towupper/towlower: fast path for ascii chars

Make a fast path for ascii chars which is assumed to be the most common
case. This has significant performance benefit on xml json and similar

diff --git a/src/ctype/towctrans.c b/src/ctype/towctrans.c
index 6af618758bcb853096fa74b8a54d820cd1626ec2..cf13a862821c70a01952962e22e3c033701d1895 100644 (file)
--- a/src/ctype/towctrans.c
+++ b/src/ctype/towctrans.c
@@ -1,3 +1,4 @@
+#include <ctype.h>
 #include <wctype.h>
 #include "libc.h"
 
@@ -9,7 +10,6 @@ static const struct {
        signed char lower;
        unsigned char len;
 } casemaps[] = {
-       CASEMAP('A','Z','a'),
        CASEMAP(0xc0,0xde,0xe0),
 
        CASELACE(0x0100,0x012e),
@@ -257,12 +257,12 @@ static wchar_t __towcase(wchar_t wc, int lower)
 
 wint_t towupper(wint_t wc)
 {
-       return __towcase(wc, 0);
+       return (unsigned)wc < 128 ? toupper(wc) : __towcase(wc, 0);
 }
 
 wint_t towlower(wint_t wc)
 {
-       return __towcase(wc, 1);
+       return (unsigned)wc < 128 ? tolower(wc) : __towcase(wc, 1);
 }
 
 wint_t __towupper_l(wint_t c, locale_t l)