LibWasm: Some more performance stuff (#8812)

* wasm: Don't try to print the function results if it traps

* LibWasm: Inline some very hot functions

These are mostly pretty small functions too, and they were about ~10%
of runtime.

* LibWasm+Everywhere: Make the instruction count limit configurable

...and enable it for LibWeb and test-wasm.
Note that `wasm` will not be limited by this.

* LibWasm: Remove a useless use of ScopeGuard

There are no multiple exit paths in that function, so we can just put
the ending logic right at the end of the function instead.

Tests/LibWasm/test-wasm.cpp

@@ -34,6 +34,7 @@ public:
     explicit WebAssemblyModule(JS::Object& prototype)
         : JS::Object(prototype)
     {
+        m_machine.enable_instruction_count_limit();
     }
 
     static Wasm::AbstractMachine& machine() { return m_machine; }

Userland/Libraries/LibWasm/AbstractMachine/AbstractMachine.cpp

@@ -128,6 +128,8 @@ InstantiationResult AbstractMachine::instantiate(Module const& module, Vector<Ex
     module.for_each_section_of_type<GlobalSection>([&](auto& global_section) {
         for (auto& entry : global_section.entries()) {
             Configuration config { m_store };
+            if (m_should_limit_instruction_count)
+                config.enable_instruction_count_limit();
             config.set_frame(Frame {
                 auxiliary_instance,
                 Vector<Value> {},
@@ -153,6 +155,8 @@ InstantiationResult AbstractMachine::instantiate(Module const& module, Vector<Ex
             Vector<Reference> references;
             for (auto& entry : segment.init) {
                 Configuration config { m_store };
+                if (m_should_limit_instruction_count)
+                    config.enable_instruction_count_limit();
                 config.set_frame(Frame {
                     main_module_instance,
                     Vector<Value> {},
@@ -204,6 +208,8 @@ InstantiationResult AbstractMachine::instantiate(Module const& module, Vector<Ex
                 return IterationDecision::Break;
             }
             Configuration config { m_store };
+            if (m_should_limit_instruction_count)
+                config.enable_instruction_count_limit();
             config.set_frame(Frame {
                 main_module_instance,
                 Vector<Value> {},
@@ -262,6 +268,8 @@ InstantiationResult AbstractMachine::instantiate(Module const& module, Vector<Ex
             segment.value().visit(
                 [&](DataSection::Data::Active const& data) {
                     Configuration config { m_store };
+                    if (m_should_limit_instruction_count)
+                        config.enable_instruction_count_limit();
                     config.set_frame(Frame {
                         main_module_instance,
                         Vector<Value> {},
@@ -439,6 +447,8 @@ Result AbstractMachine::invoke(FunctionAddress address, Vector<Value> arguments)
 Result AbstractMachine::invoke(Interpreter& interpreter, FunctionAddress address, Vector<Value> arguments)
 {
     Configuration configuration { m_store };
+    if (m_should_limit_instruction_count)
+        configuration.enable_instruction_count_limit();
     return configuration.call(interpreter, address, move(arguments));
 }
 

Userland/Libraries/LibWasm/AbstractMachine/AbstractMachine.h

@@ -130,26 +130,26 @@ public:
         }
     }
 
-    Value(Value const& value)
+    ALWAYS_INLINE Value(Value const& value)
         : m_value(AnyValueType { value.m_value })
         , m_type(value.m_type)
     {
     }
 
-    Value(Value&& value)
+    ALWAYS_INLINE Value(Value&& value)
         : m_value(move(value.m_value))
         , m_type(move(value.m_type))
     {
     }
 
-    Value& operator=(Value&& value)
+    ALWAYS_INLINE Value& operator=(Value&& value)
     {
         m_value = move(value.m_value);
         m_type = move(value.m_type);
         return *this;
     }
 
-    Value& operator=(Value const& value)
+    ALWAYS_INLINE Value& operator=(Value const& value)
     {
         m_value = value.m_value;
         m_type = value.m_type;
@@ -157,7 +157,7 @@ public:
     }
 
     template<typename T>
-    Optional<T> to()
+    ALWAYS_INLINE Optional<T> to()
     {
         Optional<T> result;
         m_value.visit(
@@ -505,10 +505,13 @@ public:
     auto& store() const { return m_store; }
     auto& store() { return m_store; }
 
