[Bug tree-optimization/100858] New: Simple common code hoisting is not performed

[nok.raven at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100858

            Bug ID: 100858
           Summary: Simple common code hoisting is not performed
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nok.raven at gmail dot com
  Target Milestone: ---

void bar();

int foo(bool f)
{
    if (f) {
        bar();
        return 1;
    }
    else {
        bar();
        return 2;
    }
}

; GCC
foo(bool):
        sub     rsp, 8
        test    dil, dil
        je      .L2
        call    bar()
        mov     eax, 1
        add     rsp, 8
        ret
.L2:
        call    bar()
        mov     eax, 2
        add     rsp, 8
        ret

; Clang
foo(bool):
        push    rbx
        mov     ebx, edi
        call    bar()
        mov     eax, 2
        sub     eax, ebx
        pop     rbx
        ret

https://godbolt.org/z/j9eKG1dds