osa1 (May 16 2020 at 19:00): osa1 (May 16 2020 at 19:00):Why is there not a jump_indirect instruction, similar to call_indirect? How do I currently generate something like jmp *%rax?
bjorn3 (May 16 2020 at 20:41):What do you want to use it for? Do you want a tail call, or a switch?
osa1 (May 16 2020 at 20:42):Tail call
osa1 (May 16 2020 at 21:11):I'm guessing this is not easily possible today: https://github.com/bytecodealliance/wasmtime/issues/1065
osa1 (May 24 2020 at 08:47):Just to make sure I'm not missing something: it's really not possible today to do an indirect jump in cranelift, right? The x64 I want to generate is something like jmp *%rax.
bjorn3 (May 24 2020 at 10:06):Yes, it is currently not possible. There is no instruction for it, nor does regalloc have any support for it.
osa1 (May 24 2020 at 10:07):Thank you.
osa1 (May 24 2020 at 10:07):I'm curious, is this really not needed all that much in general? Or maybe the main user is wasmtime and it's not needed there?
bjorn3 (May 24 2020 at 10:10):So far none of the users required tail calls. WASM doesn't support it, C and Rust don't require it. Only some functional languages guarantee tail call optimization.
Till Schneidereit (May 24 2020 at 13:59):Though note that a tails calls proposal is at stage 3 in the standardization process, which means it's ready for implementation
Last updated: Nov 22 2024 at 16:03 UTC