diff options
Diffstat (limited to 'REORG.TODO/sysdeps/x86_64/fpu/fesetround.c')
| -rw-r--r-- | REORG.TODO/sysdeps/x86_64/fpu/fesetround.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/x86_64/fpu/fesetround.c b/REORG.TODO/sysdeps/x86_64/fpu/fesetround.c new file mode 100644 index 0000000000..939297252a --- /dev/null +++ b/REORG.TODO/sysdeps/x86_64/fpu/fesetround.c @@ -0,0 +1,48 @@ +/* Set current rounding direction. + Copyright (C) 2001-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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 <fenv.h> + +int +__fesetround (int round) +{ + unsigned short int cw; + int mxcsr; + + if ((round & ~0xc00) != 0) + /* ROUND is no valid rounding mode. */ + return 1; + + /* First set the x87 FPU. */ + asm ("fnstcw %0" : "=m" (*&cw)); + cw &= ~0xc00; + cw |= round; + asm ("fldcw %0" : : "m" (*&cw)); + + /* And now the MSCSR register for SSE, the precision is at different bit + positions in the different units, we need to shift it 3 bits. */ + asm ("stmxcsr %0" : "=m" (*&mxcsr)); + mxcsr &= ~ 0x6000; + mxcsr |= round << 3; + asm ("ldmxcsr %0" : : "m" (*&mxcsr)); + + return 0; +} +libm_hidden_def (__fesetround) +weak_alias (__fesetround, fesetround) +libm_hidden_weak (fesetround) |