src/share/vm/opto/ifnode.cpp

rev 7756 : 8071996: split_if accesses NULL region of ConstraintCast
Reviewed-by: kvn

*** 143,156 ****
      // Make sure we can account for all Phi uses
      for (DUIterator_Fast kmax, k = u->fast_outs(kmax); k < kmax; k++) {
        Node* v = u->fast_out(k); // User of the phi
        // CNC - Allow only really simple patterns.
        // In particular I disallow AddP of the Phi, a fairly common pattern
!       if( v == cmp ) continue;  // The compare is OK
!       if( (v->is_ConstraintCast()) &&
!           v->in(0)->in(0) == iff )
          continue;               // CastPP/II of the IfNode is OK
        // Disabled following code because I cannot tell if exactly one
        // path dominates without a real dominator check. CNC 9/9/1999
        //uint vop = v->Opcode();
        //if( vop == Op_Phi ) {     // Phi from another merge point might be OK
        //  Node *r = v->in(0);     // Get controlling point
--- 143,164 ----
      // Make sure we can account for all Phi uses
      for (DUIterator_Fast kmax, k = u->fast_outs(kmax); k < kmax; k++) {
        Node* v = u->fast_out(k); // User of the phi
        // CNC - Allow only really simple patterns.
        // In particular I disallow AddP of the Phi, a fairly common pattern
!       if (v == cmp) continue;  // The compare is OK
!       if (v->is_ConstraintCast()) {
!         // If the cast is derived from data flow edges, it may not have a control.
!         // If so, it should be save to split. But follow-up code can not deal with
!         // this (l. 359). So skip.
!         if (v->in(0) == NULL) {
!           return NULL;
!         }
!         if (v->in(0)->in(0) == iff) {
            continue;               // CastPP/II of the IfNode is OK
+         }
+       }
        // Disabled following code because I cannot tell if exactly one
        // path dominates without a real dominator check. CNC 9/9/1999
        //uint vop = v->Opcode();
        //if( vop == Op_Phi ) {     // Phi from another merge point might be OK
        //  Node *r = v->in(0);     // Get controlling point