[Bug tree-optimization/110819] Missed optimization: when vector's size is 0 but vector::reserve has been called.

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110819

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=110137

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I guess gcc can't optimize this away because it doesn't know if operator new
has side effects. When compiled with clang, libstdc++'s std::vector uses
__builtin_operator_new which always has the -fassume-sane-operator-new
semantics, and so can be optimized.