Fix libm build for x86_64.

Change-Id: If89da2d5c3d9a88f78ffd8b260ad0f2fd391c608
diff --git a/libm/Android.mk b/libm/Android.mk
index 3e769e7..1d87dc2 100644
--- a/libm/Android.mk
+++ b/libm/Android.mk
@@ -217,7 +217,7 @@
 
 # TODO: re-enable i387/e_sqrtf.S for x86, and maybe others.
 
-libm_common_cflags := -DFLT_EVAL_METHOD=0
+libm_common_cflags := -DFLT_EVAL_METHOD=0 -std=c99
 libm_common_includes := $(LOCAL_PATH)/upstream-freebsd/lib/msun/src/
 
 libm_arm_includes := $(LOCAL_PATH)/arm
@@ -226,7 +226,7 @@
 libm_x86_includes := $(LOCAL_PATH)/i386 $(LOCAL_PATH)/i387
 libm_x86_src_files := i387/fenv.c
 
-libm_x86_64_includes := $(LOCAL_PATH)/amd64 $(LOCAL_PATH)/i387
+libm_x86_64_includes := $(LOCAL_PATH)/amd64
 libm_x86_64_src_files := amd64/fenv.c
 
 libm_mips_cflags := -fno-builtin-rintf -fno-builtin-rint
diff --git a/libm/amd64/fenv.c b/libm/amd64/fenv.c
index 8b49b35..7ad3be7 100755
--- a/libm/amd64/fenv.c
+++ b/libm/amd64/fenv.c
@@ -1,5 +1,8 @@
+/*	$OpenBSD: fenv.c,v 1.3 2012/12/05 23:20:02 deraadt Exp $	*/
+/*	$NetBSD: fenv.c,v 1.1 2010/07/31 21:47:53 joerg Exp $	*/
+
 /*-
- * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG>
+ * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -22,143 +25,384 @@
  * 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.
- *
- * $FreeBSD$
  */
 
-#include <sys/cdefs.h>
-#include <sys/types.h>
+#include <fenv.h>
 #include <machine/fpu.h>
 
-#define	__fenv_static
-#include "fenv.h"
-
-#ifdef __GNUC_GNU_INLINE__
-#error "This file must be compiled with C99 'inline' semantics"
-#endif
-
-const fenv_t __fe_dfl_env = {
-	{ 0xffff0000 | __INITIAL_FPUCW__,
-	  0xffff0000,
-	  0xffffffff,
-	  { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff }
+/*
+ * 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().
+ *
+ * x87 fpu registers are 16bit wide. The upper bits, 31-16, are marked as
+ * RESERVED.
+ */
+fenv_t __fe_dfl_env = {
+	{
+		0xffff0000 | __INITIAL_NPXCW__,	/* Control word register */
+		0xffff0000,			/* Status word register */
+		0xffffffff,			/* Tag word register */
+		{
+			0x00000000,
+			0x00000000,
+			0x00000000,
+			0xffff0000
+		}
 	},
-	__INITIAL_MXCSR__
+	__INITIAL_MXCSR__			/* MXCSR register */
 };
 
-extern inline int feclearexcept(int __excepts);
-extern inline int fegetexceptflag(fexcept_t *__flagp, int __excepts);
 
+/*
+ * The feclearexcept() function clears the supported floating-point exceptions
+ * represented by `excepts'.
+ */
 int
-fesetexceptflag(const fexcept_t *flagp, int excepts)
+feclearexcept(int excepts)
 {
-	fenv_t env;
+	fenv_t fenv;
+	unsigned int mxcsr;
 
-	__fnstenv(&env.__x87);
-	env.__x87.__status &= ~excepts;
-	env.__x87.__status |= *flagp & excepts;
-	__fldenv(env.__x87);
+	excepts &= FE_ALL_EXCEPT;
 
