1berry/ruby
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

MJIT: Refactor BitField dereference byte and bitmask (#6955)

Browse Source 
Prefer Array#unpack1 and Enumerable#sum.
I think the bitmask formula ``2 ** @width - 1`` would be clearer, but not faster for such small integers.
This commit is contained in:
Mau Magnaguagno 2022-12-17 18:06:50 -03:00 committed by GitHub
parent 6e3bc67103
commit 632beec01f
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
Notes: git 2022-12-17 21:07:09 +00:00 
Merged-By: k0kubun <takashikkbn@gmail.com>
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
lib/mjit/c_pointer.rb
View File

@ -282,12 +282,12 @@ module RubyVM::MJIT
# Dereference # Dereference
def * def *
byte = Fiddle::Pointer.new(@addr)[0, Fiddle::SIZEOF_CHAR].unpack('c').first byte = Fiddle::Pointer.new(@addr)[0, Fiddle::SIZEOF_CHAR].unpack1('c')
if @width == 1 if @width == 1
bit = (1 & (byte >> @offset)) bit = (1 & (byte >> @offset))
bit == 1 bit == 1
elsif @width <= 8 && @offset == 0 elsif @width <= 8 && @offset == 0
bitmask = @width.times.map { |i| 1 << i }.sum bitmask = @width.times.sum { |i| 1 << i }
byte & bitmask byte & bitmask
else else
raise NotImplementedError.new("not-implemented bit field access: width=#{@width} offset=#{@offset}") raise NotImplementedError.new("not-implemented bit field access: width=#{@width} offset=#{@offset}")