diff --git a/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp b/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
index fa1bfaa71db..04e32e2b8be 100644
--- a/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_LIRAssembler_x86.cpp
@@ -326,7 +326,7 @@ void LIR_Assembler::clinit_barrier(ciMethod* method) {
   Register klass = rscratch1;
 
   __ mov_metadata(klass, method->holder()->constant_encoding());
-  __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
+  __ clinit_barrier(klass, &L_skip_barrier /*L_fast_path*/);
 
   __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));
 
@@ -482,7 +482,7 @@ void LIR_Assembler::return_op(LIR_Opr result, C1SafepointPollStub* code_stub) {
 
   code_stub->set_safepoint_offset(__ offset());
   __ relocate(relocInfo::poll_return_type);
-  __ safepoint_poll(*code_stub->entry(), r15_thread, true /* at_return */, true /* in_nmethod */);
+  __ safepoint_poll(*code_stub->entry(), true /* at_return */, true /* in_nmethod */);
   __ ret(0);
 }
 
diff --git a/src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp b/src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp
index 7ffa6d9bdd4..dd8c075cb87 100644
--- a/src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_MacroAssembler_x86.cpp
@@ -62,8 +62,7 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
   }
 
   if (LockingMode == LM_LIGHTWEIGHT) {
-    const Register thread = r15_thread;
-    lightweight_lock(disp_hdr, obj, hdr, thread, tmp, slow_case);
+    lightweight_lock(disp_hdr, obj, hdr, tmp, slow_case);
   } else  if (LockingMode == LM_LEGACY) {
     Label done;
     // Load object header
@@ -128,7 +127,7 @@ void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_
   verify_oop(obj);
 
   if (LockingMode == LM_LIGHTWEIGHT) {
-    lightweight_unlock(obj, disp_hdr, r15_thread, hdr, slow_case);
+    lightweight_unlock(obj, disp_hdr, hdr, slow_case);
   } else if (LockingMode == LM_LEGACY) {
     // test if object header is pointing to the displaced header, and if so, restore
     // the displaced header in the object - if the object header is not pointing to
diff --git a/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp b/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp
index bb5111fa652..f42032bb275 100644
--- a/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_Runtime1_x86.cpp
@@ -51,7 +51,7 @@
 
 int StubAssembler::call_RT(Register oop_result1, Register metadata_result, address entry, int args_size) {
   // setup registers
-  const Register thread = r15_thread; // is callee-saved register (Visual C++ calling conventions)
+  const Register thread = r15_thread;
   assert(!(oop_result1->is_valid() || metadata_result->is_valid()) || oop_result1 != metadata_result, "registers must be different");
   assert(oop_result1 != thread && metadata_result != thread, "registers must be different");
   assert(args_size >= 0, "illegal args_size");
@@ -66,11 +66,11 @@ int StubAssembler::call_RT(Register oop_result1, Register metadata_result, addre
 
   int call_offset = -1;
   if (!align_stack) {
-    set_last_Java_frame(thread, noreg, rbp, nullptr, rscratch1);
+    set_last_Java_frame(noreg, rbp, nullptr, rscratch1);
   } else {
     address the_pc = pc();
     call_offset = offset();
-    set_last_Java_frame(thread, noreg, rbp, the_pc, rscratch1);
+    set_last_Java_frame(noreg, rbp, the_pc, rscratch1);
     andptr(rsp, -(StackAlignmentInBytes));    // Align stack
   }
 
@@ -84,7 +84,7 @@ int StubAssembler::call_RT(Register oop_result1, Register metadata_result, addre
   guarantee(thread != rax, "change this code");
   push(rax);
   { Label L;
-    get_thread(rax);
+    get_thread_slow(rax);
     cmpptr(thread, rax);
     jcc(Assembler::equal, L);
     int3();
@@ -93,7 +93,7 @@ int StubAssembler::call_RT(Register oop_result1, Register metadata_result, addre
   }
   pop(rax);
 #endif
-  reset_last_Java_frame(thread, true);
+  reset_last_Java_frame(true);
 
   // check for pending exceptions
   { Label L;
@@ -120,10 +120,10 @@ int StubAssembler::call_RT(Register oop_result1, Register metadata_result, addre
   }
   // get oop results if there are any and reset the values in the thread
   if (oop_result1->is_valid()) {
-    get_vm_result(oop_result1, thread);
+    get_vm_result(oop_result1);
   }
   if (metadata_result->is_valid()) {
-    get_vm_result_2(metadata_result, thread);
+    get_vm_result_2(metadata_result);
   }
 
   assert(call_offset >= 0, "Should be set");
@@ -715,8 +715,7 @@ OopMapSet* Runtime1::generate_patching(StubAssembler* sasm, address target) {
   const Register thread = r15_thread;
   // No need to worry about dummy
   __ mov(c_rarg0, thread);
-
-  __ set_last_Java_frame(thread, noreg, rbp, nullptr, rscratch1);
+  __ set_last_Java_frame(noreg, rbp, nullptr, rscratch1);
   // do the call
   __ call(RuntimeAddress(target));
   OopMapSet* oop_maps = new OopMapSet();
@@ -726,7 +725,7 @@ OopMapSet* Runtime1::generate_patching(StubAssembler* sasm, address target) {
   guarantee(thread != rax, "change this code");
   __ push(rax);
   { Label L;
-    __ get_thread(rax);
+    __ get_thread_slow(rax);
     __ cmpptr(thread, rax);
     __ jcc(Assembler::equal, L);
     __ stop("StubAssembler::call_RT: rdi/r15 not callee saved?");
@@ -734,7 +733,7 @@ OopMapSet* Runtime1::generate_patching(StubAssembler* sasm, address target) {
   }
   __ pop(rax);
 #endif
-  __ reset_last_Java_frame(thread, true);
+  __ reset_last_Java_frame(true);
 
