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author | Ulrich Drepper <drepper@gmail.com> | 2011-10-15 21:44:45 -0400 |
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committer | Ulrich Drepper <drepper@gmail.com> | 2011-10-15 21:44:45 -0400 |
commit | d4a285692ae21debd4518a6d4980fa7e36d104b5 (patch) | |
tree | 9c68d5e87b76a23a72bd800471f0d4ff651eba32 | |
parent | b61099b50a028d3ac69aa9500ffa9871d23e3884 (diff) | |
download | glibc-d4a285692ae21debd4518a6d4980fa7e36d104b5.tar.gz glibc-d4a285692ae21debd4518a6d4980fa7e36d104b5.tar.xz glibc-d4a285692ae21debd4518a6d4980fa7e36d104b5.zip |
Optimized floor for 64-bit architectures
-rw-r--r-- | ChangeLog | 2 | ||||
-rw-r--r-- | sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c | 79 |
2 files changed, 81 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 6ddea17f4b..426b69f425 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,7 @@ 2011-10-15 Ulrich Drepper <drepper@gmail.com> + * sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c: New file. + * sysdeps/ieee754/dbl-64/e_cosh.c: Cleanup. * sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c: New file. diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c new file mode 100644 index 0000000000..d52e4dbeb7 --- /dev/null +++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_floor.c @@ -0,0 +1,79 @@ +/* Round double to integer away from zero. + Copyright (C) 2011 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 2011. + + 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. */ + +/* Based on a version which carries the following copyright: */ + +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include "math.h" +#include "math_private.h" + +/* + * floor(x) + * Return x rounded toward -inf to integral value + * Method: + * Bit twiddling. + * Exception: + * Inexact flag raised if x not equal to floor(x). + */ + +static const double huge = 1.0e300; + + +double +__floor (double x) +{ + int64_t i0; + EXTRACT_WORDS64(i0,x); + int32_t j0 = ((i0>>52)&0x7ff)-0x3ff; + if(__builtin_expect(j0<52, 1)) { + if(j0<0) { /* raise inexact if x != 0 */ + if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */ + if(i0>=0) {i0=0;} + else if((i0&0x7fffffffffffffffl)!=0) + { i0=0xbff0000000000000l;} + } + } else { + uint64_t i = (0x000fffffffffffffl)>>j0; + if((i0&i)==0) return x; /* x is integral */ + if(huge+x>0.0) { /* raise inexact flag */ + if(i0<0) i0 += (0x0010000000000000l)>>j0; + i0 &= (~i); + } + } + INSERT_WORDS64(x,i0); + } else if (j0==0x400) + return x+x; /* inf or NaN */ + return x; +} +weak_alias (__floor, floor) +#ifdef NO_LONG_DOUBLE +strong_alias (__floor, __floorl) +weak_alias (__floor, floorl) +#endif |