MIPS: Do not go to slow mode and back to fast in initializer blocks.

src/mips/full-codegen-mips.cc

Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index bfa24252b9046e2e15e275c2c613ef6b18b5ee25..0d758a669ba998d4565ca56218c8313301ce5893 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -2208,44 +2208,17 @@ void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
   ASSERT(prop != NULL);
   ASSERT(prop->key()->AsLiteral() != NULL);
 
-  // If the assignment starts a block of assignments to the same object,
-  // change to slow case to avoid the quadratic behavior of repeatedly
-  // adding fast properties.
-  if (expr->starts_initialization_block()) {
-    __ push(result_register());
-    __ lw(t0, MemOperand(sp, kPointerSize));  // Receiver is now under value.
-    __ push(t0);
-    __ CallRuntime(Runtime::kToSlowProperties, 1);
-    __ pop(result_register());
-  }
-
   // Record source code position before IC call.
   SetSourcePosition(expr->position());
   __ mov(a0, result_register());  // Load the value.
   __ li(a2, Operand(prop->key()->AsLiteral()->handle()));
-  // Load receiver to a1. Leave a copy in the stack if needed for turning the
-  // receiver into fast case.
-  if (expr->ends_initialization_block()) {
-    __ lw(a1, MemOperand(sp));
-  } else {
-    __ pop(a1);
-  }
+  __ pop(a1);
 
   Handle<Code> ic = is_classic_mode()
         ? isolate()->builtins()->StoreIC_Initialize()
         : isolate()->builtins()->StoreIC_Initialize_Strict();
   CallIC(ic, RelocInfo::CODE_TARGET, expr->AssignmentFeedbackId());
 
-  // If the assignment ends an initialization block, revert to fast case.
-  if (expr->ends_initialization_block()) {
-    __ push(v0);  // Result of assignment, saved even if not needed.
-    // Receiver is under the result value.
-    __ lw(t0, MemOperand(sp, kPointerSize));
-    __ push(t0);
-    __ CallRuntime(Runtime::kToFastProperties, 1);
-    __ pop(v0);
-    __ Drop(1);
-  }
   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   context()->Plug(v0);
 }
@@ -2254,18 +2227,6 @@ void FullCodeGenerator::EmitNamedPropertyAssignment(Assignment* expr) {
 void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
   // Assignment to a property, using a keyed store IC.
 
-  // If the assignment starts a block of assignments to the same object,
-  // change to slow case to avoid the quadratic behavior of repeatedly
-  // adding fast properties.
-  if (expr->starts_initialization_block()) {
-    __ push(result_register());
-    // Receiver is now under the key and value.
-    __ lw(t0, MemOperand(sp, 2 * kPointerSize));
-    __ push(t0);
-    __ CallRuntime(Runtime::kToSlowProperties, 1);
-    __ pop(result_register());
-  }
-
   // Record source code position before IC call.
   SetSourcePosition(expr->position());
   // Call keyed store IC.
@@ -2275,29 +2236,13 @@ void FullCodeGenerator::EmitKeyedPropertyAssignment(Assignment* expr) {
   // - a2 is the receiver.
   __ mov(a0, result_register());
   __ pop(a1);  // Key.
-  // Load receiver to a2. Leave a copy in the stack if needed for turning the
-  // receiver into fast case.
-  if (expr->ends_initialization_block()) {
-    __ lw(a2, MemOperand(sp));
-  } else {
-    __ pop(a2);
-  }
+  __ pop(a2);
 
   Handle<Code> ic = is_classic_mode()
       ? isolate()->builtins()->KeyedStoreIC_Initialize()
       : isolate()->builtins()->KeyedStoreIC_Initialize_Strict();
   CallIC(ic, RelocInfo::CODE_TARGET, expr->AssignmentFeedbackId());
 
-  // If the assignment ends an initialization block, revert to fast case.
-  if (expr->ends_initialization_block()) {
-    __ push(v0);  // Result of assignment, saved even if not needed.
-    // Receiver is under the result value.
-    __ lw(t0, MemOperand(sp, kPointerSize));
-    __ push(t0);
-    __ CallRuntime(Runtime::kToFastProperties, 1);
-    __ pop(v0);
-    __ Drop(1);
-  }
   PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
   context()->Plug(v0);
 }