Base iDef update code.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 4f8af2b0c041f429b1992213a8f4d7571dd5bea4..b1e3a943537f3602f83b188e9b08921a63fecc0f 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -364,6 +364,54 @@ HType HType::TypeFromValue(Handle<Object> value) {
 }
 
 
+bool HValue::CheckDominanceFollowingDefinitionList(
+    HValue* dominator, HValue* dominated) {
+  if (dominator->block() != dominated->block()) {
+    // If they are in different blocks we can use the dominance relation
+    // between the blocks.
+    return dominator->block()->Dominates(dominated->block());
+  } else {
+    // Otherwise we must see which instruction comes first, considering
+    // that phis always precede regular instructions.
+    if (dominator->IsInstruction()) {
+      if (dominated->IsInstruction()) {
+        HInstruction* next = HInstruction::cast(dominator)->next();
+        while (next != NULL) {

[Jakob Kummerow, 2013/01/31 14:06:43]

I don't like endless loops very much.

[Massi, 2013/01/31 17:16:19]

Done (and it was actually an embarrassing bug...).

+          if (next == dominated) return true;
+        }
+        return false;
+      } else if (dominated->IsPhi()) {
+        return false;
+      } else {
+        UNREACHABLE();
+      }
+    } else if (dominator->IsPhi()) {
+      if (dominated->IsInstruction()) {
+        return true;
+      } else {
+        // We cannot compare which phi comes first.
+        UNREACHABLE();
+      }
+    } else {
+      UNREACHABLE();
+    }
+    return false;
+  }
+}
+
+
+bool HValue::CheckDominanceUsingProcessedFlag(
+    HValue* dominator, HValue* dominated) {
+  if (dominator->block() != dominated->block()) {
+    return dominator->block()->Dominates(dominated->block());
+  } else {
+    // If "dominated" is in the same block as the definition we check if is
+    // has already been processed or if it is a phi: if not it is dominated.
+    return dominated->CheckFlag(kIDefsProcessingDone) || dominated->IsPhi();

[Jakob Kummerow, 2013/01/31 14:06:43]

I think this condition is the wrong way round: it's dominated if it has *not*
been visited yet and is *not* a Phi.

[Massi, 2013/01/31 17:16:19]

Done.

+  }
+}
+
+
 bool HValue::IsDefinedAfter(HBasicBlock* other) const {
   return block()->block_id() > other->block_id();
 }