fenv improvements and cleanups

13 files changed, 537 insertions, 232 deletions

diff --git a/sys/arch/alpha/include/fenv.h b/sys/arch/alpha/include/fenv.h
index c3af55b79aa..c9f76150afe 100644
--- a/sys/arch/alpha/include/fenv.h
+++ b/sys/arch/alpha/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/23 22:39:14 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -31,15 +31,13 @@
 #define	FE_OVERFLOW		0x04
 #define	FE_UNDERFLOW		0x08
 #define	FE_INEXACT		0x10
-#define	FE_INTOVERFLOW		0x20
 
 /*
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW | \
-	 FE_INTOVERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | \
+				 FE_UNDERFLOW)
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -56,21 +54,30 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		\
-	(FE_TOWARDZERO | FE_DOWNWARD | FE_TONEAREST | FE_UPWARD)
+#define	_ROUND_MASK		(FE_TOWARDZERO | FE_DOWNWARD | FE_TONEAREST | \
+				 FE_UPWARD)
 #define	_ROUND_SHIFT		58
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef struct {
-	unsigned short __excepts;
-	unsigned short __mask;
-	unsigned short __round;
+typedef	struct {
+	unsigned int __sticky;
+	unsigned int __mask;
+	unsigned int __round;
 } fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -84,6 +91,6 @@ extern fenv_t			__fe_dfl_env;
  * 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 short fexcept_t;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _ALPHA_FENV_H_ */
+#endif	/* !_ALPHA_FENV_H_ */
diff --git a/sys/arch/amd64/include/fenv.h b/sys/arch/amd64/include/fenv.h
index 67c5cff7889..addc8214da1 100644
--- a/sys/arch/amd64/include/fenv.h
+++ b/sys/arch/amd64/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.2 2011/04/23 21:54:20 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.3 2011/04/28 17:34:23 martynas Exp $	*/
 /*	$NetBSD: fenv.h,v 1.1 2010/07/31 21:47:54 joerg Exp $	*/
 
 /*-
@@ -48,9 +48,9 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW | \
-	 FE_DENORMAL)
+#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
@@ -61,22 +61,20 @@
 #define	FE_TONEAREST		0x000
 #define	FE_DOWNWARD		0x400
 #define	FE_UPWARD		0x800
-#define	FE_TOWARDZERO		0xC00
+#define	FE_TOWARDZERO		0xc00
 
 /*
- * As compared to the x87 control word, the SSE unit's control word
- * has the rounding control bits offset by 3 and the exception mask
- * bits offset by 7.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_X87_ROUND_MASK		0xC00
-#define	_SSE_ROUND_MASK		(0xC00 << 3)
+#define	_X87_ROUND_MASK		(FE_TONEAREST | FE_DOWNWARD | FE_UPWARD | \
+				 FE_TOWARDZERO)
 #define	_SSE_ROUND_SHIFT	3
-#define	_SSE_EMASK_SHIFT	7
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef struct {
+typedef	struct {
 	struct {
 		unsigned int __control;		/* Control word register */
 		unsigned int __status;		/* Status word register */
@@ -86,8 +84,17 @@ typedef struct {
 	unsigned int __mxcsr;			/* Control, status register */
 } fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -101,6 +108,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _AMD64_FENV_H_ */
+#endif	/* !_AMD64_FENV_H_ */
diff --git a/sys/arch/arm/include/fenv.h b/sys/arch/arm/include/fenv.h
index 51a580a8230..8811db10c7b 100644
--- a/sys/arch/arm/include/fenv.h
+++ b/sys/arch/arm/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/24 00:20:27 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -36,8 +36,8 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW | FE_INEXACT)
+#define	FE_ALL_EXCEPT		(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | \
+				 FE_UNDERFLOW | FE_INEXACT)
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -54,20 +54,29 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		\
-	(FE_TOWARDZERO | FE_DOWNWARD | FE_TONEAREST | FE_UPWARD)
+#define	_ROUND_MASK		(FE_TONEAREST | FE_UPWARD | FE_DOWNWARD | \
+				 FE_TOWARDZERO)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef struct {
-	unsigned short __excepts;
-	unsigned short __mask;
-	unsigned short __round;
+typedef	struct {
+	unsigned int __sticky;
+	unsigned int __mask;
+	unsigned int __round;
 } fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -81,6 +90,6 @@ extern fenv_t			__fe_dfl_env;
  * 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 short fexcept_t;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _ARM_FENV_H_ */
+#endif	/* !_ARM_FENV_H_ */
diff --git a/sys/arch/hppa/include/fenv.h b/sys/arch/hppa/include/fenv.h
index 379a469a836..1cd923e827c 100644
--- a/sys/arch/hppa/include/fenv.h
+++ b/sys/arch/hppa/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/21 20:40:54 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -26,18 +26,19 @@
  *
  * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_INEXACT		0x08000000
-#define	FE_UNDERFLOW		0x10000000
-#define	FE_OVERFLOW		0x20000000
-#define	FE_DIVBYZERO		0x40000000
-#define	FE_INVALID		0x80000000
+#define	FE_INEXACT		0x01
+#define	FE_UNDERFLOW		0x02
+#define	FE_OVERFLOW		0x04
+#define	FE_DIVBYZERO		0x08
+#define	FE_INVALID		0x10
 