   // check for pending exceptions
   { Label L;
diff --git a/src/hotspot/cpu/x86/downcallLinker_x86_64.cpp b/src/hotspot/cpu/x86/downcallLinker_x86_64.cpp
index 15c311ffd39..c48940198ea 100644
--- a/src/hotspot/cpu/x86/downcallLinker_x86_64.cpp
+++ b/src/hotspot/cpu/x86/downcallLinker_x86_64.cpp
@@ -291,7 +291,7 @@ void DowncallLinker::StubGenerator::generate() {
               Assembler::StoreLoad | Assembler::StoreStore));
     }
 
-    __ safepoint_poll(L_safepoint_poll_slow_path, r15_thread, true /* at_return */, false /* in_nmethod */);
+    __ safepoint_poll(L_safepoint_poll_slow_path, true /* at_return */, false /* in_nmethod */);
     __ cmpl(Address(r15_thread, JavaThread::suspend_flags_offset()), 0);
     __ jcc(Assembler::notEqual, L_safepoint_poll_slow_path);
 
@@ -305,7 +305,7 @@ void DowncallLinker::StubGenerator::generate() {
     __ jcc(Assembler::equal, L_reguard);
     __ bind(L_after_reguard);
 
-    __ reset_last_Java_frame(r15_thread, true);
+    __ reset_last_Java_frame(true);
     __ block_comment("} thread native2java");
   }
 
diff --git a/src/hotspot/cpu/x86/interp_masm_x86.cpp b/src/hotspot/cpu/x86/interp_masm_x86.cpp
index 84a99060a3e..93117ff8b7d 100644
--- a/src/hotspot/cpu/x86/interp_masm_x86.cpp
+++ b/src/hotspot/cpu/x86/interp_masm_x86.cpp
@@ -296,7 +296,6 @@ void InterpreterMacroAssembler::call_VM_leaf_base(address entry_point,
 }
 
 void InterpreterMacroAssembler::call_VM_base(Register oop_result,
-                                             Register java_thread,
                                              Register last_java_sp,
                                              address  entry_point,
                                              int      number_of_arguments,
@@ -319,7 +318,7 @@ void InterpreterMacroAssembler::call_VM_base(Register oop_result,
   }
 #endif /* ASSERT */
   // super call
-  MacroAssembler::call_VM_base(oop_result, noreg, last_java_sp,
+  MacroAssembler::call_VM_base(oop_result, last_java_sp,
                                entry_point, number_of_arguments,
                                check_exceptions);
   // interpreter specific
@@ -379,7 +378,7 @@ void InterpreterMacroAssembler::restore_after_resume(bool is_native) {
   }
 }
 
-void InterpreterMacroAssembler::check_and_handle_popframe(Register java_thread) {
+void InterpreterMacroAssembler::check_and_handle_popframe() {
   if (JvmtiExport::can_pop_frame()) {
     Label L;
     // Initiate popframe handling only if it is not already being
@@ -389,7 +388,7 @@ void InterpreterMacroAssembler::check_and_handle_popframe(Register java_thread)
     // This method is only called just after the call into the vm in
     // call_VM_base, so the arg registers are available.
     Register pop_cond = c_rarg0;
-    movl(pop_cond, Address(java_thread, JavaThread::popframe_condition_offset()));
+    movl(pop_cond, Address(r15_thread, JavaThread::popframe_condition_offset()));
     testl(pop_cond, JavaThread::popframe_pending_bit);
     jcc(Assembler::zero, L);
     testl(pop_cond, JavaThread::popframe_processing_bit);
@@ -430,7 +429,7 @@ void InterpreterMacroAssembler::load_earlyret_value(TosState state) {
 }
 
 
-void InterpreterMacroAssembler::check_and_handle_earlyret(Register java_thread) {
+void InterpreterMacroAssembler::check_and_handle_earlyret() {
   if (JvmtiExport::can_force_early_return()) {
     Label L;
     Register tmp = c_rarg0;
@@ -810,13 +809,13 @@ void InterpreterMacroAssembler::remove_activation(
   // the stack, will call InterpreterRuntime::at_unwind.
   Label slow_path;
   Label fast_path;
-  safepoint_poll(slow_path, rthread, true /* at_return */, false /* in_nmethod */);
+  safepoint_poll(slow_path, true /* at_return */, false /* in_nmethod */);
   jmp(fast_path);
   bind(slow_path);
   push(state);
-  set_last_Java_frame(rthread, noreg, rbp, (address)pc(), rscratch1);
+  set_last_Java_frame(noreg, rbp, (address)pc(), rscratch1);
   super_call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::at_unwind), rthread);
-  reset_last_Java_frame(rthread, true);
+  reset_last_Java_frame(true);
   pop(state);
   bind(fast_path);
 