-	__stmxcsr(&env.__mxcsr);
-	env.__mxcsr &= ~excepts;
-	env.__mxcsr |= *flagp & excepts;
-	__ldmxcsr(env.__mxcsr);
+	/* Store the current x87 floating-point environment */
+	__asm__ __volatile__ ("fnstenv %0" : "=m" (fenv));
+
+	/* Clear the requested floating-point exceptions */
+	fenv.__x87.__status &= ~excepts;
+
+	/* Load the x87 floating-point environent */
+	__asm__ __volatile__ ("fldenv %0" : : "m" (fenv));
+
+	/* Same for SSE environment */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+	mxcsr &= ~excepts;
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
 
 	return (0);
 }
 
+/*
+ * The fegetexceptflag() function stores an implementation-defined
+ * representation of the states of the floating-point status flags indicated by
+ * the argument excepts in the object pointed to by the argument flagp.
+ */
+int
+fegetexceptflag(fexcept_t *flagp, int excepts)
+{
+	unsigned short status;
+	unsigned int mxcsr;
+
+	excepts &= FE_ALL_EXCEPT;
+
+	/* Store the current x87 status register */
+	__asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+	/* Store the MXCSR register */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+	/* Store the results in flagp */
+	*flagp = (status | mxcsr) & excepts;
+
+	return (0);
+}
+
+/*
+ * The feraiseexcept() function raises the supported floating-point exceptions
+ * represented by the argument `excepts'.
+ *
+ * The standard explicitly allows us to execute an instruction that has the
+ * exception as a side effect, but we choose to manipulate the status register
+ * directly.
+ *
+ * The validation of input is being deferred to fesetexceptflag().
+ */
 int
 feraiseexcept(int excepts)
 {
-	fexcept_t ex = excepts;
+	excepts &= FE_ALL_EXCEPT;
 
-	fesetexceptflag(&ex, excepts);
-	__fwait();
+	fesetexceptflag((fexcept_t *)&excepts, excepts);
+	__asm__ __volatile__ ("fwait");
+
 	return (0);
 }
 
-extern inline int fetestexcept(int __excepts);
-extern inline int fegetround(void);
-extern inline int fesetround(int __round);
+/*
+ * This function sets the floating-point status flags indicated by the argument
+ * `excepts' to the states stored in the object pointed to by `flagp'. It does
+ * NOT raise any floating-point exceptions, but only sets the state of the flags.
+ */
+int
+fesetexceptflag(const fexcept_t *flagp, int excepts)
+{
+	fenv_t fenv;
+	unsigned int mxcsr;
 
+	excepts &= FE_ALL_EXCEPT;
+
+	/* Store the current x87 floating-point environment */
+	__asm__ __volatile__ ("fnstenv %0" : "=m" (fenv));
+
+	/* Set the requested status flags */
+	fenv.__x87.__status &= ~excepts;
+	fenv.__x87.__status |= *flagp & excepts;
+
+	/* Load the x87 floating-point environent */
+	__asm__ __volatile__ ("fldenv %0" : : "m" (fenv));
+
+	/* Same for SSE environment */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+	mxcsr &= ~excepts;
+	mxcsr |= *flagp & excepts;
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
+	return (0);
+}
+
+/*
+ * The fetestexcept() function determines which of a specified subset of the
+ * floating-point exception flags are currently set. The `excepts' argument
+ * specifies the floating-point status flags to be queried.
+ */
+int
+fetestexcept(int excepts)
+{
+	unsigned short status;
+	unsigned int mxcsr;
+
+	excepts &= FE_ALL_EXCEPT;
+
+	/* Store the current x87 status register */
+	__asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+	/* Store the MXCSR register state */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+	return ((status | mxcsr) & excepts);
+}
+
+/*
+ * The fegetround() function gets the current rounding direction.
+ */
+int
+fegetround(void)
+{
+	unsigned short control;
+
+	/*
+	 * We assume that the x87 and the SSE unit agree on the
+	 * rounding mode.  Reading the control word on the x87 turns
+	 * out to be about 5 times faster than reading it on the SSE
+	 * unit on an Opteron 244.
+	 */
+	__asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+	return (control & _X87_ROUND_MASK);
+}
+
+/*
+ * The fesetround() function establishes the rounding direction represented by
+ * its argument `round'. If the argument is not equal to the value of a rounding
+ * direction macro, the rounding direction is not changed.
+ */
+int
+fesetround(int round)
+{
+	unsigned short control;
+	unsigned int mxcsr;
+
+	/* Check whether requested rounding direction is supported */
+	if (round & ~_X87_ROUND_MASK)
+		return (-1);
+
+	/* Store the current x87 control word register */
+	__asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+	/* Set the rounding direction */
+	control &= ~_X87_ROUND_MASK;
+	control |= round;
+
+	/* Load the x87 control word register */
+	__asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+	/* Same for the SSE environment */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+	mxcsr &= ~(_X87_ROUND_MASK << _SSE_ROUND_SHIFT);
+	mxcsr |= round << _SSE_ROUND_SHIFT;
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
+	return (0);
+}
+
+/*
+ * The fegetenv() function attempts to store the current floating-point
+ * environment in the object pointed to by envp.
+ */
 int
 fegetenv(fenv_t *envp)
 {
+	/* Store the current x87 floating-point environment */
+	__asm__ __volatile__ ("fnstenv %0" : "=m" (*envp));
 