 /*
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_UNDERFLOW | FE_OVERFLOW | \
+				 FE_DIVBYZERO | FE_INVALID)
+#define	_MASK_SHIFT		27
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -51,19 +52,28 @@
 #define	FE_DOWNWARD		0x600
 
 /*
- * FPSR encodes rounding modes by bits 9-10.
- * FPSR flags and exception mask shifts by 27.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		0x600
-#define	_EMASK_SHIFT		27
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef unsigned int fenv_t;
+typedef	unsigned int		fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -77,6 +87,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _HPPA_FENV_H_ */
+#endif	/* !_HPPA_FENV_H_ */
diff --git a/sys/arch/hppa64/include/fenv.h b/sys/arch/hppa64/include/fenv.h
new file mode 100644
index 00000000000..33a4ee0a879
--- /dev/null
+++ b/sys/arch/hppa64/include/fenv.h
@@ -0,0 +1,92 @@
+/*	$OpenBSD: fenv.h,v 1.1 2011/04/28 17:34:23 martynas Exp $	*/
+
+/*
+ * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef	_HPPA64_FENV_H_
+#define	_HPPA64_FENV_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 registers.
+ */
+#define	FE_INEXACT		0x01
+#define	FE_UNDERFLOW		0x02
+#define	FE_OVERFLOW		0x04
+#define	FE_DIVBYZERO		0x08
+#define	FE_INVALID		0x10
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * exception constants defined above.
+ */
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_UNDERFLOW | FE_OVERFLOW | \
+				 FE_DIVBYZERO | FE_INVALID)
+#define	_MASK_SHIFT		27
+
+/*
+ * 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 registers.
+ */
+#define	FE_TONEAREST		0x000
+#define	FE_TOWARDZERO		0x200
+#define	FE_UPWARD		0x400
+#define	FE_DOWNWARD		0x600
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
+ */
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
+
+/*
+ * fenv_t represents the entire floating-point environment.
+ */
+typedef	unsigned int		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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#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	/* !_HPPA64_FENV_H_ */
diff --git a/sys/arch/i386/include/fenv.h b/sys/arch/i386/include/fenv.h
index a756899525d..80d34a65325 100644
--- a/sys/arch/i386/include/fenv.h
+++ b/sys/arch/i386/include/fenv.h
@@ -1,5 +1,6 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/24 00:35:22 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 /*	$NetBSD: fenv.h,v 1.1.6.2 2010/10/24 22:48:02 jym Exp $	*/
+
 /*-
  * Copyright (c) 2004-2005 David Schultz <das (at) FreeBSD.ORG>
  * All rights reserved.
@@ -26,11 +27,8 @@
  * SUCH DAMAGE.
  */
 
-#ifndef	_X86_FENV_H_
-#define	_X86_FENV_H_
-
-#include <sys/stdint.h>
-#include <i386/npx.h>
+#ifndef	_I386_FENV_H_
+#define	_I386_FENV_H_
 
