We are writing a byte-code for a high-level compiled language, and after a bit of profiling and optimization, it became clear that the current largest performance overhead is the switch statement we're using to jump to the byte-code cases.
We investigated pulling out the address of each case label and storing it in the stream of byte-code itself, rather than the instruction ID that we usually switch on. If we do that, we can skip the jump table, and directly jump to the location of code of the currently executing instruction. This works fantastically in GCC, however, MSVC doesn't seem to support a feature like this.
We attempted to use inline assembly to grab the address of the labels (and to jump to them), and it works, however, using inline assembly causes the entire function to be avoided by the MSVC optimizer.
Is there a way to allow the optimizer to still run over the code? Unfortunately, we can't extract the inline assembly into another function other than the one that the labels were made in, since there's no way to reference a label for another function even in inline assembly. Any thoughts or ideas? Your input is much appreciated, thanks!