kernel / pub / scm / linux / kernel / git / joro / linux / refs/tags/v2.6.39.1 / . / include / math-emu / op-8.h

/* 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 |