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Diffstat (limited to 'include/math-emu/op-8.h')
| -rw-r--r-- | include/math-emu/op-8.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/include/math-emu/op-8.h b/include/math-emu/op-8.h new file mode 100644 index 0000000..8b8c05e --- /dev/null +++ b/include/math-emu/op-8.h @@ -0,0 +1,107 @@ +/* Software floating-point emulation. + Basic eight-word fraction declaration and manipulation. + Copyright (C) 1997,1998,1999 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 Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, write to the Free Software Foundation, Inc., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef __MATH_EMU_OP_8_H__ +#define __MATH_EMU_OP_8_H__ + +/* 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]; \ + _s |= X##_f[_i] << _up; \ +/* s is now != 0 if we want to set the LSbit */ \ + 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; \ + /* don't fix the LSB until the very end when we're sure f[0] is stable */ \ + X##_f[0] |= (_s != 0); \ + } while (0) + +#endif |
