/*****************************************************************
 *
 *               The Compcert verified compiler
 *
 *           Xavier Leroy, INRIA Paris-Rocquencourt
 *
 * Copyright (c) 2013 Institut National de Recherche en Informatique et
 *  en Automatique.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT
 * HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 **********************************************************************/

/* Helper functions for 64-bit integer arithmetic. Reference C implementation */

#include "i64.h"

/* Conversion from unsigned int64 to float32 */

float i64_utof(unsigned long long x)
{
  if (x >= 1ULL << 53) {
    /* x is large enough that double rounding can occur.
       Nudge x away from the points where double rounding occurs
       (the "round to odd" technique) */
    unsigned delta = ((unsigned) x & 0x7FF) + 0x7FF;
    x = (x | delta) & ~0x7FFULL;
  }
  /* Convert to double */
  unsigned xl = x, xh = x >> 32;
  double r = (double) xl + 0x1.0p32 * (double) xh;
  /* Round to single */
  return (float) r;
}