Implement proposed new identity spec.

runtime/vm/flow_graph_compiler_ia32.cc

Index: runtime/vm/flow_graph_compiler_ia32.cc
===================================================================
--- runtime/vm/flow_graph_compiler_ia32.cc	(revision 15270)
+++ runtime/vm/flow_graph_compiler_ia32.cc	(working copy)
@@ -1106,15 +1106,45 @@
 
 
 void FlowGraphCompiler::EmitEqualityRegConstCompare(Register reg,
-                                                    const Object& obj) {
+                                                    const Object& obj,
+                                                    bool needs_number_check) {
+  if (needs_number_check) {
+    if (!obj.IsMint() && !obj.IsDouble() && !obj.IsBigint()) {
+      needs_number_check = false;
+    }
+  }
   if (obj.IsSmi() && (Smi::Cast(obj).Value() == 0)) {
+    ASSERT(!needs_number_check);
     __ testl(reg, reg);
   } else {

[Florian Schneider, 2012/11/23 10:33:40]

Maybe reduce the nesting level by using

} else if (needs_number_check) {

here.

[srdjan, 2012/11/23 19:45:39]

changed to use returns instead of else.

-    __ CompareObject(reg, obj);
+    if (needs_number_check) {
+      __ pushl(reg);
+      __ PushObject(obj);
+      __ call(&StubCode::IdenticalWithNumberCheckLabel());

[Florian Schneider, 2012/11/23 10:33:40]

Maybe add comment that the stub return result in the flags-register.

[srdjan, 2012/11/23 19:45:39]

Done.

+      __ popl(reg);  // Discard constant.
+      __ popl(reg);  // Restore 'reg'.
+    } else {
+      __ CompareObject(reg, obj);
+    }
   }
 }
 
 
+void FlowGraphCompiler::EmitEqualityRegRegCompare(Register left,
+                                                  Register right,
+                                                  bool needs_number_check) {
+  if (needs_number_check) {
+    __ pushl(left);
+    __ pushl(right);
+    __ call(&StubCode::IdenticalWithNumberCheckLabel());
+    __ popl(right);
+    __ popl(left);
+  } else {
+    __ cmpl(left, right);
+  }
+}
+
+
 // Implement equality spec: if any of the arguments is null do identity check.
 // Fallthrough calls super equality.
 void FlowGraphCompiler::EmitSuperEqualityCallPrologue(Register result,