355 lines
9.8 KiB
C
355 lines
9.8 KiB
C
/* Software floating-point emulation.
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Copyright (C) 1997-2019 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Richard Henderson (rth@cygnus.com),
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Jakub Jelinek (jj@ultra.linux.cz),
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David S. Miller (davem@redhat.com) and
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Peter Maydell (pmaydell@chiark.greenend.org.uk).
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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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In addition to the permissions in the GNU Lesser General Public
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License, the Free Software Foundation gives you unlimited
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permission to link the compiled version of this file into
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combinations with other programs, and to distribute those
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combinations without any restriction coming from the use of this
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file. (The Lesser General Public License restrictions do apply in
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other respects; for example, they cover modification of the file,
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and distribution when not linked into a combine executable.)
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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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<http://www.gnu.org/licenses/>. */
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#ifndef SOFT_FP_H
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#define SOFT_FP_H 1
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#ifdef _LIBC
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# include <sfp-machine.h>
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#elif defined __KERNEL__
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/* The Linux kernel uses asm/ names for architecture-specific
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files. */
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# include <asm/sfp-machine.h>
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#else
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# include "sfp-machine.h"
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#endif
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/* Allow sfp-machine to have its own byte order definitions. */
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#ifndef __BYTE_ORDER
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# ifdef _LIBC
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# include <endian.h>
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# else
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# error "endianness not defined by sfp-machine.h"
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# endif
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#endif
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/* For unreachable default cases in switch statements over bitwise OR
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of FP_CLS_* values. */
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#if (defined __GNUC__ \
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&& (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
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# define _FP_UNREACHABLE __builtin_unreachable ()
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#else
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# define _FP_UNREACHABLE abort ()
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#endif
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#if ((defined __GNUC__ \
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&& (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6))) \
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|| (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L))
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# define _FP_STATIC_ASSERT(expr, msg) \
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_Static_assert ((expr), msg)
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#else
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# define _FP_STATIC_ASSERT(expr, msg) \
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extern int (*__Static_assert_function (void)) \
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[!!sizeof (struct { int __error_if_negative: (expr) ? 2 : -1; })]
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#endif
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/* In the Linux kernel, some architectures have a single function that
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uses different kinds of unpacking and packing depending on the
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instruction being emulated, meaning it is not readily visible to
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the compiler that variables from _FP_DECL and _FP_FRAC_DECL_*
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macros are only used in cases where they were initialized. */
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#ifdef __KERNEL__
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# define _FP_ZERO_INIT = 0
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#else
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# define _FP_ZERO_INIT
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#endif
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#define _FP_WORKBITS 3
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#define _FP_WORK_LSB ((_FP_W_TYPE) 1 << 3)
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#define _FP_WORK_ROUND ((_FP_W_TYPE) 1 << 2)
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#define _FP_WORK_GUARD ((_FP_W_TYPE) 1 << 1)
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#define _FP_WORK_STICKY ((_FP_W_TYPE) 1 << 0)
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#ifndef FP_RND_NEAREST
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# define FP_RND_NEAREST 0
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# define FP_RND_ZERO 1
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# define FP_RND_PINF 2
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# define FP_RND_MINF 3
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#endif
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#ifndef FP_ROUNDMODE
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# define FP_ROUNDMODE FP_RND_NEAREST
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#endif
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/* By default don't care about exceptions. */
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#ifndef FP_EX_INVALID
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# define FP_EX_INVALID 0
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#endif
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#ifndef FP_EX_OVERFLOW
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# define FP_EX_OVERFLOW 0