@@ -1031,8 +1030,7 @@ void InterpreterMacroAssembler::lock_object(Register lock_reg) {
     }
 
     if (LockingMode == LM_LIGHTWEIGHT) {
-      const Register thread = r15_thread;
-      lightweight_lock(lock_reg, obj_reg, swap_reg, thread, tmp_reg, slow_case);
+      lightweight_lock(lock_reg, obj_reg, swap_reg, tmp_reg, slow_case);
     } else if (LockingMode == LM_LEGACY) {
       // Load immediate 1 into swap_reg %rax
       movl(swap_reg, 1);
@@ -1141,7 +1139,7 @@ void InterpreterMacroAssembler::unlock_object(Register lock_reg) {
     movptr(Address(lock_reg, BasicObjectLock::obj_offset()), NULL_WORD);
 
     if (LockingMode == LM_LIGHTWEIGHT) {
-      lightweight_unlock(obj_reg, swap_reg, r15_thread, header_reg, slow_case);
+      lightweight_unlock(obj_reg, swap_reg, header_reg, slow_case);
     } else if (LockingMode == LM_LEGACY) {
       // Load the old header from BasicLock structure
       movptr(header_reg, Address(swap_reg,
diff --git a/src/hotspot/cpu/x86/interp_masm_x86.hpp b/src/hotspot/cpu/x86/interp_masm_x86.hpp
index e537e9efc96..308d700ff4f 100644
--- a/src/hotspot/cpu/x86/interp_masm_x86.hpp
+++ b/src/hotspot/cpu/x86/interp_masm_x86.hpp
@@ -42,7 +42,6 @@ class InterpreterMacroAssembler: public MacroAssembler {
  protected:
 
   virtual void call_VM_base(Register oop_result,
-                            Register java_thread,
                             Register last_java_sp,
                             address  entry_point,
                             int number_of_arguments,
@@ -58,8 +57,8 @@ class InterpreterMacroAssembler: public MacroAssembler {
 
   void jump_to_entry(address entry);
 
- virtual void check_and_handle_popframe(Register java_thread);
- virtual void check_and_handle_earlyret(Register java_thread);
+ virtual void check_and_handle_popframe();
+ virtual void check_and_handle_earlyret();
 
   void load_earlyret_value(TosState state);
 
diff --git a/src/hotspot/cpu/x86/macroAssembler_x86.cpp b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
index c92ce2f283c..a2173be609b 100644
--- a/src/hotspot/cpu/x86/macroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
@@ -724,17 +724,6 @@ void MacroAssembler::pushptr(AddressLiteral src, Register rscratch) {
   }
 }
 
-void MacroAssembler::reset_last_Java_frame(bool clear_fp) {
-  reset_last_Java_frame(r15_thread, clear_fp);
-}
-
-void MacroAssembler::set_last_Java_frame(Register last_java_sp,
-                                         Register last_java_fp,
-                                         address  last_java_pc,
-                                         Register rscratch) {
-  set_last_Java_frame(r15_thread, last_java_sp, last_java_fp, last_java_pc, rscratch);
-}
-
 static void pass_arg0(MacroAssembler* masm, Register arg) {
   if (c_rarg0 != arg ) {
     masm->mov(c_rarg0, arg);
@@ -1487,8 +1476,7 @@ void MacroAssembler::call_VM(Register oop_result,
                              address entry_point,
                              int number_of_arguments,
                              bool check_exceptions) {
-  Register thread = LP64_ONLY(r15_thread) NOT_LP64(noreg);
-  call_VM_base(oop_result, thread, last_java_sp, entry_point, number_of_arguments, check_exceptions);
+  call_VM_base(oop_result, last_java_sp, entry_point, number_of_arguments, check_exceptions);
 }
 
 void MacroAssembler::call_VM(Register oop_result,
@@ -1533,8 +1521,7 @@ void MacroAssembler::super_call_VM(Register oop_result,
                                    address entry_point,
                                    int number_of_arguments,
                                    bool check_exceptions) {
-  Register thread = LP64_ONLY(r15_thread) NOT_LP64(noreg);
-  MacroAssembler::call_VM_base(oop_result, thread, last_java_sp, entry_point, number_of_arguments, check_exceptions);
+  MacroAssembler::call_VM_base(oop_result, last_java_sp, entry_point, number_of_arguments, check_exceptions);
 }
 
 void MacroAssembler::super_call_VM(Register oop_result,
@@ -1575,31 +1562,22 @@ void MacroAssembler::super_call_VM(Register oop_result,
 }
 