+    void enable_instruction_count_limit() { m_should_limit_instruction_count = true; }
+
 private:
     Optional<InstantiationError> allocate_all_initial_phase(Module const&, ModuleInstance&, Vector<ExternValue>&, Vector<Value>& global_values);
     Optional<InstantiationError> allocate_all_final_phase(Module const&, ModuleInstance&, Vector<Vector<Reference>>& elements);
     Store m_store;
+    bool m_should_limit_instruction_count { false };
 };
 
 class Linker {

Userland/Libraries/LibWasm/AbstractMachine/BytecodeInterpreter.cpp

@@ -37,12 +37,15 @@ void BytecodeInterpreter::interpret(Configuration& configuration)
     auto& instructions = configuration.frame().expression().instructions();
     auto max_ip_value = InstructionPointer { instructions.size() };
     auto& current_ip_value = configuration.ip();
+    auto const should_limit_instruction_count = configuration.should_limit_instruction_count();
     u64 executed_instructions = 0;
 
     while (current_ip_value < max_ip_value) {
-        if (executed_instructions++ >= Constants::max_allowed_executed_instructions_per_call) [[unlikely]] {
-            m_trap = Trap { "Exceeded maximum allowed number of instructions" };
-            return;
+        if (should_limit_instruction_count) {
+            if (executed_instructions++ >= Constants::max_allowed_executed_instructions_per_call) [[unlikely]] {
+                m_trap = Trap { "Exceeded maximum allowed number of instructions" };
+                return;
+            }
         }
         auto& instruction = instructions[current_ip_value.value()];
         auto old_ip = current_ip_value;
@@ -1123,17 +1126,15 @@ void DebuggerBytecodeInterpreter::interpret(Configuration& configuration, Instru
         }
     }
 
-    ScopeGuard guard { [&] {
-        if (post_interpret_hook) {
-            auto result = post_interpret_hook(configuration, ip, instruction, *this);
-            if (!result) {
-                m_trap = Trap { "Trapped by user request" };
-                return;
-            }
-        }
-    } };
-
     BytecodeInterpreter::interpret(configuration, ip, instruction);
+
+    if (post_interpret_hook) {
+        auto result = post_interpret_hook(configuration, ip, instruction, *this);
+        if (!result) {
+            m_trap = Trap { "Trapped by user request" };
+            return;
+        }
+    }
 }
 
 }

Userland/Libraries/LibWasm/AbstractMachine/BytecodeInterpreter.h

@@ -50,7 +50,7 @@ protected:
     T read_value(ReadonlyBytes data);
 
     Vector<Value> pop_values(Configuration& configuration, size_t count);
-    bool trap_if_not(bool value, StringView reason)
+    ALWAYS_INLINE bool trap_if_not(bool value, StringView reason)
     {
         if (!value)
             m_trap = Trap { reason };

Userland/Libraries/LibWasm/AbstractMachine/Configuration.h

@@ -61,6 +61,9 @@ public:
     Result call(Interpreter&, FunctionAddress, Vector<Value> arguments);
     Result execute(Interpreter&);
 
+    void enable_instruction_count_limit() { m_should_limit_instruction_count = true; }
+    bool should_limit_instruction_count() const { return m_should_limit_instruction_count; }
+
     void dump_stack();
 
 private:
@@ -69,6 +72,7 @@ private:
     Stack m_stack;
     size_t m_depth { 0 };
     InstructionPointer m_ip;
+    bool m_should_limit_instruction_count { false };
 };
 
 }

Userland/Libraries/LibWeb/WebAssembly/WebAssemblyObject.cpp

@@ -25,6 +25,7 @@ namespace Web::Bindings {
 WebAssemblyObject::WebAssemblyObject(JS::GlobalObject& global_object)
     : Object(*global_object.object_prototype())
 {
+    s_abstract_machine.enable_instruction_count_limit();
 }
 
 void WebAssemblyObject::initialize(JS::GlobalObject& global_object)

Userland/Utilities/wasm.cpp

@@ -512,14 +512,16 @@ int main(int argc, char* argv[])
             if (debug)
                 launch_repl();
 
-            if (result.is_trap())
-                warnln("Execution trapped!");
-            if (!result.values().is_empty())
-                warnln("Returned:");
-            for (auto& value : result.values()) {
-                Wasm::Printer printer { stream };
-                g_stdout.write("  -> "sv.bytes());
-                g_printer.print(value);
+            if (result.is_trap()) {
+                warnln("Execution trapped: {}", result.trap().reason);
+            } else {
+                if (!result.values().is_empty())
+                    warnln("Returned:");
+                for (auto& value : result.values()) {
+                    Wasm::Printer printer { stream };
+                    g_stdout.write("  -> "sv.bytes());
+                    g_printer.print(value);
+                }
             }
         }
     }