diff options
author | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2008-01-19 15:23:14 +0000 |
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committer | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2008-01-19 15:23:14 +0000 |
commit | bce5bba7a01fb090f67fec5f79218c505c841af3 (patch) | |
tree | e7d7dfc12cae1f1474800071fbc4633fa509ef6e /libm/i386/fesetround.c | |
parent | d22976dd5e16e8719abd5c542e17427eeece7ff6 (diff) |
- add C99 floating point environment, rounding and exception handling functions
for i386. UCLIBC_HAS_FENV
Diffstat (limited to 'libm/i386/fesetround.c')
-rw-r--r-- | libm/i386/fesetround.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/libm/i386/fesetround.c b/libm/i386/fesetround.c new file mode 100644 index 000000000..e1ba16975 --- /dev/null +++ b/libm/i386/fesetround.c @@ -0,0 +1,52 @@ +/* Set current rounding direction. + Copyright (C) 1997, 2003, 2004, 2005 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + 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 <fenv.h> +#include <unistd.h> + +int +fesetround (int round) +{ + unsigned short int cw; + + if ((round & ~0xc00) != 0) + /* ROUND is no valid rounding mode. */ + return 1; + + __asm__ ("fnstcw %0" : "=m" (*&cw)); + cw &= ~0xc00; + cw |= round; + __asm__ ("fldcw %0" : : "m" (*&cw)); + +#if 0 + /* If the CPU supports SSE we set the MXCSR as well. */ + if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0) + { + unsigned int xcw; + + __asm__ ("stmxcsr %0" : "=m" (*&xcw)); + xcw &= ~0x6000; + xcw |= round << 3; + __asm__ ("ldmxcsr %0" : : "m" (*&xcw)); + } +#endif + + return 0; +} |