The interpreter instruction count was enabled based on RUBY_DEBUG as
opposed to YJIT_STATS. In builds with YJIT_STATS=1 but RUBY_DEBUG=0,
the count was not available.
Move YJIT_STATS in yjit.h where declarations are expoed to code outside
of YJIT. Also reduce the changes made to the interpreter for calling
into YJIT's instruction counting function.
This change fixes some cases where YJIT fails to fire tracing events.
Most of the situations YJIT did not handle correctly involves enabling
tracing while running inside generated code.
A new operation to invalidate all generated code is added, which uses
patching to make generated code exit at the next VM instruction
boundary. A new routine called `jit_prepare_routine_call()` is
introduced to facilitate this and should be used when generating code
that could allocate, or could otherwise use `RB_VM_LOCK_ENTER()`.
The `c_return` event is fired in the middle of an instruction as opposed
to at an instruction boundary, so it requires special handling. C method
call return points are patched to go to a fucntion which does everything
the interpreter does, including firing the `c_return` event. The
generated code for C method calls normally does not fire the event.
Invalided code should not change after patching so the exits are not
clobbered. A new variable is introduced to track the region of code that
should not change.
If `--disable-jit-support` is passed to configure, then `jit_func` is
removed from the iseq body and we can't compile YJIT. This commit
detects when the JIT function pointer is gone and disables YJIT in that
case.
Always using `ret` to return to the interpreter means that we never have
to check the VM_FRAME_FLAG_FINISH flag.
In the case that we return `Qundef`, the interpreter will execute the
cfp. We can take advantage of this by setting the PC to the instruction
we can't handle, and let the interpreter pick up the ball from there.
If we return a value other than Qundef, the interpreter will take that
value as the "return value" from the JIT and push that to the SP of the
caller
The leave instruction puts the return value on the top of the calling
frame's stack. YJIT does the same thing for leave instructions.
However, when we're returning back to the interpreter, the leave
instruction _should not_ put the return value on the top of the stack,
but put it in RAX and use RET. This commit pops the last value from the
stack pointer and puts it in RAX so that the interpreter is happy with
SP.
Make sure `opt_getinlinecache` is in a block all on its own, and
invalidate it from the interpreter when `opt_setinlinecache`.
It will recompile with a filled cache the second time around.
This lets YJIT runs well when the IC for constant is cold.
Alan Wu
Aaron Patterson
Maxime Chevalier-Boisvert
Maxime Chevalier-Boisvert
Jose Narvaez