New file from Schwab

	* sysdeps/unix/sysv/linux/m68k/fpu_control.h: New file.

1 files changed, 110 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/m68k/fpu_control.h b/sysdeps/unix/sysv/linux/m68k/fpu_control.h
new file mode 100644
index 0000000000..0bbbb08916
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/m68k/fpu_control.h
@@ -0,0 +1,110 @@
+/* 68k FPU control word definitions.
+Copyright (C) 1996 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#ifndef _FPU_CONTROL_H
+#define _FPU_CONTROL_H
+
+/*
+ * Motorola floating point control register bits.
+ *
+ * 31-16  -> reserved (read as 0, ignored on write)
+ * 15     -> enable trap for BSUN exception
+ * 14     -> enable trap for SNAN exception
+ * 13     -> enable trap for OPERR exception
+ * 12     -> enable trap for OVFL exception
+ * 11     -> enable trap for UNFL exception
+ * 10     -> enable trap for DZ exception
+ *  9     -> enable trap for INEX2 exception
+ *  8     -> enable trap for INEX1 exception
+ *  7-6   -> Precision Control
+ *  5-4   -> Rounding Control
+ *  3-0   -> zero (read as 0, write as 0)
+ *
+ *
+ * Precision Control:
+ * 00 - round to extended precision
+ * 01 - round to single precision
+ * 10 - round to double precision
+ * 11 - undefined
+ *
+ * Rounding Control:
+ * 00 - rounding to nearest (RN)
+ * 01 - rounding toward zero (RZ)
+ * 10 - rounding (down)toward minus infinity (RM)
+ * 11 - rounding (up) toward plus infinity (RP)
+ *
+ * The hardware default is 0x0000. I choose 0x5400.
+ */
+
+#include <features.h>
+
+/* masking of interrupts */
+#define _FPU_MASK_BSUN  0x8000
+#define _FPU_MASK_SNAN  0x4000
+#define _FPU_MASK_OPERR 0x2000
+#define _FPU_MASK_OVFL  0x1000
+#define _FPU_MASK_UNFL  0x0800
+#define _FPU_MASK_DZ    0x0400
+#define _FPU_MASK_INEX1 0x0200
+#define _FPU_MASK_INEX2 0x0100
+
+/* precision control */
+#define _FPU_EXTENDED 0x00   /* RECOMMENDED */
+#define _FPU_DOUBLE   0x80
+#define _FPU_SINGLE   0x40     /* DO NOT USE */
+
+/* rounding control */
+#define _FPU_RC_NEAREST 0x00    /* RECOMMENDED */
+#define _FPU_RC_ZERO    0x10
+#define _FPU_RC_DOWN    0x20
+#define _FPU_RC_UP      0x30
+
+#define _FPU_RESERVED 0xFFFF000F  /* Reserved bits in fpucr */
+
+
+/* Now two recommended fpucr */
+
+/* Linux default:
+     - extended precision
+     - rounding to nearest
+     - exceptions on overflow, zero divide and NaN */
+#define _FPU_DEFAULT  0x00005400
+
+/* IEEE:  same as above, but exceptions.  We must make it non-zero so
+   that __setfpucw works.  This bit will be ignored.  */
+#define _FPU_IEEE     0x00000001
+
+/* Type of the control word.  */
+typedef unsigned int fpu_control_t __attribute__ ((__mode__ (__SI__)));
+
+/* Macros for accessing the hardware control word.  */
+#define _FPU_GETCW(cw) __asm__ ("fmove%.l %!, %0" : "=dm" (cw))
+#define _FPU_SETCW(cw) __asm__ ("fmove%.l %0, %!" : "dm" (cw))
+
+/* Default control word set at startup.  */
+extern fpu_control_t __fpu_control;
+
+__BEGIN_DECLS
+
+/* Called at startup.  It can be used to manipulate fpu control register.  */
+extern void __setfpucw __P ((fpu_control_t));
+
+__END_DECLS
+
+#endif /* _M68K_FPU_CONTROL_H */