nano

commit 035b91cb15a2adc1606d9a3f573fe6175e0161f1
parent f456794045ef35efb44aca80819bacd413aab7b6
Author: Benno Schulenberg <bensberg@telfort.nl>
Date:   Sun,  8 Jul 2018 20:11:32 +0200

chars: make the UTF-8 case ever so slightly faster by eliding an 'if'

And in the bargain get rid of some duplicate code.

This makes a binary without UTF-8 support slightly slower, but that's
not important -- it is more than fast enough anyway.  Important is that
the most used and longest code path, the UTF-8 case, becomes faster.

Note that 'is_cntrl_mbchar()' will fall back to 'is_cntrl_char()' for
a non-UTF-8 build, so the deleted piece of code really was equivalent
with the remaining piece for that case.

Diffstat:
M
src/chars.c
 | 
30
++++--------------------------

1 file changed, 4 insertions(+), 26 deletions(-)
diff --git a/src/chars.c b/src/chars.c
@@ -292,10 +292,9 @@ char *make_mbchar(long chr, int *chr_mb_len)
  * col isn't NULL, add the character's width (in columns) to it. */
 int parse_mbchar(const char *buf, char *chr, size_t *col)
 {
-#ifdef ENABLE_UTF8
-	if (use_utf8) {
 		int length;
 
+#ifdef ENABLE_UTF8
 		/* If this is a UTF-8 starter byte, get the number of bytes of the character. */
 		if ((signed char)*buf < 0) {
 			length = mblen(buf, MAXCHARLEN);
@@ -304,6 +303,7 @@ int parse_mbchar(const char *buf, char *chr, size_t *col)
 			if (length <= 0)
 				length = 1;
 		} else
+#endif
 			length = 1;
 
 		/* When requested, store the multibyte character in chr. */
@@ -327,35 +327,13 @@ int parse_mbchar(const char *buf, char *chr, size_t *col)
 			/* If we have a normal character, get its width normally. */
 			} else if (length == 1)
 				*col += 1;
+#ifdef ENABLE_UTF8
 			else
 				*col += mbwidth(buf);
-		}
-
-		return length;
-	} else
 #endif
-	{
-		/* When requested, store the byte character in chr. */
-		if (chr != NULL)
-			*chr = *buf;
-
-		/* When requested, add the width of the character to col. */
-		if (col != NULL) {
-			/* If we have a tab, compute its width in columns using the
-			 * current value of col. */
-			if (*buf == '\t')
-				*col += tabsize - *col % tabsize;
-			/* If we have a control character, it's two columns wide: one
-			 * column for the "^", and one for the visible character. */
-			else if (is_cntrl_char((unsigned char)*buf))
-				*col += 2;
-			/* If we have a normal character, it's one column wide. */
-			else
-				(*col)++;
 		}
 
-		return 1;
-	}
+		return length;
 }
 
 /* Return the index in buf of the beginning of the multibyte character