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path: root/yjit/src/codegen.rs
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2024-06-18Optimized forwarding callers and calleesAaron Patterson
This patch optimizes forwarding callers and callees. It only optimizes methods that only take `...` as their parameter, and then pass `...` to other calls. Calls it optimizes look like this: ```ruby def bar(a) = a def foo(...) = bar(...) # optimized foo(123) ``` ```ruby def bar(a) = a def foo(...) = bar(1, 2, ...) # optimized foo(123) ``` ```ruby def bar(*a) = a def foo(...) list = [1, 2] bar(*list, ...) # optimized end foo(123) ``` All variants of the above but using `super` are also optimized, including a bare super like this: ```ruby def foo(...) super end ``` This patch eliminates intermediate allocations made when calling methods that accept `...`. We can observe allocation elimination like this: ```ruby def m x = GC.stat(:total_allocated_objects) yield GC.stat(:total_allocated_objects) - x end def bar(a) = a def foo(...) = bar(...) def test m { foo(123) } end test p test # allocates 1 object on master, but 0 objects with this patch ``` ```ruby def bar(a, b:) = a + b def foo(...) = bar(...) def test m { foo(1, b: 2) } end test p test # allocates 2 objects on master, but 0 objects with this patch ``` How does it work? ----------------- This patch works by using a dynamic stack size when passing forwarded parameters to callees. The caller's info object (known as the "CI") contains the stack size of the parameters, so we pass the CI object itself as a parameter to the callee. When forwarding parameters, the forwarding ISeq uses the caller's CI to determine how much stack to copy, then copies the caller's stack before calling the callee. The CI at the forwarded call site is adjusted using information from the caller's CI. I think this description is kind of confusing, so let's walk through an example with code. ```ruby def delegatee(a, b) = a + b def delegator(...) delegatee(...) # CI2 (FORWARDING) end def caller delegator(1, 2) # CI1 (argc: 2) end ``` Before we call the delegator method, the stack looks like this: ``` Executing Line | Code | Stack ---------------+---------------------------------------+-------- 1| def delegatee(a, b) = a + b | self 2| | 1 3| def delegator(...) | 2 4| # | 5| delegatee(...) # CI2 (FORWARDING) | 6| end | 7| | 8| def caller | -> 9| delegator(1, 2) # CI1 (argc: 2) | 10| end | ``` The ISeq for `delegator` is tagged as "forwardable", so when `caller` calls in to `delegator`, it writes `CI1` on to the stack as a local variable for the `delegator` method. The `delegator` method has a special local called `...` that holds the caller's CI object. Here is the ISeq disasm fo `delegator`: ``` == disasm: #<ISeq:delegator@-e:1 (1,0)-(1,39)> local table (size: 1, argc: 0 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1]) [ 1] "..."@0 0000 putself ( 1)[LiCa] 0001 getlocal_WC_0 "..."@0 0003 send <calldata!mid:delegatee, argc:0, FCALL|FORWARDING>, nil 0006 leave [Re] ``` The local called `...` will contain the caller's CI: CI1. Here is the stack when we enter `delegator`: ``` Executing Line | Code | Stack ---------------+---------------------------------------+-------- 1| def delegatee(a, b) = a + b | self 2| | 1 3| def delegator(...) | 2 -> 4| # | CI1 (argc: 2) 5| delegatee(...) # CI2 (FORWARDING) | cref_or_me 6| end | specval 7| | type 8| def caller | 9| delegator(1, 2) # CI1 (argc: 2) | 10| end | ``` The CI at `delegatee` on line 5 is tagged as "FORWARDING", so it knows to memcopy the caller's stack before calling `delegatee`. In this case, it will memcopy self, 1, and 2 to the stack before calling `delegatee`. It knows how much memory to copy from the caller because `CI1` contains stack size information (argc: 2). Before executing the `send` instruction, we push `...` on the stack. The `send` instruction pops `...`, and because it is tagged with `FORWARDING`, it knows to memcopy (using the information in the CI it just popped): ``` == disasm: #<ISeq:delegator@-e:1 (1,0)-(1,39)> local table (size: 1, argc: 0 [opts: 0, rest: -1, post: 0, block: -1, kw: -1@-1, kwrest: -1]) [ 1] "..."@0 0000 putself ( 1)[LiCa] 0001 getlocal_WC_0 "..."@0 0003 send <calldata!mid:delegatee, argc:0, FCALL|FORWARDING>, nil 0006 leave [Re] ``` Instruction 001 puts the caller's CI on the stack. `send` is tagged with FORWARDING, so it reads the CI and _copies_ the callers stack to this stack: ``` Executing Line | Code | Stack ---------------+---------------------------------------+-------- 1| def delegatee(a, b) = a + b | self 2| | 1 3| def delegator(...) | 2 4| # | CI1 (argc: 2) -> 5| delegatee(...) # CI2 (FORWARDING) | cref_or_me 6| end | specval 7| | type 8| def caller | self 9| delegator(1, 2) # CI1 (argc: 2) | 1 10| end | 2 ``` The "FORWARDING" call site combines information from CI1 with CI2 in order to support passing other values in addition to the `...