adding fpgetround(3) IEEE floating point environment support

1 files changed, 107 insertions, 0 deletions

diff --git a/sys/amd64/include/floatingpoint.h b/sys/amd64/include/floatingpoint.h
new file mode 100644
index 0000000..bc69d2e
--- /dev/null
+++ b/sys/amd64/include/floatingpoint.h
@@ -0,0 +1,107 @@
+/*-
+ * Copyright (c) 1993 Andrew Moore, Talke Studio
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ *
+ *	@(#) floatingpoint.h	1.0 (Berkeley) 9/23/93
+ */
+
+/*
+ *	IEEE floating point structure and function definitions
+ */
+
+#ifndef _FLOATINGPOINT_H_
+#define _FLOATINGPOINT_H_
+
+#include <sys/cdefs.h>
+#include <sys/ieeefp.h>
+
+#ifdef __GNUC__
+
+#define fnstcw(addr)	__asm("fnstcw %0" : "=m" (*addr) : "0" (*addr))
+#define fnstsw(addr)	__asm("fnstsw %0" : "=m" (*addr) : "0" (*addr))
+#define fnstenv(addr)	__asm("fnstenv %0" : "=m" (*addr) : "0" (*addr))
+#define fldenv(addr)	__asm("fldenv %0" : : "m" (*addr))
+
+#ifdef __i386__
+
+/*
+ * return the contents of a FP register
+ */
+static __inline__
+__fpgetreg(reg)
+{
+	unsigned short mem;
+
+	switch(reg) {
+	default:
+		fnstcw(&mem);
+		break;
+	case FP_STKY_REG:
+		fnstsw(&mem);
+		break;
+	}
+	return mem;
+}
+
+/*
+ * set a FP mode; return previous mode
+ */
+static __inline__
+__fpsetreg(m, reg, fld, off)
+{
+	unsigned env[7];
+	unsigned p;
+
+	fnstenv(env);
+	p =  (env[reg] & fld) >> off;
+	env[reg] = (env[reg] & ~fld) | (m << off & fld);
+	fldenv(env);
+	return p;
+}
+
+#endif /* __i386__ */
+
+#endif /* __GNUC__ */
+
+/*
+ * SysV/386 FP control interface
+ */
+#define fpgetround()	((__fpgetreg(FP_RND_REG) & FP_RND_FLD) >> FP_RND_OFF)
+#define fpsetround(m)	__fpsetreg((m), FP_RND_REG, FP_RND_FLD, FP_RND_OFF)
+#define fpgetprec()	((__fpgetreg(FP_PRC_REG) & FP_PRC_FLD) >> FP_PRC_OFF)
+#define fpsetprec(m)	__fpsetreg((m), FP_PRC_REG, FP_PRC_FLD, FP_PRC_OFF)
+#define fpgetmask()	((~__fpgetreg(FP_MSKS_REG) & FP_MSKS_FLD) >> FP_MSKS_OFF)
+#define fpsetmask(m)	__fpsetreg(~(m), FP_MSKS_REG, FP_MSKS_FLD, FP_MSKS_OFF)
+#define fpgetsticky()	((__fpgetreg(FP_STKY_REG) & FP_STKY_FLD) >> FP_STKY_OFF)
+#define fpresetsticky(m)	__fpsetreg(0, FP_STKY_REG, (m), FP_STKY_OFF)
+#define fpsetsticky(m)	fpresetsticky(m)
+
+#endif /* !_FLOATINGPOINT_H_ */