Update to build msun for arm64

 * The long double type on arm64 is quad-precision
 * Add fenv.c to export the required symbols
 * Fix _fpmath.h to be the correct size and pull out the correct bits

_fpmath.h is now based on the arm version.

lib/libc/arm64/_fpmath.h

@@ -1,5 +1,6 @@
 /*-
- * Copyright (c) 2003 David Schultz <das@FreeBSD.ORG>
+ * Copyright (c) 2002, 2003 David Schultz <das@FreeBSD.ORG>
+ * Copyright (2) 2014 The FreeBSD Foundation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -29,21 +30,29 @@
 union IEEEl2bits {
 	long double	e;
 	struct {
-		unsigned int		sign	:1;
-		unsigned int		exp	:11;
-		unsigned int		manh	:20;
-		unsigned int		manl	:32;
+		unsigned long	manl	:64;
+		unsigned long	manh	:48;
+		unsigned int	exp	:15;
+		unsigned int	sign	:1;
 	} bits;
+	/* TODO andrew: Check the packing here */
+	struct {
+		unsigned long	manl	:64;
+		unsigned long	manh	:48;
+		unsigned int	expsign	:16;
+	} xbits;
 };
 
-#define	mask_nbit_l(u)	((void)0)
-#define	LDBL_IMPLICIT_NBIT
 #define	LDBL_NBIT	0
+#define	LDBL_IMPLICIT_NBIT
+#define	mask_nbit_l(u)	((void)0)
 
-#define	LDBL_MANH_SIZE	20
-#define	LDBL_MANL_SIZE	32
+#define	LDBL_MANH_SIZE	48
+#define	LDBL_MANL_SIZE	64
 
 #define	LDBL_TO_ARRAY32(u, a) do {			\
 	(a)[0] = (uint32_t)(u).bits.manl;		\
-	(a)[1] = (uint32_t)(u).bits.manh;		\
+	(a)[1] = (uint32_t)((u).bits.manl >> 32);	\
+	(a)[2] = (uint32_t)(u).bits.manh;		\
+	(a)[3] = (uint32_t)((u).bits.manh >> 32);	\
 } while(0)

lib/msun/arm64/Makefile.inc

@@ -1,5 +1,5 @@
 # $FreeBSD$
 
 #TODO: Check this
-LDBL_PREC = 64
+LDBL_PREC = 113
 

lib/msun/arm64/fenv.c

@@ -0,0 +1,56 @@
+/*-
+ * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
+ * Copyright (c) 2013 Andrew Turner <andrew@FreeBSD.ORG>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#define	__fenv_static
+#include "fenv.h"
+
+/*
+ * Hopefully the system ID byte is immutable, so it's valid to use
+ * this as a default environment.
+ */
+const fenv_t __fe_dfl_env = 0;
+
+#ifdef __GNUC_GNU_INLINE__
+#error "This file must be compiled with C99 'inline' semantics"
+#endif
+
+extern inline int feclearexcept(int __excepts);
+extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
+extern inline int fesetexceptflag(const fexcept_t *__flagp, int __excepts);
+extern inline int feraiseexcept(int __excepts);
+extern inline int fetestexcept(int __excepts);
+extern inline int fegetround(void);
+extern inline int fesetround(int __round);
+extern inline int fegetenv(fenv_t *__envp);
+extern inline int feholdexcept(fenv_t *__envp);
+extern inline int fesetenv(const fenv_t *__envp);
+extern inline int feupdateenv(const fenv_t *__envp);
+extern inline int feenableexcept(int __mask);
+extern inline int fedisableexcept(int __mask);
+extern inline int fegetexcept(void);