aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/ieee754/ldbl-128ibm/s_modfl.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_modfl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_modfl.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_modfl.c b/sysdeps/ieee754/ldbl-128ibm/s_modfl.c
new file mode 100644
index 0000000000..f2e65f0c44
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_modfl.c
@@ -0,0 +1,94 @@
+/* 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"
+#include <math_ldbl_opt.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);
+ i1 &= 0x000fffffffffffffLL;
+ j0 = ((i0>>52)&0x7ff)-0x3ff; /* exponent of x */
+ if(j0<52) { /* integer part in high x */
+ if(j0<0) { /* |x|<1 */
+ /* *iptr = +-0 */
+ SET_LDOUBLE_WORDS64(*iptr,i0&0x8000000000000000ULL,0);
+ return x;
+ } else {
+ i = (0x000fffffffffffffLL)>>j0;
+ if(((i0&i)|(i1&0x7fffffffffffffffLL))==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>103) { /* no fraction part */
+ *iptr = x*one;
+ /* We must handle NaNs separately. */
+ if (j0 == 0x400 && ((i0 & 0x000fffffffffffffLL) | i1))
+ return x*one;
+ /* return +-0 */
+ SET_LDOUBLE_WORDS64(x,i0&0x8000000000000000ULL,0);
+ return x;
+ } else { /* fraction part in low x */
+ i = -1ULL>>(j0-52);
+ 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;
+ }
+ }
+}
+#ifdef IS_IN_libm
+long_double_symbol (libm, __modfl, modfl);
+#else
+long_double_symbol (libc, __modfl, modfl);
+#endif