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#endif
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#ifndef FP_EX_UNDERFLOW
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# define FP_EX_UNDERFLOW 0
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#endif
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#ifndef FP_EX_DIVZERO
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# define FP_EX_DIVZERO 0
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#endif
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#ifndef FP_EX_INEXACT
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# define FP_EX_INEXACT 0
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#endif
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#ifndef FP_EX_DENORM
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# define FP_EX_DENORM 0
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#endif
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/* Sub-exceptions of "invalid". */
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/* Signaling NaN operand. */
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#ifndef FP_EX_INVALID_SNAN
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# define FP_EX_INVALID_SNAN 0
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#endif
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/* Inf * 0. */
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#ifndef FP_EX_INVALID_IMZ
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# define FP_EX_INVALID_IMZ 0
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#endif
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/* fma (Inf, 0, c). */
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#ifndef FP_EX_INVALID_IMZ_FMA
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# define FP_EX_INVALID_IMZ_FMA 0
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#endif
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/* Inf - Inf. */
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#ifndef FP_EX_INVALID_ISI
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# define FP_EX_INVALID_ISI 0
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#endif
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/* 0 / 0. */
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#ifndef FP_EX_INVALID_ZDZ
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# define FP_EX_INVALID_ZDZ 0
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#endif
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/* Inf / Inf. */
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#ifndef FP_EX_INVALID_IDI
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# define FP_EX_INVALID_IDI 0
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#endif
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/* sqrt (negative). */
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#ifndef FP_EX_INVALID_SQRT
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# define FP_EX_INVALID_SQRT 0
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#endif
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/* Invalid conversion to integer. */
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#ifndef FP_EX_INVALID_CVI
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# define FP_EX_INVALID_CVI 0
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#endif
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/* Invalid comparison. */
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#ifndef FP_EX_INVALID_VC
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# define FP_EX_INVALID_VC 0
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#endif
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/* _FP_STRUCT_LAYOUT may be defined as an attribute to determine the
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struct layout variant used for structures where bit-fields are used
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to access specific parts of binary floating-point numbers. This is
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required for systems where the default ABI uses struct layout with
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differences in how consecutive bit-fields are laid out from the
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default expected by soft-fp. */
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#ifndef _FP_STRUCT_LAYOUT
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# define _FP_STRUCT_LAYOUT
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#endif
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#ifdef _FP_DECL_EX
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# define FP_DECL_EX \
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int _fex = 0; \
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_FP_DECL_EX
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#else
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# define FP_DECL_EX int _fex = 0
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#endif
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/* Initialize any machine-specific state used in FP_ROUNDMODE,
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FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS. */
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#ifndef FP_INIT_ROUNDMODE
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# define FP_INIT_ROUNDMODE do {} while (0)
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#endif
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/* Initialize any machine-specific state used in
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FP_TRAPPING_EXCEPTIONS or FP_HANDLE_EXCEPTIONS. */
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#ifndef FP_INIT_TRAPPING_EXCEPTIONS
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# define FP_INIT_TRAPPING_EXCEPTIONS FP_INIT_ROUNDMODE
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#endif
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/* Initialize any machine-specific state used in
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FP_HANDLE_EXCEPTIONS. */
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#ifndef FP_INIT_EXCEPTIONS
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# define FP_INIT_EXCEPTIONS FP_INIT_TRAPPING_EXCEPTIONS
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#endif
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#ifndef FP_HANDLE_EXCEPTIONS
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# define FP_HANDLE_EXCEPTIONS do {} while (0)
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#endif
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/* Whether to flush subnormal inputs to zero with the same sign. */
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#ifndef FP_DENORM_ZERO
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# define FP_DENORM_ZERO 0
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#endif
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#ifndef FP_INHIBIT_RESULTS
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/* By default we write the results always.
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sfp-machine may override this and e.g.