` value, as well as perfectly forward splat args, kwargs, etc. Since we're able to copy the stack from `caller` in to `delegator`'s stack, we can avoid allocating objects. I want to do this to eliminate object allocations for delegate methods. My long term goal is to implement `Class#new` in Ruby and it uses `...`. I was able to implement `Class#new` in Ruby [here](https://github.com/ruby/ruby/pull/9289). If we adopt the technique in this patch, then we can optimize allocating objects that take keyword parameters for `initialize`. For example, this code will allocate 2 objects: one for `SomeObject`, and one for the kwargs: ```ruby SomeObject.new(foo: 1) ``` If we combine this technique, plus implement `Class#new` in Ruby, then we can reduce allocations for this common operation. Co-Authored-By: John Hawthorn <john@hawthorn.email> Co-Authored-By: Alan Wu <XrXr@users.noreply.github.com>
2024-06-07YJIT: implement variable-length context encoding scheme (#10888)Maxime Chevalier-Boisvert
* Implement BitVector data structure for variable-length context encoding * Rename method to make intent clearer * Rename write_uint => push_uint to make intent clearer * Implement debug trait for BitVector * Fix bug in BitVector::read_uint_at(), enable more tests * Add one more test for good measure * Start sketching Context::encode() * Progress on variable length context encoding * Add tests. Fix bug. * Encode stack state * Add comments. Try to estimate context encoding size. * More compact encoding for stack size * Commit before rebase * Change Context::encode() to take a BitVector as input * Refactor BitVector::read_uint(), add helper read functions * Implement Context::decode() function. Add test. * Fix bug, add tests * Rename methods * Add Context::encode() and decode() methods using global data * Make encode and decode methods use u32 indices * Refactor YJIT to use variable-length context encoding * Tag functions as allow unused * Add a simple caching mechanism and stats for bytes per context etc * Add comments, fix formatting * Grow vector of bytes by 1.2x instead of 2x * Add debug assert to check round-trip encoding-decoding * Take some rustfmt formatting * Add decoded_from field to Context to reuse previous encodings * Remove olde context stats * Re-add stack_size assert * Disable decoded_from optimization for now
2024-06-04Do not emit shape transition warnings when YJIT is compilingJean Boussier
[Bug #20522] If `Warning.warn` is redefined in Ruby, emitting a warning would invoke Ruby code, which can't safely be done when YJIT is compiling.
2024-06-04YJIT: Fix getconstant exits after opt_ltlt fusion (#10903)Takashi Kokubun
Co-authored-by: Alan Wu <alansi.xingwu@shopify.com>
2024-05-31YJIT: Fix out of bounds access when splatting empty arrayAlan Wu
Previously, we read the last element array even when the array was empty, doing an out-of-bounds access. This sometimes caused a SEGV. [Bug #20496]
2024-05-28Stop marking chilled strings as frozenÉtienne Barrié
They were initially made frozen to avoid false positives for cases such as: str = str.dup if str.frozen? But this may cause bugs and is generally confusing for users. [Feature #20205] Co-authored-by: Jean Boussier <byroot@ruby-lang.org>
2024-05-23Introduce a specialize instruction for Array#packNobuyoshi Nakada
Instructions for this code: ```ruby # frozen_string_literal: true [a].pack("C") ``` Before this commit: ``` == disasm: #<ISeq:<main>@test.rb:1 (1,0)-(3,13)> 0000 putself ( 3)[Li] 0001 opt_send_without_block <calldata!mid:a, argc:0, FCALL|VCALL|ARGS_SIMPLE> 0003 newarray 1 0005 putobject "C" 0007 opt_send_without_block <calldata!mid:pack, argc:1, ARGS_SIMPLE> 0009 leave ``` After this commit: ``` == disasm: #<ISeq:<main>@test.rb:1 (1,0)-(3,13)> 0000 putself ( 3)[Li] 0001 opt_send_without_block <calldata!mid:a, argc:0, FCALL|VCALL|ARGS_SIMPLE> 0003 putobject "C" 0005 opt_newarray_send 2, :pack 0008 leave ``` Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
2024-05-01YJIT: Fix `Struct` accessors not firing tracing events (#10690)Alan Wu
* YJIT: Fix `Struct` accessors not firing tracing events Reading and writing to structs should fire `c_call` and `c_return`, but YJIT wasn't correctly dropping those calls when tracing. This has been missing since this functionality was added in 3081c83169c, but the added test only fails when ran in isolation with `--yjit-call-threshold=1`. The test sometimes failed on CI. * RJIT: YJIT: Fix `Struct` readers not firing tracing events Same issue as YJIT, but it looks like RJIT doesn't support writing to structs, so only reading needs changing.
