--- a/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp	Tue Feb 20 07:46:40 2018 -0500
+++ b/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp	Tue Feb 20 16:10:21 2018 +0100
@@ -529,12 +529,16 @@
 
   if (SafepointMechanism::uses_thread_local_poll()) {
 #ifdef _LP64
-    __ movptr(rscratch1, Address(r15_thread, Thread::polling_page_offset()));
+    const Register poll_addr = rscratch1;
+    __ movptr(poll_addr, Address(r15_thread, Thread::polling_page_offset()));
+#else
+    const Register poll_addr = rbx;
+    assert(FrameMap::is_caller_save_register(poll_addr), "will overwrite");
+    __ get_thread(poll_addr);
+    __ movptr(poll_addr, Address(poll_addr, Thread::polling_page_offset()));
+#endif
     __ relocate(relocInfo::poll_return_type);
-    __ testl(rax, Address(rscratch1, 0));
-#else
-    ShouldNotReachHere();
-#endif
+    __ testl(rax, Address(poll_addr, 0));
   } else {
     AddressLiteral polling_page(os::get_polling_page(), relocInfo::poll_return_type);
 
@@ -555,16 +559,20 @@
   int offset = __ offset();
   if (SafepointMechanism::uses_thread_local_poll()) {
 #ifdef _LP64
-    __ movptr(rscratch1, Address(r15_thread, Thread::polling_page_offset()));
+    const Register poll_addr = rscratch1;
+    __ movptr(poll_addr, Address(r15_thread, Thread::polling_page_offset()));
+#else
+    assert(tmp->is_cpu_register(), "needed");
+    const Register poll_addr = tmp->as_register();
+    __ get_thread(poll_addr);
+    __ movptr(poll_addr, Address(poll_addr, in_bytes(Thread::polling_page_offset())));
+#endif
     add_debug_info_for_branch(info);
     __ relocate(relocInfo::poll_type);
     address pre_pc = __ pc();
-    __ testl(rax, Address(rscratch1, 0));
+    __ testl(rax, Address(poll_addr, 0));
     address post_pc = __ pc();
-    guarantee(pointer_delta(post_pc, pre_pc, 1) == 3, "must be exact length");
-#else
-    ShouldNotReachHere();
-#endif
+    guarantee(pointer_delta(post_pc, pre_pc, 1) == 2 LP64_ONLY(+1), "must be exact length");
   } else {
     AddressLiteral polling_page(os::get_polling_page(), relocInfo::poll_type);
     if (Assembler::is_polling_page_far()) {