Setup R10/EDX to be valid Oops before stub calls

runtime/vm/flow_graph_compiler_ia32.cc

Index: runtime/vm/flow_graph_compiler_ia32.cc
diff --git a/runtime/vm/flow_graph_compiler_ia32.cc b/runtime/vm/flow_graph_compiler_ia32.cc
index de52c6496a4365956caf07907c51509da512b77a..25d3fd95da2b963690161b3dd02dc09fe162f3f3 100644
--- a/runtime/vm/flow_graph_compiler_ia32.cc
+++ b/runtime/vm/flow_graph_compiler_ia32.cc
@@ -1182,6 +1182,7 @@ void FlowGraphCompiler::EmitUnoptimizedStaticCall(
     UNIMPLEMENTED();
   }
   ExternalLabel target_label(label_address);
+  __ movl(EDX, Immediate(0));

[Florian Schneider, 2014/06/20 12:48:54]

This is bad for unoptimized code size.

[Ivan Posva, 2014/06/20 14:03:31]

We were fully aware of the code size issue when we implemented this fix. The
real fix will be to have different stubs, based on the call patterns and the
corresponding live registers.

   __ LoadObject(ECX, ic_data);
   GenerateDartCall(deopt_id,
                    token_pos,
@@ -1189,6 +1190,9 @@ void FlowGraphCompiler::EmitUnoptimizedStaticCall(
                    PcDescriptors::kUnoptStaticCall,
                    locs);
   __ Drop(argument_count);
+#if defined(DEBUG)
+  __ movl(EDX, Immediate(kInvalidObjectPointer));
+#endif
 }
 
 
@@ -1239,6 +1243,7 @@ void FlowGraphCompiler::EmitInstanceCall(ExternalLabel* target_label,
                                          intptr_t token_pos,
                                          LocationSummary* locs) {
   ASSERT(Array::Handle(ic_data.arguments_descriptor()).Length() > 0);
+  __ movl(EDX, Immediate(0));
   __ LoadObject(ECX, ic_data);
   GenerateDartCall(deopt_id,
                    token_pos,
@@ -1246,6 +1251,9 @@ void FlowGraphCompiler::EmitInstanceCall(ExternalLabel* target_label,
                    PcDescriptors::kIcCall,
                    locs);
   __ Drop(argument_count);
+#if defined(DEBUG)
+  __ movl(EDX, Immediate(kInvalidObjectPointer));
+#endif
 }
 
 
@@ -1375,6 +1383,8 @@ void FlowGraphCompiler::EmitEqualityRegRegCompare(Register left,
     if (is_optimizing()) {
       __ call(&StubCode::OptimizedIdenticalWithNumberCheckLabel());
     } else {
+      __ movl(EDX, Immediate(0));
+      __ movl(ECX, Immediate(0));
       __ call(&StubCode::UnoptimizedIdenticalWithNumberCheckLabel());
     }
     if (token_pos != Scanner::kNoSourcePos) {
@@ -1382,6 +1392,13 @@ void FlowGraphCompiler::EmitEqualityRegRegCompare(Register left,
                            Isolate::kNoDeoptId,
                            token_pos);
     }
+#if defined(DEBUG)
+    if (!is_optimizing()) {
+      // Do this *after* adding the pc descriptor!
+      __ movl(EDX, Immediate(kInvalidObjectPointer));
+      __ movl(ECX, Immediate(kInvalidObjectPointer));
+    }
+#endif
     // Stub returns result in flags (result of a cmpl, we need ZF computed).
     __ popl(right);
     __ popl(left);