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| Copyright 1999, 2001-2022 Free Software Foundation, Inc. | |
| Contributed by the AriC and Caramba projects, INRIA. | |
| This file is part of the GNU MPFR Library. | |
| The GNU MPFR 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 3 of the License, or (at your | |
| option) any later version. | |
| The GNU MPFR 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 MPFR Library; see the file COPYING.LESSER. If not, see | |
| https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., | |
| 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. | |
| ############################################################################## | |
| Known bugs: | |
| * The overflow/underflow exceptions may be badly handled in some functions; | |
| specially when the intermediary internal results have exponent which | |
| exceeds the hardware limit (2^30 for a 32 bits CPU, and 2^62 for a 64 bits | |
| CPU) or the exact result is close to an overflow/underflow threshold. | |
| * Under Linux/x86 with the traditional FPU, some functions do not work | |
| if the FPU rounding precision has been changed to single (this is a | |
| bad practice and should be useless, but one never knows what other | |
| software will do). | |
| * Some functions do not use MPFR_SAVE_EXPO_* macros, thus do not behave | |
| correctly in a reduced exponent range. | |
| * Function hypot gives incorrect result when on the one hand the difference | |
| between parameters' exponents is near 2*MPFR_EMAX_MAX and on the other hand | |
| the output precision or the precision of the parameter with greatest | |
| absolute value is greater than 2*MPFR_EMAX_MAX-4. | |
| Potential bugs: | |
| * Possible incorrect results due to internal underflow, which can lead to | |
| a huge loss of accuracy while the error analysis doesn't take that into | |
| account. If the underflow occurs at the last function call (just before | |
| the MPFR_CAN_ROUND), the result should be correct (or MPFR gets into an | |
| infinite loop). TODO: check the code and the error analysis. | |
| * Possible bugs with huge precisions (> 2^30) and a 32-bit ABI, in particular | |
| undetected integer overflows. TODO: use the MPFR_ADD_PREC macro. | |
| * Possible bugs if the chosen exponent range does not allow to represent | |
| the range [1/16, 16]. | |
| * Possible infinite loop in some functions for particular cases: when | |
| the exact result is an exactly representable number or the middle of | |
| consecutive two such numbers. However, for non-algebraic functions, it is | |
| believed that no such case exists, except the well-known cases like cos(0)=1, | |
| exp(0)=1, and so on, and the x^y function when y is an integer or y=1/2^k. | |
| * The mpfr_set_ld function may be quite slow if the long double type has an | |
| exponent of more than 15 bits. | |
| * mpfr_set_d may give wrong results on some non-IEEE architectures. | |
| * Error analysis for some functions may be incorrect (out-of-date due | |
| to modifications in the code?). | |
| * Possible use of non-portable feature (pre-C99) of the integer division | |
| with negative result. | |