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111
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1 // { dg-do compile }
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2 // { dg-options "-O2 -std=gnu++11 -fdump-tree-optimized" } */
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3
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4 #include <array>
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5
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6 // Return a copy of the underlying memory of an arbitrary value.
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7 template <
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8 typename T,
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9 typename = typename std::enable_if<std::is_trivially_copyable<T>::value>::type
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10 >
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11 auto getMem(
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12 T const & value
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13 ) -> std::array<char, sizeof(T)> {
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14 auto ret = std::array<char, sizeof(T)>{};
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15 __builtin_memcpy(ret.data(), &value, sizeof(T));
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16 return ret;
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17 }
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18
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19 template <
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20 typename T,
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21 typename = typename std::enable_if<std::is_trivially_copyable<T>::value>::type
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22 >
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23 auto fromMem(
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24 std::array<char, sizeof(T)> const & buf
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25 ) -> T {
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26 auto ret = T{};
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27 __builtin_memcpy(&ret, buf.data(), sizeof(T));
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28 return ret;
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29 }
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30
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31 double foo1(std::uint64_t arg) {
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32 return fromMem<double>(getMem(arg));
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33 }
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34
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35 double foo2(std::uint64_t arg) {
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36 return *reinterpret_cast<double*>(&arg);
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37 }
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38
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39 double foo3(std::uint64_t arg) {
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40 double ret;
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41 __builtin_memcpy(&ret, &arg, sizeof(arg));
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42 return ret;
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43 }
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44
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45 // { dg-final { scan-tree-dump-not "BIT_FIELD_REF" "optimized" } }
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