Specialize possible direct calls to eval

To avoid additional overhead on most function calls

Change-Id: I2477b91fda6216b508c8331884a02b601f65590c
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

6 files changed, 50 insertions, 9 deletions

diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 0b8091d70e..273856e541 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -1199,7 +1199,11 @@ bool Codegen::visit(CallExpression *ast)
         call.callData = calldata;
         bytecodeGenerator->addInstruction(call);
     } else if (base.type == Reference::Name) {
-        if (useFastLookups && base.global) {
+        if (base.name == QStringLiteral("eval")) {
+            Instruction::CallPossiblyDirectEval call;
+            call.callData = calldata;
+            bytecodeGenerator->addInstruction(call);
+        } else if (useFastLookups && base.global) {
             Instruction::CallGlobalLookup call;
             call.index = registerGlobalGetterLookup(base.nameAsIndex());
             call.callData = calldata;
diff --git a/src/qml/compiler/qv4instr_moth.cpp b/src/qml/compiler/qv4instr_moth.cpp
index a6d0691db7..9101537236 100644
--- a/src/qml/compiler/qv4instr_moth.cpp
+++ b/src/qml/compiler/qv4instr_moth.cpp
@@ -274,6 +274,10 @@ void dumpBytecode(const char *code, int len, int nLocals, int nFormals)
             d << instr.name << "(" << instr.callData.dump(nFormals) << ")";
         MOTH_END_INSTR(CallName)
 
+        MOTH_BEGIN_INSTR(CallPossiblyDirectEval)
+            d << "(" << instr.callData.dump(nFormals) << ")";
+        MOTH_END_INSTR(CallPossiblyDirectEval)
+
         MOTH_BEGIN_INSTR(CallGlobalLookup)
             d << instr.index << "(" << instr.callData.dump(nFormals) << ")";
         MOTH_END_INSTR(CallGlobalLookup)
diff --git a/src/qml/compiler/qv4instr_moth_p.h b/src/qml/compiler/qv4instr_moth_p.h
index 3d004d10e9..2ce0ff7b22 100644
--- a/src/qml/compiler/qv4instr_moth_p.h
+++ b/src/qml/compiler/qv4instr_moth_p.h
@@ -110,6 +110,7 @@ QT_BEGIN_NAMESPACE
     F(CallPropertyLookup, callPropertyLookup) \
     F(CallElement, callElement) \
     F(CallName, callName) \
+    F(CallPossiblyDirectEval, callPossiblyDirectEval) \
     F(CallGlobalLookup, callGlobalLookup) \
     F(SetExceptionHandler, setExceptionHandler) \
     F(ThrowException, throwException) \
@@ -440,6 +441,10 @@ union Instr
         int name;
         StackSlot callData;
     };
+    struct instr_callPossiblyDirectEval {
+        MOTH_INSTR_HEADER
+        StackSlot callData;
+    };
     struct instr_callGlobalLookup {
         MOTH_INSTR_HEADER
         int index;
@@ -750,6 +755,7 @@ union Instr
     instr_callPropertyLookup callPropertyLookup;
     instr_callElement callElement;
     instr_callName callName;
+    instr_callPossiblyDirectEval callPossiblyDirectEval;
     instr_callGlobalLookup callGlobalLookup;
     instr_throwException throwException;
     instr_getException getException;
diff --git a/src/qml/jsruntime/qv4runtime.cpp b/src/qml/jsruntime/qv4runtime.cpp
index a1d480160f..9c5ddece2a 100644
--- a/src/qml/jsruntime/qv4runtime.cpp
+++ b/src/qml/jsruntime/qv4runtime.cpp
@@ -1023,13 +1023,36 @@ ReturnedValue Runtime::method_callGlobalLookup(ExecutionEngine *engine, uint ind
     if (!o)
         return engine->throwTypeError();
 
-    ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[l->nameIndex]);
-    if (o->d() == scope.engine->evalFunction()->d() && name->equals(scope.engine->id_eval()))
-        return static_cast<EvalFunction *>(o.getPointer())->evalCall(callData, true);
-
     return o->call(callData);
 }
 
