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1 | Copyright 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. |

2 | Contributed by the AriC and Caramel projects, INRIA. | |

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3 | |

4 | This file is part of the GNU MPFR Library. | |

5 | ||

6 | The GNU MPFR Library is free software; you can redistribute it and/or modify | |

7 | it under the terms of the GNU Lesser General Public License as published by | |

4a238c70 | 8 | the Free Software Foundation; either version 3 of the License, or (at your |

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9 | option) any later version. |

10 | ||

11 | The GNU MPFR Library is distributed in the hope that it will be useful, but | |

12 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |

13 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public | |

14 | License for more details. | |

15 | ||

16 | You should have received a copy of the GNU Lesser General Public License | |

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17 | along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see |

18 | http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., | |

19 | 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. | |

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20 | |

21 | ############################################################################## | |

22 | ||

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23 | Known bugs: |

24 | ||

25 | * The overflow/underflow exceptions may be badly handled in some functions; | |

26 | specially when the intermediary internal results have exponent which | |

27 | exceeds the hardware limit (2^30 for a 32 bits CPU, and 2^62 for a 64 bits | |

28 | CPU) or the exact result is close to an overflow/underflow threshold. | |

29 | ||

30 | * Under Linux/x86 with the traditional FPU, some functions do not work | |

31 | if the FPU rounding precision has been changed to single (this is a | |

32 | bad practice and should be useless, but one never knows what other | |

33 | software will do). | |

34 | ||

35 | * Some functions do not use MPFR_SAVE_EXPO_* macros, thus do not behave | |

36 | correctly in a reduced exponent range. | |

37 | ||

38 | * Function hypot gives incorrect result when on the one hand the difference | |

39 | between parameters' exponents is near 2*MPFR_EMAX_MAX and on the other hand | |

40 | the output precision or the precision of the parameter with greatest | |

41 | absolute value is greater than 2*MPFR_EMAX_MAX-4. | |

42 | ||

43 | Potential bugs: | |

44 | ||

45 | * Possible incorrect results due to internal underflow, which can lead to | |

46 | a huge loss of accuracy while the error analysis doesn't take that into | |

47 | account. If the underflow occurs at the last function call (just before | |

48 | the MPFR_CAN_ROUND), the result should be correct (or MPFR gets into an | |

49 | infinite loop). TODO: check the code and the error analysis. | |

50 | ||

51 | * Possible integer overflows on some machines. | |

52 | ||

53 | * Possible bugs with huge precisions (> 2^30). | |

54 | ||

55 | * Possible bugs if the chosen exponent range does not allow to represent | |

56 | the range [1/16, 16]. | |

57 | ||

58 | * Possible infinite loop in some functions for particular cases: when | |

59 | the exact result is an exactly representable number or the middle of | |

60 | consecutive two such numbers. However for non-algebraic functions, it is | |

61 | believed that no such case exists, except the well-known cases like cos(0)=1, | |

62 | exp(0)=1, and so on, and the x^y function when y is an integer or y=1/2^k. | |

63 | ||

64 | * The mpfr_set_ld function may be quite slow if the long double type has an | |

65 | exponent of more than 15 bits. | |

66 | ||

67 | * mpfr_set_d may give wrong results on some non-IEEE architectures. | |

68 | ||

69 | * Error analysis for some functions may be incorrect (out-of-date due | |

70 | to modifications in the code?). | |

71 | ||

72 | * Possible use of non-portable feature (pre-C99) of the integer division | |

73 | with negative result. |