From 632beec01f6a293aa03da06f5f0e6f9a7c22a8c5 Mon Sep 17 00:00:00 2001
From: Mau Magnaguagno <maumagnaguagno@gmail.com>
Date: Sat, 17 Dec 2022 18:06:50 -0300
Subject: [PATCH] MJIT: Refactor BitField dereference byte and bitmask (#6955)

Prefer Array#unpack1 and Enumerable#sum.
I think the bitmask formula ``2 ** @width - 1`` would be clearer, but not faster for such small integers.
---
 lib/mjit/c_pointer.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/mjit/c_pointer.rb b/lib/mjit/c_pointer.rb
index aadf80e804..ee0be54a3c 100644
--- a/lib/mjit/c_pointer.rb
+++ b/lib/mjit/c_pointer.rb
@@ -282,12 +282,12 @@ module RubyVM::MJIT
 
       # Dereference
       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
           bit = (1 & (byte >> @offset))
           bit == 1
         elsif @width <= 8 && @offset == 0
-          bitmask = @width.times.map { |i| 1 << i }.sum
+          bitmask = @width.times.sum { |i| 1 << i }
           byte & bitmask
         else
           raise NotImplementedError.new("not-implemented bit field access: width=#{@width} offset=#{@offset}")