Implement C99 floating-point environment for Alpha.

Delivering FPE with non-masked exceptions doesn't work on Alpha; I
suspect there's a bug in the kernel trap handler.

FE_INEXACT is intentionally left out of FE_ALL_EXCEPT;  since the
inexact exception is not being maintained.  Otherwise it will lead
to the bogus results.

1 files changed, 89 insertions, 0 deletions

diff --git a/sys/arch/alpha/include/fenv.h b/sys/arch/alpha/include/fenv.h
new file mode 100644
index 00000000000..c3af55b79aa
--- /dev/null
+++ b/sys/arch/alpha/include/fenv.h
@@ -0,0 +1,89 @@
+/*	$OpenBSD: fenv.h,v 1.1 2011/04/23 22:39:14 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	_ALPHA_FENV_H_
+#define	_ALPHA_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_INVALID		0x01
+#define	FE_DIVBYZERO		0x02
+#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)
+
+/*
+ * 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_TOWARDZERO		0x0
+#define	FE_DOWNWARD		0x1
+#define	FE_TONEAREST		0x2
+#define	FE_UPWARD		0x3
+
+/*
+ * 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_SHIFT		58
+
+/*
+ * fenv_t represents the entire floating-point environment
+ */
+typedef struct {
+	unsigned short __excepts;
+	unsigned short __mask;
+	unsigned short __round;
+} fenv_t;
+
+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 short fexcept_t;
+
+#endif	/* ! _ALPHA_FENV_H_ */