From: Kim Nguyễn <kn@lri.fr>
Date: Fri, 20 Apr 2012 14:01:53 +0000 (+0200)
Subject: Favor {first,next}_element calls instead of select_{descendant,following_below},
X-Git-Url: http://git.nguyen.vg/gitweb/?p=SXSI%2Fxpathcomp.git;a=commitdiff_plain;h=48ae36d48bba10ab1bcb8ddcb798b936095a2804

Favor {first,next}_element calls instead of select_{descendant,following_below},
when the set of target tags is large (esp. it contains everything but attributes).
---

diff --git a/src/l2JIT.ml b/src/l2JIT.ml
index c15d236..efe7854 100644
--- a/src/l2JIT.ml
+++ b/src/l2JIT.ml
@@ -146,6 +146,12 @@ let has_text l = Ptset.Int.mem Tag.pcdata l
 
 let rec translate_jump tree tag (jkind:Ata.jump_kind) dir s =
   let child, desc, sib, fol = Tree.tags tree tag in
+  let not_elements =
+    Ptset.Int.add Tag.pcdata
+      (Ptset.Int.add Tag.attribute
+         (Ptset.Int.add Tag.attribute_data
+            (Tree.attribute_tags tree)))
+  in
   match jkind, dir with
   | NIL, _ -> _nop
   | NODE, DIR_LEFT -> FIRST_CHILD s
@@ -179,9 +185,21 @@ let rec translate_jump tree tag (jkind:Ata.jump_kind) dir s =
     let labels = Ptset.Int.inter l_many t in
     let c = Ptset.Int.cardinal labels in
     if c == 0 then _nop
-    else if c == 1 then tagged_many s (Ptset.Int.choose labels)
-    else if c > 5 then if has_text labels then any s else any_notext s
-    else select_many s labels
+    else
+      let not_t = Ptset.Int.diff l_many labels in
+      let () =
+        LOG(__ "level2-jit" 3 "Would jump for tag %s to labels %a, not relevant tags: %a"
+              (Tag.to_string tag)
+              TagSet.print (TagSet.inj_positive labels)
+              TagSet.print (TagSet.inj_positive not_t))
+      in
+      if Ptset.Int.subset not_t not_elements then
+        if has_text labels then any s else any_notext s
+      else if c == 1 then tagged_many s (Ptset.Int.choose labels)
+      else
+        if c >= 5 then
+          if has_text labels then any s else any_notext s
+        else select_many s labels
 
   | CAPTURE_MANY (t), DIR_LEFT ->
     if Ptset.Int.is_singleton t then TAGGED_SUBTREE(s, Ptset.Int.choose t)