 /*
  * Each symbol representing a floating point exception expands to an integer
@@ -39,19 +37,20 @@
  *
  * We use such values that allow direct bitwise operations on FPU/SSE registers.
  */
-#define	FE_INVALID	0x01	/* 000000000001 */
-#define	FE_DENORMAL	0x02	/* 000000000010 */
-#define	FE_DIVBYZERO	0x04	/* 000000000100 */
-#define	FE_OVERFLOW	0x08	/* 000000001000 */
-#define	FE_UNDERFLOW	0x10	/* 000000010000 */
-#define	FE_INEXACT	0x20	/* 000000100000 */
+#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_DIVBYZERO | FE_DENORMAL | FE_INEXACT | \
-			 FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#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
@@ -59,34 +58,30 @@
  *
  * We use such values that allow direct bitwise operations on FPU/SSE registers.
  */
-#define	FE_TONEAREST	0x000	/* 000000000000 */
-#define	FE_DOWNWARD	0x400	/* 010000000000 */
-#define	FE_UPWARD	0x800	/* 100000000000 */
-#define	FE_TOWARDZERO	0xC00	/* 110000000000 */
+#define	FE_TONEAREST		0x000
+#define	FE_DOWNWARD		0x400
+#define	FE_UPWARD		0x800
+#define	FE_TOWARDZERO		0xc00
 
 /*
- * As compared to the x87 control word, the SSE unit's control has the rounding
- * control bits offset by 3 and the exception mask bits offset by 7
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	__X87_ROUND_MASK	0xC00		/* 110000000000 */
-#define	__SSE_ROUND_SHIFT	3
-#define	__SSE_EMASK_SHIFT	7
+#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
+ * fenv_t represents the entire floating-point environment.
  */
-typedef struct {
+typedef	struct {
 	struct {
-		uint16_t control;	/* Control word register */
-		uint16_t unused1;
-		uint16_t status;	/* Status word register */
-		uint16_t unused2;
-		uint16_t tag;		/* Tag word register */
-		uint16_t unused3;
-		uint32_t others[4];	/* EIP, Pointer Selector, etc */
-	} x87;
-		
-	uint32_t mxcsr;			/* Control and status register */
+		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;
 
 /*
@@ -95,10 +90,11 @@ typedef struct {
  * 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.
+ * that manage the floating-point environment, namely fesetenv() and
+ * feupdateenv().
  */
-extern  fenv_t		__fe_dfl_env;
-#define FE_DFL_ENV      ((const fenv_t *) &__fe_dfl_env)
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -112,6 +108,6 @@ extern  fenv_t		__fe_dfl_env;
  * 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 uint32_t fexcept_t;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _X86_FENV_H_ */
+#endif	/* !_I386_FENV_H_ */
diff --git a/sys/arch/m68k/include/fenv.h b/sys/arch/m68k/include/fenv.h
index abf3de866e0..c7a0acf9e72 100644
--- a/sys/arch/m68k/include/fenv.h
+++ b/sys/arch/m68k/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/20 22:27:59 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -36,8 +36,9 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
+				 FE_OVERFLOW | FE_INVALID)
+#define	_MASK_SHIFT		6
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -51,22 +52,31 @@
 #define	FE_UPWARD		0x30
 
