Optimized IR:
/// @use-src 0:"ir_with_assembly_no_memoryguard_runtime/input.sol"
object "D_8" {
    code {
        {
            /// @src 0:82:166  "contract D {..."
            let _1 := memoryguard(0x80)
            mstore(64, _1)
            if callvalue() { revert(0, 0) }
            let _2 := datasize("D_8_deployed")
            codecopy(_1, dataoffset("D_8_deployed"), _2)
            return(_1, _2)
        }
    }
    /// @use-src 0:"ir_with_assembly_no_memoryguard_runtime/input.sol"
    object "D_8_deployed" {
        code {
            {
                /// @src 0:82:166  "contract D {..."
                if iszero(lt(calldatasize(), 4))
                {
                    let _1 := 0
                    if eq(0x26121ff0, shr(224, calldataload(_1)))
                    {
                        if callvalue() { revert(_1, _1) }
                        if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
                        return(_1, _1)
                    }
                }
                revert(0, 0)
            }
        }
        data ".metadata" hex"<BYTECODE REMOVED>"
    }
}
