https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105838
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jason at gcc dot gnu.org, | |redi at gcc dot gnu.org --- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Note, for say #include <string> #include <vector> void foo (const std::vector<std::string> &); int main () { const std::vector<std::string> lst = { "aahing", "aaliis", "aarrgh", "abacas", "abacus", "abakas", "abamps", "abands", "abased", "abaser", "abases", "abasia" }; foo (lst); } one gets terrible code from both g++ and clang++, in both cases it is serial code calling many std::string ctors with the string literal arguments that perhaps later on are inlined. Over 21000 times in a row. That also means over 21000 memory allocations etc. For your game, the obvious first question would be if you really need std::vector of std::string in this case and if a normal array of const char * strings wouldn't be better, that can be initialized at compile time. Or, if you really need std::vector<std::string>, if it wouldn't be better to use array of const char * and build the vector from it (sizeof (arr) / sizeof (arr[0]) to reserve that many elts in the vector, then a loop that will construct the std::string objects and move them into the list). On the compiler side, a question is if we shouldn't detect such kind of initializers and if they have over some param determined number of elements which have the same type / kind (or at least a large sequence of such), don't emit those std::allocator<char>::allocator (&D.37541); try { std::__cxx11::basic_string<char>::basic_string<> (_4, "aahing", &D.37541); D.37581 = D.37581 + 32; D.37582 = D.37582 + -1; _5 = D.37581; try { std::allocator<char>::allocator (&D.37543); try { std::__cxx11::basic_string<char>::basic_string<> (_5, "aaliis", &D.37543); D.37581 = D.37581 + 32; D.37582 = D.37582 + -1; _6 = D.37581; try { ... but a loop. Doesn't have to be just for the STL types, if we have struct S { S (int); ... }; const S s[] = { 1, 3, 22, 42, 132, -12, 18, 19, 32, 0, 25, ... }; then again there should be some upper limit over which we'd just emit: const S s[count]; static const int stemp[count] = { 1, 3, 22, 42, 132, -12, 18, 19, 32, 0, 25, ... }; for (size_t x = 0; x < count; ++x) S (&s[x], stemp[x]); or so (of course, with destruction possibility if some ctor may throw).