diff options
| author | Xavier ASUS <xavi92psx@gmail.com> | 2019-10-18 00:31:54 +0200 |
|---|---|---|
| committer | Xavier ASUS <xavi92psx@gmail.com> | 2019-10-18 00:31:54 +0200 |
| commit | 268a53de823a6750d6256ee1fb1e7707b4b45740 (patch) | |
| tree | 42c1799a9a82b2f7d9790ee9fe181d72a7274751 /device/lib/pic16/libsdcc/float/fsdiv.c | |
| download | sdcc-gas-268a53de823a6750d6256ee1fb1e7707b4b45740.tar.gz | |
sdcc-3.9.0 fork implementing GNU assembler syntax
This fork aims to provide better support for stm8-binutils
Diffstat (limited to 'device/lib/pic16/libsdcc/float/fsdiv.c')
| -rw-r--r-- | device/lib/pic16/libsdcc/float/fsdiv.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/device/lib/pic16/libsdcc/float/fsdiv.c b/device/lib/pic16/libsdcc/float/fsdiv.c new file mode 100644 index 0000000..fb353dd --- /dev/null +++ b/device/lib/pic16/libsdcc/float/fsdiv.c @@ -0,0 +1,129 @@ +/*------------------------------------------------------------------------- + fsdiv.c + + Copyright (C) 1991, Pipeline Associates, Inc + + This library is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by the + Free Software Foundation; either version 2, or (at your option) any + later version. + + This 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this library; see the file COPYING. If not, write to the + Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston, + MA 02110-1301, USA. + + As a special exception, if you link this library with other files, + some of which are compiled with SDCC, to produce an executable, + this library does not by itself cause the resulting executable to + be covered by the GNU General Public License. This exception does + not however invalidate any other reasons why the executable file + might be covered by the GNU General Public License. +-------------------------------------------------------------------------*/ +/* +** libgcc support for software floating point. +** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved. +** Permission is granted to do *anything* you want with this file, +** commercial or otherwise, provided this message remains intact. So there! +** I would appreciate receiving any updates/patches/changes that anyone +** makes, and am willing to be the repository for said changes (am I +** making a big mistake?). +** +** Pat Wood +** Pipeline Associates, Inc. +** pipeline!phw@motown.com or +** sun!pipeline!phw or +** uunet!motown!pipeline!phw +*/ + +/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */ + +#include <float.h> + +union float_long + { + float f; + long l; + }; + +/* divide two floats */ +float +__fsdiv (float a1, float a2) _FS_REENTRANT +{ + volatile union float_long fl1, fl2; + long result; + unsigned long mask; + long mant1, mant2; + int exp; + char sign; + + fl1.f = a1; + fl2.f = a2; + + /* subtract exponents */ + exp = EXP (fl1.l) ; + exp -= EXP (fl2.l); + exp += EXCESS; + + /* compute sign */ + sign = SIGN (fl1.l) ^ SIGN (fl2.l); + + /* divide by zero??? */ + if (!fl2.l) + {/* return NaN or -NaN */ + fl2.l = 0x7FC00000; + return fl2.f; + } + + /* numerator zero??? */ + if (!fl1.l) + return 0; + + /* now get mantissas */ + mant1 = MANT (fl1.l); + mant2 = MANT (fl2.l); + + /* this assures we have 25 bits of precision in the end */ + if (mant1 < mant2) + { + mant1 <<= 1; + --exp; + } + + /* now we perform repeated subtraction of fl2.l from fl1.l */ + mask = 0x1000000; + result = 0; + while (mask) + { + if (mant1 >= mant2) + { + result |= mask; + mant1 -= mant2; + } + mant1 <<= 1; + mask >>= 1; + } + + /* round */ + result += 1; + + /* normalize down */ + ++exp; + result >>= 1; + + result &= ~HIDDEN; + + /* pack up and go home */ + if (exp >= 0x100) + fl1.l = (sign ? SIGNBIT : 0) | 0x7F800000; + else if (exp < 0) + fl1.l = 0; + else + fl1.l = PACK (sign ? SIGNBIT : 0 , exp, result); + return fl1.f; +} |
