scc

commit 86648da0334bde1671813c6906d74ce8508ead5d
parent 05daa1d657c80dba6a7a3ea38ef9d94ac8d718e8
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 26 Sep 2017 10:56:48 +0100

[as] Reduce the number of calls to casecmp()

In both cases the common case is to have a different first letter,
so this small optimize improves a lot the performance in both cases.

Diffstat:
M
as/main.c
 | 
9
++++++++-
M
as/symbol.c
 | 
4
++--

2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/as/main.c b/as/main.c
@@ -1,5 +1,6 @@
 static char sccsid[] = "@(#) ./as/main.c";
 
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -17,8 +18,14 @@ static int
 cmp(const void *f1, const void *f2)
 {
 	const Ins *ins = f2;
+	const char *s = f1;
+	int d;
 
-	return casecmp(f1, ins->str);
+	d = toupper(*ins->str) - toupper(*s);
+	if (d != 0)
+		return d;
+
+	return casecmp(s, ins->str);
 }
 
 static void
diff --git a/as/symbol.c b/as/symbol.c
@@ -56,11 +56,11 @@ lookup(char *name)
 		h = h*33 ^ c;
 	h &= HASHSIZ-1;
 
-	c = *name;
+	c = toupper(*name);
 	list = &hashtbl[h];
 	for (sym = *list; sym; sym = sym->next) {
 		t = sym->name;
-		if (c == *t && !casecmp(t, name))
+		if (c == toupper(*t) && !casecmp(t, name))
 			return sym;
 	}