Option 4 is sometimes compiler annotations like __builtin_expect_with_probability which you could use to assign a branch a value of 50% which should coerce it to pick cmov (same risk as 3 though in that you need to inspect compiler output).
Yep, there's an entire book to be written on techniques that you can use to express your understanding of code to the compiler so that the compiler's chosen implementation of it matches yours. Plenty of __builtins and __attributes__, and even just the ordering of if/else statements, grouping statements into local scopes with {}, using or not using a temporary variable...
