/* Split a double into fraction and mantissa.
- Copyright (C) 2007-2008 Free Software Foundation, Inc.
+ Copyright (C) 2007-2013 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
/* Written by Paolo Bonzini <bonzini@gnu.org>, 2003, and
Bruno Haible <bruno@clisp.org>, 2007. */
-#include <config.h>
+#if ! defined USE_LONG_DOUBLE
+# include <config.h>
+#endif
/* Specification. */
#include <math.h>
exponent = 0;
if (x >= L_(1.0))
{
- /* A positive exponent. */
- DOUBLE pow2_i; /* = pow2[i] */
- DOUBLE powh_i; /* = powh[i] */
-
- /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
- x * 2^exponent = argument, x >= 1.0. */
- for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
- ;
- i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
- {
- if (x >= pow2_i)
- {
- exponent += (1 << i);
- x *= powh_i;
- }
- else
- break;
-
- pow2[i] = pow2_i;
- powh[i] = powh_i;
- }
- /* Avoid making x too small, as it could become a denormalized
- number and thus lose precision. */
- while (i > 0 && x < pow2[i - 1])
- {
- i--;
- powh_i = powh[i];
- }
- exponent += (1 << i);
- x *= powh_i;
- /* Here 2^-2^i <= x < 1.0. */
+ /* A positive exponent. */
+ DOUBLE pow2_i; /* = pow2[i] */
+ DOUBLE powh_i; /* = powh[i] */
+
+ /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
+ x * 2^exponent = argument, x >= 1.0. */
+ for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
+ ;
+ i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
+ {
+ if (x >= pow2_i)
+ {
+ exponent += (1 << i);
+ x *= powh_i;
+ }
+ else
+ break;
+
+ pow2[i] = pow2_i;
+ powh[i] = powh_i;
+ }
+ /* Avoid making x too small, as it could become a denormalized
+ number and thus lose precision. */
+ while (i > 0 && x < pow2[i - 1])
+ {
+ i--;
+ powh_i = powh[i];
+ }
+ exponent += (1 << i);
+ x *= powh_i;
+ /* Here 2^-2^i <= x < 1.0. */
}
else
{
- /* A negative or zero exponent. */
- DOUBLE pow2_i; /* = pow2[i] */
- DOUBLE powh_i; /* = powh[i] */
-
- /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
- x * 2^exponent = argument, x < 1.0. */
- for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
- ;
- i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
- {
- if (x < powh_i)
- {
- exponent -= (1 << i);
- x *= pow2_i;
- }
- else
- break;
-
- pow2[i] = pow2_i;
- powh[i] = powh_i;
- }
- /* Here 2^-2^i <= x < 1.0. */
+ /* A negative or zero exponent. */
+ DOUBLE pow2_i; /* = pow2[i] */
+ DOUBLE powh_i; /* = powh[i] */
+
+ /* Invariants: pow2_i = 2^2^i, powh_i = 2^-2^i,
+ x * 2^exponent = argument, x < 1.0. */
+ for (i = 0, pow2_i = L_(2.0), powh_i = L_(0.5);
+ ;
+ i++, pow2_i = pow2_i * pow2_i, powh_i = powh_i * powh_i)
+ {
+ if (x < powh_i)
+ {
+ exponent -= (1 << i);
+ x *= pow2_i;
+ }
+ else
+ break;
+
+ pow2[i] = pow2_i;
+ powh[i] = powh_i;
+ }
+ /* Here 2^-2^i <= x < 1.0. */
}
/* Invariants: x * 2^exponent = argument, and 2^-2^i <= x < 1.0. */
while (i > 0)
{
- i--;
- if (x < powh[i])
- {
- exponent -= (1 << i);
- x *= pow2[i];
- }
+ i--;
+ if (x < powh[i])
+ {
+ exponent -= (1 << i);
+ x *= pow2[i];
+ }
}
/* Here 0.5 <= x < 1.0. */
}