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check if some exceptions are unmasked
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and inhibit it in such a case. */
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# define FP_INHIBIT_RESULTS 0
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#endif
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#define FP_SET_EXCEPTION(ex) \
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_fex |= (ex)
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#define FP_CUR_EXCEPTIONS \
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(_fex)
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#ifndef FP_TRAPPING_EXCEPTIONS
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# define FP_TRAPPING_EXCEPTIONS 0
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#endif
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/* A file using soft-fp may define FP_NO_EXCEPTIONS before including
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soft-fp.h to indicate that, although a macro used there could raise
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exceptions, or do rounding and potentially thereby raise
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exceptions, for some arguments, for the particular arguments used
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in that file no exceptions or rounding can occur. Such a file
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should not itself use macros relating to handling exceptions and
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rounding modes; this is only for indirect uses (in particular, in
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_FP_FROM_INT and the macros it calls). */
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#ifdef FP_NO_EXCEPTIONS
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# undef FP_SET_EXCEPTION
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# define FP_SET_EXCEPTION(ex) do {} while (0)
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# undef FP_CUR_EXCEPTIONS
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# define FP_CUR_EXCEPTIONS 0
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# undef FP_TRAPPING_EXCEPTIONS
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# define FP_TRAPPING_EXCEPTIONS 0
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# undef FP_ROUNDMODE
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# define FP_ROUNDMODE FP_RND_ZERO
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# undef _FP_TININESS_AFTER_ROUNDING
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# define _FP_TININESS_AFTER_ROUNDING 0
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#endif
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/* A file using soft-fp may define FP_NO_EXACT_UNDERFLOW before
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including soft-fp.h to indicate that, although a macro used there
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could allow for the case of exact underflow requiring the underflow
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exception to be raised if traps are enabled, for the particular
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arguments used in that file no exact underflow can occur. */
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#ifdef FP_NO_EXACT_UNDERFLOW
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# undef FP_TRAPPING_EXCEPTIONS
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# define FP_TRAPPING_EXCEPTIONS 0
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#endif
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#define _FP_ROUND_NEAREST(wc, X) \
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do \
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{ \
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if ((_FP_FRAC_LOW_##wc (X) & 15) != _FP_WORK_ROUND) \
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_FP_FRAC_ADDI_##wc (X, _FP_WORK_ROUND); \
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} \
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while (0)
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#define _FP_ROUND_ZERO(wc, X) (void) 0
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#define _FP_ROUND_PINF(wc, X) \
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do \
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{ \
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if (!X##_s && (_FP_FRAC_LOW_##wc (X) & 7)) \
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_FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB); \
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} \
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while (0)
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#define _FP_ROUND_MINF(wc, X) \
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do \
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{ \
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if (X##_s && (_FP_FRAC_LOW_##wc (X) & 7)) \
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_FP_FRAC_ADDI_##wc (X, _FP_WORK_LSB); \
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} \
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while (0)
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#define _FP_ROUND(wc, X) \
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do \
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{ \
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if (_FP_FRAC_LOW_##wc (X) & 7) \
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{ \
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FP_SET_EXCEPTION (FP_EX_INEXACT); \
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switch (FP_ROUNDMODE) \
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{ \
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case FP_RND_NEAREST: \
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_FP_ROUND_NEAREST (wc, X); \
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break; \
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case FP_RND_ZERO: \
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_FP_ROUND_ZERO (wc, X); \
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break; \
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case FP_RND_PINF: \
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_FP_ROUND_PINF (wc, X); \
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break; \
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case FP_RND_MINF: \
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_FP_ROUND_MINF (wc, X); \
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break; \
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} \
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} \
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} \
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while (0)
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#define FP_CLS_NORMAL 0
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#define FP_CLS_ZERO 1
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#define FP_CLS_INF 2
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#define FP_CLS_NAN 3
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#define _FP_CLS_COMBINE(x, y) (((x) << 2) | (y))
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#include "op-1.h"
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#include "op-2.h"
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#include "op-4.h"
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#include "op-8.h"
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#include "op-common.h"
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/* Sigh. Silly things longlong.h needs. */
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#define UWtype _FP_W_TYPE
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#define W_TYPE_SIZE _FP_W_TYPE_SIZE
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typedef int QItype __attribute__ ((mode (QI)));
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typedef int SItype __attribute__ ((mode (SI)));
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typedef int DItype __attribute__ ((mode (DI)));
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typedef unsigned int UQItype __attribute__ ((mode (QI)));
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typedef unsigned int USItype __attribute__ ((mode (SI)));
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typedef unsigned int UDItype __attribute__ ((mode (DI)));
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#if _FP_W_TYPE_SIZE == 32
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typedef unsigned int UHWtype __attribute__ ((mode (HI)));
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#elif _FP_W_TYPE_SIZE == 64
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typedef USItype UHWtype;
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#endif
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#ifndef CMPtype
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# define CMPtype int
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#endif
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#define SI_BITS (__CHAR_BIT__ * (int) sizeof (SItype))
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#define DI_BITS (__CHAR_BIT__ * (int) sizeof (DItype))
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#ifndef umul_ppmm
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# ifdef _LIBC
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# include <stdlib/longlong.h>
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# else
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# include "longlong.h"
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# endif
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#endif
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#endif /* !SOFT_FP_H */
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