1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
ruby--ruby/tool/ruby_vm/models/attribute.rb
Alan Wu 89e7997622 Combine call info and cache to speed up method invocation
To perform a regular method call, the VM needs two structs,
`rb_call_info` and `rb_call_cache`. At the moment, we allocate these two
structures in separate buffers. In the worst case, the CPU needs to read
4 cache lines to complete a method call. Putting the two structures
together reduces the maximum number of cache line reads to 2.

Combining the structures also saves 8 bytes per call site as the current
layout uses separate two pointers for the call info and the call cache.
This saves about 2 MiB on Discourse.

This change improves the Optcarrot benchmark at least 3%. For more
details, see attached bugs.ruby-lang.org ticket.

Complications:
 - A new instruction attribute `comptime_sp_inc` is introduced to
 calculate SP increase at compile time without using call caches. At
 compile time, a `TS_CALLDATA` operand points to a call info struct, but
 at runtime, the same operand points to a call data struct. Instruction
 that explicitly define `sp_inc` also need to define `comptime_sp_inc`.
 - MJIT code for copying call cache becomes slightly more complicated.
 - This changes the bytecode format, which might break existing tools.

[Misc #16258]
2019-10-24 18:03:42 +09:00

59 lines
1.5 KiB
Ruby

#! /your/favourite/path/to/ruby
# -*- Ruby -*-
# -*- frozen_string_literal: true; -*-
# -*- warn_indent: true; -*-
#
# Copyright (c) 2017 Urabe, Shyouhei. All rights reserved.
#
# This file is a part of the programming language Ruby. Permission is hereby
# granted, to either redistribute and/or modify this file, provided that the
# conditions mentioned in the file COPYING are met. Consult the file for
# details.
require_relative 'c_expr'
class RubyVM::Attribute
include RubyVM::CEscape
attr_reader :insn, :key, :type, :expr
def initialize opts = {}
@insn = opts[:insn]
@key = opts[:name]
@expr = RubyVM::CExpr.new location: opts[:location], expr: opts[:expr]
@type = opts[:type]
@ope_decls = @insn.opes.map do |operand|
decl = operand[:decl]
if @key == 'comptime_sp_inc' && operand[:type] == 'CALL_DATA'
decl = decl.gsub('CALL_DATA', 'CALL_INFO').gsub('cd', 'ci')
end
decl
end
end
def name
as_tr_cpp "attr #{@key} @ #{@insn.name}"
end
def pretty_name
"attr #{type} #{key} @ #{insn.pretty_name}"
end
def declaration
if @ope_decls.empty?
argv = "void"
else
argv = @ope_decls.join(', ')
end
sprintf '%s %s(%s)', @type, name, argv
end
def definition
if @ope_decls.empty?
argv = "void"
else
argv = @ope_decls.map {|decl| "MAYBE_UNUSED(#{decl})" }.join(",\n ")
argv = "\n #{argv}\n" if @ope_decls.size > 1
end
sprintf "%s\n%s(%s)", @type, name, argv
end
end