[wasm] Faster version of GetExportWrapperIndex

Hashing FunctionSigs can be quite expensive for large modules;
luckily in some cases we can avoid doing that work.

Change-Id: Ia18060b4c27ab34b44bda4bb81ea05299ecb0f49
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3038523
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75819}

src/wasm/wasm-module.cc

@@ -51,13 +51,23 @@ int MaxNumExportWrappers(const WasmModule* module) {
   return static_cast<int>(module->signature_map.size()) * 2;
 }
 
-// static
+int GetExportWrapperIndexInternal(const WasmModule* module,
+                                  int canonical_sig_index, bool is_import) {
+  if (is_import) canonical_sig_index += module->signature_map.size();
+  return canonical_sig_index;
+}
+
 int GetExportWrapperIndex(const WasmModule* module, const FunctionSig* sig,
                           bool is_import) {
-  int result = module->signature_map.Find(*sig);
-  CHECK_GE(result, 0);
-  result += is_import ? module->signature_map.size() : 0;
-  return result;
+  int canonical_sig_index = module->signature_map.Find(*sig);
+  CHECK_GE(canonical_sig_index, 0);
+  return GetExportWrapperIndexInternal(module, canonical_sig_index, is_import);
+}
+
+int GetExportWrapperIndex(const WasmModule* module, uint32_t sig_index,
+                          bool is_import) {
+  uint32_t canonical_sig_index = module->canonicalized_type_ids[sig_index];
+  return GetExportWrapperIndexInternal(module, canonical_sig_index, is_import);
 }
 
 // static

src/wasm/wasm-module.h

@@ -396,9 +396,12 @@ size_t EstimateStoredSize(const WasmModule* module);
 V8_EXPORT_PRIVATE int MaxNumExportWrappers(const WasmModule* module);
 
 // Returns the wrapper index for a function in {module} with signature {sig}
-// and origin defined by {is_import}.
+// or {sig_index} and origin defined by {is_import}.
+// Prefer to use the {sig_index} consuming version, as it is much faster.
 int GetExportWrapperIndex(const WasmModule* module, const FunctionSig* sig,
                           bool is_import);
+int GetExportWrapperIndex(const WasmModule* module, uint32_t sig_index,
+                          bool is_import);
 
 // Return the byte offset of the function identified by the given index.
 // The offset will be relative to the start of the module bytes.

src/wasm/wasm-objects.cc

@@ -1469,7 +1469,9 @@ WasmInstanceObject::GetOrCreateWasmExternalFunction(
   const WasmModule* module = module_object->module();
   const WasmFunction& function = module->functions[function_index];
   int wrapper_index =
-      GetExportWrapperIndex(module, function.sig, function.imported);
+      GetExportWrapperIndex(module, function.sig_index, function.imported);
+  DCHECK_EQ(wrapper_index,
+            GetExportWrapperIndex(module, function.sig, function.imported));
 
   Handle<Object> entry =
       FixedArray::get(module_object->export_wrappers(), wrapper_index, isolate);

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

@@ -439,7 +439,8 @@ class WasmRunnerBase : public InitializedHandleScope {
                                     const char* name = nullptr) {
     functions_.emplace_back(
         new WasmFunctionCompiler(&zone_, sig, &builder_, name));
-    builder().AddSignature(sig);
+    byte sig_index = builder().AddSignature(sig);
+    functions_.back()->SetSigIndex(sig_index);
     return *functions_.back();
   }