Fix libm build for x86_64.

Change-Id: If89da2d5c3d9a88f78ffd8b260ad0f2fd391c608

libm/include/amd64/fenv.h

@@ -0,0 +1,117 @@
+/*	$OpenBSD: fenv.h,v 1.4 2011/05/25 21:46:49 martynas Exp $	*/
+/*	$NetBSD: fenv.h,v 1.1 2010/07/31 21:47:54 joerg Exp $	*/
+
+/*-
+ * Copyright (c) 2004-2005 David Schultz <das (at) 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.
+ */
+
+#ifndef	_AMD64_FENV_H_
+#define	_AMD64_FENV_H_
+
+#include <sys/types.h>
+
+/*
+ * Each symbol representing a floating point exception expands to an integer
+ * constant expression with values, such that bitwise-inclusive ORs of _all
+ * combinations_ of the constants result in distinct values.
+ *
+ * We use such values that allow direct bitwise operations on FPU/SSE registers.
+ */
+#define	FE_INVALID		0x01
+#define	FE_DENORMAL		0x02
+#define	FE_DIVBYZERO		0x04
+#define	FE_OVERFLOW		0x08
+#define	FE_UNDERFLOW		0x10
+#define	FE_INEXACT		0x20
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * exception constants defined above.
+ */
+#define	FE_ALL_EXCEPT		(FE_INVALID | FE_DENORMAL | FE_DIVBYZERO | \
+				 FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
+#define	_SSE_MASK_SHIFT		7
+
+/*
+ * Each symbol representing the rounding direction, expands to an integer
+ * constant expression whose value is distinct non-negative value.
+ *
+ * We use such values that allow direct bitwise operations on FPU/SSE registers.
+ */
+#define	FE_TONEAREST		0x000
+#define	FE_DOWNWARD		0x400
+#define	FE_UPWARD		0x800
+#define	FE_TOWARDZERO		0xc00
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
+ */
+#define	_X87_ROUND_MASK		(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | \
+				 FE_TOWARDZERO)
+#define	_SSE_ROUND_SHIFT	3
+
+/*
+ * fenv_t represents the entire floating-point environment.
+ */
+typedef	struct {
+	struct {
+		unsigned int __control;		/* Control word register */
+		unsigned int __status;		/* Status word register */
+		unsigned int __tag;		/* Tag word register */
+		unsigned int __others[4];	/* EIP, Pointer Selector, etc */
+	} __x87;
+	unsigned int __mxcsr;			/* Control, status register */
+} fenv_t;
+
+/*
+ * The following constant represents the default floating-point environment
+ * (that is, the one installed at program startup) and has type pointer to
+ * const-qualified fenv_t.
+ *
+ * It can be used as an argument to the functions within the <fenv.h> header
+ * that manage the floating-point environment, namely fesetenv() and
+ * feupdateenv().
+ */
+__BEGIN_DECLS
+extern	fenv_t			__fe_dfl_env;
+__END_DECLS
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
+
+/*
+ * fexcept_t represents the floating-point status flags collectively, including
+ * any status the implementation associates with the flags.
+ *
+ * A floating-point status flag is a system variable whose value is set (but
+ * never cleared) when a floating-point exception is raised, which occurs as a
+ * side effect of exceptional floating-point arithmetic to provide auxiliary
+ * information.
+ *
+ * A floating-point control mode is a system variable whose value may be set by
+ * the user to affect the subsequent behavior of floating-point arithmetic.
+ */
+typedef	unsigned int		fexcept_t;
+
+#endif	/* !_AMD64_FENV_H_ */