Fix LP64 libm for 128-bit long doubles
* reworked amd64/_fpmath.h and arm64/_fpmath.h to support 128-bit long
doubles.
* improved tests to cover long double cases
* made modfl an alias for LP32
Tests pass on x86, x86_64, arm, arm64 and mips.
Bug: 12921273
Change-Id: Ibe39acde57972447a8950fa45b1e702acc68ebeb
diff --git a/libm/upstream-freebsd/lib/msun/src/e_acoshl.c b/libm/upstream-freebsd/lib/msun/src/e_acoshl.c
new file mode 100644
index 0000000..59faeb0
--- /dev/null
+++ b/libm/upstream-freebsd/lib/msun/src/e_acoshl.c
@@ -0,0 +1,89 @@
+/* from: FreeBSD: head/lib/msun/src/e_acosh.c 176451 2008-02-22 02:30:36Z das */
+
+/* @(#)e_acosh.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * See e_acosh.c for complete comments.
+ *
+ * Converted to long double by David Schultz <das@FreeBSD.ORG> and
+ * Bruce D. Evans.
+ */
+
+#include <float.h>
+#ifdef __i386__
+#include <ieeefp.h>
+#endif
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
+
+/* EXP_LARGE is the threshold above which we use acosh(x) ~= log(2x). */
+#if LDBL_MANT_DIG == 64
+#define EXP_LARGE 34
+#elif LDBL_MANT_DIG == 113
+#define EXP_LARGE 58
+#else
+#error "Unsupported long double format"
+#endif
+
+#if LDBL_MAX_EXP != 0x4000
+/* We also require the usual expsign encoding. */
+#error "Unsupported long double format"
+#endif
+
+#define BIAS (LDBL_MAX_EXP - 1)
+
+static const double
+one = 1.0;
+
+#if LDBL_MANT_DIG == 64
+static const union IEEEl2bits
+u_ln2 = LD80C(0xb17217f7d1cf79ac, -1, 6.93147180559945309417e-1L);
+#define ln2 u_ln2.e
+#elif LDBL_MANT_DIG == 113
+static const long double
+ln2 = 6.93147180559945309417232121458176568e-1L; /* 0x162e42fefa39ef35793c7673007e6.0p-113 */
+#else
+#error "Unsupported long double format"
+#endif
+
+long double
+acoshl(long double x)
+{
+ long double t;
+ int16_t hx;
+
+ ENTERI();
+ GET_LDBL_EXPSIGN(hx, x);
+ if (hx < 0x3fff) { /* x < 1, or misnormal */
+ RETURNI((x-x)/(x-x));
+ } else if (hx >= BIAS + EXP_LARGE) { /* x >= LARGE */
+ if (hx >= 0x7fff) { /* x is inf, NaN or misnormal */
+ RETURNI(x+x);
+ } else
+ RETURNI(logl(x)+ln2); /* acosh(huge)=log(2x), or misnormal */
+ } else if (hx == 0x3fff && x == 1) {
+ RETURNI(0.0); /* acosh(1) = 0 */
+ } else if (hx >= 0x4000) { /* LARGE > x >= 2, or misnormal */
+ t=x*x;
+ RETURNI(logl(2.0*x-one/(x+sqrtl(t-one))));
+ } else { /* 1<x<2 */
+ t = x-one;
+ RETURNI(log1pl(t+sqrtl(2.0*t+t*t)));
+ }
+}