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Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c')
-rw-r--r--sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c b/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c
new file mode 100644
index 0000000000..50bd8cb0b6
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_scalbnl.c
@@ -0,0 +1,109 @@
+/* s_scalbnl.c -- long double version of s_scalbn.c.
+ * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
+ */
+
+/* @(#)s_scalbn.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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
+
+/*
+ * scalbnl (long double x, int n)
+ * scalbnl(x,n) returns x* 2**n computed by exponent
+ * manipulation rather than by actually performing an
+ * exponentiation or a multiplication.
+ */
+
+#include "math.h"
+#include "math_private.h"
+#include <math_ldbl_opt.h>
+
+#ifdef __STDC__
+static const long double
+#else
+static long double
+#endif
+twolm54 = 5.55111512312578270212e-17, /* 0x3C90000000000000, 0 */
+huge = 1.0E+300L,
+tiny = 1.0E-300L;
+#ifdef __STDC__
+static const double
+#else
+static double
+#endif
+two54 = 1.80143985094819840000e+16, /* 0x4350000000000000 */
+twom54 = 5.55111512312578270212e-17; /* 0x3C90000000000000 */
+
+#ifdef __STDC__
+ long double __scalbnl (long double x, int n)
+#else
+ long double __scalbnl (x,n)
+ long double x; int n;
+#endif
+{
+ int64_t k,l,hx,lx;
+ union { int64_t i; double d; } u;
+ GET_LDOUBLE_WORDS64(hx,lx,x);
+ k = (hx>>52)&0x7ff; /* extract exponent */
+ l = (lx>>52)&0x7ff;
+ if (k==0) { /* 0 or subnormal x */
+ if (((hx|lx)&0x7fffffffffffffffULL)==0) return x; /* +-0 */
+ u.i = hx;
+ u.d *= two54;
+ hx = u.i;
+ k = ((hx>>52)&0x7ff) - 54;
+ }
+ else if (k==0x7ff) return x+x; /* NaN or Inf */
+ k = k+n;
+ if (n> 50000 || k > 0x7fe)
+ return huge*__copysignl(huge,x); /* overflow */
+ if (n< -50000) return tiny*__copysignl(tiny,x); /*underflow */
+ if (k > 0) { /* normal result */
+ hx = (hx&0x800fffffffffffffULL)|(k<<52);
+ if ((lx & 0x7fffffffffffffffULL) == 0) { /* low part +-0 */
+ SET_LDOUBLE_WORDS64(x,hx,lx);
+ return x;
+ }
+ if (l == 0) { /* low part subnormal */
+ u.i = lx;
+ u.d *= two54;
+ lx = u.i;
+ l = ((lx>>52)&0x7ff) - 54;
+ }
+ l = l + n;
+ if (l > 0)
+ lx = (lx&0x800fffffffffffffULL)|(l<<52);
+ else if (l <= -54)
+ lx = (lx&0x8000000000000000ULL);
+ else {
+ l += 54;
+ u.i = (lx&0x800fffffffffffffULL)|(l<<52);
+ u.d *= twom54;
+ lx = u.i;
+ }
+ SET_LDOUBLE_WORDS64(x,hx,lx);
+ return x;
+ }
+ if (k <= -54)
+ return tiny*__copysignl(tiny,x); /*underflow*/
+ k += 54; /* subnormal result */
+ lx &= 0x8000000000000000ULL;
+ SET_LDOUBLE_WORDS64(x,(hx&0x800fffffffffffffULL)|(k<<52),lx);
+ return x*twolm54;
+}
+#ifdef IS_IN_libm
+long_double_symbol (libm, __scalbnl, scalbnl);
+#else
+long_double_symbol (libc, __scalbnl, scalbnl);
+#endif