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

Revert of [wasm] Call a runtime function for a MemorySize instruction. (patchset #2 id:20001 of https://codereview.chromium.org/2386183004/ )

Reason for revert:
Patch problem

Original issue's description:
> [wasm] Call a runtime function for a MemorySize instruction.
>
> The implementation of MemorySize with RelocatableInt32Constants is
> problematic if MemorySize is placed close to a GrowMemory instruction in
> the code. The use of a runtime function guarantees that the order in
> which MemorySize and GrowMemory is executed is correct.
>
> R=titzer@chromium.org
> BUG=chromium:651961
> TEST=mjsunit/regress/wasm/regression-651961
>
> Committed: https://crrev.com/2c12a9a42d454a36fcd2931fa458d72832eeb689
> Cr-Commit-Position: refs/heads/master@{#39972}

TBR=titzer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:651961

Review-Url: https://codereview.chromium.org/2391223002
Cr-Commit-Position: refs/heads/master@{#39973}

src/compiler/wasm-compiler.cc

@@ -2759,27 +2759,8 @@ Node* WasmGraphBuilder::MemBuffer(uint32_t offset) {
 }
 
 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) {

src/runtime/runtime-wasm.cc

@@ -18,37 +18,6 @@
 namespace v8 {
 namespace internal {
 
-RUNTIME_FUNCTION(Runtime_WasmMemorySize) {
-  HandleScope scope(isolate);
-  DCHECK_EQ(0, args.length());
-
-  Handle<JSObject> module_instance;
-  {
-    // Get the module JSObject
-    DisallowHeapAllocation no_allocation;
-    const Address entry = Isolate::c_entry_fp(isolate->thread_local_top());
-    Address pc =
-        Memory::Address_at(entry + StandardFrameConstants::kCallerPCOffset);
-    Code* code =
-        isolate->inner_pointer_to_code_cache()->GetCacheEntry(pc)->code;
-    Object* owning_instance = wasm::GetOwningWasmInstance(code);
-    CHECK_NOT_NULL(owning_instance);
-    module_instance = handle(JSObject::cast(owning_instance), isolate);
-  }
-
-  // Get mem buffer associated with module object
-  MaybeHandle<JSArrayBuffer> maybe_mem_buffer =
-      wasm::GetInstanceMemory(isolate, module_instance);
-  Handle<JSArrayBuffer> old_buffer;
-  if (!maybe_mem_buffer.ToHandle(&old_buffer)) {
-    return *isolate->factory()->NewNumberFromInt(0);
-  } else {
-    uint32_t old_size = old_buffer->byte_length()->Number();
-    return *isolate->factory()->NewNumberFromInt(old_size /
-                                                 wasm::WasmModule::kPageSize);
-  }
-}
-
 RUNTIME_FUNCTION(Runtime_WasmGrowMemory) {
   HandleScope scope(isolate);
   DCHECK_EQ(1, args.length());

src/runtime/runtime.h

@@ -917,7 +917,6 @@ namespace internal {
 
 #define FOR_EACH_INTRINSIC_WASM(F) \
   F(WasmGrowMemory, 1, 1)          \
-  F(WasmMemorySize, 0, 1)          \
   F(WasmThrowTypeError, 0, 1)      \
   F(WasmThrow, 2, 1)               \
   F(WasmGetCaughtExceptionValue, 1, 1)

test/cctest/wasm/test-run-wasm-module.cc

@@ -253,21 +253,6 @@ TEST(Run_WasmModule_Serialization) {
   }
 }
 
-TEST(MemorySize) {
-  // Initial memory size is 16, see wasm-module-builder.cc
-  static const int kExpectedValue = 16;
-  TestSignatures sigs;
-  v8::internal::AccountingAllocator allocator;
-  Zone zone(&allocator);
-
-  WasmModuleBuilder* builder = new (&zone) WasmModuleBuilder(&zone);
-  WasmFunctionBuilder* f = builder->AddFunction(sigs.i_v());
-  ExportAsMain(f);
-  byte code[] = {WASM_MEMORY_SIZE};
-  f->EmitCode(code, sizeof(code));
-  TestModule(&zone, builder, kExpectedValue);
-}
-
 TEST(Run_WasmModule_MemSize_GrowMem) {
   // Initial memory size = 16 + GrowMemory(10)
   static const int kExpectedValue = 26;

test/cctest/wasm/test-run-wasm.cc

@@ -79,6 +79,22 @@ WASM_EXEC_TEST(Int32Const_many) {
   }
 }
 
+WASM_EXEC_TEST(MemorySize1) {
+  TestingModule module(execution_mode);
+  WasmRunner<int32_t> r(&module);
+  module.AddMemory(WasmModule::kPageSize * 1);
+  BUILD(r, kExprMemorySize);
+  CHECK_EQ(1, r.Call());
+}
+
+WASM_EXEC_TEST(MemorySize2) {
+  TestingModule module(execution_mode);
+  WasmRunner<int32_t> r(&module);
+  module.AddMemory(WasmModule::kPageSize * 3);
+  BUILD(r, kExprMemorySize);
+  CHECK_EQ(3, r.Call());
+}
+
 WASM_EXEC_TEST(Int32Param0) {
   WasmRunner<int32_t> r(execution_mode, MachineType::Int32());
   // return(local[0])

test/mjsunit/regress/wasm/regression-651961.js

-// Copyright 2016 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.
-
-// Flags: --expose-wasm
-
-load("test/mjsunit/wasm/wasm-constants.js");
-load("test/mjsunit/wasm/wasm-module-builder.js");
-
-(function() {
-  var builder = new WasmModuleBuilder();
-  builder.addMemory(1, 1, false);
-  builder.addFunction("foo", kSig_i_v)
-    .addBody([
-              kExprMemorySize,
-              kExprI32Const, 0x10,
-              kExprGrowMemory,
-              kExprI32Mul,
-              ])
-              .exportFunc();
-  var module = builder.instantiate();
-  var result = module.exports.foo();
-  assertEquals(1, result);
-})();