63 lines
1.3 KiB
C++
63 lines
1.3 KiB
C++
///////////////////////////////////////////////////////////////////////////////
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/// make the compiler think a particular variable may now be aliased somewhere.
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///
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/// useful for preventing optimisations eliding a variable.
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///
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/// stolen from Chandler Carruth's 2015 talk: "Tuning C++".
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namespace cruft::debug {
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template <class T>
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inline T*
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escape (T *t)
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{
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asm volatile ("": : "g"(t): "memory");
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return t;
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}
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template <class T>
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inline const T*
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escape (const T *t)
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{
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asm volatile ("": : "g"(t): "memory");
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return t;
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}
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template <class T>
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inline const T&
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escape (const T &t)
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{
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return *escape (&t);
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}
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template <class T>
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inline T&
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escape (T &t)
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{
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return *escape (&t);
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}
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template <typename T, typename ...Args>
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inline void
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escape (T t, Args ...args)
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{
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escape (t);
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escape (args...);
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}
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}
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///////////////////////////////////////////////////////////////////////////////
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/// force the compiler to conceptually dirty the global memory space.
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///
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/// stolen from Chandler Carruth's 2015 talk: "Tuning C++".
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namespace cruft::debug {
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inline void
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clobber (void)
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{
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asm volatile ("": : : "memory");
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}
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}
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