From: Richard M. Stallman <rms@gnu.org>
Date: Fri, 19 Jul 2013 16:15:51 +0000 (-0400)
Subject: (decode_coding_utf_8): Add simple loop for fast processing of ASCII characters.
X-Git-Tag: emacs-24.3.90~173^2^2~42^2~45^2~387^2~1759^2~3
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=a1aeeffedd3b05a33bdd73737651debbda00cf5f;p=emacs.git

(decode_coding_utf_8): Add simple loop for fast processing of ASCII characters.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index 3f67e37a107..975bcaaba0e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2013-07-19  Richard Stallman  <rms@gnu.org>
+
+	* coding.c (decode_coding_utf_8): Add simple loop for fast
+	processing of ASCII characters.
+
 2013-07-19  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* conf_post.h (RE_TRANSLATE_P) [emacs]: Remove obsolete optimization.
diff --git a/src/coding.c b/src/coding.c
index e779197bbde..385a22a188d 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -1363,6 +1363,45 @@ decode_coding_utf_8 (struct coding_system *coding)
 	  break;
 	}
 
+      /* In the simple case, rapidly handle ordinary characters */
+      if (multibytep && ! eol_dos
+	  && charbuf < charbuf_end - 6 && src < src_end - 6)
+	{
+	  while (charbuf < charbuf_end - 6 && src < src_end - 6)
+	    {
+	      c1 = *src;
+	      if (c1 & 0x80)
+		break;
+	      src++;
+	      consumed_chars++;
+	      *charbuf++ = c1;
+
+	      c1 = *src;
+	      if (c1 & 0x80)
+		break;
+	      src++;
+	      consumed_chars++;
+	      *charbuf++ = c1;
+
+	      c1 = *src;
+	      if (c1 & 0x80)
+		break;
+	      src++;
+	      consumed_chars++;
+	      *charbuf++ = c1;
+
+	      c1 = *src;
+	      if (c1 & 0x80)
+		break;
+	      src++;
+	      consumed_chars++;
+	      *charbuf++ = c1;
+	    }
+	  /* If we handled at least one character, restart the main loop.  */
+	  if (src != src_base)
+	    continue;
+	}
+
       if (byte_after_cr >= 0)
 	c1 = byte_after_cr, byte_after_cr = -1;
       else