* Rename --jit to --mjit
[Feature #18349]
* Fix a few more --jit references
* Fix MJIT Actions
* More s/jit/mjit/ and re-introduce --disable-jit
* Update NEWS.md
* Fix test_bug_reporter_add
As part of YJIT's strategy for promoting Ruby constant expressions into
constants in the output native code, the interpreter calls
rb_yjit_constant_ic_update() from opt_setinlinecache.
The block invalidation loop indirectly calls rb_darray_remove_unordered(),
which does a shuffle remove. Because of this, looping with an
incrementing counter like done previously can miss some elements in the
array. Repeatedly invalidate the first element instead.
The bug this commit resolves does not seem to cause crashes or divergent
behaviors.
Co-authored-by: Jemma Issroff <jemmaissroff@gmail.com>
On Rails we're seeing a lot of exits for ivars in the Active Record
tests. In trying to track them down it was hard to find what code is
exiting.
This change adds a counted exit for when an object is "megamorphic". In
these cases there are too many specializations in the Ruby code so YJIT
exits.
Co-authored-by: Aaron Patterson tenderlove@ruby-lang.org
Previously, YJIT crashes with rb_bug() when asked to compile new methods
while out of executable memory.
To handle this situation gracefully, this change keeps track of all the
blocks compiled each invocation in case YJIT runs out of memory in the
middle of a compliation sequence. The list is used to free all blocks in
case compilation fails.
yjit_gen_block() is renamed to gen_single_block() to make it distinct from
gen_block_version(). Call to limit_block_version() and block_t
allocation is moved into the function to help tidy error checking in the
outer loop.
limit_block_version() now returns by value. I feel that an out parameter
with conditional mutation is unnecessarily hard to read in code that
does not need to go for last drop performance. There is a good chance
that the optimizer is able to output identical code anyways.
Previously, YJIT assumed that it's always possible to generate a new
basic block when servicing a stub in branch_stub_hit(). When YJIT is out
of executable memory, for example, this assumption doesn't hold up.
Add handling to branch_stub_hit() for servicing stubs without consuming
more executable memory by adding a code path that exits to the
interpreter at the location the branch stub represents. The new code
path reconstructs interpreter state in branch_stub_hit() and then exits
with a new snippet called `code_for_exit_from_stub` that returns
`Qundef` from the YJIT native stack frame.
As this change adds another place where we regenerate code from
`branch_t`, extract the logic for it into a new function and call it
regenerate_branch(). While we are at it, make the branch shrinking code
path in branch_stub_hit() more explicit.
This new functionality is hard to test without full support for out of
memory conditions. To verify this change, I ran
`RUBY_YJIT_ENABLE=1 make check -j12` with the following patch to stress
test the new code path:
```diff
diff --git a/yjit_core.c b/yjit_core.c
index 4ab63d9806..5788b8c5ed 100644
--- a/yjit_core.c
+++ b/yjit_core.c
@@ -878,8 +878,12 @@ branch_stub_hit(branch_t *branch, const uint32_t target_idx, rb_execution_contex
cb_set_write_ptr(cb, branch->end_addr);
}
+if (rand() < RAND_MAX/2) {
// Compile the new block version
p_block = gen_block_version(target, target_ctx, ec);
+}else{
+ p_block = NULL;
+}
if (!p_block && branch_modified) {
// We couldn't generate a new block for the branch, but we modified the branch.
```
We can enable the new test along with other OOM tests once full support
lands.
Other small changes:
* yjit_utils.c (print_str): Update to work with new native frame shape.
Follow up for 8fa0ee4d40.
* yjit_iface.c (rb_yjit_init): Run yjit_init_core() after
yjit_init_codegen() so `cb` and `ocb` are available.
* YJIT: Implement optimized_method_struct_aref
* YJIT: Implement struct_aref without method call
Struct member reads can be compiled directly into a memory read (with
either one or two levels of indirection).
* YJIT: Implement optimized struct aset
* YJIT: Update tests for struct access
* YJIT: Add counters for remaining optimized methods
* Check for INT32_MAX overflow
It only takes a struct with 0x7fffffff/8+1 members. Also add some
cheap compile time checks.
* Add tests for non-embedded struct aref/aset
Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
* YJIT: Support kwargs sends with all defaults
Previously keyword argument methods were only compiled by YJIT when all
keywords were specified in the caller.
This adds support for calling methods with keyword arguments when no
keyword arguments are specified and all are filled with the defaults.
* Remove unused send_iseq_kwargs_none_passed
In an effort to minimize build issues on non x64 platforms, we can
decide at build time to not build the bulk of YJIT. This should fix
obscure build errors like this one on riscv64:
yjit_asm.c:137:(.text+0x3fa): relocation truncated to fit: R_RISCV_PCREL_HI20 against `alloc_exec_mem'
We also don't need to bulid YJIT on `--disable-jit-support` builds.
One wrinkle to this is that the YJIT Ruby module will not be defined
when YJIT is stripped from the build. I think that's a fair change as
it's only meant to be used for YJIT development.
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?
Takashi Kokubun
Alan Wu
eileencodes
John Hawthorn
Kevin Newton