96 bit long double rintl implementation. See sysdeps/libm-ieee754/s_rintl.c for...
authordrepper <drepper>
Wed, 14 Jul 1999 00:14:52 +0000 (00:14 +0000)
committerdrepper <drepper>
Wed, 14 Jul 1999 00:14:52 +0000 (00:14 +0000)
sysdeps/ieee754/ldbl-96/s_rintl.c [new file with mode: 0644]

diff --git a/sysdeps/ieee754/ldbl-96/s_rintl.c b/sysdeps/ieee754/ldbl-96/s_rintl.c
new file mode 100644 (file)
index 0000000..9d4777d
--- /dev/null
@@ -0,0 +1,91 @@
+/* s_rintl.c -- long double version of s_rint.c.
+ * Conversion to long double by Ulrich Drepper,
+ * Cygnus Support, drepper@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: $";
+#endif
+
+/*
+ * rintl(x)
+ * Return x rounded to integral value according to the prevailing
+ * rounding mode.
+ * Method:
+ *     Using floating addition.
+ * Exception:
+ *     Inexact flag raised if x not equal to rintl(x).
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double
+#else
+static long double
+#endif
+TWO63[2]={
+  9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
+ -9.223372036854775808000000e+18  /* 0xC03E, 0x00000000, 0x00000000 */
+};
+
+#ifdef __STDC__
+       long double __rintl(long double x)
+#else
+       long double __rintl(x)
+       long double x;
+#endif
+{
+       int32_t se,j0,sx;
+       u_int32_t i,i0,i1;
+       long double w,t;
+       GET_LDOUBLE_WORDS(se,i0,i1,x);
+       sx = (se>>15)&1;
+       j0 = (se&0x7fff)-0x3fff;
+       if(j0<31) {
+           if(j0<0) {
+               if(((se&0x7fff)|i0|i1)==0) return x;
+               i1 |= i0;
+               i0 &= 0xe0000000;
+               i0 |= (i1|-i1)&0x80000000;
+               SET_LDOUBLE_MSW(x,i0);
+               w = TWO63[sx]+x;
+               t = w-TWO63[sx];
+               GET_LDOUBLE_EXP(i0,t);
+               SET_LDOUBLE_EXP(t,(i0&0x7fff)|(sx<<15));
+               return t;
+           } else {
+               i = (0x7fffffff)>>j0;
+               if(((i0&i)|i1)==0) return x; /* x is integral */
+               i>>=1;
+               if(((i0&i)|i1)!=0) {
+                   if(j0==30) i1 = 0x40000000; else
+                   i0 = (i0&(~i))|((0x20000000)>>j0);
+               }
+           }
+       } else if (j0>62) {
+           if(j0==0x4000) return x+x;  /* inf or NaN */
+           else return x;              /* x is integral */
+       } else {
+           i = ((u_int32_t)(0xffffffff))>>(j0-31);
+           if((i1&i)==0) return x;     /* x is integral */
+           i>>=1;
+           if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-31));
+       }
+       SET_LDOUBLE_WORDS(x,se,i0,i1);
+       w = TWO63[sx]+x;
+       return w-TWO63[sx];
+}
+weak_alias (__rintl, rintl)