| /* Set the FPU control word for x86. |
| Copyright (C) 2003-2018 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 <math.h> |
| #include <fpu_control.h> |
| #include <fenv.h> |
| #include <unistd.h> |
| #include <ldsodefs.h> |
| #include <dl-procinfo.h> |
| |
| void |
| __setfpucw (fpu_control_t set) |
| { |
| fpu_control_t cw; |
| |
| /* Fetch the current control word. */ |
| __asm__ ("fnstcw %0" : "=m" (*&cw)); |
| |
| /* Preserve the reserved bits, and set the rest as the user |
| specified (or the default, if the user gave zero). */ |
| cw &= _FPU_RESERVED; |
| cw |= set & ~_FPU_RESERVED; |
| |
| __asm__ ("fldcw %0" : : "m" (*&cw)); |
| |
| /* If the CPU supports SSE, we set the MXCSR as well. */ |
| if (HAS_CPU_FEATURE (SSE)) |
| { |
| unsigned int xnew_exc; |
| |
| /* Get the current MXCSR. */ |
| __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc)); |
| |
| xnew_exc &= ~((0xc00 << 3) | (FE_ALL_EXCEPT << 7)); |
| xnew_exc |= ((set & 0xc00) << 3) | ((set & FE_ALL_EXCEPT) << 7); |
| |
| __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc)); |
| } |
| } |