 void MacroAssembler::call_VM_base(Register oop_result,
-                                  Register java_thread,
                                   Register last_java_sp,
                                   address  entry_point,
                                   int      number_of_arguments,
                                   bool     check_exceptions) {
-  // determine java_thread register
-  if (!java_thread->is_valid()) {
-#ifdef _LP64
-    java_thread = r15_thread;
-#else
-    java_thread = rdi;
-    get_thread(java_thread);
-#endif // LP64
-  }
+  Register java_thread = r15_thread;
+
   // determine last_java_sp register
   if (!last_java_sp->is_valid()) {
     last_java_sp = rsp;
   }
   // debugging support
   assert(number_of_arguments >= 0   , "cannot have negative number of arguments");
-  LP64_ONLY(assert(java_thread == r15_thread, "unexpected register"));
 #ifdef ASSERT
   // TraceBytecodes does not use r12 but saves it over the call, so don't verify
   // r12 is the heapbase.
-  LP64_ONLY(if (UseCompressedOops && !TraceBytecodes) verify_heapbase("call_VM_base: heap base corrupted?");)
+  if (UseCompressedOops && !TraceBytecodes) verify_heapbase("call_VM_base: heap base corrupted?");
 #endif // ASSERT
 
   assert(java_thread != oop_result  , "cannot use the same register for java_thread & oop_result");
@@ -1607,53 +1585,42 @@ void MacroAssembler::call_VM_base(Register oop_result,
 
   // push java thread (becomes first argument of C function)
 
-  NOT_LP64(push(java_thread); number_of_arguments++);
-  LP64_ONLY(mov(c_rarg0, r15_thread));
+  mov(c_rarg0, r15_thread);
 
   // set last Java frame before call
   assert(last_java_sp != rbp, "can't use ebp/rbp");
 
   // Only interpreter should have to set fp
-  set_last_Java_frame(java_thread, last_java_sp, rbp, nullptr, rscratch1);
+  set_last_Java_frame(last_java_sp, rbp, nullptr, rscratch1);
 
   // do the call, remove parameters
   MacroAssembler::call_VM_leaf_base(entry_point, number_of_arguments);
 
-  // restore the thread (cannot use the pushed argument since arguments
-  // may be overwritten by C code generated by an optimizing compiler);
-  // however can use the register value directly if it is callee saved.
-  if (LP64_ONLY(true ||) java_thread == rdi || java_thread == rsi) {
-    // rdi & rsi (also r15) are callee saved -> nothing to do
 #ifdef ASSERT
-    guarantee(java_thread != rax, "change this code");
-    push(rax);
-    { Label L;
-      get_thread(rax);
-      cmpptr(java_thread, rax);
-      jcc(Assembler::equal, L);
-      STOP("MacroAssembler::call_VM_base: rdi not callee saved?");
-      bind(L);
-    }
-    pop(rax);
-#endif
-  } else {
-    get_thread(java_thread);
+  // Check that thread register is not clobbered.
+  guarantee(java_thread != rax, "change this code");
+  push(rax);
+  { Label L;
+    get_thread_slow(rax);
+    cmpptr(java_thread, rax);
+    jcc(Assembler::equal, L);
+    STOP("MacroAssembler::call_VM_base: java_thread not callee saved?");
+    bind(L);
   }
+  pop(rax);
+#endif
+
   // reset last Java frame
   // Only interpreter should have to clear fp
-  reset_last_Java_frame(java_thread, true);
+  reset_last_Java_frame(true);
 
    // C++ interp handles this in the interpreter
-  check_and_handle_popframe(java_thread);
-  check_and_handle_earlyret(java_thread);
+  check_and_handle_popframe();
+  check_and_handle_earlyret();
 
   if (check_exceptions) {
     // check for pending exceptions (java_thread is set upon return)
-    cmpptr(Address(java_thread, Thread::pending_exception_offset()), NULL_WORD);
-#ifndef _LP64
-    jump_cc(Assembler::notEqual,
-            RuntimeAddress(StubRoutines::forward_exception_entry()));
-#else
+    cmpptr(Address(r15_thread, Thread::pending_exception_offset()), NULL_WORD);
     // This used to conditionally jump to forward_exception however it is
     // possible if we relocate that the branch will not reach. So we must jump
     // around so we can always reach
@@ -1662,36 +1629,24 @@ void MacroAssembler::call_VM_base(Register oop_result,
     jcc(Assembler::equal, ok);
     jump(RuntimeAddress(StubRoutines::forward_exception_entry()));
     bind(ok);
-#endif // LP64
   }
 
   // get oop result if there is one and reset the value in the thread
   if (oop_result->is_valid()) {
-    get_vm_result(oop_result, java_thread);
+    get_vm_result(oop_result);
   }
 }
 
 void MacroAssembler::call_VM_helper(Register oop_result, address entry_point, int number_of_arguments, bool check_exceptions) {
+  // Calculate the value for last_Java_sp somewhat subtle.
+  // call_VM does an intermediate call which places a return address on
+  // the stack just under the stack pointer as the user finished with it.
+  // This allows use to retrieve last_Java_pc from last_Java_sp[-1].
 
