[wasm] Remove obsolete code specialization support.

R=clemensh@chromium.org

Change-Id: Id8a0849d3456be1062a065a23f51bac250de4f7d
Reviewed-on: https://chromium-review.googlesource.com/1107936Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54026}

BUILD.gn

@@ -2447,8 +2447,6 @@ v8_source_set("v8_base") {
     "src/wasm/value-type.h",
     "src/wasm/wasm-code-manager.cc",
     "src/wasm/wasm-code-manager.h",
-    "src/wasm/wasm-code-specialization.cc",
-    "src/wasm/wasm-code-specialization.h",
     "src/wasm/wasm-constants.h",
     "src/wasm/wasm-debug.cc",
     "src/wasm/wasm-engine.cc",

src/arm/assembler-arm.cc

@@ -356,8 +356,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return static_cast<uint32_t>(
       Assembler::target_address_at(pc_, constant_pool_));
 }

src/arm64/assembler-arm64.cc

@@ -203,8 +203,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   Instruction* instr = reinterpret_cast<Instruction*>(pc_);
   if (instr->IsLdrLiteralX()) {
     return static_cast<uint32_t>(

src/assembler.h

@@ -581,7 +581,7 @@ class RelocInfo {
   Address wasm_stub_call_address() const;
   Address js_to_wasm_address() const;
 
-  uint32_t wasm_stub_call_tag() const;
+  uint32_t wasm_call_tag() const;
 
   void set_wasm_call_address(
       Address, ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);

src/ia32/assembler-ia32.cc

@@ -223,8 +223,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return Memory::uint32_at(pc_);
 }
 

src/mips/assembler-mips.cc

@@ -216,8 +216,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return static_cast<uint32_t>(
       Assembler::target_address_at(pc_, constant_pool_));
 }

src/mips64/assembler-mips64.cc

@@ -194,8 +194,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return static_cast<uint32_t>(
       Assembler::target_address_at(pc_, constant_pool_));
 }

src/ppc/assembler-ppc.cc

@@ -179,8 +179,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return static_cast<uint32_t>(
       Assembler::target_address_at(pc_, constant_pool_));
 }

src/s390/assembler-s390.cc

@@ -289,8 +289,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Assembler::target_address_at(pc_, constant_pool_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return static_cast<uint32_t>(
       Assembler::target_address_at(pc_, constant_pool_));
 }

src/wasm/module-compiler.cc

@@ -18,7 +18,6 @@
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/streaming-decoder.h"
 #include "src/wasm/wasm-code-manager.h"
-#include "src/wasm/wasm-code-specialization.h"
 #include "src/wasm/wasm-engine.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-limits.h"
@@ -414,10 +413,6 @@ wasm::WasmCode* LazyCompileFunction(Isolate* isolate,
   // module creation time, and return a function that always traps here.
   CHECK(!thrower.error());
 
-  // Now specialize the generated code for this instance.
-  CodeSpecialization code_specialization;
-  code_specialization.RelocateDirectCalls(native_module);
-  code_specialization.ApplyToWasmCode(wasm_code, SKIP_ICACHE_FLUSH);
   int64_t func_size =
       static_cast<int64_t>(func->code.end_offset() - func->code.offset());
   int64_t compilation_time = compilation_timer.Elapsed().InMicroseconds();
@@ -873,7 +868,6 @@ class FinishCompileTask : public CancelableTask {
       ErrorThrower thrower(compilation_state_->isolate(), "AsyncCompile");
       wasm::WasmCode* result = unit->FinishCompilation(&thrower);
 
-      NativeModule* native_module = unit->native_module();
       if (thrower.error()) {
         DCHECK_NULL(result);
         compilation_state_->OnError(&thrower);
@@ -885,13 +879,9 @@ class FinishCompileTask : public CancelableTask {
       if (compilation_state_->baseline_compilation_finished()) {
         // If Liftoff compilation finishes it will directly start executing.
         // As soon as we have Turbofan-compiled code available, it will
-        // directly be used by Liftoff-compiled code. Therefore we need
-        // to patch the compiled Turbofan function directly after finishing it.
+        // directly be used by Liftoff-compiled code via the jump table.
         DCHECK_EQ(CompileMode::kTiering, compilation_state_->compile_mode());
         DCHECK(!result->is_liftoff());
-        CodeSpecialization code_specialization;
-        code_specialization.RelocateDirectCalls(native_module);
-        code_specialization.ApplyToWasmCode(result);
 
         if (wasm::WasmCode::ShouldBeLogged(isolate)) result->LogCode(isolate);
 
@@ -1299,11 +1289,8 @@ MaybeHandle<WasmInstanceObject> InstanceBuilder::Build() {
   }
 
