Possible ARM bug

This program behaves differently with optimizations enabled on ARM:

use core::ffi::*;
extern "C" {
    pub fn printf(format: *const c_char, ...) -> c_int;
}
fn dump_var(val3: f32) {
    if val3 != 1902660900.0 {
        unsafe { printf(b"wrong\n\0".as_ptr() as *const _) };
    }
}
fn main() {
    let mut _9 = 43619u128;
    let _64 = &mut _9;
    let _27 = _9 as f32;
    let _29 = 43619.0 * _27;
    dump_var(_29 + 43619.0)
}

Unoptimized: 

Optimized:
wrong

(I am using printf here to make porting the code to C easier)

No repository file or test is named. Run the supplied Rust reproducer on ARM with and without optimizations, compare the output, and inspect the optimized codegen path for the differing floating-point result. Done means identifying whether the optimized result is incorrect and documenting or testing the failure in the appropriate codegen area.