-  // Calculate the value for last_Java_sp
-  // somewhat subtle. call_VM does an intermediate call
-  // which places a return address on the stack just under the
-  // stack pointer as the user finished with it. This allows
-  // use to retrieve last_Java_pc from last_Java_sp[-1].
-  // On 32bit we then have to push additional args on the stack to accomplish
-  // the actual requested call. On 64bit call_VM only can use register args
-  // so the only extra space is the return address that call_VM created.
-  // This hopefully explains the calculations here.
-
-#ifdef _LP64
   // We've pushed one address, correct last_Java_sp
   lea(rax, Address(rsp, wordSize));
-#else
-  lea(rax, Address(rsp, (1 + number_of_arguments) * wordSize));
-#endif // LP64
-
-  call_VM_base(oop_result, noreg, rax, entry_point, number_of_arguments, check_exceptions);
 
+  call_VM_base(oop_result, rax, entry_point, number_of_arguments, check_exceptions);
 }
 
 // Use this method when MacroAssembler version of call_VM_leaf_base() should be called from Interpreter.
@@ -1768,21 +1723,21 @@ void MacroAssembler::super_call_VM_leaf(address entry_point, Register arg_0, Reg
   MacroAssembler::call_VM_leaf_base(entry_point, 4);
 }
 
-void MacroAssembler::get_vm_result(Register oop_result, Register java_thread) {
-  movptr(oop_result, Address(java_thread, JavaThread::vm_result_offset()));
-  movptr(Address(java_thread, JavaThread::vm_result_offset()), NULL_WORD);
+void MacroAssembler::get_vm_result(Register oop_result) {
+  movptr(oop_result, Address(r15_thread, JavaThread::vm_result_offset()));
+  movptr(Address(r15_thread, JavaThread::vm_result_offset()), NULL_WORD);
   verify_oop_msg(oop_result, "broken oop in call_VM_base");
 }
 
-void MacroAssembler::get_vm_result_2(Register metadata_result, Register java_thread) {
-  movptr(metadata_result, Address(java_thread, JavaThread::vm_result_2_offset()));
-  movptr(Address(java_thread, JavaThread::vm_result_2_offset()), NULL_WORD);
+void MacroAssembler::get_vm_result_2(Register metadata_result) {
+  movptr(metadata_result, Address(r15_thread, JavaThread::vm_result_2_offset()));
+  movptr(Address(r15_thread, JavaThread::vm_result_2_offset()), NULL_WORD);
 }
 
-void MacroAssembler::check_and_handle_earlyret(Register java_thread) {
+void MacroAssembler::check_and_handle_earlyret() {
 }
 
-void MacroAssembler::check_and_handle_popframe(Register java_thread) {
+void MacroAssembler::check_and_handle_popframe() {
 }
 
 void MacroAssembler::cmp32(AddressLiteral src1, int32_t imm, Register rscratch) {
@@ -3170,20 +3125,16 @@ void MacroAssembler::stop_if_in_cont(Register cont, const char* name) {
 }
 #endif
 
-void MacroAssembler::reset_last_Java_frame(Register java_thread, bool clear_fp) { // determine java_thread register
-  if (!java_thread->is_valid()) {
-    java_thread = rdi;
-    get_thread(java_thread);
-  }
+void MacroAssembler::reset_last_Java_frame(bool clear_fp) { // determine java_thread register
   // we must set sp to zero to clear frame
-  movptr(Address(java_thread, JavaThread::last_Java_sp_offset()), NULL_WORD);
+  movptr(Address(r15_thread, JavaThread::last_Java_sp_offset()), NULL_WORD);
   // must clear fp, so that compiled frames are not confused; it is
   // possible that we need it only for debugging
   if (clear_fp) {
-    movptr(Address(java_thread, JavaThread::last_Java_fp_offset()), NULL_WORD);
+    movptr(Address(r15_thread, JavaThread::last_Java_fp_offset()), NULL_WORD);
   }
   // Always clear the pc because it could have been set by make_walkable()
-  movptr(Address(java_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
+  movptr(Address(r15_thread, JavaThread::last_Java_pc_offset()), NULL_WORD);
   vzeroupper();
 }
 
@@ -3202,15 +3153,15 @@ void MacroAssembler::save_rax(Register tmp) {
   else if (tmp != rax) mov(tmp, rax);
 }
 
-void MacroAssembler::safepoint_poll(Label& slow_path, Register thread_reg, bool at_return, bool in_nmethod) {
+void MacroAssembler::safepoint_poll(Label& slow_path, bool at_return, bool in_nmethod) {
   if (at_return) {
     // Note that when in_nmethod is set, the stack pointer is incremented before the poll. Therefore,
     // we may safely use rsp instead to perform the stack watermark check.
-    cmpptr(in_nmethod ? rsp : rbp, Address(thread_reg, JavaThread::polling_word_offset()));
+    cmpptr(in_nmethod ? rsp : rbp, Address(r15_thread, JavaThread::polling_word_offset()));
     jcc(Assembler::above, slow_path);
     return;
   }
-  testb(Address(thread_reg, JavaThread::polling_word_offset()), SafepointMechanism::poll_bit());
+  testb(Address(r15_thread, JavaThread::polling_word_offset()), SafepointMechanism::poll_bit());
   jcc(Assembler::notZero, slow_path); // handshake bit set implies poll
 }
 