   //--------------------------------------------------------------------------
-  // Patch all code with the relocations registered in code_specialization.
+  // Flush the processors instruction cache.
   //--------------------------------------------------------------------------
-  CodeSpecialization code_specialization;
-  code_specialization.RelocateDirectCalls(native_module);
-  code_specialization.ApplyToWholeModule(native_module, SKIP_ICACHE_FLUSH);
   FlushICache(native_module);
 
   //--------------------------------------------------------------------------

src/wasm/wasm-code-manager.cc

@@ -183,10 +183,19 @@ void WasmCode::Validate() const {
        !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     switch (mode) {
+      case RelocInfo::WASM_CALL: {
+        Address target = it.rinfo()->wasm_call_address();
+        WasmCode* code = native_module_->Lookup(target);
+        CHECK_NOT_NULL(code);
+        CHECK_EQ(WasmCode::kJumpTable, code->kind());
+        CHECK(code->contains(target));
+        break;
+      }
       case RelocInfo::WASM_STUB_CALL: {
         Address target = it.rinfo()->wasm_stub_call_address();
         WasmCode* code = native_module_->Lookup(target);
-        CHECK(code && code->kind() == WasmCode::kRuntimeStub);
+        CHECK_NOT_NULL(code);
+        CHECK_EQ(WasmCode::kRuntimeStub, code->kind());
         CHECK_EQ(target, code->instruction_start());
         break;
       }
@@ -196,7 +205,6 @@ void WasmCode::Validate() const {
         CHECK(contains(target));
         break;
       }
-      case RelocInfo::WASM_CALL:
       case RelocInfo::JS_TO_WASM_CALL:
       case RelocInfo::EXTERNAL_REFERENCE:
       case RelocInfo::OFF_HEAP_TARGET:
@@ -490,7 +498,7 @@ WasmCode* NativeModule::AddAnonymousCode(Handle<Code> code,
        !it.done(); it.next(), orig_it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (RelocInfo::IsWasmStubCall(mode)) {
-      uint32_t stub_call_tag = orig_it.rinfo()->wasm_stub_call_tag();
+      uint32_t stub_call_tag = orig_it.rinfo()->wasm_call_tag();
       DCHECK_LT(stub_call_tag, WasmCode::kRuntimeStubCount);
       WasmCode* code =
           runtime_stub(static_cast<WasmCode::RuntimeStubId>(stub_call_tag));
@@ -530,16 +538,20 @@ WasmCode* NativeModule::AddCode(
       std::move(protected_instructions), tier, WasmCode::kNoFlushICache);
 
   // Apply the relocation delta by iterating over the RelocInfo.
-  AllowDeferredHandleDereference embedding_raw_address;
   intptr_t delta = ret->instructions().start() - desc.buffer;
   int mode_mask = RelocInfo::kApplyMask |
+                  RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
                   RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL);
   for (RelocIterator it(ret->instructions(), ret->reloc_info(),
                         ret->constant_pool(), mode_mask);
        !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
-    if (RelocInfo::IsWasmStubCall(mode)) {
-      uint32_t stub_call_tag = it.rinfo()->wasm_stub_call_tag();
+    if (RelocInfo::IsWasmCall(mode)) {
+      uint32_t call_tag = it.rinfo()->wasm_call_tag();
+      Address target = GetCallTargetForFunction(call_tag);
+      it.rinfo()->set_wasm_call_address(target, SKIP_ICACHE_FLUSH);
+    } else if (RelocInfo::IsWasmStubCall(mode)) {
+      uint32_t stub_call_tag = it.rinfo()->wasm_call_tag();
       DCHECK_LT(stub_call_tag, WasmCode::kRuntimeStubCount);
       WasmCode* code =
           runtime_stub(static_cast<WasmCode::RuntimeStubId>(stub_call_tag));

