45 lines
985 B
C++
45 lines
985 B
C++
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/*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2019 Danny Robson <danny@nerdcruft.net>
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*/
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#include "rdrand.hpp"
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using cruft::rand::rdrand;
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///////////////////////////////////////////////////////////////////////////////
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rdrand::rdrand ()
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{ ; }
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//---------------------------------------------------------------------------------------
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rdrand::rdrand (std::string const &)
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: rdrand ()
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{ ; }
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///////////////////////////////////////////////////////////////////////////////
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rdrand::result_type
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rdrand::operator() ()
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{
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uint64_t res;
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char success;
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__asm__ __volatile__ (
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"rdrand %0;"
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"setc %1;"
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: "=r" (res)
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, "=qm" (success)
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);
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if (!__builtin_expect(success, 1))
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throw std::runtime_error ("no value available for rdrand");
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return res;
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}
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