Merge pull request #595 from undingen/generator_gc2

Skip initializing exc fields inside JITed code

src/codegen/irgen/irgenerator.cpp

@@ -179,16 +179,11 @@ llvm::Value* IRGenState::getFrameInfoVar() {
             // The "normal" case
 
             // frame_info.exc.type = NULL
-            // frame_info.exc.value = NULL
-            // frame_info.exc.traceback = NULL
             llvm::Constant* null_value = getNullPtr(g.llvm_value_type_ptr);
             llvm::Value* exc_info = getExcinfoGep(builder, al);
             builder.CreateStore(
                 null_value, builder.CreateConstInBoundsGEP2_32(exc_info, 0, offsetof(ExcInfo, type) / sizeof(Box*)));
-            builder.CreateStore(
-                null_value, builder.CreateConstInBoundsGEP2_32(exc_info, 0, offsetof(ExcInfo, value) / sizeof(Box*)));
-            builder.CreateStore(null_value, builder.CreateConstInBoundsGEP2_32(exc_info, 0, offsetof(ExcInfo, traceback)
-                                                                                                / sizeof(Box*)));
+
             // frame_info.boxedLocals = NULL
             llvm::Value* boxed_locals_gep = getBoxedLocalsGep(builder, al);
             builder.CreateStore(getNullPtr(g.llvm_value_type_ptr), boxed_locals_gep);

src/runtime/objmodel.cpp

@@ -179,6 +179,13 @@ extern "C" Box* deopt(AST_expr* expr, Box* value) {
     // Should we only do this selectively?
     execution_point.cf->speculationFailed();
 
+    // Except of exc.type we skip initializing the exc fields inside the JITed code path (small perf improvement) that's
+    // why we have todo it now if we didn't set an exception (which sets all fields)
+    if (frame_state.frame_info->exc.type == NULL) {
+        frame_state.frame_info->exc.traceback = NULL;
+        frame_state.frame_info->exc.value = NULL;
+    }
+
     return astInterpretFrom(execution_point.cf, expr, execution_point.current_stmt, value, frame_state);
 }