@@ -3219,44 +3170,36 @@ void MacroAssembler::safepoint_poll(Label& slow_path, Register thread_reg, bool
 // When entering C land, the rbp, & rsp of the last Java frame have to be recorded
 // in the (thread-local) JavaThread object. When leaving C land, the last Java fp
 // has to be reset to 0. This is required to allow proper stack traversal.
-void MacroAssembler::set_last_Java_frame(Register java_thread,
-                                         Register last_java_sp,
+void MacroAssembler::set_last_Java_frame(Register last_java_sp,
                                          Register last_java_fp,
                                          address  last_java_pc,
                                          Register rscratch) {
   vzeroupper();
-  // determine java_thread register
-  if (!java_thread->is_valid()) {
-    java_thread = rdi;
-    get_thread(java_thread);
-  }
   // determine last_java_sp register
   if (!last_java_sp->is_valid()) {
     last_java_sp = rsp;
   }
   // last_java_fp is optional
   if (last_java_fp->is_valid()) {
-    movptr(Address(java_thread, JavaThread::last_Java_fp_offset()), last_java_fp);
+    movptr(Address(r15_thread, JavaThread::last_Java_fp_offset()), last_java_fp);
   }
   // last_java_pc is optional
   if (last_java_pc != nullptr) {
-    Address java_pc(java_thread,
+    Address java_pc(r15_thread,
                     JavaThread::frame_anchor_offset() + JavaFrameAnchor::last_Java_pc_offset());
     lea(java_pc, InternalAddress(last_java_pc), rscratch);
   }
-  movptr(Address(java_thread, JavaThread::last_Java_sp_offset()), last_java_sp);
+  movptr(Address(r15_thread, JavaThread::last_Java_sp_offset()), last_java_sp);
 }
 
-#ifdef _LP64
 void MacroAssembler::set_last_Java_frame(Register last_java_sp,
                                          Register last_java_fp,
                                          Label &L,
                                          Register scratch) {
   lea(scratch, L);
   movptr(Address(r15_thread, JavaThread::last_Java_pc_offset()), scratch);
-  set_last_Java_frame(r15_thread, last_java_sp, last_java_fp, nullptr, scratch);
+  set_last_Java_frame(last_java_sp, last_java_fp, nullptr, scratch);
 }
-#endif
 
 void MacroAssembler::shlptr(Register dst, int imm8) {
   LP64_ONLY(shlq(dst, imm8)) NOT_LP64(shll(dst, imm8));
@@ -4111,8 +4054,8 @@ void MacroAssembler::clear_jobject_tag(Register possibly_non_local) {
 }
 
 void MacroAssembler::resolve_jobject(Register value,
-                                     Register thread,
                                      Register tmp) {
+  Register thread = r15_thread;
   assert_different_registers(value, thread, tmp);
   Label done, tagged, weak_tagged;
   testptr(value, value);
@@ -4144,8 +4087,8 @@ void MacroAssembler::resolve_jobject(Register value,
 }
 
 void MacroAssembler::resolve_global_jobject(Register value,
-                                            Register thread,
                                             Register tmp) {
+  Register thread = r15_thread;
   assert_different_registers(value, thread, tmp);
   Label done;
 
@@ -5476,7 +5419,7 @@ void MacroAssembler::verify_secondary_supers_table(Register r_sub_klass,
 
 #endif // LP64
 
-void MacroAssembler::clinit_barrier(Register klass, Register thread, Label* L_fast_path, Label* L_slow_path) {
+void MacroAssembler::clinit_barrier(Register klass, Label* L_fast_path, Label* L_slow_path) {
   assert(L_fast_path != nullptr || L_slow_path != nullptr, "at least one is required");
 
   Label L_fallthrough;
@@ -5492,7 +5435,7 @@ void MacroAssembler::clinit_barrier(Register klass, Register thread, Label* L_fa
   jcc(Assembler::equal, *L_fast_path);
 
   // Fast path check: current thread is initializer thread
-  cmpptr(thread, Address(klass, InstanceKlass::init_thread_offset()));
+  cmpptr(r15_thread, Address(klass, InstanceKlass::init_thread_offset()));
   if (L_slow_path == &L_fallthrough) {
     jcc(Assembler::equal, *L_fast_path);
     bind(*L_slow_path);
@@ -10746,33 +10689,29 @@ Assembler::Condition MacroAssembler::negate_condition(Assembler::Condition cond)
 }
 
 // This is simply a call to Thread::current()
-void MacroAssembler::get_thread(Register thread) {
+void MacroAssembler::get_thread_slow(Register thread) {
   if (thread != rax) {
     push(rax);
   }
-  LP64_ONLY(push(rdi);)
-  LP64_ONLY(push(rsi);)
+  push(rdi);
+  push(rsi);
   push(rdx);
   push(rcx);
-#ifdef _LP64
   push(r8);
   push(r9);
   push(r10);
   push(r11);
-#endif
 
   MacroAssembler::call_VM_leaf_base(CAST_FROM_FN_PTR(address, Thread::current), 0);
 