 /*
- * FPCR encodes rounding modes by bits 4-5.
- * FPCR and FPSR exception mask shifts by 6.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		0x30
-#define	_EMASK_SHIFT		6
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_DOWNWARD | \
+				 FE_UPWARD)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef struct {
-	unsigned int __control;		/* Control register */
-	unsigned int __status;		/* Status register */
+typedef	struct {
+	unsigned int __control;			/* Control register */
+	unsigned int __status;			/* Status register */
 } fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -80,6 +90,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _M68K_FENV_H_ */
+#endif	/* !_M68K_FENV_H_ */
diff --git a/sys/arch/m88k/include/fenv.h b/sys/arch/m88k/include/fenv.h
new file mode 100644
index 00000000000..f229e98557e
--- /dev/null
+++ b/sys/arch/m88k/include/fenv.h
@@ -0,0 +1,94 @@
+/*	$OpenBSD: fenv.h,v 1.1 2011/04/28 17:34:23 martynas Exp $	*/
+
+/*
+ * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef	_M88K_FENV_H_
+#define	_M88K_FENV_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 registers.
+ */
+#define	FE_INEXACT		0x01
+#define	FE_OVERFLOW		0x02
+#define	FE_UNDERFLOW		0x04
+#define	FE_DIVBYZERO		0x08
+#define	FE_INVALID		0x10
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * exception constants defined above.
+ */
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
+				 FE_OVERFLOW | FE_INVALID)
+
+/*
+ * 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 registers.
+ */
+#define	FE_TONEAREST		0x0000
+#define	FE_TOWARDZERO		0x4000
+#define	FE_DOWNWARD		0x8000
+#define	FE_UPWARD		0xC000
+
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
+ */
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_DOWNWARD | \
+				 FE_UPWARD)
+
+/*
+ * fenv_t represents the entire floating-point environment.
+ */
+typedef	struct {
+	unsigned int __control;			/* Control register */
+	unsigned int __status;			/* 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#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	/* !_M88K_FENV_H_ */
diff --git a/sys/arch/mips64/include/fenv.h b/sys/arch/mips64/include/fenv.h
index 149572b1594..5b3b7df82bb 100644
--- a/sys/arch/mips64/include/fenv.h
+++ b/sys/arch/mips64/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/26 21:14:07 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -26,18 +26,19 @@
  *
  * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_INEXACT	0x04
-#define	FE_UNDERFLOW	0x08
-#define	FE_OVERFLOW	0x10
-#define	FE_DIVBYZERO	0x20
-#define	FE_INVALID	0x40
+#define	FE_INEXACT		0x04
+#define	FE_UNDERFLOW		0x08
+#define	FE_OVERFLOW		0x10
+#define	FE_DIVBYZERO		0x20
+#define	FE_INVALID		0x40
 
 /*
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_UNDERFLOW | FE_OVERFLOW | \
+				 FE_DIVBYZERO | FE_INVALID)
+#define	_MASK_SHIFT		5
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -51,19 +52,28 @@
 #define	FE_DOWNWARD		0x3
 
 /*
- * FPSCR encodes rounding modes by bits 0-1.
- * FPSCR flags and exception mask shifts by 5.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		0x3
-#define	_EMASK_SHIFT		5
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef unsigned int fenv_t;
+typedef	unsigned int fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -77,6 +87,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _MIPS64_FENV_H_ */
+#endif	/* !_MIPS64_FENV_H_ */
diff --git a/sys/arch/powerpc/include/fenv.h b/sys/arch/powerpc/include/fenv.h
index a09f5bbf7ce..df2ab25c00b 100644
--- a/sys/arch/powerpc/include/fenv.h
+++ b/sys/arch/powerpc/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/25 20:34:09 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -38,8 +38,9 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
+				 FE_OVERFLOW | FE_INVALID)
+#define	_MASK_SHIFT		22
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -53,19 +54,28 @@
 #define	FE_DOWNWARD		0x3
 
 /*
- * FPSCR encodes rounding modes by bits 0-1.
- * FPSCR flags and exception mask shifts by 22.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		0x3
-#define	_EMASK_SHIFT		22
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef unsigned int fenv_t;
+typedef	unsigned int		fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -79,6 +89,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _POWERPC_FENV_H_ */
+#endif	/* !_POWERPC_FENV_H_ */
diff --git a/sys/arch/sh/include/fenv.h b/sys/arch/sh/include/fenv.h
index 4b66fee051f..e07aae472f0 100644
--- a/sys/arch/sh/include/fenv.h
+++ b/sys/arch/sh/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/24 15:05:12 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 
 /*
  * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
@@ -36,8 +36,9 @@
  * The following symbol is simply the bitwise-inclusive OR of all floating-point
  * exception constants defined above.
  */
-#define	FE_ALL_EXCEPT		\
-	(FE_DIVBYZERO | FE_INEXACT | FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_UNDERFLOW | FE_OVERFLOW | \
+				 FE_DIVBYZERO | FE_INVALID)
+#define	_MASK_SHIFT		5
 
 /*
  * Each symbol representing the rounding direction, expands to an integer
@@ -51,19 +52,28 @@
 #define	FE_DOWNWARD		0x3
 
