It does not and cannot use the input value. The branch predictor runs like a dozen cycles before execution, it generally cannot possibly see values in registers. It also runs like 3-4 cycles before decode, so it cannot even use any bits from the instruction that is being executed.⁰ Branch predictors strictly use branch history, but this is more complex than just looking at the probability of branching on a single branch, there are things like tables that maintain all branches over the past tens of thousands of cycles, and try to cover common patterns.

0: This is why the first prediction is always "don't branch", because the first time executing code the predictor has literally no information at all. Every now and then people ask for hint bits on branches, but, er, how are you planning to do that when the instruction with the branch hasn't arrived from L1 when the prediction is due?