Revert of [wasm] Call a runtime function for a MemorySize instruction.

src/compiler/wasm-compiler.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/wasm-compiler.h"
 
 #include <memory>
 
 #include "src/isolate-inl.h"
 
@@ skipping 2741 matching lines @@
     }
     return mem_buffer_;
   } else {
     return jsgraph()->RelocatableIntPtrConstant(
         reinterpret_cast<uintptr_t>(module_->instance->mem_start + offset),
         RelocInfo::WASM_MEMORY_REFERENCE);
   }
 }
 
 Node* WasmGraphBuilder::CurrentMemoryPages() {
-  Runtime::FunctionId function_id = Runtime::kWasmMemorySize;
-  const Runtime::Function* function = Runtime::FunctionForId(function_id);
-  CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
-      jsgraph()->zone(), function_id, function->nargs, Operator::kNoThrow,
-      CallDescriptor::kNoFlags);
-  wasm::ModuleEnv* module = module_;
-  Node* inputs[] = {
-      jsgraph()->CEntryStubConstant(function->result_size),  // C entry
-      jsgraph()->ExternalConstant(
-          ExternalReference(function_id, jsgraph()->isolate())),  // ref
-      jsgraph()->Int32Constant(function->nargs),                  // arity
-      jsgraph()->HeapConstant(module->instance->context),         // context
-      *effect_,
-      *control_};
-  Node* call = graph()->NewNode(jsgraph()->common()->Call(desc),
-                                static_cast<int>(arraysize(inputs)), inputs);
-
-  Node* result = BuildChangeSmiToInt32(call);
-
-  *effect_ = call;
-  return result;
+  return graph()->NewNode(jsgraph()->machine()->Word32Shr(), MemSize(0),
+                          jsgraph()->Int32Constant(16));
 }
 
 Node* WasmGraphBuilder::MemSize(uint32_t offset) {
   DCHECK(module_ && module_->instance);
   uint32_t size = static_cast<uint32_t>(module_->instance->mem_size);
   if (offset == 0) {
     if (!mem_size_)
       mem_size_ = jsgraph()->RelocatableInt32Constant(
           size, RelocInfo::WASM_MEMORY_SIZE_REFERENCE);
     return mem_size_;
@@ skipping 609 matching lines @@
                             function_->code_start_offset),
            compile_ms);
   }
 
   return code;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8