The new backend isn't used at the moment and adds to our diff against
upstream so remove it for now. We can reverse the removal later with git
history.
We were exporting a couple of symbols in yjit.h because they could be
used by code generated by MJIT. We don't want MJIT calling into YJIT
code anyways so let's stop exporting them to libruby.so.
Also adjust indentation and comments in mjit_exec().
For upstreaming, we want functions we export either prefixed with "rb_"
or made static. Historically we haven't been following this rule, so we
were "leaking" a lot of symbols as `make leak-globals` would tell us.
This change unifies everything YJIT into a single compilation unit,
yjit.o, and makes everything unprefixed static to pass `make leak-globals`.
This manual "unified build" setup is similar to that of vm.o.
Having everything in one compilation unit allows static functions to
be visible across YJIT files and removes the need for declarations in
headers in some cases. Unnecessary declarations were removed.
Other changes of note:
- switched to MJIT_SYMBOL_EXPORT_BEGIN which indicates stuff as being
off limits for native extensions
- the first include of each YJIT file is change to be "internal.h"
- undefined MAP_STACK before explicitly redefining it since it
collide's with a definition in system headers. Consider renaming?
We need to reconstruct interpreter state before calling into the
routines to be able to raise exceptions. I'm getting a crash in
debug build with:
make test-all 'TESTS=test/ruby/variable.rb' RUN_OPTS='--yjit-call-threshold=1 --yjit-max-versions=1'
The old heap object check is not as efficient as the one in
jit_guard_known_klass(). Also, the old code saves cfp->sp after popping
the operands off the stack, which might cause the operands to be not
marked by the GC in some circumstances.
When calling "to_s" on an instance of String, the method simply returns
self. In this situation most of the work comes from setting up the
method call. It turns out that both railsbench and liquid-render do this
a lot.
When generating code for opt_send_without_block, we already generate a
known class guard, so we can detect when the receiver is a String
instance. Since gen_send_cfunc() is also used for gen_invokesuper(), and
gen_invokesuper() doesn't generate a known class guard, a new nullable
parameter for specialized codegen function is added.
Closes GH-245
Before this change, when we encounter a constant cache that is specific
to a lexical scope, we unconditionally exit. This change falls back to
the interpreter's cache in this situation.
This should help constant expressions in `class << self`, which is popular
at Shopify due to the style guide.
This change relies on the cache being warm while compiling to detect the
need for checking the lexical scope for simplicity.
YJIT expects the VM to invalidate opt_getinlinecache when updating the
constant cache, and the invalidation used to happen even when YJIT can't
use the cached value.
Once the first invalidation happens, the block for opt_getinlinecache
becomes a stub. When the stub is hit, YJIT fails to compile the
instruction as the cache is not usable. The stub becomes a block that
exits for opt_getinlinecache which can be invalidated again. Some
workloads that bust the interpreter's constant cache can create an
invalidation loop with this behavior.
Check if the cache is usable become doing invalidation to fix this
problem.
In the test harness, evaluate the test script in a lambda instead of a
proc so `return` doesn't return out of the harness.