-	__fnstenv(&envp->__x87);
-	__stmxcsr(&envp->__mxcsr);
+	/* Store the MXCSR register state */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (envp->__mxcsr));
+
 	/*
-	 * fnstenv masks all exceptions, so we need to restore the
-	 * control word to avoid this side effect.
+	 * When an FNSTENV instruction is executed, all pending exceptions are
+	 * essentially lost (either the x87 FPU status register is cleared or
+	 * all exceptions are masked).
+	 *
+	 * 8.6 X87 FPU EXCEPTION SYNCHRONIZATION -
+	 * Intel(R) 64 and IA-32 Architectures Softare Developer's Manual - Vol1
 	 */
-	__fldcw(envp->__x87.__control);
+	__asm__ __volatile__ ("fldcw %0" : : "m" (envp->__x87.__control));
+
 	return (0);
 }
 
+/*
+ * The feholdexcept() function saves the current floating-point environment
+ * in the object pointed to by envp, clears the floating-point status flags, and
+ * then installs a non-stop (continue on floating-point exceptions) mode, if
+ * available, for all floating-point exceptions.
+ */
 int
 feholdexcept(fenv_t *envp)
 {
-	__uint32_t mxcsr;
+	unsigned int mxcsr;
 
-	__stmxcsr(&mxcsr);
-	__fnstenv(&envp->__x87);
-	__fnclex();
-	envp->__mxcsr = mxcsr;
+	/* Store the current x87 floating-point environment */
+	__asm__ __volatile__ ("fnstenv %0" : "=m" (*envp));
+
+	/* Clear all exception flags in FPU */
+	__asm__ __volatile__ ("fnclex");
+
+	/* Store the MXCSR register state */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (envp->__mxcsr));
+
+	/* Clear exception flags in MXCSR */
+	mxcsr = envp->__mxcsr;
 	mxcsr &= ~FE_ALL_EXCEPT;
-	mxcsr |= FE_ALL_EXCEPT << _SSE_EMASK_SHIFT;
-	__ldmxcsr(mxcsr);
+
+	/* Mask all exceptions */
+	mxcsr |= FE_ALL_EXCEPT << _SSE_MASK_SHIFT;
+
+	/* Store the MXCSR register */
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
 	return (0);
 }
 
-extern inline int fesetenv(const fenv_t *__envp);
+/*
+ * The fesetenv() function attempts to establish the floating-point environment
+ * represented by the object pointed to by envp. The argument `envp' points
+ * to an object set by a call to fegetenv() or feholdexcept(), or equal a
+ * floating-point environment macro. The fesetenv() function does not raise
+ * floating-point exceptions, but only installs the state of the floating-point
+ * status flags represented through its argument.
+ */
+int
+fesetenv(const fenv_t *envp)
+{
+	/* Load the x87 floating-point environent */
+	__asm__ __volatile__ ("fldenv %0" : : "m" (*envp));
 
