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- /* Software floating-point emulation.
- Basic eight-word fraction declaration and manipulation.
- Copyright (C) 1997,1998,1999,2006 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Richard Henderson (rth@cygnus.com),
- Jakub Jelinek (jj@ultra.linux.cz) and
- Peter Maydell (pmaydell@chiark.greenend.org.uk).
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- In addition to the permissions in the GNU Lesser General Public
- License, the Free Software Foundation gives you unlimited
- permission to link the compiled version of this file into
- combinations with other programs, and to distribute those
- combinations without any restriction coming from the use of this
- file. (The Lesser General Public License restrictions do apply in
- other respects; for example, they cover modification of the file,
- and distribution when not linked into a combine executable.)
- 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
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
- MA 02110-1301, USA. */
- /* We need just a few things from here for op-4, if we ever need some
- other macros, they can be added. */
- #define _FP_FRAC_DECL_8(X) _FP_W_TYPE X##_f[8]
- #define _FP_FRAC_HIGH_8(X) (X##_f[7])
- #define _FP_FRAC_LOW_8(X) (X##_f[0])
- #define _FP_FRAC_WORD_8(X,w) (X##_f[w])
- #define _FP_FRAC_SLL_8(X,N) \
- do { \
- _FP_I_TYPE _up, _down, _skip, _i; \
- _skip = (N) / _FP_W_TYPE_SIZE; \
- _up = (N) % _FP_W_TYPE_SIZE; \
- _down = _FP_W_TYPE_SIZE - _up; \
- if (!_up) \
- for (_i = 7; _i >= _skip; --_i) \
- X##_f[_i] = X##_f[_i-_skip]; \
- else \
- { \
- for (_i = 7; _i > _skip; --_i) \
- X##_f[_i] = X##_f[_i-_skip] << _up \
- | X##_f[_i-_skip-1] >> _down; \
- X##_f[_i--] = X##_f[0] << _up; \
- } \
- for (; _i >= 0; --_i) \
- X##_f[_i] = 0; \
- } while (0)
- #define _FP_FRAC_SRL_8(X,N) \
- do { \
- _FP_I_TYPE _up, _down, _skip, _i; \
- _skip = (N) / _FP_W_TYPE_SIZE; \
- _down = (N) % _FP_W_TYPE_SIZE; \
- _up = _FP_W_TYPE_SIZE - _down; \
- if (!_down) \
- for (_i = 0; _i <= 7-_skip; ++_i) \
- X##_f[_i] = X##_f[_i+_skip]; \
- else \
- { \
- for (_i = 0; _i < 7-_skip; ++_i) \
- X##_f[_i] = X##_f[_i+_skip] >> _down \
- | X##_f[_i+_skip+1] << _up; \
- X##_f[_i++] = X##_f[7] >> _down; \
- } \
- for (; _i < 8; ++_i) \
- X##_f[_i] = 0; \
- } while (0)
- /* Right shift with sticky-lsb.
- * What this actually means is that we do a standard right-shift,
- * but that if any of the bits that fall off the right hand side
- * were one then we always set the LSbit.
- */
- #define _FP_FRAC_SRS_8(X,N,size) \
- do { \
- _FP_I_TYPE _up, _down, _skip, _i; \
- _FP_W_TYPE _s; \
- _skip = (N) / _FP_W_TYPE_SIZE; \
- _down = (N) % _FP_W_TYPE_SIZE; \
- _up = _FP_W_TYPE_SIZE - _down; \
- for (_s = _i = 0; _i < _skip; ++_i) \
- _s |= X##_f[_i]; \
- if (!_down) \
- for (_i = 0; _i <= 7-_skip; ++_i) \
- X##_f[_i] = X##_f[_i+_skip]; \
- else \
- { \
- _s |= X##_f[_i] << _up; \
- for (_i = 0; _i < 7-_skip; ++_i) \
- X##_f[_i] = X##_f[_i+_skip] >> _down \
- | X##_f[_i+_skip+1] << _up; \
- X##_f[_i++] = X##_f[7] >> _down; \
- } \
- for (; _i < 8; ++_i) \
- X##_f[_i] = 0; \
- /* don't fix the LSB until the very end when we're sure f[0] is stable */ \
- X##_f[0] |= (_s != 0); \
- } while (0)
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