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authorUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
committerUlrich Drepper <drepper@redhat.com>2004-12-22 20:10:10 +0000
commita334319f6530564d22e775935d9c91663623a1b4 (patch)
treeb5877475619e4c938e98757d518bb1e9cbead751 /sysdeps/m68k/fpu_control.h
parent0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (diff)
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(CFLAGS-tst-align.c): Add -mpreferred-stack-boundary=4.
Diffstat (limited to 'sysdeps/m68k/fpu_control.h')
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1 files changed, 101 insertions, 0 deletions
diff --git a/sysdeps/m68k/fpu_control.h b/sysdeps/m68k/fpu_control.h
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+/* 68k FPU control word definitions.
+   Copyright (C) 1996, 1997, 1998 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 Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 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 */
+
+/* The fdlibm code requires no interrupts for exceptions.  Don't
+   change the rounding mode, it would break long double I/O!  */
+#define _FPU_DEFAULT  0x00000000
+
+/* 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__ volatile ("fmove%.l %0, %!" : : "dm" (cw))
+
+/* Default control word set at startup.  */
+extern fpu_control_t __fpu_control;
+
+#endif /* _M68K_FPU_CONTROL_H */