bug 465030 - Support terminating long-running scripts without using extra threads or signals. r=gal,sayrer

js/src/jstracer.cpp

@@ -1062,14 +1062,13 @@ TraceRecorder::TraceRecorder(JSContext* cx, VMSideExit* _anchor, Fragment* _frag
     /* read into registers all values on the stack and all globals we know so far */
     import(treeInfo, lirbuf->sp, ngslots, callDepth, globalTypeMap, stackTypeMap);
 
-#if defined(JS_HAS_OPERATION_COUNT) && !JS_HAS_OPERATION_COUNT
     if (fragment == fragment->root) {
-        guard(false, 
-              lir->ins_eq0(lir->insLoadi(cx_ins, 
-                                         offsetof(JSContext, operationCount))), 
-              snapshot(TIMEOUT_EXIT));
+        LIns* counter = lir->insLoadi(cx_ins,
+                                      offsetof(JSContext, operationCount));
+        LIns* updated = lir->ins2i(LIR_sub, counter, JSOW_SCRIPT_JUMP);
+        lir->insStorei(updated, cx_ins, offsetof(JSContext, operationCount));
+        guard(false, lir->ins2i(LIR_le, updated, 0), snapshot(TIMEOUT_EXIT));
     }
-#endif
 
     /* If we are attached to a tree call guard, make sure the guard the inner tree exited from
        is what we expect it to be. */