/* Round toward nearest, breaking ties away from zero.
- Copyright (C) 2007 Free Software Foundation, Inc.
+ Copyright (C) 2007, 2009, 2010 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
DOUBLE
FLOOR_BASED_ROUND (DOUBLE x)
{
- if (x >= L_(0.0))
+ if (x >= L_(0.0))
{
DOUBLE y = FLOOR (x);
if (x - y >= L_(0.5))
{
/* Avoid rounding error for x = 0.5 - 2^(-MANT_DIG-1). */
if (z < L_(0.5))
- z = L_(0.0);
+ z = L_(0.0);
/* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1. */
else if (z < TWO_MANT_DIG)
- {
- /* Add 0.5 to the absolute value. */
- y = z += L_(0.5);
- /* Round to the next integer (nearest or up or down, doesn't
+ {
+ /* Add 0.5 to the absolute value. */
+ y = z += L_(0.5);
+ /* Round to the next integer (nearest or up or down, doesn't
matter). */
- z += TWO_MANT_DIG;
- z -= TWO_MANT_DIG;
- /* Enforce rounding down. */
- if (z > y)
- z -= L_(1.0);
- }
+ z += TWO_MANT_DIG;
+ z -= TWO_MANT_DIG;
+ /* Enforce rounding down. */
+ if (z > y)
+ z -= L_(1.0);
+ }
}
else if (z < L_(0.0))
{
/* Avoid rounding error for x = -(0.5 - 2^(-MANT_DIG-1)). */
if (z > - L_(0.5))
- z = L_(0.0);
+ z = L_(0.0);
/* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1. */
else if (z > -TWO_MANT_DIG)
- {
- /* Add 0.5 to the absolute value. */
- y = z -= L_(0.5);
- /* Round to the next integer (nearest or up or down, doesn't
+ {
+ /* Add 0.5 to the absolute value. */
+ y = z -= L_(0.5);
+ /* Round to the next integer (nearest or up or down, doesn't
matter). */
- z -= TWO_MANT_DIG;
- z += TWO_MANT_DIG;
- /* Enforce rounding up. */
- if (z < y)
- z += L_(1.0);
- }
+ z -= TWO_MANT_DIG;
+ z += TWO_MANT_DIG;
+ /* Enforce rounding up. */
+ if (z < y)
+ z += L_(1.0);
+ }
}
return z;
}