97 lines
3.0 KiB
C
97 lines
3.0 KiB
C
/* FPU control word bits. Mips version.
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Copyright (C) 1996, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Olaf Flebbe.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If not,
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write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#ifndef _FPU_CONTROL_H
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#define _FPU_CONTROL_H
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/* FP control/status register bit assignments.
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*
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* 31-25 24 23 22-18 17-12 11-7 6-2 1-0
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* (cause) (enables) (flags)
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* | reserved | FS | C | reserved | E V Z O U I | V Z O U I | V Z O U I | RM
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*
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* FS: When set, denormalized results are flushed to zero instead of
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* causing an unimplemented operation exception.
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* C: Condition bit.
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* E: Unimplemented Operation.
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* V: Invalid Operation.
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* Z: Division by zero.
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* O: Overflow.
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* U: Underflow.
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* I: Inexact Operation
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* RM: Rounding mode bits
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* 00 (RN) - rounding to nearest
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* 01 (RZ) - rounding toward zero
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* 10 (RP) - rounding down (toward - infinity)
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* 11 (RM) - rounding up (toward + infinity)
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*
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*/
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#include <features.h>
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/* masking of interrupts */
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#define _FPU_MASK_IM (1 << 11)
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#define _FPU_MASK_DM (1 << 24) /* XXX */
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#define _FPU_MASK_ZM (1 << 10)
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#define _FPU_MASK_OM (1 << 9)
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#define _FPU_MASK_UM (1 << 8)
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#define _FPU_MASK_PM (1 << 7)
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/* precision control */
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#define _FPU_EXTENDED 0
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#define _FPU_DOUBLE 0
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#define _FPU_SINGLE 0
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/* rounding control */
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#define _FPU_RC_NEAREST 0x0 /* RECOMMENDED */
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#define _FPU_RC_DOWN 0x2
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#define _FPU_RC_UP 0x3
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#define _FPU_RC_ZERO 0x1
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#define _FPU_RESERVED 0xfe7c0000 /* Reserved bits */
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/* The fdlibm code requires strict IEEE double precision arithmetic,
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and no interrupts for exceptions, rounding to nearest. */
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#define _FPU_DEFAULT 0x0
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/* IEEE: same as above, but exceptions */
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#define _FPU_IEEE (0x1f << 7)
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/* Type of the control word. */
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typedef unsigned int fpu_control_t;
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/* Macros for accessing the hardware control word. */
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#define _FPU_GETCW(cw) __asm__ ("cfc1 %0, $31; nop; nop" : "=r" (cw))
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#define _FPU_SETCW(cw) __asm__ ("ctc1 %0, $31; nop; nop" : : "r" (cw))
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/* Default control word set at startup. */
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extern fpu_control_t __fpu_control;
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__BEGIN_DECLS
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/* Called at startup. It can be used to manipulate fpu control register. */
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extern void __setfpucw __P ((fpu_control_t));
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__END_DECLS
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#endif /* fpu_control.h */
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