126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
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/* Determine floating-point rounding mode within libc. Generic version.
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Copyright (C) 2012-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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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 Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifndef _GET_ROUNDING_MODE_H
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#define _GET_ROUNDING_MODE_H 1
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#include <fpu_control.h>
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#include <stdlib.h>
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/* Define values for FE_* modes not defined for this architecture. */
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#ifdef FE_DOWNWARD
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# define ORIG_FE_DOWNWARD FE_DOWNWARD
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#else
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# define ORIG_FE_DOWNWARD 0
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#endif
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#ifdef FE_TONEAREST
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# define ORIG_FE_TONEAREST FE_TONEAREST
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#else
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# define ORIG_FE_TONEAREST 0
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#endif
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#ifdef FE_TOWARDZERO
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# define ORIG_FE_TOWARDZERO FE_TOWARDZERO
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#else
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# define ORIG_FE_TOWARDZERO 0
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#endif
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#ifdef FE_UPWARD
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# define ORIG_FE_UPWARD FE_UPWARD
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#else
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# define ORIG_FE_UPWARD 0
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#endif
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#define FE_CONSTRUCT_DISTINCT_VALUE(X, Y, Z) \
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((((X) & 1) | ((Y) & 2) | ((Z) & 4)) ^ 7)
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#ifndef FE_DOWNWARD
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# define FE_DOWNWARD FE_CONSTRUCT_DISTINCT_VALUE (ORIG_FE_TONEAREST, \
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ORIG_FE_TOWARDZERO, \
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ORIG_FE_UPWARD)
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#endif
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#ifndef FE_TONEAREST
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# define FE_TONEAREST FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
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ORIG_FE_TOWARDZERO, \
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ORIG_FE_UPWARD)
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#endif
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#ifndef FE_TOWARDZERO
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# define FE_TOWARDZERO FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
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FE_TONEAREST, \
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ORIG_FE_UPWARD)
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#endif
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#ifndef FE_UPWARD
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# define FE_UPWARD FE_CONSTRUCT_DISTINCT_VALUE (FE_DOWNWARD, \
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FE_TONEAREST, \
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FE_TOWARDZERO)
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#endif
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/* Return the floating-point rounding mode. */
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static inline int
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get_rounding_mode (void)
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{
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#if (defined _FPU_RC_DOWN \
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|| defined _FPU_RC_NEAREST \
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|| defined _FPU_RC_ZERO \
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|| defined _FPU_RC_UP)
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fpu_control_t fc;
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const fpu_control_t mask = (0
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# ifdef _FPU_RC_DOWN
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| _FPU_RC_DOWN
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# endif
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# ifdef _FPU_RC_NEAREST
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| _FPU_RC_NEAREST
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# endif
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# ifdef _FPU_RC_ZERO
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| _FPU_RC_ZERO
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# endif
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# ifdef _FPU_RC_UP
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| _FPU_RC_UP
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# endif
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);
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_FPU_GETCW (fc);
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switch (fc & mask)
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{
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# ifdef _FPU_RC_DOWN
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case _FPU_RC_DOWN:
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return FE_DOWNWARD;
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# endif
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# ifdef _FPU_RC_NEAREST
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case _FPU_RC_NEAREST:
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return FE_TONEAREST;
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# endif
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# ifdef _FPU_RC_ZERO
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case _FPU_RC_ZERO:
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return FE_TOWARDZERO;
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# endif
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# ifdef _FPU_RC_UP
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case _FPU_RC_UP:
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return FE_UPWARD;
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# endif
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default:
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abort ();
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}
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#else
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return FE_TONEAREST;
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#endif
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}
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#endif /* get-rounding-mode.h */
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