Okay time to improve performances, gprof session:

before  real 0m2.483s (2.3.2 release yesterday)
current real 0m1.763s
when parsing (with tree build/freeing) db10000.xml from XSLTMark:
- xmlmemory.h HTMLparser.c HTMLtree.c entities.c parser.c
  xpath.c xpointer.c tree.c uri.c valid.c xinclude.c xmlIO.c:
  avoiding memcpy in production builds MEM_CLEANUP macro use
- parser.[ch] parserInternals.c: optimizations of the tightest
  internal loops inside the parser. Better checking of I/O
  flushing/loading conditions
- xmllint.c : added --timing
Daniel

HTMLparser.c

@@ -1651,7 +1651,7 @@ htmlFreeInputStream(htmlParserInputPtr input) {
         input->free((xmlChar *) input->base);
     if (input->buf != NULL) 
         xmlFreeParserInputBuffer(input->buf);
-    memset(input, -1, sizeof(htmlParserInput));
+    MEM_CLEANUP(input, sizeof(htmlParserInput));
     xmlFree(input);
 }