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authorAndreas Jaeger <aj@suse.de>2001-06-11 12:32:56 +0000
committerAndreas Jaeger <aj@suse.de>2001-06-11 12:32:56 +0000
commit92ec5b31c6336fda16656c3dda5e267707eefcad (patch)
treeddb55f13c6fc6393183a3a09bb1ee54abcb342d3 /sysdeps/ieee754
parent207390f763c23b7db63ddfea36793b657da431fe (diff)
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Update.
2001-06-11 Andreas Jaeger <aj@suse.de> * sysdeps/ieee754/ldbl-128/e_coshl.c: New file. Contributed by Stephen L Moshier <moshier@mediaone.net>. * aclocal.m4: Quote AC_FD_MSG and AC_FD_CC. * sysdeps/powerpc/fpu/libm-test-ulps: Add ULPs for tanh (-0.7). * sysdeps/s390/fpu/libm-test-ulps: Likewise.
Diffstat (limited to 'sysdeps/ieee754')
-rw-r--r--sysdeps/ieee754/ldbl-128/e_coshl.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/e_coshl.c b/sysdeps/ieee754/ldbl-128/e_coshl.c
new file mode 100644
index 0000000000..7ffc4d5159
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/e_coshl.c
@@ -0,0 +1,103 @@
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* Changes for 128-bit long double contributed by
+ Stephen L. Moshier <moshier@na-net.ornl.gov> */
+
+/* __ieee754_coshl(x)
+ * Method :
+ * mathematically coshl(x) if defined to be (exp(x)+exp(-x))/2
+ * 1. Replace x by |x| (coshl(x) = coshl(-x)).
+ * 2.
+ * [ exp(x) - 1 ]^2
+ * 0 <= x <= ln2/2 : coshl(x) := 1 + -------------------
+ * 2*exp(x)
+ *
+ * exp(x) + 1/exp(x)
+ * ln2/2 <= x <= 22 : coshl(x) := -------------------
+ * 2
+ * 22 <= x <= lnovft : coshl(x) := expl(x)/2
+ * lnovft <= x <= ln2ovft: coshl(x) := expl(x/2)/2 * expl(x/2)
+ * ln2ovft < x : coshl(x) := huge*huge (overflow)
+ *
+ * Special cases:
+ * coshl(x) is |x| if x is +INF, -INF, or NaN.
+ * only coshl(0)=1 is exact for finite x.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double one = 1.0, half = 0.5, huge = 1.0e4900L,
+ovf_thresh = 1.1357216553474703894801348310092223067821E4L;
+#else
+static long double one = 1.0, half = 0.5, huge = 1.0e4900L,
+ovf_thresh = 1.1357216553474703894801348310092223067821E4L;
+#endif
+
+#ifdef __STDC__
+long double
+__ieee754_coshl (long double x)
+#else
+long double
+__ieee754_coshl (x)
+ long double x;
+#endif
+{
+ long double t, w;
+ int32_t ex;
+ u_int32_t mx, lx;
+ ieee854_long_double_shape_type u;
+
+ u.value = x;
+ ex = u.parts32.w0 & 0x7fffffff;
+
+ /* Absolute value of x. */
+ u.parts32.w0 = ex;
+
+ /* x is INF or NaN */
+ if (ex >= 0x7fff0000)
+ return x * x;
+
+ /* |x| in [0,0.5*ln2], return 1+expm1l(|x|)^2/(2*expl(|x|)) */
+ if (ex < 0x3ffd62e4) /* 0.3465728759765625 */
+ {
+ t = __expm1l (u.value);
+ w = one + t;
+ if (ex < 0x3fc60000) /* |x| < 2^-57 */
+ return w; /* cosh(tiny) = 1 */
+
+ return one + (t * t) / (w + w);
+ }
+
+ /* |x| in [0.5*ln2,40], return (exp(|x|)+1/exp(|x|)/2; */
+ if (ex < 0x40044000)
+ {
+ t = __ieee754_expl (u.value);
+ return half * t + half / t;
+ }
+
+ /* |x| in [22, ln(maxdouble)] return half*exp(|x|) */
+ if (ex <= 0x400c62e3) /* 11356.375 */
+ return half * __ieee754_expl (u.value);
+
+ /* |x| in [log(maxdouble), overflowthresold] */
+ if (u.value <= ovf_thresh)
+ {
+ w = __ieee754_expl (half * u.value);
+ t = half * w;
+ return t * w;
+ }
+
+ /* |x| > overflowthresold, cosh(x) overflow */
+ return huge * huge;
+}