2024-04-29YJIT: Expand codegen for `TrueClass#===` to `FalseClass` and `NilClass` (#10679)Randy Stauner
2024-04-29YJIT: Add specialized codegen function for `TrueClass#===` (#10640)Randy Stauner
* YJIT: Add specialized codegen function for `TrueClass#===` TrueClass#=== is currently number 10 in the most frequent C calls list of the lobsters benchmark. ``` require "benchmark/ips" def wrap true === true true === false true === :x end Benchmark.ips do |x| x.report(:wrap) do wrap end end ``` ``` before Warming up -------------------------------------- wrap 1.791M i/100ms Calculating ------------------------------------- wrap 17.806M (± 1.0%) i/s - 89.544M in 5.029363s after Warming up -------------------------------------- wrap 4.024M i/100ms Calculating ------------------------------------- wrap 40.149M (± 1.1%) i/s - 201.223M in 5.012527s ``` Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> Co-authored-by: Takashi Kokubun (k0kubun) <takashikkbn@gmail.com> Co-authored-by: Kevin Menard <kevin.menard@shopify.com> Co-authored-by: Alan Wu <XrXr@users.noreply.github.com> * Fix the new test for RJIT --------- Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> Co-authored-by: Takashi Kokubun (k0kubun) <takashikkbn@gmail.com> Co-authored-by: Kevin Menard <kevin.menard@shopify.com> Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
2024-04-26Revert "YJIT: Try splitting getlocal/setlocal blocks (#10648)"Takashi Kokubun
This reverts commit ab228bd0844758a1c444e39030c153874adf9120.
2024-04-26YJIT: Try splitting getlocal/setlocal blocks (#10648)Takashi Kokubun
2024-04-25YJIT: Relax `--yjit-verify-ctx` after singleton class creationAlan Wu
Types like `Type::CString` really only assert that at one point the object had its class field equal to `String`. Once a singleton class is created for any strings, the type makes no assertion about any class field anymore, and becomes the same as `Type::TString`. Previously, the `--yjit-verify-ctx` option wasn't allowing objects of these kind that have have singleton classes to pass verification even though the code generators handle it just fine. Found through `ruby/spec`.
2024-04-25YJIT: Optimize local variables when EP == BP (take 2) (#10607)Takashi Kokubun
* Revert "Revert "YJIT: Optimize local variables when EP == BP" (#10584)" This reverts commit c8783441952217c18e523749c821f82cd7e5d222. * YJIT: Take care of GC references in ISEQ invariants Co-authored-by: Alan Wu <alansi.xingwu@shopify.com> --------- Co-authored-by: Alan Wu <alansi.xingwu@shopify.com>
2024-04-24YJIT: Add a specialized codegen function for `Class#superclass`. (#10613)Kevin Menard
Add a specialized codegen function for `Class#superclass`. Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> Co-authored-by: Takashi Kokubun (k0kubun) <takashikkbn@gmail.com> Co-authored-by: Randy Stauner <randy.stauner@shopify.com> Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>
2024-04-19Revert "YJIT: Optimize local variables when EP == BP" (#10584)Alan Wu
This reverts commit 4cc58ea0b865f2fd20f1e881ddbd4c4fab0b072c. Since the change landed call-threshold=1 CI runs have been timing out. There has also been `verify-ctx` violations. Revert for now while we debug.
