mirror of
https://github.com/ruby/ruby.git
synced 2022-11-09 12:17:21 -05:00
d594a5a8bd
Object Shapes is used for accessing instance variables and representing the
"frozenness" of objects. Object instances have a "shape" and the shape
represents some attributes of the object (currently which instance variables are
set and the "frozenness"). Shapes form a tree data structure, and when a new
instance variable is set on an object, that object "transitions" to a new shape
in the shape tree. Each shape has an ID that is used for caching. The shape
structure is independent of class, so objects of different types can have the
same shape.
For example:
```ruby
class Foo
def initialize
# Starts with shape id 0
@a = 1 # transitions to shape id 1
@b = 1 # transitions to shape id 2
end
end
class Bar
def initialize
# Starts with shape id 0
@a = 1 # transitions to shape id 1
@b = 1 # transitions to shape id 2
end
end
foo = Foo.new # `foo` has shape id 2
bar = Bar.new # `bar` has shape id 2
```
Both `foo` and `bar` instances have the same shape because they both set
instance variables of the same name in the same order.
This technique can help to improve inline cache hits as well as generate more
efficient machine code in JIT compilers.
This commit also adds some methods for debugging shapes on objects. See
`RubyVM::Shape` for more details.
For more context on Object Shapes, see [Feature: #18776]
Co-Authored-By: Aaron Patterson <tenderlove@ruby-lang.org>
Co-Authored-By: Eileen M. Uchitelle <eileencodes@gmail.com>
Co-Authored-By: John Hawthorn <john@hawthorn.email>
58 lines
2.6 KiB
C
58 lines
2.6 KiB
C
// This file is parsed by tool/mjit/generate.rb for MJIT's C/Ruby interop.
|
|
#ifndef MJIT_COMPILER_H
|
|
#define MJIT_COMPILER_H
|
|
|
|
#include "ruby/internal/config.h"
|
|
#include "vm_core.h"
|
|
#include "vm_callinfo.h"
|
|
#include "builtin.h"
|
|
#include "mjit.h"
|
|
#include "mjit_unit.h"
|
|
#include "shape.h"
|
|
|
|
// Macros to check if a position is already compiled using compile_status.stack_size_for_pos
|
|
#define NOT_COMPILED_STACK_SIZE -1
|
|
#define ALREADY_COMPILED_P(status, pos) (status->stack_size_for_pos[pos] != NOT_COMPILED_STACK_SIZE)
|
|
|
|
// Storage to keep data which is consistent in each conditional branch.
|
|
// This is created and used for one `compile_insns` call and its values
|
|
// should be copied for extra `compile_insns` call.
|
|
struct compile_branch {
|
|
unsigned int stack_size; // this simulates sp (stack pointer) of YARV
|
|
bool finish_p; // if true, compilation in this branch should stop and let another branch to be compiled
|
|
};
|
|
|
|
// For propagating information needed for lazily pushing a frame.
|
|
struct inlined_call_context {
|
|
int orig_argc; // ci->orig_argc
|
|
VALUE me; // vm_cc_cme(cc)
|
|
int param_size; // def_iseq_ptr(vm_cc_cme(cc)->def)->body->param.size
|
|
int local_size; // def_iseq_ptr(vm_cc_cme(cc)->def)->body->local_table_size
|
|
};
|
|
|
|
// Storage to keep compiler's status. This should have information
|
|
// which is global during one `mjit_compile` call. Ones conditional
|
|
// in each branch should be stored in `compile_branch`.
|
|
struct compile_status {
|
|
bool success; // has true if compilation has had no issue
|
|
int *stack_size_for_pos; // stack_size_for_pos[pos] has stack size for the position (otherwise -1)
|
|
// If true, JIT-ed code will use local variables to store pushed values instead of
|
|
// using VM's stack and moving stack pointer.
|
|
bool local_stack_p;
|
|
// Safely-accessible ivar cache entries copied from main thread.
|
|
union iseq_inline_storage_entry *is_entries;
|
|
// Index of call cache entries captured to compiled_iseq to be marked on GC
|
|
int cc_entries_index;
|
|
// A pointer to root (i.e. not inlined) iseq being compiled.
|
|
const struct rb_iseq_constant_body *compiled_iseq;
|
|
int compiled_id; // Just a copy of compiled_iseq->jit_unit->id
|
|
// Mutated optimization levels
|
|
struct rb_mjit_compile_info *compile_info;
|
|
bool merge_ivar_guards_p; // If true, merge guards of ivar accesses
|
|
size_t max_ivar_index; // Max IVC index in is_entries (used only when merge_ivar_guards_p)
|
|
// If `inlined_iseqs[pos]` is not NULL, `mjit_compile_body` tries to inline ISeq there.
|
|
const struct rb_iseq_constant_body **inlined_iseqs;
|
|
struct inlined_call_context inline_context;
|
|
};
|
|
|
|
#endif /* MJIT_COMPILER_H */
|