+	/* Store the MXCSR register */
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (envp->__mxcsr));
+
+	return (0);
+}
+
+/*
+ * The feupdateenv() function saves the currently raised floating-point
+ * exceptions in its automatic storage, installs the floating-point environment
+ * represented by the object pointed to by `envp', and then raises the saved
+ * floating-point exceptions. The argument `envp' shall point to an object set
+ * by a call to feholdexcept() or fegetenv(), or equal a floating-point
+ * environment macro.
+ */
 int
 feupdateenv(const fenv_t *envp)
 {
-	__uint32_t mxcsr;
-	__uint16_t status;
+	unsigned short status;
+	unsigned int mxcsr;
 
-	__fnstsw(&status);
-	__stmxcsr(&mxcsr);
+	/* Store the x87 status register */
+	__asm__ __volatile__ ("fnstsw %0" : "=am" (status));
+
+	/* Store the MXCSR register */
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+	/* Install new floating-point environment */
 	fesetenv(envp);
-	feraiseexcept((mxcsr | status) & FE_ALL_EXCEPT);
+
+	/* Raise any previously accumulated exceptions */
+	feraiseexcept(status | mxcsr);
+
 	return (0);
 }
 
+/*
+ * The following functions are extentions to the standard
+ */
 int
-__feenableexcept(int mask)
+feenableexcept(int mask)
 {
-	__uint32_t mxcsr, omask;
-	__uint16_t control;
+	unsigned int mxcsr, omask;
+	unsigned short control;
 
 	mask &= FE_ALL_EXCEPT;
-	__fnstcw(&control);
-	__stmxcsr(&mxcsr);
-	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
+
+	__asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+	omask = ~(control | (mxcsr >> _SSE_MASK_SHIFT)) & FE_ALL_EXCEPT;
 	control &= ~mask;
-	__fldcw(control);
-	mxcsr &= ~(mask << _SSE_EMASK_SHIFT);
-	__ldmxcsr(mxcsr);
+	__asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+	mxcsr &= ~(mask << _SSE_MASK_SHIFT);
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
 	return (omask);
 }
 
 int
-__fedisableexcept(int mask)
+fedisableexcept(int mask)
 {
-	__uint32_t mxcsr, omask;
-	__uint16_t control;
+	unsigned int mxcsr, omask;
+	unsigned short control;
 
 	mask &= FE_ALL_EXCEPT;
-	__fnstcw(&control);
-	__stmxcsr(&mxcsr);
-	omask = ~(control | mxcsr >> _SSE_EMASK_SHIFT) & FE_ALL_EXCEPT;
+
+	__asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+	__asm__ __volatile__ ("stmxcsr %0" : "=m" (mxcsr));
+
+	omask = ~(control | (mxcsr >> _SSE_MASK_SHIFT)) & FE_ALL_EXCEPT;
 	control |= mask;
-	__fldcw(control);
-	mxcsr |= mask << _SSE_EMASK_SHIFT;
-	__ldmxcsr(mxcsr);
+	__asm__ __volatile__ ("fldcw %0" : : "m" (control));
+
+	mxcsr |= mask << _SSE_MASK_SHIFT;
+	__asm__ __volatile__ ("ldmxcsr %0" : : "m" (mxcsr));
+
 	return (omask);
 }
 
-__weak_reference(__feenableexcept, feenableexcept);
-__weak_reference(__fedisableexcept, fedisableexcept);
+int
+fegetexcept(void)
+{
+	unsigned short control;
+
+	/*
+	 * We assume that the masks for the x87 and the SSE unit are
+	 * the same.
+	 */
+	__asm__ __volatile__ ("fnstcw %0" : "=m" (control));
+
+	return (~control & FE_ALL_EXCEPT);
+}
diff --git a/libm/include/amd64/fenv.h b/libm/include/amd64/fenv.h
new file mode 100644
index 0000000..037778e
--- /dev/null
+++ b/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_ */