-#ifdef _LP64
   pop(r11);
   pop(r10);
   pop(r9);
   pop(r8);
-#endif
   pop(rcx);
   pop(rdx);
-  LP64_ONLY(pop(rsi);)
-  LP64_ONLY(pop(rdi);)
+  pop(rsi);
+  pop(rdi);
   if (thread != rax) {
     mov(thread, rax);
     pop(rax);
@@ -10801,7 +10740,9 @@ void MacroAssembler::check_stack_alignment(Register sp, const char* msg, unsigne
 // reg_rax: rax
 // thread: the thread which attempts to lock obj
 // tmp: a temporary register
-void MacroAssembler::lightweight_lock(Register basic_lock, Register obj, Register reg_rax, Register thread, Register tmp, Label& slow) {
+void MacroAssembler::lightweight_lock(Register basic_lock, Register obj, Register reg_rax, Register tmp, Label& slow) {
+  Register thread = r15_thread;
+
   assert(reg_rax == rax, "");
   assert_different_registers(basic_lock, obj, reg_rax, thread, tmp);
 
@@ -10855,7 +10796,9 @@ void MacroAssembler::lightweight_lock(Register basic_lock, Register obj, Registe
 // reg_rax: rax
 // thread: the thread
 // tmp: a temporary register
-void MacroAssembler::lightweight_unlock(Register obj, Register reg_rax, Register thread, Register tmp, Label& slow) {
+void MacroAssembler::lightweight_unlock(Register obj, Register reg_rax, Register tmp, Label& slow) {
+  Register thread = r15_thread;
+
   assert(reg_rax == rax, "");
   assert_different_registers(obj, reg_rax, thread, tmp);
 
diff --git a/src/hotspot/cpu/x86/macroAssembler_x86.hpp b/src/hotspot/cpu/x86/macroAssembler_x86.hpp
index 36ef3a69d49..79f99afded2 100644
--- a/src/hotspot/cpu/x86/macroAssembler_x86.hpp
+++ b/src/hotspot/cpu/x86/macroAssembler_x86.hpp
@@ -59,13 +59,10 @@ class MacroAssembler: public Assembler {
   // may customize this version by overriding it for its purposes (e.g., to save/restore
   // additional registers when doing a VM call).
   //
-  // If no java_thread register is specified (noreg) than rdi will be used instead. call_VM_base
-  // returns the register which contains the thread upon return. If a thread register has been
-  // specified, the return value will correspond to that register. If no last_java_sp is specified
-  // (noreg) than rsp will be used instead.
+  // call_VM_base returns the register which contains the thread upon return.
+  // If no last_java_sp is specified (noreg) than rsp will be used instead.
   virtual void call_VM_base(           // returns the register containing the thread upon return
     Register oop_result,               // where an oop-result ends up if any; use noreg otherwise
-    Register java_thread,              // the thread if computed before     ; use noreg otherwise
     Register last_java_sp,             // to set up last_Java_frame in stubs; use noreg otherwise
     address  entry_point,              // the entry point
     int      number_of_arguments,      // the number of arguments (w/o thread) to pop after the call
@@ -85,8 +82,8 @@ class MacroAssembler: public Assembler {
  // These routines should emit JVMTI PopFrame and ForceEarlyReturn handling code.
  // The implementation is only non-empty for the InterpreterMacroAssembler,
  // as only the interpreter handles PopFrame and ForceEarlyReturn requests.
- virtual void check_and_handle_popframe(Register java_thread);
- virtual void check_and_handle_earlyret(Register java_thread);
+ virtual void check_and_handle_popframe();
+ virtual void check_and_handle_earlyret();
 
   Address as_Address(AddressLiteral adr);
   Address as_Address(ArrayAddress adr, Register rscratch);
@@ -224,9 +221,10 @@ class MacroAssembler: public Assembler {
   void enter();
   void leave();
 
-  // Support for getting the JavaThread pointer (i.e.; a reference to thread-local information)
-  // The pointer will be loaded into the thread register.
-  void get_thread(Register thread);
+  // Support for getting the JavaThread pointer (i.e.; a reference to thread-local information).
+  // The pointer will be loaded into the thread register. This is a slow version that does native call.
+  // Normally, JavaThread pointer is available in r15_thread, use that where possible.
+  void get_thread_slow(Register thread);
 
 #ifdef _LP64
   // Support for argument shuffling
@@ -291,8 +289,8 @@ class MacroAssembler: public Assembler {
                Register arg_1, Register arg_2, Register arg_3,
                bool check_exceptions = true);
 
-  void get_vm_result  (Register oop_result, Register thread);
-  void get_vm_result_2(Register metadata_result, Register thread);
+  void get_vm_result  (Register oop_result);
+  void get_vm_result_2(Register metadata_result);
 
   // These always tightly bind to MacroAssembler::call_VM_base
   // bypassing the virtual implementation
@@ -323,35 +321,22 @@ class MacroAssembler: public Assembler {
   void super_call_VM_leaf(address entry_point, Register arg_1, Register arg_2, Register arg_3);
   void super_call_VM_leaf(address entry_point, Register arg_1, Register arg_2, Register arg_3, Register arg_4);
 
-  // last Java Frame (fills frame anchor)
-  void set_last_Java_frame(Register thread,
-                           Register last_java_sp,
-                           Register last_java_fp,
-                           address  last_java_pc,
-                           Register rscratch);
-
-  // thread in the default location (r15_thread on 64bit)
   void set_last_Java_frame(Register last_java_sp,
                            Register last_java_fp,
                            address  last_java_pc,
                            Register rscratch);
 
