diff options
| -rw-r--r-- | ChangeLog | 2 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/m68k/fpu_control.h | 110 |
2 files changed, 112 insertions, 0 deletions
@@ -31,6 +31,8 @@ Sat Feb 10 13:09:03 1996 Andreas Schwab <schwab@issan.informatik.uni-dortmund. sysdeps/unix/sysv/linux/m68k/sysdep.S, sysdeps/unix/sysv/linux/m68k/sysdep.h: New files. + * sysdeps/unix/sysv/linux/m68k/fpu_control.h: New file. + * sysdeps/m68k/fpu/isinfl.c, sysdeps/m68k/fpu/isnanl.c, sysdeps/m68k/isinfl.c, sysdeps/m68k/isnanl.c: New files. 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 0000000..0bbbb08 --- /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 */ |