I have a C++ function that defines multiple labels and attempts to compute a target address based on an input value. The function then uses a goto statement to jump to the computed address. However, when I compile this code with GCC or Clang, it only uses the first two labels. (compiler explorer)

Why do GCC and Clang fail to compile this code correctly, and how can I fix it? Is this behavior intended according to the C++ standard, or is it a compiler bug? Should I report it?

#include <cstdint>
#include <cstddef>
#include <cstring>

uint8_t SWARfloor64OverNGoto(const uint64_t n)
{
    // Define the labels
    void *label0_address = &&label0;
    void *label1_address = &&label1;

    // Calculate the offset at compile time
    const uint64_t offset = reinterpret_cast<uintptr_t>(label1_address) - reinterpret_cast<uintptr_t>(label0_address);

    // Compute the target address
    void *target = reinterpret_cast<void *>(reinterpret_cast<uintptr_t>(label0_address) + n * offset);

    // Jump to the target address
    goto *reinterpret_cast<void**>(target);

label0:
    return 0;
label1:
    return 64;
label2:
    return 32;
label3:
    return 21;
label4:
    return 16;
label5:
    return 12;
label6:
    return 10;
label7:
    return 9;
label8:
    return 8;
label9:
    return 7;
label10:
    return 6;
label11:
    return 5;
label12:
    return 5;
label13:
    return 4;
label14:
    return 4;
label15:
    return 4;
label16:
    return 4;
label17:
    return 3;
label18:
    return 3;
label19:
    return 3;
label20:
    return 3;
label21:
    return 3;
label22:
    return 2;
label23:
    return 2;
label24:
    return 2;
label25:
    return 2;
label26:
    return 2;
label27:
    return 2;
label28:
    return 2;
label29:
    return 2;
label30:
    return 2;
label31:
    return 2;
label32:
    return 2;
label33:
    return 1;
label34:
    return 1;
label35:
    return 1;
label36:
    return 1;
label37:
    return 1;
label38:
    return 1;
label39:
    return 1;
label40:
    return 1;
label41:
    return 1;
label42:
    return 1;
label43:
    return 1;
label44:
    return 1;
label45:
    return 1;
label46:
    return 1;
label47:
    return 1;
label48:
    return 1;
label49:
    return 1;
label50:
    return 1;
label51:
    return 1;
label52:
    return 1;
label53:
    return 1;
label54:
    return 1;
label55:
    return 1;
label56:
    return 1;
label57:
    return 1;
label58:
    return 1;
label59:
    return 1;
label60:
    return 1;
label61:
    return 1;
label62:
    return 1;
label63:
    return 1;
}

The compiled assembly code only uses the first two labels, which is not the intended behavior.

SWARfloor64OverNGoto(unsigned long):
        mov     eax, OFFSET FLAT:.L3
        sub     rax, OFFSET FLAT:.L2
        imul    rax, rdi
        add     rax, OFFSET FLAT:.L2
        jmp     rax
.L2:
        xor     eax, eax
        ret
.L3:
        mov     eax, 64
        ret