Why do (only) some compilers use the same address for identical string literals?

Question

https://godbolt.org/z/cyBiWY

I can see two \'some\' literals in assembler code generated by MSVC, but only one with clang and gcc. This leads to totally

Answer 1

Whether or not a compiler chooses to use the same string location for A and B is up to the implementation. Formally you can say that the behaviour of your code is unspecified.

Both choices implement the C++ standard correctly.