diff options
Diffstat (limited to 'sysdeps/alpha/fpu/s_trunc.c')
-rw-r--r-- | sysdeps/alpha/fpu/s_trunc.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/sysdeps/alpha/fpu/s_trunc.c b/sysdeps/alpha/fpu/s_trunc.c new file mode 100644 index 0000000000..9216c03caf --- /dev/null +++ b/sysdeps/alpha/fpu/s_trunc.c @@ -0,0 +1,52 @@ +/* Copyright (C) 2007-2014 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, see + <http://www.gnu.org/licenses/>. */ + +#include <math.h> +#include <math_ldbl_opt.h> + + +/* Use the chopped rounding mode conversion instructions to implement trunc. */ + +double +__trunc (double x) +{ + double two52 = copysign (0x1.0p52, x); + double r, tmp; + + __asm ( +#ifdef _IEEE_FP_INEXACT + "addt/suic %2, %3, %1\n\tsubt/suic %1, %3, %0" +#else + "addt/suc %2, %3, %1\n\tsubt/suc %1, %3, %0" +#endif + : "=&f"(r), "=&f"(tmp) + : "f"(x), "f"(two52)); + + /* trunc(-0) == -0, and in general we'll always have the same + sign as our input. */ + return copysign (r, x); +} + +weak_alias (__trunc, trunc) +#ifdef NO_LONG_DOUBLE +strong_alias (__trunc, __truncl) +weak_alias (__trunc, truncl) +#endif +#if LONG_DOUBLE_COMPAT(libm, GLIBC_2_1) +compat_symbol (libm, __trunc, truncl, GLIBC_2_1); +#endif |