[gcc] GCC 4.5.0=>4.5.1

gcc/gmp/mpf/get_ui.c

-/* mpf_get_ui -- mpf to ulong conversion
-
-Copyright 2001, 2002, 2004 Free Software Foundation, Inc.
-
-This file is part of the GNU MP Library.
-
-The GNU MP 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 MP 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 MP Library.  If not, see http://www.gnu.org/licenses/.  */
-
-#include "gmp.h"
-#include "gmp-impl.h"
-
-
-/* Any fraction bits are truncated, meaning simply discarded.
-
-   For values bigger than a ulong, the low bits are returned (the low
-   absolute value bits actually), like mpz_get_ui, but this isn't
-   documented.
-
-   Notice this is equivalent to mpz_set_f + mpz_get_ui.
-
-
-   Implementation:
-
-   The limb just above the radix point for us to extract is ptr[size-exp].
-
-   We need to check that the size-exp index falls in our available data
-   range, 0 to size-1 inclusive.  We test this without risk of an overflow
-   involving exp by requiring size>=exp (giving size-exp >= 0) and exp>0
-   (giving size-exp <= size-1).
-
-   Notice if size==0 there's no fetch, since of course size>=exp and exp>0
-   can only be true if size>0.  So there's no special handling for size==0,
-   it comes out as 0 the same as any other time we have no data at our
-   target index.
-
-   For nails, the second limb above the radix point is also required, this
-   is ptr[size-exp+1].
-
-   Again we need to check that size-exp+1 falls in our data range, 0 to
-   size-1 inclusive.  We test without risk of overflow by requiring
-   size+1>=exp (giving size-exp+1 >= 0) and exp>1 (giving size-exp+1 <=
-   size-1).
-
-   And again if size==0 these second fetch conditions are not satisfied
-   either since size+1>=exp and exp>1 are only true if size>0.
-
-   The code is arranged with exp>0 wrapping the exp>1 test since exp>1 is
-   mis-compiled by alpha gcc prior to version 3.4.  It re-writes it as
-   exp-1>0, which is incorrect when exp==MP_EXP_T_MIN.  By having exp>0
-   tested first we ensure MP_EXP_T_MIN doesn't reach exp>1.  */
-
-unsigned long
-mpf_get_ui (mpf_srcptr f)
-{
-  mp_size_t size;
-  mp_exp_t exp;
-  mp_srcptr fp;
-  mp_limb_t fl;
-
-  exp = EXP (f);
-  size = SIZ (f);
-  fp = PTR (f);
-
-  fl = 0;
-  if (exp > 0)
-    {
-      /* there are some limbs above the radix point */
-
-      size = ABS (size);
-      if (size >= exp)
-        fl = fp[size-exp];
-
-#if BITS_PER_ULONG > GMP_NUMB_BITS
-      if (exp > 1 && size+1 >= exp)
-        fl += (fp[size-exp+1] << GMP_NUMB_BITS);
-#endif
-    }
-
-  return (unsigned long) fl;
-}