Allow call-known-global to be used for call-sites with mismatched number of arguments.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 392c74dc23bc29a4fac7f93c62f3cb6aaecaaa9f..291901e537e334256481a26b9d354566be30f408 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2565,7 +2565,7 @@ void LCodeGen::DoApplyArguments(LApplyArguments* instr) {
   RecordPosition(pointers->position());
   SafepointGenerator safepoint_generator(
       this, pointers, Safepoint::kLazyDeopt);
-  v8::internal::ParameterCount actual(rax);
+  ParameterCount actual(rax);
   __ InvokeFunction(function, actual, CALL_FUNCTION,
                     safepoint_generator, CALL_AS_METHOD);
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
@@ -2615,35 +2615,48 @@ void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
                                  int arity,
                                  LInstruction* instr,
                                  CallKind call_kind) {
-  // Change context if needed.
-  bool change_context =
-      (info()->closure()->context() != function->context()) ||
-      scope()->contains_with() ||
-      (scope()->num_heap_slots() > 0);
-  if (change_context) {
-    __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
-  }
-
-  // Set rax to arguments count if adaption is not needed. Assumes that rax
-  // is available to write to at this point.
-  if (!function->NeedsArgumentsAdaption()) {
-    __ Set(rax, arity);
-  }
+  bool can_invoke_directly = !function->NeedsArgumentsAdaption() ||
+      function->shared()->formal_parameter_count() == arity;
 
   LPointerMap* pointers = instr->pointer_map();
   RecordPosition(pointers->position());
 
-  // Invoke function.
-  __ SetCallKind(rcx, call_kind);
-  if (*function == *info()->closure()) {
-    __ CallSelf();
+  if (can_invoke_directly) {
+    __ LoadHeapObject(rdi, function);
+
+    // Change context if needed.
+    bool change_context =
+        (info()->closure()->context() != function->context()) ||
+        scope()->contains_with() ||
+        (scope()->num_heap_slots() > 0);
+    if (change_context) {
+      __ movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));
+    }
+
+    // Set rax to arguments count if adaption is not needed. Assumes that rax
+    // is available to write to at this point.
+    if (!function->NeedsArgumentsAdaption()) {
+      __ Set(rax, arity);
+    }
+
+    // Invoke function.
+    __ SetCallKind(rcx, call_kind);
+    if (*function == *info()->closure()) {
+      __ CallSelf();
+    } else {
+      __ call(FieldOperand(rdi, JSFunction::kCodeEntryOffset));
+    }
+
+    // Set up deoptimization.
+    RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT, 0);
   } else {
-    __ call(FieldOperand(rdi, JSFunction::kCodeEntryOffset));
+    // We need to adapt arguments.
+    SafepointGenerator generator(
+        this, pointers, Safepoint::kLazyDeopt);
+    ParameterCount count(arity);
+    __ InvokeFunction(function, count, CALL_FUNCTION, generator, call_kind);
   }
 
-  // Set up deoptimization.
-  RecordSafepointWithLazyDeopt(instr, RECORD_SIMPLE_SAFEPOINT, 0);
-
   // Restore context.
   __ movq(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
 }
@@ -2651,7 +2664,6 @@ void LCodeGen::CallKnownFunction(Handle<JSFunction> function,
 
 void LCodeGen::DoCallConstantFunction(LCallConstantFunction* instr) {
   ASSERT(ToRegister(instr->result()).is(rax));
-  __ LoadHeapObject(rdi, instr->function());
   CallKnownFunction(instr->function(),
                     instr->arity(),
                     instr,
@@ -3094,7 +3106,6 @@ void LCodeGen::DoCallGlobal(LCallGlobal* instr) {
 
 void LCodeGen::DoCallKnownGlobal(LCallKnownGlobal* instr) {
   ASSERT(ToRegister(instr->result()).is(rax));
-  __ LoadHeapObject(rdi, instr->target());
   CallKnownFunction(instr->target(), instr->arity(), instr, CALL_AS_FUNCTION);
 }