+ReturnedValue Runtime::method_callPossiblyDirectEval(ExecutionEngine *engine, CallData *callData)
+{
+    Q_ASSERT(callData->thisObject.isUndefined());
+    Scope scope(engine);
+    ScopedObject base(scope);
+    ExecutionContext &ctx = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context);
+    ScopedValue func(scope, ctx.getPropertyAndBase(engine->id_eval(), base.getRef()));
+    if (scope.engine->hasException)
+        return Encode::undefined();
+
+    if (base)
+        callData->thisObject = base;
+
+    FunctionObject *o = func->as<FunctionObject>();
+    if (!o) {
+        QString objectAsString = QStringLiteral("[null]");
+        if (base)
+            objectAsString = ScopedValue(scope, base.asReturnedValue())->toQStringNoThrow();
+        QString msg = QStringLiteral("Property 'eval' of object %2 is not a function").arg(objectAsString);
+        return engine->throwTypeError(msg);
+    }
+
+    if (o->d() == scope.engine->evalFunction()->d())
+        return static_cast<EvalFunction *>(o)->evalCall(callData, true);
+
+    return o->call(callData);
+}
 
 ReturnedValue Runtime::method_callName(ExecutionEngine *engine, int nameIndex, CallData *callData)
 {
@@ -1038,7 +1061,8 @@ ReturnedValue Runtime::method_callName(ExecutionEngine *engine, int nameIndex, C
     ScopedString name(scope, engine->currentStackFrame->v4Function->compilationUnit->runtimeStrings[nameIndex]);
 
     ScopedObject base(scope);
-    ScopedValue func(scope, static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context).getPropertyAndBase(name, base.getRef()));
+    ExecutionContext &ctx = static_cast<ExecutionContext &>(engine->currentStackFrame->jsFrame->context);
+    ScopedValue func(scope, ctx.getPropertyAndBase(name, base.getRef()));
     if (scope.engine->hasException)
         return Encode::undefined();
 
@@ -1054,9 +1078,6 @@ ReturnedValue Runtime::method_callName(ExecutionEngine *engine, int nameIndex, C
         return engine->throwTypeError(msg);
     }
 
-    if (o->d() == scope.engine->evalFunction()->d() && name->equals(scope.engine->id_eval()))
-        return static_cast<EvalFunction *>(o)->evalCall(callData, true);
-
     return o->call(callData);
 }
 
diff --git a/src/qml/jsruntime/qv4runtimeapi_p.h b/src/qml/jsruntime/qv4runtimeapi_p.h
index d8e1b4f443..c46e848ca4 100644
--- a/src/qml/jsruntime/qv4runtimeapi_p.h
+++ b/src/qml/jsruntime/qv4runtimeapi_p.h
@@ -98,6 +98,7 @@ struct ExceptionCheck<void (*)(QV4::NoThrowEngine *, A, B, C)> {
     F(ReturnedValue, callPropertyLookup, (ExecutionEngine *engine, uint index, CallData *callData)) \
     F(ReturnedValue, callElement, (ExecutionEngine *engine, const Value &index, CallData *callData)) \
     F(ReturnedValue, callValue, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
+    F(ReturnedValue, callPossiblyDirectEval, (ExecutionEngine *engine, CallData *callData)) \
     \
     /* construct */ \
     F(ReturnedValue, construct, (ExecutionEngine *engine, const Value &func, CallData *callData)) \
diff --git a/src/qml/jsruntime/qv4vme_moth.cpp b/src/qml/jsruntime/qv4vme_moth.cpp
index 6d20fcc426..6aad96c0c8 100644
--- a/src/qml/jsruntime/qv4vme_moth.cpp
+++ b/src/qml/jsruntime/qv4vme_moth.cpp
@@ -744,6 +744,11 @@ QV4::ReturnedValue VME::exec(const FunctionObject *jsFunction, CallData *callDat
         STORE_ACCUMULATOR(Runtime::method_callName(engine, instr.name, callData));
     MOTH_END_INSTR(CallName)
 
+    MOTH_BEGIN_INSTR(CallPossiblyDirectEval)
+        QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData.stackSlot());
+        STORE_ACCUMULATOR(Runtime::method_callPossiblyDirectEval(engine, callData));
+    MOTH_END_INSTR(CallPossiblyDirectEval)
+
     MOTH_BEGIN_INSTR(CallGlobalLookup)
         QV4::CallData *callData = reinterpret_cast<QV4::CallData *>(stack + instr.callData.stackSlot());
         STORE_ACCUMULATOR(Runtime::method_callGlobalLookup(engine, instr.index, callData));