Optimised strlen

libsrc/common/strlen.s

@@ -5,17 +5,27 @@
 ; the usage of only ptr2 here! Keep in mind when appling changes
 ; and check the other implementations too!
 ;
-; int strlen (const char* s);
+; size_t __fastcall__ strlen (const char* s);
 ;
 
         .export         _strlen
         .importzp       ptr2
+        .macpack        cpu
 
 _strlen:
         sta     ptr2            ; Save s
         stx     ptr2+1
+.if (.cpu .bitand ::CPU_ISET_HUC6280)
+        clx
+        cly
+.else
         ldx     #0              ; YX used as counter
+.if (.cpu .bitand ::CPU_ISET_65816)
+        txy
+.else
         ldy     #0
+.endif
+.endif
 
 L1:     lda     (ptr2),y
         beq     L9