Put live register bits in stackmaps.

runtime/vm/flow_graph_compiler.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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
@@ skipping 219 matching lines @@
                                        deopt_id,
                                        token_pos,
                                        try_index);
 }
 
 
 void FlowGraphCompiler::RecordSafepoint(LocationSummary* locs) {
   if (is_optimizing()) {
     BitmapBuilder* bitmap = locs->stack_bitmap();
     ASSERT(bitmap != NULL);
+    ASSERT(bitmap->Length() <= StackSize());
+    // Pad the bitmap out to describe all the spill slots.
     bitmap->SetLength(StackSize());
-    stackmap_table_builder_->AddEntry(assembler()->CodeSize(), bitmap);
+
+    // Slow path code can have registers at the safepoint.
+    if (!locs->always_calls()) {
+      for (intptr_t i = 0; i < kNumberOfCpuRegisters; ++i) {

[Vyacheslav Egorov (Google), 2012/08/27 14:54:51]

This is tightly couple with the way we push registers. Consider adding a comment
for that.

[Kevin Millikin (Google), 2012/08/29 12:40:41]

Done.

+        Register reg = static_cast<Register>(i);
+        if (locs->live_registers()->ContainsRegister(reg)) {
+          bitmap->Set(bitmap->Length(), true);
+        }
+      }

[Vyacheslav Egorov (Google), 2012/08/27 14:54:51]

Also please handle XMMRegisters here and remove a hack used for this currently.
This will be a good test.

+    }
+
+    intptr_t register_count = bitmap->Length() - StackSize();
+    stackmap_table_builder_->AddEntry(assembler()->CodeSize(),
+                                      bitmap,
+                                      register_count);
   }
 }
 
 
 Label* FlowGraphCompiler::AddDeoptStub(intptr_t deopt_id,
                                        intptr_t try_index,
                                        DeoptReasonId reason) {
   DeoptimizationStub* stub =
       new DeoptimizationStub(deopt_id, try_index, reason);
   ASSERT(is_optimizing_);
@@ skipping 486 matching lines @@
       return;
     }
   }
 
   // This move is not blocked.
   EmitMove(index);
 }
 
 
 }  // namespace dart