hotspot/src/share/vm/opto/loopopts.cpp
changeset 208 40859a3e0db9
parent 1 489c9b5090e2
child 237 fba97e902303
--- a/hotspot/src/share/vm/opto/loopopts.cpp	Fri Feb 29 11:22:27 2008 -0800
+++ b/hotspot/src/share/vm/opto/loopopts.cpp	Fri Feb 29 19:07:15 2008 -0800
@@ -435,9 +435,11 @@
 
   // Check profitability
   int cost = 0;
+  int phis = 0;
   for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) {
     Node *out = region->fast_out(i);
     if( !out->is_Phi() ) continue; // Ignore other control edges, etc
+    phis++;
     PhiNode* phi = out->as_Phi();
     switch (phi->type()->basic_type()) {
     case T_LONG:
@@ -489,6 +491,12 @@
     }
   }
   if( cost >= ConditionalMoveLimit ) return NULL; // Too much goo
+  Node* bol = iff->in(1);
+  assert( bol->Opcode() == Op_Bool, "" );
+  int cmp_op = bol->in(1)->Opcode();
+  // It is expensive to generate flags from a float compare.
+  // Avoid duplicated float compare.
+  if( phis > 1 && (cmp_op == Op_CmpF || cmp_op == Op_CmpD)) return NULL;
 
   // --------------
   // Now replace all Phis with CMOV's