Fix bug in assigning the positions of safepoints.

runtime/vm/flow_graph_allocator.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_allocator.h"
 
 #include "vm/bit_vector.h"
 #include "vm/intermediate_language.h"
 #include "vm/il_printer.h"
 #include "vm/flow_graph.h"
@@ skipping 37 matching lines @@
 static bool IsInstructionEndPosition(intptr_t pos) {
   return (pos & 1) == 1;
 }
 
 
 static intptr_t ToInstructionStart(intptr_t pos) {
   return (pos & ~1);
 }
 
 
+static intptr_t ToInstructionEnd(intptr_t pos) {
+  return (pos | 1);
+}
+
+
 FlowGraphAllocator::FlowGraphAllocator(const FlowGraph& flow_graph)
   : flow_graph_(flow_graph),
     block_order_(flow_graph.reverse_postorder()),
     postorder_(flow_graph.postorder()),
     live_out_(block_order_.length()),
     kill_(block_order_.length()),
     live_in_(block_order_.length()),
     vreg_count_(flow_graph.max_virtual_register_number()),
     live_ranges_(flow_graph.max_virtual_register_number()),
     cpu_regs_(),
@@ skipping 229 matching lines @@
   if ((uses_ != NULL) &&
       (uses_->pos() == pos) &&
       (uses_->location_slot() == location_slot)) {
     return;
   }
   uses_ = new UsePosition(pos, uses_, location_slot);
 }
 
 
 void LiveRange::AddSafepoint(intptr_t pos, LocationSummary* locs) {
-  SafepointPosition* safepoint = new SafepointPosition(pos, locs);
+  ASSERT(IsInstructionStartPosition(pos));
+  SafepointPosition* safepoint =
+      new SafepointPosition(ToInstructionEnd(pos), locs);
 
   if (first_safepoint_ == NULL) {
     ASSERT(last_safepoint_ == NULL);
     first_safepoint_ = last_safepoint_ = safepoint;
   } else {
     ASSERT(last_safepoint_ != NULL);
     // We assume that safepoints list is sorted by position and that
     // safepoints are added in this order.
     ASSERT(last_safepoint_->pos() < pos);
     last_safepoint_->set_next(safepoint);
@@ skipping 1876 matching lines @@
     OS::Print("-- [after ssa allocator] ir [%s] -------------\n",
               function.ToFullyQualifiedCString());
     FlowGraphPrinter printer(flow_graph_, true);
     printer.PrintBlocks();
     OS::Print("----------------------------------------------\n");
   }
 }
 
 
 }  // namespace dart