2024-04-18chore: remove repetitive words (#10573)careworry
Signed-off-by: careworry <worrycare@outlook.com>
2024-04-18YJIT: Fix canary crash with Array#<< (#10568)Alan Wu
Previously, we got "We are killing the stack canary set by opt_ltlt" from `$./miniruby --yjit-call-threshold=1 -e 'a = [].freeze; a << 1'` Found by running ruby-spec with yjit-call-threshold=1.
2024-04-17YJIT: Optimize local variables when EP == BP (#10487)Takashi Kokubun
2024-04-16YJIT: End send fallback blocks (#10539)Takashi Kokubun
2024-04-11YJIT: x64: Remove register shuffle with `opt_and` and friends (#10498)Alan Wu
This is best understood by looking at the change to the output: ```diff # Insn: 0002 opt_and (stack_size: 2) - mov rax, rsi - and rax, rdi - mov rsi, rax + and rsi, rdi ``` It's a bit awkward to match against due to how stack operands are lowered, but hey, it's nice to save the 2 unnecessary MOVs.
2024-04-03YJIT: Let sp_opnd take the number of slots (#10442)Takashi Kokubun
2024-03-28YJIT: Optimize putobject+opt_ltlt for integersAlan Wu
In `jit_rb_int_lshift()`, we guard against the right hand side changing since we want to avoid generating variable length shifts. When control reaches a `putobject` and `opt_ltlt` pair, though, we know that the right hand side never changes. This commit detects this situation and substitutes an implementation that does not guard against the right hand side changing, saving that work. Deleted some `putobject` Rust tests since they aren't that valuable and cause linking issues. Nice boost to `optcarrot` and `protoboeuf`: ``` ---------- ------------------ bench yjit-pre/yjit-post optcarrot 1.09 protoboeuf 1.12 ---------- ------------------ ```
2024-03-25YJIT: Inline simple getlocal+leave iseqsAlan Wu
This mainly targets things like `T.unsafe()` from Sorbet, which is just an identity function at runtime and only a hint for the static checker. Only deal with simple caller and callees (no keywords and splat etc.). Co-authored-by: Takashi Kokubun (k0kubun) <takashikkbn@gmail.com>
2024-03-25YJIT: Propagate Array, Hash, and String classes (#10323)Takashi Kokubun
2024-03-20YJIT: Get rid of Type::TProc (#10287)Takashi Kokubun
2024-03-19Implement chilled stringsÉtienne Barrié
[Feature #20205] As a path toward enabling frozen string literals by default in the future, this commit introduce "chilled strings". From a user perspective chilled strings pretend to be frozen, but on the first attempt to mutate them, they lose their frozen status and emit a warning rather than to raise a `FrozenError`. Implementation wise, `rb_compile_option_struct.frozen_string_literal` is no longer a boolean but a tri-state of `enabled/disabled/unset`. When code is compiled with frozen string literals neither explictly enabled or disabled, string literals are compiled with a new `putchilledstring` instruction. This instruction is identical to `putstring` except it marks the String with the `STR_CHILLED (FL_USER3)` and `FL_FREEZE` flags. Chilled strings have the `FL_FREEZE` flag as to minimize the need to check for chilled strings across the codebase, and to improve compatibility with C extensions. Notes: - `String#freeze`: clears the chilled flag. - `String#-@`: acts as if the string was mutable. - `String#+@`: acts as if the string was mutable. - `String#clone`: copies the chilled flag. Co-authored-by: Jean Boussier <byroot@ruby-lang.org>
2024-03-18YJIT: Support arity=-2 cfuncs (#10268)Alan Wu
This type of cfuncs shows up as consume a lot of cycles in profiles of the lobsters benchmark, even though in the stats they don't happen that frequently. Might be a bug in the profiling, but these calls are not too bad to support, so might as well do it. Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
2024-03-13YJIT: Fallback cfunc varg splat for ruby2_keywords (#10226)Takashi Kokubun
2024-03-06YJIT: String#getbyte codegen (#10188)Maxime Chevalier-Boisvert
* WIP getbyte implementation * WIP String#getbyte implementation * Fix whitespace in stats.rs * fix? * Fix whitespace, add comment --------- Co-authored-by: Aaron Patterson <aaron.patterson@shopify.com>
2024-03-05[DOC] fix some commentscui fliter
Signed-off-by: cui fliter <imcusg@gmail.com>
2024-03-01Correctly set anon_kwrest flag for def f(b: 1, **)Jeremy Evans
In cases where a method accepts both keywords and an anonymous keyword splat, the method was not marked as taking an anonymous keyword splat. Fix that in the compiler. Doing that broke handling of nil keyword splats in yjit, so update yjit to handle that. Add a test to check that calling a method that accepts both a keyword argument and an anonymous keyword splat does not modify a passed keyword splat hash. Move the anon_kwrest check from setup_parameters_complex to ignore_keyword_hash_p, and only use it if the keyword hash is already a hash. This should speed things up slightly as it avoids a check previously used for all callers of setup_parameters_complex. Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>
2024-03-01YJIT: No need to set cfp->sp when setting escaped localsAlan Wu
While writing to the env object can add it to the remember set, it shouldn't trigger a GC run.
