aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_llrintl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_llrintl.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
new file mode 100644
index 0000000..bacf1be
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_llrintl.c
@@ -0,0 +1,124 @@
+/* Round to int long double floating-point values.
+ IBM extended format long double version.
+ Copyright (C) 2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* This has been coded in assembler because GCC makes such a mess of it
+ when it's coded in C. */
+
+#include <math.h>
+#include <math_ldbl_opt.h>
+#include <float.h>
+#include <ieee754.h>
+
+
+#ifdef __STDC__
+long long
+__llrintl (long double x)
+#else
+long long
+__llrintl (x)
+ long double x;
+#endif
+{
+ static const double TWO52 = 4503599627370496.0L;
+ union ibm_extended_long_double u;
+ long long result = __LONG_LONG_MAX__;
+
+ u.d = x;
+
+ if (fabs (u.dd[0]) < TWO52)
+ {
+ double high = u.dd[0];
+ if (high > 0.0)
+ {
+ high += TWO52;
+ high -= TWO52;
+ if (high == -0.0) high = 0.0;
+ }
+ else if (high < 0.0)
+ {
+ high -= TWO52;
+ high += TWO52;
+ if (high == 0.0) high = -0.0;
+ }
+ result = high;
+ }
+ else if (fabs (u.dd[1]) < TWO52 && u.dd[1] != 0.0)
+ {
+ double high, low, tau;
+ long long lowint;
+ /* In this case we have to round the low double and handle any
+ adjustment to the high double that may be caused by rounding
+ (up). This is complicated by the fact that the high double
+ may already be rounded and the low double may have the
+ opposite sign to compensate. */
+ if (u.dd[0] > 0.0)
+ {
+ if (u.dd[1] > 0.0)
+ {
+ /* If the high/low doubles are the same sign then simply
+ round the low double. */
+ high = u.dd[0];
+ low = u.dd[1];
+ }
+ else if (u.dd[1] < 0.0)
+ {
+ /* Else the high double is pre rounded and we need to
+ adjust for that. */
+
+ tau = nextafter (u.dd[0], 0.0);
+ tau = (u.dd[0] - tau) * 2.0;
+ high = u.dd[0] - tau;
+ low = u.dd[1] + tau;
+ }
+ low += TWO52;
+ low -= TWO52;
+ }
+ else if (u.dd[0] < 0.0)
+ {
+ if (u.dd[1] < 0.0)
+ {
+ /* If the high/low doubles are the same sign then simply
+ round the low double. */
+ high = u.dd[0];
+ low = u.dd[1];
+ }
+ else if (u.dd[1] > 0.0)
+ {
+ /* Else the high double is pre rounded and we need to
+ adjust for that. */
+ tau = nextafter (u.dd[0], 0.0);
+ tau = (u.dd[0] - tau) * 2.0;
+ high = u.dd[0] - tau;
+ low = u.dd[1] + tau;
+ }
+ low = TWO52 - low;
+ low = -(low - TWO52);
+ }
+ lowint = low;
+ result = high;
+ result += lowint;
+ }
+ else
+ result = u.dd[0];
+
+ return result;
+}
+
+long_double_symbol (libm, __llrintl, llrintl);