 /*
- * FPSCR encodes rounding modes by bits 0-1.
- * FPSCR flags and exception mask shifts by 5.
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
  */
-#define	_ROUND_MASK		0x3
-#define	_EMASK_SHIFT		5
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
 
 /*
- * fenv_t represents the entire floating-point environment
+ * fenv_t represents the entire floating-point environment.
  */
-typedef unsigned int fenv_t;
+typedef	unsigned int		fenv_t;
 
-extern fenv_t			__fe_dfl_env;
-#define	FE_DFL_ENV		((const fenv_t *) &__fe_dfl_env)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
 /*
  * fexcept_t represents the floating-point status flags collectively, including
@@ -77,6 +87,6 @@ extern fenv_t			__fe_dfl_env;
  * 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;
+typedef	unsigned int		fexcept_t;
 
-#endif	/* ! _SH_FENV_H_ */
+#endif	/* !_SH_FENV_H_ */
diff --git a/sys/arch/sparc/include/fenv.h b/sys/arch/sparc/include/fenv.h
index ecde9342f3e..7869d44c353 100644
--- a/sys/arch/sparc/include/fenv.h
+++ b/sys/arch/sparc/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.1 2011/04/25 21:04:29 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.2 2011/04/28 17:34:23 martynas Exp $	*/
 /*	$NetBSD: fenv.h,v 1.1.2.2 2011/02/08 16:19:41 bouyer Exp $	*/
 
 /*-
@@ -32,50 +32,75 @@
 #ifndef	_SPARC_FENV_H_
 #define	_SPARC_FENV_H_
 
-#include <sys/stdint.h>
-
-typedef	unsigned long int	fenv_t;
-typedef	unsigned long int	fexcept_t;
-
 /*
- * Exception flags
+ * 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.
  *
- * Symbols are defined in such a way, to correspond to the accrued
- * exception bits (aexc) fields of FSR.
+ * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_INEXACT      0x00000020	/* 0000100000 */
-#define	FE_DIVBYZERO    0x00000040	/* 0001000000 */
-#define	FE_UNDERFLOW    0x00000080	/* 0010000000 */
-#define	FE_OVERFLOW     0x00000100	/* 0100000000 */
-#define	FE_INVALID	0x00000200	/* 1000000000 */
+#define	FE_INEXACT		0x020
+#define	FE_DIVBYZERO		0x040
+#define	FE_UNDERFLOW		0x080
+#define	FE_OVERFLOW		0x100
+#define	FE_INVALID		0x200
 
-#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
-    FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * exception constants defined above.
+ */
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
+				 FE_OVERFLOW | FE_INVALID)
+#define	_MASK_SHIFT		18
 
 /*
- * Rounding modes
+ * Each symbol representing the rounding direction, expands to an integer
+ * constant expression whose value is distinct non-negative value.
  *
- * We can't just use the hardware bit values here, because that would
- * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed.
+ * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_TONEAREST	0x0
-#define	FE_TOWARDZERO	0x1
-#define	FE_UPWARD	0x2
-#define	FE_DOWNWARD	0x3
-#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
-    FE_UPWARD | FE_TOWARDZERO)
-#define	_ROUND_SHIFT	30
+#define	FE_TONEAREST		0x0
+#define	FE_TOWARDZERO		0x1
+#define	FE_UPWARD		0x2
+#define	FE_DOWNWARD		0x3
 
-__BEGIN_DECLS
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
+ */
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
+#define	_ROUND_SHIFT		30
 
-/* Default floating-point environment */
-extern const fenv_t	__fe_dfl_env;
-#define	FE_DFL_ENV	(&__fe_dfl_env)
+/*
+ * fenv_t represents the entire floating-point environment.
+ */
+typedef	unsigned long		fenv_t;
 
-/* We need to be able to map status flag positions to mask flag positions */
-#define	_FPUSW_SHIFT	18
-#define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
-__END_DECLS
+/*
+ * 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 long		fexcept_t;
 
