| /* Set FP exception mask and rounding mode. |
| Copyright (C) 1996-2014 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 <fpu_control.h> |
| #include <fenv_libc.h> |
| |
| |
| #define convert_bit(M, F, T) \ |
| ((T) < (F) \ |
| ? ((M) / ((F) / (T))) & (T) \ |
| : ((M) & (F)) * ((T) / (F))) |
| |
| |
| void |
| __setfpucw (fpu_control_t fpu_control) |
| { |
| unsigned long fpcr, swcr, fc = (int)fpu_control; |
| |
| /* ??? If this was a real external interface we'd want to read the current |
| exception state with __ieee_get_fp_control. But this is an internal |
| function only called at process startup, so there's no point in trying |
| to preserve exceptions that cannot have been raised yet. Indeed, this |
| entire function is likely to be one big nop unless the user overrides |
| the default __fpu_control variable. */ |
| |
| /* Convert the rounding mode from fpu_control.h format. */ |
| const unsigned long conv_rnd |
| = ( (FE_TOWARDZERO << (_FPU_RC_ZERO >> 8)) |
| | (FE_DOWNWARD << (_FPU_RC_DOWN >> 8)) |
| | (FE_TONEAREST << (_FPU_RC_NEAREST >> 8)) |
| | (FE_UPWARD << (_FPU_RC_UP >> 8))); |
| |
| fpcr = ((conv_rnd >> ((fc >> 8) & 3)) & 3) << FPCR_ROUND_SHIFT; |
| |
| /* Convert the exception mask from fpu_control.h format. */ |
| swcr = convert_bit (~fc, _FPU_MASK_IM, FE_INVALID >> SWCR_ENABLE_SHIFT); |
| swcr |= convert_bit (~fc, _FPU_MASK_DM, FE_UNDERFLOW >> SWCR_ENABLE_SHIFT); |
| swcr |= convert_bit (~fc, _FPU_MASK_ZM, FE_DIVBYZERO >> SWCR_ENABLE_SHIFT); |
| swcr |= convert_bit (~fc, _FPU_MASK_OM, FE_OVERFLOW >> SWCR_ENABLE_SHIFT); |
| swcr |= convert_bit (~fc, _FPU_MASK_PM, FE_INEXACT >> SWCR_ENABLE_SHIFT); |
| |
| /* Install everything. */ |
| __fpu_control = fc; |
| asm volatile ("mt_fpcr %0" : : "f"(fpcr)); |
| __ieee_set_fp_control(swcr); |
| } |