| /* Install given floating-point environment. |
| Copyright (C) 2001-2018 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 <fenv.h> |
| #include <fpu_control.h> |
| #include <assert.h> |
| |
| |
| /* All exceptions, including the x86-specific "denormal operand" |
| exception. */ |
| #define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM) |
| |
| |
| int |
| __fesetenv (const fenv_t *envp) |
| { |
| fenv_t temp; |
| |
| /* Install the environment specified by ENVP. But there are a few |
| values which we do not want to come from the saved environment. |
| Therefore, we get the current environment and replace the values |
| we want to use from the environment specified by the parameter. */ |
| __asm__ ("fnstenv %0\n" |
| "stmxcsr %1" : "=m" (*&temp), "=m" (*&temp.__mxcsr)); |
| |
| if (envp == FE_DFL_ENV) |
| { |
| temp.__control_word |= FE_ALL_EXCEPT_X86; |
| temp.__control_word &= ~FE_TOWARDZERO; |
| temp.__control_word |= _FPU_EXTENDED; |
| temp.__status_word &= ~FE_ALL_EXCEPT_X86; |
| temp.__eip = 0; |
| temp.__cs_selector = 0; |
| temp.__opcode = 0; |
| temp.__data_offset = 0; |
| temp.__data_selector = 0; |
| /* Clear SSE exceptions. */ |
| temp.__mxcsr &= ~FE_ALL_EXCEPT_X86; |
| /* Set mask for SSE MXCSR. */ |
| temp.__mxcsr |= (FE_ALL_EXCEPT_X86 << 7); |
| /* Set rounding to FE_TONEAREST. */ |
| temp.__mxcsr &= ~ 0x6000; |
| temp.__mxcsr |= (FE_TONEAREST << 3); |
| /* Clear the FZ and DAZ bits. */ |
| temp.__mxcsr &= ~0x8040; |
| } |
| else if (envp == FE_NOMASK_ENV) |
| { |
| temp.__control_word &= ~(FE_ALL_EXCEPT | FE_TOWARDZERO); |
| /* Keep the "denormal operand" exception masked. */ |
| temp.__control_word |= __FE_DENORM; |
| temp.__control_word |= _FPU_EXTENDED; |
| temp.__status_word &= ~FE_ALL_EXCEPT_X86; |
| temp.__eip = 0; |
| temp.__cs_selector = 0; |
| temp.__opcode = 0; |
| temp.__data_offset = 0; |
| temp.__data_selector = 0; |
| /* Clear SSE exceptions. */ |
| temp.__mxcsr &= ~FE_ALL_EXCEPT_X86; |
| /* Set mask for SSE MXCSR. */ |
| /* Set rounding to FE_TONEAREST. */ |
| temp.__mxcsr &= ~ 0x6000; |
| temp.__mxcsr |= (FE_TONEAREST << 3); |
| /* Do not mask exceptions. */ |
| temp.__mxcsr &= ~(FE_ALL_EXCEPT << 7); |
| /* Keep the "denormal operand" exception masked. */ |
| temp.__mxcsr |= (__FE_DENORM << 7); |
| /* Clear the FZ and DAZ bits. */ |
| temp.__mxcsr &= ~0x8040; |
| } |
| else |
| { |
| temp.__control_word &= ~(FE_ALL_EXCEPT_X86 |
| | FE_TOWARDZERO |
| | _FPU_EXTENDED); |
| temp.__control_word |= (envp->__control_word |
| & (FE_ALL_EXCEPT_X86 |
| | FE_TOWARDZERO |
| | _FPU_EXTENDED)); |
| temp.__status_word &= ~FE_ALL_EXCEPT_X86; |
| temp.__status_word |= envp->__status_word & FE_ALL_EXCEPT_X86; |
| temp.__eip = envp->__eip; |
| temp.__cs_selector = envp->__cs_selector; |
| temp.__opcode = envp->__opcode; |
| temp.__data_offset = envp->__data_offset; |
| temp.__data_selector = envp->__data_selector; |
| temp.__mxcsr = envp->__mxcsr; |
| } |
| |
| __asm__ ("fldenv %0\n" |
| "ldmxcsr %1" : : "m" (temp), "m" (temp.__mxcsr)); |
| |
| /* Success. */ |
| return 0; |
| } |
| libm_hidden_def (__fesetenv) |
| weak_alias (__fesetenv, fesetenv) |
| libm_hidden_weak (fesetenv) |
