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

HTMLtree.c

@@ -663,7 +663,7 @@ htmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int *size) {
     htmlDocContentDump(buf, cur);
     *mem = buf->content;
     *size = buf->use;
-    memset(buf, -1, sizeof(xmlBuffer));
+    MEM_CLEANUP(buf, sizeof(xmlBuffer));
     xmlFree(buf);
 }