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Diffstat (limited to 'libatomic/config/x86/fenv.c')
| -rw-r--r-- | libatomic/config/x86/fenv.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/libatomic/config/x86/fenv.c b/libatomic/config/x86/fenv.c new file mode 100644 index 00000000000..154983e5f45 --- /dev/null +++ b/libatomic/config/x86/fenv.c @@ -0,0 +1,116 @@ +/* Copyright (C) 2013 Free Software Foundation, Inc. + + This file is part of the GNU Atomic Library (libatomic). + + Libatomic is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + Libatomic 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 General Public License for + more details. + + Under Section 7 of GPL version 3, you are granted additional + permissions described in the GCC Runtime Library Exception, version + 3.1, as published by the Free Software Foundation. + + You should have received a copy of the GNU General Public License and + a copy of the GCC Runtime Library Exception along with this program; + see the files COPYING3 and COPYING.RUNTIME respectively. If not, see + <http://www.gnu.org/licenses/>. */ + +#include "libatomic_i.h" + +#define FE_INVALID 0x01 +#define FE_DENORM 0x02 +#define FE_DIVBYZERO 0x04 +#define FE_OVERFLOW 0x08 +#define FE_UNDERFLOW 0x10 +#define FE_INEXACT 0x20 + +struct fenv +{ + unsigned short int __control_word; + unsigned short int __unused1; + unsigned short int __status_word; + unsigned short int __unused2; + unsigned short int __tags; + unsigned short int __unused3; + unsigned int __eip; + unsigned short int __cs_selector; + unsigned int __opcode:11; + unsigned int __unused4:5; + unsigned int __data_offset; + unsigned short int __data_selector; + unsigned short int __unused5; +}; + +/* Raise the supported floating-point exceptions from EXCEPTS. Other + bits in EXCEPTS are ignored. */ + +void +__atomic_feraiseexcept (int excepts) +{ + if (excepts & FE_INVALID) + { + float f = 0.0f; +#ifdef __x86_64__ + volatile float r __attribute__ ((unused)); + asm volatile ("%vdivss\t{%0, %d0|%d0, %0}" : "+x" (f)); + r = f; /* Needed to trigger exception. */ +#else + asm volatile ("fdiv\t{%y0, %0|%0, %y0}" : "+t" (f)); + /* No need for fwait, exception is triggered by emitted fstp. */ +#endif + } + if (excepts & FE_DENORM) + { + struct fenv temp; + asm volatile ("fnstenv\t%0" : "=m" (temp)); + temp.__status_word |= FE_DENORM; + asm volatile ("fldenv\t%0" : : "m" (temp)); + asm volatile ("fwait"); + } + if (excepts & FE_DIVBYZERO) + { + float f = 1.0f, g = 0.0f; +#ifdef __x86_64__ + volatile float r __attribute__ ((unused)); + asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g)); + r = f; /* Needed to trigger exception. */ +#else + asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g)); + /* No need for fwait, exception is triggered by emitted fstp. */ +#endif + } + if (excepts & FE_OVERFLOW) + { + struct fenv temp; + asm volatile ("fnstenv\t%0" : "=m" (temp)); + temp.__status_word |= FE_OVERFLOW; + asm volatile ("fldenv\t%0" : : "m" (temp)); + asm volatile ("fwait"); + } + if (excepts & FE_UNDERFLOW) + { + struct fenv temp; + asm volatile ("fnstenv\t%0" : "=m" (temp)); + temp.__status_word |= FE_UNDERFLOW; + asm volatile ("fldenv\t%0" : : "m" (temp)); + asm volatile ("fwait"); + } + if (excepts & FE_INEXACT) + { + float f = 1.0f, g = 3.0f; +#ifdef __x86_64__ + volatile float r __attribute__ ((unused)); + asm volatile ("%vdivss\t{%1, %d0|%d0, %1}" : "+x" (f) : "xm" (g)); + r = f; /* Needed to trigger exception. */ +#else + asm volatile ("fdivs\t%1" : "+t" (f) : "m" (g)); + /* No need for fwait, exception is triggered by emitted fstp. */ +#endif + } +} |