[Bug middle-end/82404] Unnecessary instructions in switch table

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82404

--- Comment #4 from Martin Liška <marxin at gcc dot gnu.org> ---
I can confirm in C, clang adds guard checks:

$ cat pr82405-2.c
enum eShape { eSquare, eCircle, eShpere, eTetraeder };

double test_switch_native(enum eShape shape, double r) {
    switch(shape) {
    case eSquare:    return 2;
    case eCircle:    return 3;
    case eShpere:    return 4;
    case eTetraeder: return 5;
    }
}

$ clang pr82405-2.c -O2 -o/dev/stdout -S
test_switch_native:                     # @test_switch_native
        .cfi_startproc
# BB#0:
        cmpl    $3, %edi
        ja      .LBB0_2
# BB#1:
        movslq  %edi, %rax
        movsd   .Lswitch.table(,%rax,8), %xmm0 # xmm0 = mem[0],zero
...