Given the simple function:

double uniform_double_from_int(unsigned n) {
    return n / 4294967296.0;
}

GCC 13.2 with -O3 generates the following assembly:

uniform_double_from_int(unsigned int):
        mov     edi, edi
        vxorps  xmm0, xmm0, xmm0
        vcvtsi2sd       xmm0, xmm0, rdi
        vmulsd  xmm0, xmm0, QWORD PTR .LC0[rip]
        ret
.LC0:
        .long   0
        .long   1039138816

Why on earth is GCC performing the no-op mov edi, edi at the begining of this function?