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48 lines
1.5 KiB
C
48 lines
1.5 KiB
C
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/*
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* Copyright (C) 2007, 2009 Free Software Foundation, Inc.
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*
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* This file is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 3, or (at your option) any
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* later version.
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*
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* This file is distributed in the hope that it will be useful, but
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* 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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* General Public License for more details.
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*
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* Under Section 7 of GPL version 3, you are granted additional
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* permissions described in the GCC Runtime Library Exception, version
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* 3.1, as published by the Free Software Foundation.
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*
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* You should have received a copy of the GNU General Public License and
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* a copy of the GCC Runtime Library Exception along with this program;
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* see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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* <http://www.gnu.org/licenses/>.
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*/
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#if __PREC == 32
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#define X87CW (0 << 8) /* Single precision (24 bits) */
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#elif __PREC == 64
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#define X87CW (2 << 8) /* Double precision (53 bits) */
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#elif __PREC == 80
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#define X87CW (3 << 8) /* Extended precision (64 bits) */
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#else
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#error "Wrong precision requested."
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#endif
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#define X87CW_PCMASK (3 << 8)
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static void __attribute__((constructor))
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set_precision (void)
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{
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unsigned short int cwd;
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asm volatile ("fstcw\t%0" : "=m" (cwd));
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cwd &= ~X87CW_PCMASK;
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cwd |= X87CW;
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asm volatile ("fldcw\t%0" : : "m" (cwd));
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}
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