[gcc] GCC 4.5.0=>4.5.1

gcc/mpfr/BUGS

-Copyright 1999, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
-Contributed by the Arenaire and Cacao 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 2.1 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.LIB.  If not, write to
-the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
-MA 02110-1301, USA.
-
-##############################################################################
-
-Probably many bugs.
-
-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 integer overflows on some machines.
-
-* Possible bugs with huge precisions (> 2^30).
-
-* 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.