patch 9.2.0310: unnecessary work in vim_strchr() and find_term_bykeys()

mattn · chrisbra · commit f9981bbc8e4b · 2026-04-06T13:12:39.000Z
problem:  unnecessary work in vim_strchr() and find_term_bykeys()
Solution: Redirect vim_strchr() to vim_strbyte() for ASCII input
          Add an early exit to find_term_bykeys() using the terminal
          leader table, mirroring check_termcode(). Reduces instruction
          count on startup by about 27%. (Yasuhiro Matsumoto)

closes: #19902

Signed-off-by: Yasuhiro Matsumoto &lt;mattn.jp@gmail.com&gt;
Signed-off-by: Christian Brabandt &lt;cb@256bit.org&gt;
diff --git a/src/strings.c b/src/strings.c
@@ -626,6 +626,8 @@ vim_strchr(char_u *string, int c)
     int		b;
 
     p = string;
+    if (enc_utf8 && c > 0 && c < 0x80)
+	return vim_strbyte(string, c);
     if (enc_utf8 && c >= 0x80)
     {
 	while (*p != NUL)
diff --git a/src/term.c b/src/term.c
@@ -7209,6 +7209,13 @@ find_term_bykeys(char_u *src, int *matchlen)
     int         slen, modslen;
     int         thislen;
 
+    // Most input bytes cannot start a terminal code.  Reuse the same leader
+    // table as check_termcode() to avoid scanning termcodes[] unnecessarily.
+    if (need_gather)
+	gather_termleader();
+    if (*src == NUL || vim_strchr(termleader, *src) == NULL)
+	return -1;
+
     // find longest match
     // borrows part of check_termcode
     for (i = 0; i < tc_len; ++i)
diff --git a/src/version.c b/src/version.c
@@ -734,6 +734,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    310,
 /**/
     309,
 /**/

Original file line number	Diff line number	Diff line change
`@@ -626,6 +626,8 @@ vim_strchr(char_u *string, int c)`
`626`	`626`	`int b;`
`627`	`627`
`628`	`628`	`p = string;`
	`629`	`+ if (enc_utf8 && c > 0 && c < 0x80)`
	`630`	`+ return vim_strbyte(string, c);`
`629`	`631`	`if (enc_utf8 && c >= 0x80)`
`630`	`632`	`{`
`631`	`633`	`while (*p != NUL)`