Fast-codegen: Added support for arguments in functions.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 1329cd692f17c94d57492d33439e19649eb674c4..2b30bda79a80ab82481c98258f4b6cc7495ffdc3 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -600,8 +600,8 @@ CodeGenSelector::CodeGenTag CodeGenSelector::Select(FunctionLiteral* fun) {
   }
 
   if (scope->arguments() != NULL) {
-    if (FLAG_trace_bailout) PrintF("function uses 'arguments'\n");
-    return NORMAL;
+    // if (FLAG_trace_bailout) PrintF("function uses 'arguments'\n");
+    // return NORMAL;

[William Hesse, 2009/11/12 09:56:49]

Remove.

[Lasse Reichstein, 2009/11/13 08:54:37]

Done.

   }
 
   has_supported_syntax_ = true;
@@ -792,21 +792,23 @@ void CodeGenSelector::VisitSlot(Slot* expr) {
 
 void CodeGenSelector::VisitVariableProxy(VariableProxy* expr) {
   Expression* rewrite = expr->var()->rewrite();
-  // A rewrite of NULL indicates a global variable.
+  // A rewrite of NULL indicates a global variable or explict arguments access.

[William Hesse, 2009/11/12 09:56:49]

Lie!

[Lasse Reichstein, 2009/11/13 08:54:37]

Truthified.

   if (rewrite != NULL) {
     // Non-global.
     Slot* slot = rewrite->AsSlot();
-    if (slot == NULL) {
-      // This is a variable rewritten to an explicit property access
-      // on the arguments object.
-      BAILOUT("non-global/non-slot variable reference");
-    }
-
-    Slot::Type type = slot->type();
-    // When LOOKUP slots are enabled, some currently dead code
-    // implementing unary typeof will become live.
-    if (type == Slot::LOOKUP) {
-      BAILOUT("Lookup slot");
+    if (slot != NULL) {
+      Slot::Type type = slot->type();
+      // When LOOKUP slots are enabled, some currently dead code
+      // implementing unary typeof will become live.
+      if (type == Slot::LOOKUP) {
+        BAILOUT("Lookup slot");
+      }
+    } else {
+      Property* property = rewrite->AsProperty();

[William Hesse, 2009/11/12 09:56:49]

Put a comment, indicating what this code is for.

[Lasse Reichstein, 2009/11/13 08:54:37]

Added

+      ASSERT_NOT_NULL(property);
+      ASSERT_NE(Expression::kUninitialized, context_);
+      Visit(property);
+      property->set_context(context_);

[Kevin Millikin (Chromium), 2009/11/12 14:23:13]

I'm surprised that this works.

For a variable in a scope, all proxies should point to the same variable and
thus the rewrite is shared.  At codegen time, you will just get whatever is the
last context set in the selector, right?

I would think that we do not (ever) set the context or other code gen state on
rewrites, but instead on the proxy itself.  Then in the case of visiting a
variable proxy at code gen time, compile it based on the proxy's state.

     }
   }
 }