[wasm] Remove dead code from wasm-code-specialization

R=clemensh@chromium.org

Change-Id: I97cadf40e441c5d19a1ea9b03a5d2f04505f04c5
Reviewed-on: https://chromium-review.googlesource.com/964365Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51968}

src/wasm/wasm-code-specialization.cc

@@ -55,16 +55,6 @@ class PatchDirectCallsHelper {
         comp_mod->shared()->module()->functions[func_index].code.offset();
   }
 
-  PatchDirectCallsHelper(NativeModule* native_module, Code* code)
-      : source_pos_it(code->SourcePositionTable()), decoder(nullptr, nullptr) {
-    FixedArray* deopt_data = code->deoptimization_data();
-    DCHECK_EQ(2, deopt_data->length());
-    WasmSharedModuleData* shared = native_module->compiled_module()->shared();
-    int func_index = Smi::ToInt(deopt_data->get(1));
-    func_bytes = shared->module_bytes()->GetChars() +
-                 shared->module()->functions[func_index].code.offset();
-  }
-
   SourcePositionTableIterator source_pos_it;
   Decoder decoder;
   const byte* func_bytes;
@@ -88,12 +78,6 @@ void CodeSpecialization::RelocateDirectCalls(NativeModule* native_module) {
   relocate_direct_calls_module_ = native_module;
 }
 
-void CodeSpecialization::RelocatePointer(Address old_ptr, Address new_ptr) {
-  DCHECK_EQ(0, pointers_to_relocate_.count(old_ptr));
-  DCHECK_EQ(0, pointers_to_relocate_.count(new_ptr));
-  pointers_to_relocate_.insert(std::make_pair(old_ptr, new_ptr));
-}
-
 bool CodeSpecialization::ApplyToWholeModule(NativeModule* native_module,
                                             ICacheFlushMode icache_flush_mode) {
   DisallowHeapAllocation no_gc;
@@ -168,14 +152,12 @@ bool CodeSpecialization::ApplyToWasmCode(wasm::WasmCode* code,
   DCHECK_EQ(wasm::WasmCode::kFunction, code->kind());
 
   bool reloc_direct_calls = relocate_direct_calls_module_ != nullptr;
-  bool reloc_pointers = pointers_to_relocate_.size() > 0;
 
   int reloc_mode = 0;
   auto add_mode = [&reloc_mode](bool cond, RelocInfo::Mode mode) {
     if (cond) reloc_mode |= RelocInfo::ModeMask(mode);
   };
   add_mode(reloc_direct_calls, RelocInfo::WASM_CALL);
-  add_mode(reloc_pointers, RelocInfo::WASM_GLOBAL_HANDLE);
 
   base::Optional<PatchDirectCallsHelper> patch_direct_calls_helper;
   bool changed = false;
@@ -209,16 +191,6 @@ bool CodeSpecialization::ApplyToWasmCode(wasm::WasmCode* code,
                                           icache_flush_mode);
         changed = true;
       } break;
-      case RelocInfo::WASM_GLOBAL_HANDLE: {
-        DCHECK(reloc_pointers);
-        Address old_ptr = it.rinfo()->global_handle();
-        auto entry = pointers_to_relocate_.find(old_ptr);
-        if (entry != pointers_to_relocate_.end()) {
-          Address new_ptr = entry->second;
-          it.rinfo()->set_global_handle(new_ptr, icache_flush_mode);
-          changed = true;
-        }
-      } break;
       default:
         UNREACHABLE();
     }

src/wasm/wasm-code-specialization.h

@@ -32,9 +32,6 @@ class CodeSpecialization {
   void RelocateWasmContextReferences(Address new_context);
   // Update all direct call sites based on the code table in the given instance.
   void RelocateDirectCalls(NativeModule* module);
-  // Relocate an arbitrary object (e.g. function table).
-  void RelocatePointer(Address old_obj, Address new_obj);
-
   // Apply all relocations and patching to all code in the instance (wasm code
   // and exported functions).
   bool ApplyToWholeModule(NativeModule*,
@@ -47,8 +44,6 @@ class CodeSpecialization {
   Address new_wasm_context_address_ = 0;
 
   NativeModule* relocate_direct_calls_module_ = nullptr;
-
-  std::unordered_map<Address, Address> pointers_to_relocate_;
 };
 
 }  // namespace wasm