--- a/hotspot/src/cpu/x86/vm/assembler_x86.cpp	Tue Nov 23 13:22:55 2010 -0800
+++ b/hotspot/src/cpu/x86/vm/assembler_x86.cpp	Mon Nov 29 15:43:36 2010 -0500
@@ -5538,17 +5538,14 @@
 }
 
 void MacroAssembler::warn(const char* msg) {
-  push(r12);
-  movq(r12, rsp);
+  push(rsp);
   andq(rsp, -16);     // align stack as required by push_CPU_state and call
 
   push_CPU_state();   // keeps alignment at 16 bytes
   lea(c_rarg0, ExternalAddress((address) msg));
   call_VM_leaf(CAST_FROM_FN_PTR(address, warning), c_rarg0);
   pop_CPU_state();
-
-  movq(rsp, r12);
-  pop(r12);
+  pop(rsp);
 }
 
 #ifndef PRODUCT
@@ -5860,6 +5857,10 @@
   // debugging support
   assert(number_of_arguments >= 0   , "cannot have negative number of arguments");
   LP64_ONLY(assert(java_thread == r15_thread, "unexpected register"));
+#ifdef ASSERT
+  LP64_ONLY(if (UseCompressedOops) verify_heapbase("call_VM_base");)
+#endif // ASSERT
+
   assert(java_thread != oop_result  , "cannot use the same register for java_thread & oop_result");
   assert(java_thread != last_java_sp, "cannot use the same register for java_thread & last_java_sp");
 

--- a/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp	Tue Nov 23 13:22:55 2010 -0800
+++ b/hotspot/src/cpu/x86/vm/interp_masm_x86_64.cpp	Mon Nov 29 15:43:36 2010 -0500
@@ -449,10 +449,9 @@
     // JVMTI events, such as single-stepping, are implemented partly by avoiding running
     // compiled code in threads for which the event is enabled.  Check here for
     // interp_only_mode if these events CAN be enabled.
-    get_thread(temp);
     // interp_only is an int, on little endian it is sufficient to test the byte only
-    // Is a cmpl faster (ce
-    cmpb(Address(temp, JavaThread::interp_only_mode_offset()), 0);
+    // Is a cmpl faster?
+    cmpb(Address(r15_thread, JavaThread::interp_only_mode_offset()), 0);
     jcc(Assembler::zero, run_compiled_code);
     jmp(Address(method, methodOopDesc::interpreter_entry_offset()));
     bind(run_compiled_code);

--- a/hotspot/src/cpu/x86/vm/templateInterpreter_x86_64.cpp	Tue Nov 23 13:22:55 2010 -0800
+++ b/hotspot/src/cpu/x86/vm/templateInterpreter_x86_64.cpp	Mon Nov 29 15:43:36 2010 -0500
@@ -1069,7 +1069,7 @@
     // runtime call by hand.
     //
     __ mov(c_rarg0, r15_thread);
-    __ mov(r12, rsp); // remember sp
+    __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
     __ andptr(rsp, -16); // align stack as required by ABI
     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, JavaThread::check_special_condition_for_native_trans)));
@@ -1116,7 +1116,7 @@
     __ jcc(Assembler::notEqual, no_reguard);
 
     __ pusha(); // XXX only save smashed registers
-    __ mov(r12, rsp); // remember sp
+    __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
     __ subptr(rsp, frame::arg_reg_save_area_bytes); // windows
     __ andptr(rsp, -16); // align stack as required by ABI
     __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::reguard_yellow_pages)));
@@ -1907,7 +1907,7 @@
 
   assert(Interpreter::trace_code(t->tos_in()) != NULL,
          "entry must have been generated");
-  __ mov(r12, rsp); // remember sp
+  __ mov(r12, rsp); // remember sp (can only use r12 if not using call_VM)
   __ andptr(rsp, -16); // align stack as required by ABI
   __ call(RuntimeAddress(Interpreter::trace_code(t->tos_in())));
   __ mov(rsp, r12); // restore sp

--- a/hotspot/src/cpu/x86/vm/templateTable_x86_64.cpp	Tue Nov 23 13:22:55 2010 -0800
+++ b/hotspot/src/cpu/x86/vm/templateTable_x86_64.cpp	Mon Nov 29 15:43:36 2010 -0500
@@ -2762,7 +2762,7 @@
     // access constant pool cache entry
     __ get_cache_entry_pointer_at_bcp(c_rarg2, rcx, 1);
     __ verify_oop(rax);
-    __ mov(r12, rax);  // save object pointer before call_VM() clobbers it
+    __ push_ptr(rax);  // save object pointer before call_VM() clobbers it
     __ mov(c_rarg1, rax);
     // c_rarg1: object pointer copied above
     // c_rarg2: cache entry pointer
@@ -2770,8 +2770,7 @@
                CAST_FROM_FN_PTR(address,
                                 InterpreterRuntime::post_field_access),
                c_rarg1, c_rarg2);
-    __ mov(rax, r12); // restore object pointer
-    __ reinit_heapbase();
+    __ pop_ptr(rax); // restore object pointer
     __ bind(L1);
   }
 
@@ -3365,10 +3364,7 @@
           JVM_CONSTANT_Class);
   __ jcc(Assembler::equal, quicked);
   __ push(atos); // save receiver for result, and for GC
-  __ mov(r12, rcx); // save rcx XXX
   call_VM(rax, CAST_FROM_FN_PTR(address, InterpreterRuntime::quicken_io_cc));
-  __ movq(rcx, r12); // restore rcx XXX
-  __ reinit_heapbase();
   __ pop_ptr(rdx); // restore receiver
   __ jmpb(resolved);
 
@@ -3422,11 +3418,9 @@
   __ jcc(Assembler::equal, quicked);
 
   __ push(atos); // save receiver for result, and for GC
-  __ mov(r12, rcx); // save rcx
   call_VM(rax, CAST_FROM_FN_PTR(address, InterpreterRuntime::quicken_io_cc));
-  __ movq(rcx, r12); // restore rcx
-  __ reinit_heapbase();
   __ pop_ptr(rdx); // restore receiver
+  __ verify_oop(rdx);
   __ load_klass(rdx, rdx);
   __ jmpb(resolved);