src/wasm/wasm-code-specialization.cc

-// Copyright 2017 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/wasm/wasm-code-specialization.h"
-
-#include "src/assembler-inl.h"
-#include "src/base/optional.h"
-#include "src/objects-inl.h"
-#include "src/source-position-table.h"
-#include "src/wasm/decoder.h"
-#include "src/wasm/wasm-code-manager.h"
-#include "src/wasm/wasm-module.h"
-#include "src/wasm/wasm-objects-inl.h"
-
-namespace v8 {
-namespace internal {
-namespace wasm {
-
-uint32_t ExtractDirectCallIndex(wasm::Decoder& decoder, const byte* pc) {
-  DCHECK_EQ(static_cast<int>(kExprCallFunction), static_cast<int>(*pc));
-  decoder.Reset(pc + 1, pc + 6);
-  uint32_t call_idx = decoder.consume_u32v("call index");
-  DCHECK(decoder.ok());
-  DCHECK_GE(kMaxInt, call_idx);
-  return call_idx;
-}
-
-namespace {
-
-int AdvanceSourcePositionTableIterator(SourcePositionTableIterator& iterator,
-                                       size_t offset_l) {
-  DCHECK_GE(kMaxInt, offset_l);
-  int offset = static_cast<int>(offset_l);
-  DCHECK(!iterator.done());
-  int byte_pos;
-  do {
-    byte_pos = iterator.source_position().ScriptOffset();
-    iterator.Advance();
-  } while (!iterator.done() && iterator.code_offset() <= offset);
-  return byte_pos;
-}
-
-class PatchDirectCallsHelper {
- public:
-  PatchDirectCallsHelper(NativeModule* native_module, const WasmCode* code)
-      : source_pos_it(code->source_positions()), decoder(nullptr, nullptr) {
-    uint32_t func_index = code->index();
-    const WasmModule* module = native_module->module();
-    func_bytes = native_module->wire_bytes().start() +
-                 module->functions[func_index].code.offset();
-  }
-
-  SourcePositionTableIterator source_pos_it;
-  Decoder decoder;
-  const byte* func_bytes;
-};
-
-}  // namespace
-
-CodeSpecialization::CodeSpecialization() {}
-
-CodeSpecialization::~CodeSpecialization() {}
-
-void CodeSpecialization::RelocateDirectCalls(NativeModule* native_module) {
-  DCHECK_NULL(relocate_direct_calls_module_);
-  DCHECK_NOT_NULL(native_module);
-  relocate_direct_calls_module_ = native_module;
-}
-
-bool CodeSpecialization::ApplyToWholeModule(NativeModule* native_module,
-                                            ICacheFlushMode icache_flush_mode) {
-  DisallowHeapAllocation no_gc;
-
-  bool changed = false;
-
-  // Patch all wasm functions.
-  for (WasmCode* wasm_code : native_module->code_table()) {
-    if (wasm_code == nullptr) continue;
-    if (wasm_code->kind() != WasmCode::kFunction) continue;
-    changed |= ApplyToWasmCode(wasm_code, icache_flush_mode);
-  }
-
-  return changed;
-}
-
-bool CodeSpecialization::ApplyToWasmCode(wasm::WasmCode* code,
-                                         ICacheFlushMode icache_flush_mode) {
-  DisallowHeapAllocation no_gc;
-  DCHECK_EQ(wasm::WasmCode::kFunction, code->kind());
-
-  bool reloc_direct_calls = relocate_direct_calls_module_ != nullptr;
-
-  int reloc_mode = 0;
-  if (reloc_direct_calls) {
-    reloc_mode |= RelocInfo::ModeMask(RelocInfo::WASM_CALL);
-  }
-  if (!reloc_mode) return false;
-
-  base::Optional<PatchDirectCallsHelper> patch_direct_calls_helper;
-  bool changed = false;
-
-  NativeModule* native_module = code->native_module();
-
-  RelocIterator it(code->instructions(), code->reloc_info(),
-                   code->constant_pool(), reloc_mode);
-  for (; !it.done(); it.next()) {
-    RelocInfo::Mode mode = it.rinfo()->rmode();
-    switch (mode) {
-      case RelocInfo::WASM_CALL: {
-        DCHECK(reloc_direct_calls);
-        // Iterate simultaneously over the relocation information and the source
-        // position table. For each call in the reloc info, move the source
-        // position iterator forward to that position to find the byte offset of
-        // the respective call. Then extract the call index from the module wire
-        // bytes to find the new compiled function.
-        size_t offset = it.rinfo()->pc() - code->instruction_start();
-        if (!patch_direct_calls_helper) {
-          patch_direct_calls_helper.emplace(relocate_direct_calls_module_,
-                                            code);
-        }
-        int byte_pos = AdvanceSourcePositionTableIterator(
-            patch_direct_calls_helper->source_pos_it, offset);
-        uint32_t called_func_index = ExtractDirectCallIndex(
-            patch_direct_calls_helper->decoder,
-            patch_direct_calls_helper->func_bytes + byte_pos);
-        Address new_target =
-            native_module->GetCallTargetForFunction(called_func_index);
-        it.rinfo()->set_wasm_call_address(new_target, icache_flush_mode);
-        changed = true;
-      } break;
-
-      default:
-        UNREACHABLE();
-    }
-  }
-
-  return changed;
-}
-
-}  // namespace wasm
-}  // namespace internal
-}  // namespace v8