 #endif	/* !_SPARC_FENV_H_ */
diff --git a/sys/arch/sparc64/include/fenv.h b/sys/arch/sparc64/include/fenv.h
index efc95f987dd..882203e2cc6 100644
--- a/sys/arch/sparc64/include/fenv.h
+++ b/sys/arch/sparc64/include/fenv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fenv.h,v 1.2 2011/04/25 21:04:29 martynas Exp $	*/
+/*	$OpenBSD: fenv.h,v 1.3 2011/04/28 17:34:23 martynas Exp $	*/
 /*	$NetBSD: fenv.h,v 1.1.2.2 2011/02/08 16:19:41 bouyer Exp $	*/
 
 /*-
@@ -32,50 +32,75 @@
 #ifndef	_SPARC64_FENV_H_
 #define	_SPARC64_FENV_H_
 
-#include <sys/stdint.h>
-
-typedef	unsigned long int	fenv_t;
-typedef	unsigned long int	fexcept_t;
-
 /*
- * Exception flags
+ * 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.
  *
- * Symbols are defined in such a way, to correspond to the accrued
- * exception bits (aexc) fields of FSR.
+ * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_INEXACT      0x00000020	/* 0000100000 */
-#define	FE_DIVBYZERO    0x00000040	/* 0001000000 */
-#define	FE_UNDERFLOW    0x00000080	/* 0010000000 */
-#define	FE_OVERFLOW     0x00000100	/* 0100000000 */
-#define	FE_INVALID	0x00000200	/* 1000000000 */
+#define	FE_INEXACT		0x020
+#define	FE_DIVBYZERO		0x040
+#define	FE_UNDERFLOW		0x080
+#define	FE_OVERFLOW		0x100
+#define	FE_INVALID		0x200
 
-#define	FE_ALL_EXCEPT	(FE_DIVBYZERO | FE_INEXACT | \
-    FE_INVALID | FE_OVERFLOW | FE_UNDERFLOW)
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * exception constants defined above.
+ */
+#define	FE_ALL_EXCEPT		(FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | \
+				 FE_OVERFLOW | FE_INVALID)
+#define	_MASK_SHIFT		18
 
 /*
- * Rounding modes
+ * Each symbol representing the rounding direction, expands to an integer
+ * constant expression whose value is distinct non-negative value.
  *
- * We can't just use the hardware bit values here, because that would
- * make FE_UPWARD and FE_DOWNWARD negative, which is not allowed.
+ * We use such values that allow direct bitwise operations on FPU registers.
  */
-#define	FE_TONEAREST	0x0
-#define	FE_TOWARDZERO	0x1
-#define	FE_UPWARD	0x2
-#define	FE_DOWNWARD	0x3
-#define	_ROUND_MASK	(FE_TONEAREST | FE_DOWNWARD | \
-    FE_UPWARD | FE_TOWARDZERO)
-#define	_ROUND_SHIFT	30
+#define	FE_TONEAREST		0x0
+#define	FE_TOWARDZERO		0x1
+#define	FE_UPWARD		0x2
+#define	FE_DOWNWARD		0x3
 
-__BEGIN_DECLS
+/*
+ * The following symbol is simply the bitwise-inclusive OR of all floating-point
+ * rounding direction constants defined above.
+ */
+#define	_ROUND_MASK		(FE_TONEAREST | FE_TOWARDZERO | FE_UPWARD | \
+				 FE_DOWNWARD)
+#define	_ROUND_SHIFT		30
 
-/* Default floating-point environment */
-extern const fenv_t	__fe_dfl_env;
-#define	FE_DFL_ENV	(&__fe_dfl_env)
+/*
+ * fenv_t represents the entire floating-point environment.
+ */
+typedef	unsigned long		fenv_t;
 
-/* We need to be able to map status flag positions to mask flag positions */
-#define	_FPUSW_SHIFT	18
-#define	_ENABLE_MASK	(FE_ALL_EXCEPT << _FPUSW_SHIFT)
+/*
+ * 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().
+ */
+extern	fenv_t			__fe_dfl_env;
+#define	FE_DFL_ENV		((const fenv_t *)&__fe_dfl_env)
 
-__END_DECLS
+/*
+ * 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 long		fexcept_t;
 
 #endif	/* !_SPARC64_FENV_H_ */