> The compiler isn't smart enough to convert it to direct-threading, to the best of my knowledge.
If you read the URL I linked to, you will see that it is.
> The point of direct threading is that there is no loop - you simply jump directly to the handler for the next character at the end of each handler.
No, the point of direct threading is that you give the branch predictor more context to work with (effectively, the previous opcode), which was relevant with the branch predictors in typical CPUs 10+ years ago. (Modern ones, ITTAGE-style, have per-branch history also for indirect jumps.)
If you read the URL I linked to, you will see that it is.
> The point of direct threading is that there is no loop - you simply jump directly to the handler for the next character at the end of each handler.
No, the point of direct threading is that you give the branch predictor more context to work with (effectively, the previous opcode), which was relevant with the branch predictors in typical CPUs 10+ years ago. (Modern ones, ITTAGE-style, have per-branch history also for indirect jumps.)