CCM) Open Source Project
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  //=========================================================================
  
  /*
   *  Licensed to the Apache Software Foundation (ASF) under one or more
   *  contributor license agreements.  See the NOTICE file distributed with
   *  this work for additional information regarding copyright ownership.
   *  The ASF licenses this file to You under the Apache License, Version 2.0
   *  (the "License"); you may not use this file except in compliance with
   *  the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  
  #ifndef __CCM_CORE_CBIGINT_H__
  #define __CCM_CORE_CBIGINT_H__
  
  #include <sys/types.h>
  #include <sys/param.h>
  #include <stdint.h>
  
  /* IEEE floats consist of: sign bit, exponent field, significand field
      single:  31 = sign bit, 30..23 = exponent (8 bits), 22..0 = significand (23 bits)
      double:  63 = sign bit, 62..52 = exponent (11 bits), 51..0 = significand (52 bits)
      inf                ==    (all exponent bits set) and (all mantissa bits clear)
      nan                ==    (all exponent bits set) and (at least one mantissa bit set)
      finite             ==    (at least one exponent bit clear)
      zero               ==    (all exponent bits clear) and (all mantissa bits clear)
      denormal           ==    (all exponent bits clear) and (at least one mantissa bit set)
      positive           ==    sign bit clear
      negative           ==    sign bit set
  */
  #if __BYTE_ORDER == __LITTLE_ENDIAN
  #define DOUBLE_LO_OFFSET        0
  #define DOUBLE_HI_OFFSET        1
  #define LONG_LO_OFFSET          0
  #define LONG_HI_OFFSET          1
  #else
  #define DOUBLE_LO_OFFSET        1
  #define DOUBLE_HI_OFFSET        0
  #define LONG_LO_OFFSET          1
  #define LONG_HI_OFFSET          0
  #endif
  
  #define DOUBLE_EXPONENT_MASK_HI 0x7FF00000
  #define DOUBLE_MANTISSA_MASK_HI 0x000FFFFF
  
  union U64U32DBL {
      uint64_t    u64val;
      uint32_t    u32val[2];
      int32_t    i32val[2];
      double  dval;
  };
  
  #define DOUBLE_TO_LONGBITS(dbl) (*(reinterpret_cast<uint64_t*>(&dbl)))
  #define FLOAT_TO_INTBITS(flt) (*(reinterpret_cast<uint32_t*>(&flt)))
  #define INTBITS_TO_FLOAT(bits) (*(reinterpret_cast<float*>(&bits)))
  
  /* Replace P_FLOAT_HI and P_FLOAT_LOW */
  /* These macros are used to access the high and low 32-bit parts of a double (64-bit) value. */
  #define LOW_U32_FROM_DBL_PTR(dblptr) ((reinterpret_cast<U64U32DBL*>(dblptr))->u32val[DOUBLE_LO_OFFSET])
  #define HIGH_U32_FROM_DBL_PTR(dblptr) ((reinterpret_cast<U64U32DBL*>(dblptr))->u32val[DOUBLE_HI_OFFSET])
  #define LOW_I32_FROM_DBL_PTR(dblptr) ((reinterpret_cast<U64U32DBL*>(dblptr))->i32val[DOUBLE_LO_OFFSET])
  #define HIGH_I32_FROM_DBL_PTR(dblptr) ((reinterpret_cast<U64U32DBL*>(dblptr))->i32val[DOUBLE_HI_OFFSET])
  #define LOW_U32_FROM_DBL(dbl) LOW_U32_FROM_DBL_PTR(&(dbl))
  #define HIGH_U32_FROM_DBL(dbl) HIGH_U32_FROM_DBL_PTR(&(dbl))
  #define LOW_U32_FROM_LONG64_PTR(long64ptr) ((reinterpret_cast<U64U32DBL*>(long64ptr))->u32val[LONG_LO_OFFSET])
  #define HIGH_U32_FROM_LONG64_PTR(long64ptr) ((reinterpret_cast<U64U32DBL*>(long64ptr))->u32val[LONG_HI_OFFSET])
  #define LOW_I32_FROM_LONG64_PTR(long64ptr) ((reinterpret_cast<U64U32DBL*>(long64ptr))->i32val[LONG_LO_OFFSET])
  #define HIGH_I32_FROM_LONG64_PTR(long64ptr) ((reinterpret_cast<U64U32DBL*>(long64ptr))->i32val[LONG_HI_OFFSET])
  #define LOW_U32_FROM_LONG64(long64) LOW_U32_FROM_LONG64_PTR(&(long64))
  #define HIGH_U32_FROM_LONG64(long64) HIGH_U32_FROM_LONG64_PTR(&(long64))
  #define LOW_I32_FROM_LONG64(long64) LOW_I32_FROM_LONG64_PTR(&(long64))
  #define HIGH_I32_FROM_LONG64(long64) HIGH_I32_FROM_LONG64_PTR(&(long64))
  #define IS_DENORMAL_DBL_PTR(dblptr) (((HIGH_U32_FROM_DBL_PTR(dblptr) & DOUBLE_EXPONENT_MASK_HI) == 0) && ((HIGH_U32_FROM_DBL_PTR(dblptr) & DOUBLE_MANTISSA_MASK_HI) != 0 || (LOW_U32_FROM_DBL_PTR(dblptr) != 0)))
  #define IS_DENORMAL_DBL(dbl) IS_DENORMAL_DBL_PTR(&(dbl))
  
  #define LOW_U32_FROM_VAR(u64)     LOW_U32_FROM_LONG64(u64)
  #define LOW_U32_FROM_PTR(u64ptr)  LOW_U32_FROM_LONG64_PTR(u64ptr)
  #define HIGH_U32_FROM_VAR(u64)    HIGH_U32_FROM_LONG64(u64)
  #define HIGH_U32_FROM_PTR(u64ptr) HIGH_U32_FROM_LONG64_PTR(u64ptr)
  
  void multiplyHighPrecision(uint64_t* arg1, int32_t length1, uint64_t* arg2, int32_t length2,
          uint64_t* result, int32_t length);
  uint32_t simpleAppendDecimalDigitHighPrecision(uint64_t* arg1, int32_t length, uint64_t digit);
  double toDoubleHighPrecision(uint64_t* arg, int32_t length);
  uint64_t doubleMantissa(double z);
  int32_t compareHighPrecision(uint64_t* arg1, int32_t length1, uint64_t* arg2, int32_t length2);
  int32_t highestSetBitHighPrecision(uint64_t* arg, int32_t length);
  void subtractHighPrecision(uint64_t* arg1, int32_t length1, uint64_t* arg2, int32_t length2);
  int32_t doubleExponent(double z);
  int32_t addHighPrecision(uint64_t* arg1, int32_t length1, uint64_t* arg2, int32_t length2);
  int32_t lowestSetBit(uint64_t* y);
  int32_t timesTenToTheEHighPrecision(uint64_t* result, int32_t length, int e);
  int32_t highestSetBit(uint64_t* y);
  int32_t lowestSetBitHighPrecision(uint64_t* arg, int32_t length);
  void simpleShiftLeftHighPrecision(uint64_t* arg1, int32_t length, int32_t arg2);
  uint32_t floatMantissa(float z);
  int32_t simpleAddHighPrecision(uint64_t* arg1, int32_t length, uint64_t arg2);
  int32_t floatExponent(float z);
  
  #endif // __CCM_CORE_CBIGINT_H__
  