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Rev 8793 Rev 9765
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 * inflicting too much of a performance hit.
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 * inflicting too much of a performance hit.
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 *
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 *
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 */
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 */
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/// #include
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#include
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/// #include
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#include
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#include
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#include
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/* Approximate square roots of DBL_MAX and DBL_MIN.  Numbers
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/* Approximate square roots of DBL_MAX and DBL_MIN.  Numbers
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   between these two shouldn't neither overflow nor underflow
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   between these two shouldn't neither overflow nor underflow
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   when squared.  */
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   when squared.  */
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#define __SQRT_DBL_MAX 1.3e+154
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#define __SQRT_DBL_MIN 2.3e-162
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#define __SQRT_DBL_MAX 1.3e+154
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#define __SQRT_DBL_MIN 2.3e-162
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double
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hypot(double x, double y)
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double hypot(double x, double y)
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{
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{
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  double abig = fabs(x), asmall = fabs(y);
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    double abig = fabs(x), asmall = fabs(y);
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  double ratio;
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    double ratio;
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  /* Make abig = max(|x|, |y|), asmall = min(|x|, |y|).  */
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  if (abig < asmall)
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    /* Make abig = max(|x|, |y|), asmall = min(|x|, |y|).  */
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    {
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    if (abig < asmall) {
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     significant digits.  Dividing ASMALL by ABIG scales them
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       significant digits.  Dividing ASMALL by ABIG scales them
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     to a certain degree, so that accuracy is better.  */
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       to a certain degree, so that accuracy is better.  */
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  if ((ratio = asmall / abig) > __SQRT_DBL_MIN && abig < __SQRT_DBL_MAX)
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    if ((ratio = asmall / abig) > __SQRT_DBL_MIN && abig < __SQRT_DBL_MAX)
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    return abig * sqrt(1.0 + ratio*ratio);
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        return abig * sqrt(1.0 + ratio * ratio);
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  else
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    {
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    else {
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      /* Slower but safer algorithm due to Moler and Morrison.  Never
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        /* Slower but safer algorithm due to Moler and Morrison.  Never
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         produces any intermediate result greater than roughly the
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           produces any intermediate result greater than roughly the
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         larger of X and Y.  Should converge to machine-precision
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           larger of X and Y.  Should converge to machine-precision
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#ifdef  TEST
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#ifdef TEST
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#include
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#include
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int
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main(void)
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int main(void)
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{
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{
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  printf("hypot(3, 4) =\t\t\t %25.17e\n", hypot(3., 4.));
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    printf("hypot(3, 4) =\t\t\t %25.17e\n", hypot(3., 4.));