| /* Copyright (C) 1998, 1999, 2000, 2006, 2007 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Richard Henderson. |
| |
| The GNU C 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 C 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 C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <math.h> |
| #include <math_ldbl_opt.h> |
| |
| |
| /* Use the -inf rounding mode conversion instructions to implement |
| floor. We note when the exponent is large enough that the value |
| must be integral, as this avoids unpleasant integer overflows. */ |
| |
| double |
| __floor (double x) |
| { |
| if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ |
| { |
| double tmp1, new_x; |
| |
| __asm ( |
| #ifdef _IEEE_FP_INEXACT |
| "cvttq/svim %2,%1\n\t" |
| #else |
| "cvttq/svm %2,%1\n\t" |
| #endif |
| "cvtqt/m %1,%0\n\t" |
| : "=f"(new_x), "=&f"(tmp1) |
| : "f"(x)); |
| |
| /* floor(-0) == -0, and in general we'll always have the same |
| sign as our input. */ |
| x = copysign(new_x, x); |
| } |
| return x; |
| } |
| |
| weak_alias (__floor, floor) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__floor, __floorl) |
| weak_alias (__floor, floorl) |
| #endif |
| #if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0) |
| compat_symbol (libm, __floor, floorl, GLIBC_2_0); |
| #endif |
