[Bug tree-optimization/94010] New: [missed optimization] -fmerge-all-constants misses simple array merging

[aleksey.covacevice at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94010

            Bug ID: 94010
           Summary: [missed optimization] -fmerge-all-constants misses
                    simple array merging
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: aleksey.covacevice at gmail dot com
  Target Milestone: ---

-fmerge-all-constants misses a very simple optimization scenario involving an
array:

    extern void g(const char* c);

    void f() {
        const char c[] = "12345";
        g(c);
    }

produces a local array (with or without the flag).

If `const char c[]` is replaced by `const char* c`, the above code produces a
global array as expected.

This seems to be the case in every GCC version I have tested, starting from
4.9.