Collect type feedback for power-of-2 right operands in BinaryOps.

src/x64/code-stubs-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1170 matching lines @@
       (ERECT_FRAME | NO_STRING_CHECK_RIGHT_IN_STUB));
   BinaryOpStub_GenerateRegisterArgsPushUnderReturn(masm);
   __ TailCallStub(&string_add_right_stub);
 
   // Neither argument is a string.
   __ bind(&call_runtime);
 }
 
 
 void BinaryOpStub::GenerateSmiStub(MacroAssembler* masm) {
-  Label call_runtime;
+  Label right_arg_changed, call_runtime;
+
+  if (op_ == Token::MOD && has_fixed_right_arg_) {
+    // It is guaranteed that the value will fit into a Smi, because if it
+    // didn't, we wouldn't be here, see BinaryOp_Patch.
+    __ Cmp(rax, Smi::FromInt(fixed_right_arg_value()));
+    __ j(not_equal, &right_arg_changed);
+  }
+
   if (result_type_ == BinaryOpIC::UNINITIALIZED ||
       result_type_ == BinaryOpIC::SMI) {
     // Only allow smi results.
     BinaryOpStub_GenerateSmiCode(masm, NULL, NO_HEAPNUMBER_RESULTS, op_);
   } else {
     // Allow heap number result and don't make a transition if a heap number
     // cannot be allocated.
     BinaryOpStub_GenerateSmiCode(
         masm, &call_runtime, ALLOW_HEAPNUMBER_RESULTS, op_);
   }
 
   // Code falls through if the result is not returned as either a smi or heap
   // number.
+  __ bind(&right_arg_changed);
   GenerateTypeTransition(masm);
 
   if (call_runtime.is_linked()) {
     __ bind(&call_runtime);
     {
       FrameScope scope(masm, StackFrame::INTERNAL);
       GenerateRegisterArgsPush(masm);
       GenerateCallRuntime(masm);
     }
     __ Ret();
@@ skipping 5705 matching lines @@
     __ jmp(generic_construct_stub, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64