--- old/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Tue Aug 25 01:30:27 2015
+++ new/src/cpu/x86/vm/stubGenerator_x86_64.cpp	Tue Aug 25 01:30:25 2015
@@ -367,16 +367,20 @@
 #ifdef ASSERT
     // verify that threads correspond
     {
-      Label L, S;
+     Label L1, L2, L3;
       __ cmpptr(r15_thread, thread);
-      __ jcc(Assembler::notEqual, S);
+      __ jcc(Assembler::equal, L1);
+      __ stop("StubRoutines::call_stub: r15_thread is corrupted");
+      __ bind(L1);
       __ get_thread(rbx);
+      __ cmpptr(r15_thread, thread);
+      __ jcc(Assembler::equal, L2);
+      __ stop("StubRoutines::call_stub: r15_thread is modified by call");
+      __ bind(L2);
       __ cmpptr(r15_thread, rbx);
-      __ jcc(Assembler::equal, L);
-      __ bind(S);
-      __ jcc(Assembler::equal, L);
+      __ jcc(Assembler::equal, L3);
       __ stop("StubRoutines::call_stub: threads must correspond");
-      __ bind(L);
+      __ bind(L3); 
     }
 #endif
 
@@ -450,15 +454,20 @@
 #ifdef ASSERT
     // verify that threads correspond
     {
-      Label L, S;
+      Label L1, L2, L3;
       __ cmpptr(r15_thread, thread);
-      __ jcc(Assembler::notEqual, S);
+      __ jcc(Assembler::equal, L1);
+      __ stop("StubRoutines::catch_exception: r15_thread is corrupted");
+      __ bind(L1);
       __ get_thread(rbx);
+      __ cmpptr(r15_thread, thread);
+      __ jcc(Assembler::equal, L2);
+      __ stop("StubRoutines::catch_exception: r15_thread is modified by call");
+      __ bind(L2);
       __ cmpptr(r15_thread, rbx);
-      __ jcc(Assembler::equal, L);
-      __ bind(S);
+      __ jcc(Assembler::equal, L3);
       __ stop("StubRoutines::catch_exception: threads must correspond");
-      __ bind(L);
+      __ bind(L3); 
     }
 #endif