2024-02-29YJIT: Support inlining putself (#10137)Takashi Kokubun
2024-02-28YJIT: Squash canary before falling backAlan Wu
Recent flaky canary-related CI failures have all happened while trying to fall back. It's unclear what is leaving the canary on the stack and causing gen_send_dynamic() to falsely assume that it should be leaf, and this patch isn't going to help us find the source. One source I found is Array#<< with a frozen array, but it's unclear if that's what's causing the CI failures. I'm somewhat afraid to add a canary check to rb_longjmp() since that might introduce more flaky failures, and maybe ones unrelated to YJIT. See: https://github.com/ruby/ruby/actions/runs/8083502532/job/22086714152 See: https://github.com/ruby/ruby/actions/runs/8066858522/job/22035963315
2024-02-28YJIT: Reject keywords hash in -1 arity cfunc splat supportAlan Wu
`test_keyword.rb` caught this issue. Just need to run with `threshold=1`
2024-02-27YJIT: Support splat with C methods with -1 arityAlan Wu
Usually we deal with splats by speculating that they're of a specific size. In this case, the C method takes a pointer and a length, so we can support changing sizes just fine.
2024-02-23[DOC] Fix a typoTakashi Kokubun
2024-02-23YJIT: Lazily push a frame for specialized C funcs (#10080)Takashi Kokubun
* YJIT: Lazily push a frame for specialized C funcs Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> * Fix a comment on pc_to_cfunc * Rename rb_yjit_check_pc to rb_yjit_lazy_push_frame * Rename it to jit_prepare_lazy_frame_call * Fix a typo * Optimize String#getbyte as well * Optimize String#byteslice as well --------- Co-authored-by: Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com>
2024-02-22YJIT: Optimize attr_writer (#9986)Takashi Kokubun
* YJIT: Optimize attr_writer * Comment about StackOpnd vs SelfOpnd
2024-02-21YJIT: Grab stack operands after SP change in String#byteslice (#10060)Alan Wu
Previously, `StackOperand`s caching `sp_offset` was held across a jit_prepare_call_with_gc(), which invalidates the offsets. With the right register allocation state, the canary overlapped with the old address of the receiver and YJIT clobbered the receiver writing the canary.
2024-02-21YJIT: Allow non-leaf calls on opt_* insns (#10033)Takashi Kokubun
* YJIT: Allow non-leaf calls on opt_* insns * s/on_send_insn/is_sendish/ * Repeat known_cfunc_codegen
2024-02-20YJIT: rb_str_concat_literals is not leaf (#10035)Takashi Kokubun
2024-02-20YJIT: Fix calling leaf builtins with empty splat and kw_splatAlan Wu
These don't pass anything and just need to be popped off the stack. https://github.com/ruby/ruby/actions/runs/7977363890/job/21780095289#step:13:104
2024-02-20YJIT: Verify the assumption of leaf C calls (#10002)Takashi Kokubun
2024-02-20YJIT: Support `**nil` for cfuncsAlan Wu
Similar to the iseq call support. Fairly straight forward.
2024-02-16YJIT: Support empty splatAlan Wu
Previously we rejected empty splat calls to methods with no parameters as `iseq_arity_error` which didn't work well with delegated calls.
2024-02-16YJIT: Support `**nil`Alan Wu
This adds YJIT support for VM_CALL_KW_SPLAT with nil, specifically for when we already know from the context that it's done with a nil. This is enough to support forwarding with `...` when there no keyword arguments are present. Amend the kw_rest support to propagate the type of the parameter to help with this. Test interactions with splat, since the splat array sits lower on the stack when a kw_splat argument is present.
2024-02-15Pop the operand at the endTakashi Kokubun
2024-02-15Update a comment on spill_temps()Takashi Kokubun