diff options
Diffstat (limited to 'sysdeps/alpha/fpu/s_floorf.c')
-rw-r--r-- | sysdeps/alpha/fpu/s_floorf.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/sysdeps/alpha/fpu/s_floorf.c b/sysdeps/alpha/fpu/s_floorf.c new file mode 100644 index 0000000000..fe4c40b929 --- /dev/null +++ b/sysdeps/alpha/fpu/s_floorf.c @@ -0,0 +1,55 @@ +/* Copyright (C) 1998-2014 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> + + +/* 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. */ + +float +__floorf (float x) +{ + if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */ + { + /* Note that Alpha S_Floating is stored in registers in a + restricted T_Floating format, so we don't even need to + convert back to S_Floating in the end. The initial + conversion to T_Floating is needed to handle denormals. */ + + float tmp1, tmp2, new_x; + + __asm ("cvtst/s %3,%2\n\t" +#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"(tmp2) + : "f"(x)); + + /* floor(-0) == -0, and in general we'll always have the same + sign as our input. */ + x = copysignf(new_x, x); + } + return x; +} + +weak_alias (__floorf, floorf) |