diff options
Diffstat (limited to 'gcc-4.8/libstdc++-v3/src/c++11/random.cc')
| -rw-r--r-- | gcc-4.8/libstdc++-v3/src/c++11/random.cc | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/gcc-4.8/libstdc++-v3/src/c++11/random.cc b/gcc-4.8/libstdc++-v3/src/c++11/random.cc new file mode 100644 index 000000000..2bd713260 --- /dev/null +++ b/gcc-4.8/libstdc++-v3/src/c++11/random.cc @@ -0,0 +1,148 @@ +// random -*- C++ -*- + +// Copyright (C) 2012-2013 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library 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, or (at your option) +// any later version. + +// This 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 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 <random> + +#ifdef _GLIBCXX_USE_C99_STDINT_TR1 + +#if defined __i386__ || defined __x86_64__ +# include <cpuid.h> +#endif + + +namespace std _GLIBCXX_VISIBILITY(default) +{ + + namespace + { + static unsigned long + _M_strtoul(const std::string& __str) + { + unsigned long __ret = 5489UL; + if (__str != "mt19937") + { + const char* __nptr = __str.c_str(); + char* __endptr; + __ret = std::strtoul(__nptr, &__endptr, 0); + if (*__nptr == '\0' || *__endptr != '\0') + std::__throw_runtime_error(__N("random_device::_M_strtoul" + "(const std::string&)")); + } + return __ret; + } + +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND + unsigned int + __attribute__ ((target("rdrnd"))) + __x86_rdrand(void) + { + unsigned int retries = 100; + unsigned int val; + + while (__builtin_ia32_rdrand32_step(&val) == 0) + if (--retries == 0) + std::__throw_runtime_error(__N("random_device::__x86_rdrand(void)")); + + return val; + } +#endif + } + + + void + random_device::_M_init(const std::string& token) + { + const char *fname = token.c_str(); + + if (token == "default") + { +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND + unsigned int eax, ebx, ecx, edx; + // Check availability of cpuid and, for now at least, also the + // CPU signature for Intel's + if (__get_cpuid_max(0, &ebx) > 0 && ebx == signature_INTEL_ebx) + { + __cpuid(1, eax, ebx, ecx, edx); + if (ecx & bit_RDRND) + { + _M_file = nullptr; + return; + } + } +#endif + + fname = "/dev/urandom"; + } + else if (token != "/dev/urandom" && token != "/dev/random") + fail: + std::__throw_runtime_error(__N("random_device::" + "random_device(const std::string&)")); + + _M_file = std::fopen(fname, "rb"); + if (! _M_file) + goto fail; + } + + void + random_device::_M_init_pretr1(const std::string& token) + { + _M_mt.seed(_M_strtoul(token)); + } + + void + random_device::_M_fini() + { + if (_M_file) + std::fclose(_M_file); + } + + random_device::result_type + random_device::_M_getval() + { +#if (defined __i386__ || defined __x86_64__) && defined _GLIBCXX_X86_RDRAND + if (! _M_file) + return __x86_rdrand(); +#endif + + result_type __ret; + std::fread(reinterpret_cast<void*>(&__ret), sizeof(result_type), + 1, _M_file); + return __ret; + } + + random_device::result_type + random_device::_M_getval_pretr1() + { + return _M_mt(); + } + + template class mersenne_twister_engine< + uint_fast32_t, + 32, 624, 397, 31, + 0x9908b0dfUL, 11, + 0xffffffffUL, 7, + 0x9d2c5680UL, 15, + 0xefc60000UL, 18, 1812433253UL>; +} +#endif |