From be0b5f8ceea320e4494bbb444b1c0bb708eba9c9 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Wed, 25 May 2022 11:22:28 +0900
Subject: [PATCH] mruby-string-ext/string.c: reduce UTF-8 table size.

---
 mrbgems/mruby-string-ext/src/string.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c
index 394583da9..4e154d2a8 100644
--- a/mrbgems/mruby-string-ext/src/string.c
+++ b/mrbgems/mruby-string-ext/src/string.c
@@ -989,16 +989,10 @@ mrb_str_succ(mrb_state *mrb, mrb_value self)
 }
 
 #ifdef MRB_UTF8_STRING
-static const char utf8len_codepage_zero[256] =
+static const char utf8len_table[] =
 {
-  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
-  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
-  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
-  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
-  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
-  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
-  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0,
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+  0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 3, 3, 4, 0
 };
 
 static mrb_int
@@ -1009,7 +1003,7 @@ utf8code(unsigned char* p, mrb_int limit)
   if (p[0] < 0x80)
     return p[0];
 
-  len = utf8len_codepage_zero[p[0]];
+  len = utf8len_table[p[0]>>3];
   if (len <= limit && len > 1 && (p[1] & 0xc0) == 0x80) {
     if (len == 2)
       return ((p[0] & 0x1f) << 6) + (p[1] & 0x3f);