Emit stackmaps even in unoptimized code if slow path pushes untagged values.

runtime/vm/locations.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_LOCATIONS_H_
 #define VM_LOCATIONS_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/bitfield.h"
@@ skipping 441 matching lines @@
   SmallSet() : data_(0) { }
 
   explicit SmallSet(intptr_t data) : data_(data) { }
 
   bool Contains(T value) const { return (data_ & ToMask(value)) != 0; }
 
   void Add(T value) { data_ |= ToMask(value); }
 
   void Remove(T value) { data_ &= ~ToMask(value); }
 
+  bool IsEmpty() const { return data_ != 0; }
+
   intptr_t data() const { return data_; }
 
  private:
   static intptr_t ToMask(T value) {
     ASSERT(static_cast<intptr_t>(value) < (kWordSize * kBitsPerByte));
     return 1 << static_cast<intptr_t>(value);
   }
 
   intptr_t data_;
 };
@@ skipping 56 matching lines @@
         ISL_Print("%s\n", Assembler::FpuRegisterName(r));
       }
     }
   }
 
   void MarkUntagged(Location loc) {
     ASSERT(loc.IsRegister());
     untagged_cpu_registers_.Add(loc.reg());
   }
 
+  bool HasUntaggedValues() const {
+    return !untagged_cpu_registers_.IsEmpty() || !fpu_registers_.IsEmpty();
+  }
+
   bool IsTagged(Register reg) const {
     return !untagged_cpu_registers_.Contains(reg);
   }
 
   bool ContainsRegister(Register reg) const {
     return cpu_registers_.Contains(reg);
   }
 
   bool ContainsFpuRegister(FpuRegister fpu_reg) const {
     return fpu_registers_.Contains(fpu_reg);
@@ skipping 155 matching lines @@
 
 #if defined(DEBUG)
   intptr_t writable_inputs_;
 #endif
 };
 
 
 }  // namespace dart
 
 #endif  // VM_LOCATIONS_H_