src/wasm/wasm-code-specialization.h

-// Copyright 2017 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.
-
-#ifndef V8_WASM_WASM_CODE_SPECIALIZATION_H_
-#define V8_WASM_WASM_CODE_SPECIALIZATION_H_
-
-#include "src/assembler.h"
-#include "src/wasm/decoder.h"
-#include "src/wasm/wasm-objects.h"
-
-namespace v8 {
-namespace internal {
-namespace wasm {
-
-uint32_t ExtractDirectCallIndex(wasm::Decoder& decoder, const byte* pc);
-
-// Helper class to specialize wasm code for a specific module.
-//
-// Note that code is shared among instances belonging to one module, hence all
-// specialization actions will implicitly apply to all instances of a module.
-//
-// Set up all relocations / patching that should be performed by the Relocate* /
-// Patch* methods, then apply all changes in one step using the Apply* methods.
-class CodeSpecialization {
- public:
-  CodeSpecialization();
-  ~CodeSpecialization();
-
-  // Update all direct call sites based on the code table in the given module.
-  void RelocateDirectCalls(NativeModule* module);
-  // Apply all relocations and patching to all code in the module.
-  bool ApplyToWholeModule(NativeModule*,
-                          ICacheFlushMode = FLUSH_ICACHE_IF_NEEDED);
-  // Apply all relocations and patching to one wasm code object.
-  bool ApplyToWasmCode(wasm::WasmCode*,
-                       ICacheFlushMode = FLUSH_ICACHE_IF_NEEDED);
-
- private:
-  NativeModule* relocate_direct_calls_module_ = nullptr;
-};
-
-}  // namespace wasm
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_WASM_WASM_CODE_SPECIALIZATION_H_

src/wasm/wasm-module.cc

@@ -17,7 +17,6 @@
 #include "src/v8.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-code-manager.h"
-#include "src/wasm/wasm-code-specialization.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-objects-inl.h"

src/wasm/wasm-serialization.cc

@@ -478,13 +478,20 @@ bool NativeModuleDeserializer::ReadCode(uint32_t fn_index, Reader* reader) {
                                  WasmCode::kFlushICache);
 
   // Relocate the code.
-  int mask = RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL) |
+  int mask = RelocInfo::ModeMask(RelocInfo::WASM_CALL) |
+             RelocInfo::ModeMask(RelocInfo::WASM_STUB_CALL) |
              RelocInfo::ModeMask(RelocInfo::EXTERNAL_REFERENCE);
   for (RelocIterator iter(ret->instructions(), ret->reloc_info(),
                           ret->constant_pool(), mask);
        !iter.done(); iter.next()) {
     RelocInfo::Mode mode = iter.rinfo()->rmode();
     switch (mode) {
+      case RelocInfo::WASM_CALL: {
+        uint32_t tag = GetWasmCalleeTag(iter.rinfo());
+        Address target = native_module_->GetCallTargetForFunction(tag);
+        iter.rinfo()->set_wasm_call_address(target, SKIP_ICACHE_FLUSH);
+        break;
+      }
       case RelocInfo::WASM_STUB_CALL: {
         uint32_t tag = GetWasmCalleeTag(iter.rinfo());
         DCHECK_LT(tag, WasmCode::kRuntimeStubCount);

src/x64/assembler-x64.cc

@@ -138,8 +138,8 @@ Address RelocInfo::js_to_wasm_address() const {
   return Memory::Address_at(pc_);
 }
 
-uint32_t RelocInfo::wasm_stub_call_tag() const {
-  DCHECK_EQ(rmode_, WASM_STUB_CALL);
+uint32_t RelocInfo::wasm_call_tag() const {
+  DCHECK(rmode_ == WASM_CALL || rmode_ == WASM_STUB_CALL);
   return Memory::uint32_at(pc_);
 }
 

test/cctest/wasm/wasm-run-utils.h

@@ -26,7 +26,6 @@
 #include "src/wasm/function-body-decoder.h"
 #include "src/wasm/local-decl-encoder.h"
 #include "src/wasm/wasm-code-manager.h"
-#include "src/wasm/wasm-code-specialization.h"
 #include "src/wasm/wasm-external-refs.h"
 #include "src/wasm/wasm-interpreter.h"
 #include "src/wasm/wasm-js.h"
@@ -212,9 +211,6 @@ class TestingModuleBuilder {
   }
   void Link() {
     if (linked_) return;
-    CodeSpecialization code_specialization;
-    code_specialization.RelocateDirectCalls(native_module_);
-    code_specialization.ApplyToWholeModule(native_module_);
     linked_ = true;
     native_module_->SetExecutable(true);
   }