about summary refs log tree commit diff
path: root/sysdeps/ieee754/ldbl-128/s_modfl.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
committerUlrich Drepper <drepper@redhat.com>1999-07-14 00:54:57 +0000
commitabfbdde177c3a7155070dda1b2cdc8292054cc26 (patch)
treee021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/ieee754/ldbl-128/s_modfl.c
parent86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff)
downloadglibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz
glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.xz
glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip
Update.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/s_modfl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128/s_modfl.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/s_modfl.c b/sysdeps/ieee754/ldbl-128/s_modfl.c
new file mode 100644
index 0000000000..63d66e7114
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_modfl.c
@@ -0,0 +1,88 @@
+/* s_modfl.c -- long double version of s_modf.c.
+ * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
+ */
+
+/*
+ * ====================================================
+ * 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
+
+/*
+ * modfl(long double x, long double *iptr)
+ * return fraction part of x, and return x's integral part in *iptr.
+ * Method:
+ *	Bit twiddling.
+ *
+ * Exception:
+ *	No exception.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double one = 1.0;
+#else
+static long double one = 1.0;
+#endif
+
+#ifdef __STDC__
+	long double __modfl(long double x, long double *iptr)
+#else
+	long double __modfl(x, iptr)
+	long double x,*iptr;
+#endif
+{
+	int64_t i0,i1,j0;
+	u_int64_t i;
+	GET_LDOUBLE_WORDS64(i0,i1,x);
+	j0 = ((i0>>48)&0x7fff)-0x3fff;	/* exponent of x */
+	if(j0<48) {			/* integer part in high x */
+	    if(j0<0) {			/* |x|<1 */
+		/* *iptr = +-0 */
+	        SET_LDOUBLE_WORDS64(*iptr,i0&0x8000000000000000ULL,0);
+		return x;
+	    } else {
+		i = (0x0000ffffffffffffLL)>>j0;
+		if(((i0&i)|i1)==0) {		/* x is integral */
+		    *iptr = x;
+		    /* return +-0 */
+		    SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0);
+		    return x;
+		} else {
+		    SET_LDOUBLE_WORDS64(*iptr,i0&(~i),0);
+		    return x - *iptr;
+		}
+	    }
+	} else if (j0>111) {		/* no fraction part */
+	    *iptr = x*one;
+	    /* We must handle NaNs separately.  */
+	    if (j0 == 0x4000 && ((i0 & 0x0000ffffffffffffLL) | i1))
+	      return x*one;
+	    /* return +-0 */
+	    SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0);
+	    return x;
+	} else {			/* fraction part in low x */
+	    i = -1ULL>>(j0-48);
+	    if((i1&i)==0) { 		/* x is integral */
+		*iptr = x;
+		/* return +-0 */
+		SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0);
+		return x;
+	    } else {
+		SET_LDOUBLE_WORDS64(*iptr,i0,i1&(~i));
+		return x - *iptr;
+	    }
+	}
+}
+weak_alias (__modfl, modfl)