Make the GCVisitor non-virtual for a small speedup

src/codegen/llvm_interpreter.h

@@ -21,15 +21,18 @@ class Function;
 
 namespace pyston {
 
+namespace gc {
+class GCVisitor;
+}
+
 class Box;
 class BoxedDict;
-class GCVisitor;
 class LineInfo;
 
 Box* interpretFunction(llvm::Function* f, int nargs, Box* closure, Box* generator, Box* arg1, Box* arg2, Box* arg3,
                        Box** args);
 
-void gatherInterpreterRoots(GCVisitor* visitor);
+void gatherInterpreterRoots(gc::GCVisitor* visitor);
 const LineInfo* getLineInfoForInterpretedFrame(void* frame_ptr);
 BoxedDict* localsForInterpretedFrame(void* frame_ptr, bool only_user_visible);
 }

src/core/types.h

@@ -72,16 +72,26 @@ struct ArgPassSpec {
 };
 static_assert(sizeof(ArgPassSpec) <= sizeof(void*), "ArgPassSpec doesn't fit in register!");
 
+namespace gc {
+
+class TraceStack;
 class GCVisitor {
+private:
+    bool isValid(void* p);
+
 public:
-    virtual ~GCVisitor() {}
-    virtual void visit(void* p) = 0;
-    virtual void visitRange(void* const* start, void* const* end) = 0;
-    virtual void visitPotential(void* p) = 0;
-    virtual void visitPotentialRange(void* const* start, void* const* end) = 0;
+    TraceStack* stack;
+    GCVisitor(TraceStack* stack) : stack(stack) {}
+
+    // These all work on *user* pointers, ie pointers to the user_data section of GCAllocations
+    void visit(void* p);
+    void visitRange(void* const* start, void* const* end);
+    void visitPotential(void* p);
+    void visitPotentialRange(void* const* start, void* const* end);
 };
 
-
+} // namespace gc
+using gc::GCVisitor;
 
 namespace EffortLevel {
 enum EffortLevel {

src/gc/collector.cpp

@@ -86,11 +86,11 @@ GCRootHandle::~GCRootHandle() {
 
 
 
-bool TraceStackGCVisitor::isValid(void* p) {
+bool GCVisitor::isValid(void* p) {
     return global_heap.getAllocationFromInteriorPointer(p) != NULL;
 }
 
-void TraceStackGCVisitor::visit(void* p) {
+void GCVisitor::visit(void* p) {
     if (isNonheapRoot(p)) {
         return;
     } else {
@@ -99,21 +99,21 @@ void TraceStackGCVisitor::visit(void* p) {
     }
 }
 
-void TraceStackGCVisitor::visitRange(void* const* start, void* const* end) {
+void GCVisitor::visitRange(void* const* start, void* const* end) {
     while (start < end) {
         visit(*start);
         start++;
     }
 }
 
-void TraceStackGCVisitor::visitPotential(void* p) {
+void GCVisitor::visitPotential(void* p) {
     GCAllocation* a = global_heap.getAllocationFromInteriorPointer(p);
     if (a) {
         visit(a->user_data);
     }
 }
 
-void TraceStackGCVisitor::visitPotentialRange(void* const* start, void* const* end) {
+void GCVisitor::visitPotentialRange(void* const* start, void* const* end) {
     while (start < end) {
         visitPotential(*start);
         start++;
@@ -130,7 +130,7 @@ static void markPhase() {
     TraceStack stack(roots);
     collectStackRoots(&stack);
 
-    TraceStackGCVisitor visitor(&stack);
+    GCVisitor visitor(&stack);
 
     for (void* p : nonheap_roots) {
         Box* b = reinterpret_cast<Box*>(p);

src/gc/collector.h

@@ -45,21 +45,6 @@ public:
     }
 };
 
-class TraceStackGCVisitor : public GCVisitor {
-private:
-    bool isValid(void* p);
-
-public:
-    TraceStack* stack;
-    TraceStackGCVisitor(TraceStack* stack) : stack(stack) {}
-
-    // These all work on *user* pointers, ie pointers to the user_data section of GCAllocations
-    void visit(void* p) override;
-    void visitRange(void* const* start, void* const* end) override;
-    void visitPotential(void* p) override;
-    void visitPotentialRange(void* const* start, void* const* end) override;
-};
-
 // Mark this gc-allocated object as being a root, even if there are no visible references to it.
 // (Note: this marks the gc allocation itself, not the pointer that points to one.  For that, use
 // a GCRootHandle)

src/gc/root_finder.cpp

@@ -42,7 +42,7 @@ void collectRoots(void* start, void* end, TraceStack* stack) {
 
     ASSERT((char*)end - (char*)start <= 1000000000, "Asked to scan %.1fGB -- a bug?",
            ((char*)end - (char*)start) * 1.0 / (1 << 30));
-    TraceStackGCVisitor(stack).visitPotentialRange((void**)start, (void**)end);
+    GCVisitor(stack).visitPotentialRange((void**)start, (void**)end);
 }
 
 
@@ -81,7 +81,7 @@ void collectStackRoots(TraceStack* stack) {
     collectLocalStack(stack);
     collectOtherThreadsStacks(stack);
 
-    TraceStackGCVisitor visitor(stack);
+    GCVisitor visitor(stack);
     gatherInterpreterRoots(&visitor);
 }
 }