1/* Software floating-point emulation. 2 Basic eight-word fraction declaration and manipulation. 3 Copyright (C) 1997,1998,1999 Free Software Foundation, Inc. 4 This file is part of the GNU C Library. 5 Contributed by Richard Henderson (rth@cygnus.com), 6 Jakub Jelinek (jj@ultra.linux.cz) and 7 Peter Maydell (pmaydell@chiark.greenend.org.uk). 8 9 The GNU C Library is free software; you can redistribute it and/or 10 modify it under the terms of the GNU Library General Public License as 11 published by the Free Software Foundation; either version 2 of the 12 License, or (at your option) any later version. 13 14 The GNU C Library is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 Library General Public License for more details. 18 19 You should have received a copy of the GNU Library General Public 20 License along with the GNU C Library; see the file COPYING.LIB. If 21 not, write to the Free Software Foundation, Inc., 22 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 23 24#ifndef __MATH_EMU_OP_8_H__ 25#define __MATH_EMU_OP_8_H__ 26 27/* We need just a few things from here for op-4, if we ever need some 28 other macros, they can be added. */ 29#define _FP_FRAC_DECL_8(X) _FP_W_TYPE X##_f[8] 30#define _FP_FRAC_HIGH_8(X) (X##_f[7]) 31#define _FP_FRAC_LOW_8(X) (X##_f[0]) 32#define _FP_FRAC_WORD_8(X,w) (X##_f[w]) 33 34#define _FP_FRAC_SLL_8(X,N) \ 35 do { \ 36 _FP_I_TYPE _up, _down, _skip, _i; \ 37 _skip = (N) / _FP_W_TYPE_SIZE; \ 38 _up = (N) % _FP_W_TYPE_SIZE; \ 39 _down = _FP_W_TYPE_SIZE - _up; \ 40 if (!_up) \ 41 for (_i = 7; _i >= _skip; --_i) \ 42 X##_f[_i] = X##_f[_i-_skip]; \ 43 else \ 44 { \ 45 for (_i = 7; _i > _skip; --_i) \ 46 X##_f[_i] = X##_f[_i-_skip] << _up \ 47 | X##_f[_i-_skip-1] >> _down; \ 48 X##_f[_i--] = X##_f[0] << _up; \ 49 } \ 50 for (; _i >= 0; --_i) \ 51 X##_f[_i] = 0; \ 52 } while (0) 53 54#define _FP_FRAC_SRL_8(X,N) \ 55 do { \ 56 _FP_I_TYPE _up, _down, _skip, _i; \ 57 _skip = (N) / _FP_W_TYPE_SIZE; \ 58 _down = (N) % _FP_W_TYPE_SIZE; \ 59 _up = _FP_W_TYPE_SIZE - _down; \ 60 if (!_down) \ 61 for (_i = 0; _i <= 7-_skip; ++_i) \ 62 X##_f[_i] = X##_f[_i+_skip]; \ 63 else \ 64 { \ 65 for (_i = 0; _i < 7-_skip; ++_i) \ 66 X##_f[_i] = X##_f[_i+_skip] >> _down \ 67 | X##_f[_i+_skip+1] << _up; \ 68 X##_f[_i++] = X##_f[7] >> _down; \ 69 } \ 70 for (; _i < 8; ++_i) \ 71 X##_f[_i] = 0; \ 72 } while (0) 73 74 75/* Right shift with sticky-lsb. 76 * What this actually means is that we do a standard right-shift, 77 * but that if any of the bits that fall off the right hand side 78 * were one then we always set the LSbit. 79 */ 80#define _FP_FRAC_SRS_8(X,N,size) \ 81 do { \ 82 _FP_I_TYPE _up, _down, _skip, _i; \ 83 _FP_W_TYPE _s; \ 84 _skip = (N) / _FP_W_TYPE_SIZE; \ 85 _down = (N) % _FP_W_TYPE_SIZE; \ 86 _up = _FP_W_TYPE_SIZE - _down; \ 87 for (_s = _i = 0; _i < _skip; ++_i) \ 88 _s |= X##_f[_i]; \ 89 _s |= X##_f[_i] << _up; \ 90/* s is now != 0 if we want to set the LSbit */ \ 91 if (!_down) \ 92 for (_i = 0; _i <= 7-_skip; ++_i) \ 93 X##_f[_i] = X##_f[_i+_skip]; \ 94 else \ 95 { \ 96 for (_i = 0; _i < 7-_skip; ++_i) \ 97 X##_f[_i] = X##_f[_i+_skip] >> _down \ 98 | X##_f[_i+_skip+1] << _up; \ 99 X##_f[_i++] = X##_f[7] >> _down; \ 100 } \ 101 for (; _i < 8; ++_i) \ 102 X##_f[_i] = 0; \ 103 /* don't fix the LSB until the very end when we're sure f[0] is stable */ \ 104 X##_f[0] |= (_s != 0); \ 105 } while (0) 106 107#endif 108