-#ifdef _LP64
   void set_last_Java_frame(Register last_java_sp,
                            Register last_java_fp,
                            Label &last_java_pc,
                            Register scratch);
-#endif
 
-  void reset_last_Java_frame(Register thread, bool clear_fp);
-
-  // thread in the default location (r15_thread on 64bit)
   void reset_last_Java_frame(bool clear_fp);
 
   // jobjects
   void clear_jobject_tag(Register possibly_non_local);
-  void resolve_jobject(Register value, Register thread, Register tmp);
-  void resolve_global_jobject(Register value, Register thread, Register tmp);
+  void resolve_jobject(Register value, Register tmp);
+  void resolve_global_jobject(Register value, Register tmp);
 
   // C 'boolean' to Java boolean: x == 0 ? 0 : 1
   void c2bool(Register x);
@@ -762,7 +747,6 @@ public:
                            Label& L_success);
 
   void clinit_barrier(Register klass,
-                      Register thread,
                       Label* L_fast_path = nullptr,
                       Label* L_slow_path = nullptr);
 
@@ -837,7 +821,7 @@ public:
   // Check for reserved stack access in method being exited (for JIT)
   void reserved_stack_check();
 
-  void safepoint_poll(Label& slow_path, Register thread_reg, bool at_return, bool in_nmethod);
+  void safepoint_poll(Label& slow_path, bool at_return, bool in_nmethod);
 
   void verify_tlab();
 
@@ -2247,8 +2231,8 @@ public:
 
   void check_stack_alignment(Register sp, const char* msg, unsigned bias = 0, Register tmp = noreg);
 
-  void lightweight_lock(Register basic_lock, Register obj, Register reg_rax, Register thread, Register tmp, Label& slow);
-  void lightweight_unlock(Register obj, Register reg_rax, Register thread, Register tmp, Label& slow);
+  void lightweight_lock(Register basic_lock, Register obj, Register reg_rax, Register tmp, Label& slow);
+  void lightweight_unlock(Register obj, Register reg_rax, Register tmp, Label& slow);
 
 #ifdef _LP64
   void save_legacy_gprs();
diff --git a/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp b/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp
index d3e7e23678a..09c102aa5d1 100644
--- a/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp
+++ b/src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp
@@ -1104,7 +1104,7 @@ AdapterHandlerEntry* SharedRuntime::generate_i2c2i_adapters(MacroAssembler *masm
 
     Register klass = rscratch1;
     __ load_method_holder(klass, method);
-    __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
+    __ clinit_barrier(klass, &L_skip_barrier /*L_fast_path*/);
 
     __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub())); // slow path
 
@@ -2003,7 +2003,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
     Label L_skip_barrier;
     Register klass = r10;
     __ mov_metadata(klass, method->method_holder()); // InstanceKlass*
-    __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
+    __ clinit_barrier(klass, &L_skip_barrier /*L_fast_path*/);
 
     __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub())); // slow path
 
@@ -2280,7 +2280,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
       __ inc_held_monitor_count();
     } else {
       assert(LockingMode == LM_LIGHTWEIGHT, "must be");
-      __ lightweight_lock(lock_reg, obj_reg, swap_reg, r15_thread, rscratch1, slow_path_lock);
+      __ lightweight_lock(lock_reg, obj_reg, swap_reg, rscratch1, slow_path_lock);
     }
 
     // Slow path will re-enter here
@@ -2340,7 +2340,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
     Label Continue;
     Label slow_path;
 
-    __ safepoint_poll(slow_path, r15_thread, true /* at_return */, false /* in_nmethod */);
+    __ safepoint_poll(slow_path, true /* at_return */, false /* in_nmethod */);
 
     __ cmpl(Address(r15_thread, JavaThread::suspend_flags_offset()), 0);
     __ jcc(Assembler::equal, Continue);
@@ -2431,7 +2431,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
       __ dec_held_monitor_count();
     } else {
       assert(LockingMode == LM_LIGHTWEIGHT, "must be");
-      __ lightweight_unlock(obj_reg, swap_reg, r15_thread, lock_reg, slow_path_unlock);
+      __ lightweight_unlock(obj_reg, swap_reg, lock_reg, slow_path_unlock);
     }
 
     // slow path re-enters here
@@ -2456,7 +2456,6 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
   // Unbox oop result, e.g. JNIHandles::resolve value.
   if (is_reference_type(ret_type)) {
     __ resolve_jobject(rax /* value */,
-                       r15_thread /* thread */,
                        rcx /* tmp */);
   }
 
@@ -3234,7 +3233,7 @@ RuntimeStub* SharedRuntime::generate_resolve_blob(SharedStubId id, address desti
   __ jcc(Assembler::notEqual, pending);
 
   // get the returned Method*
-  __ get_vm_result_2(rbx, r15_thread);
+  __ get_vm_result_2(rbx);
   __ movptr(Address(rsp, RegisterSaver::rbx_offset_in_bytes()), rbx);
 
   __ movptr(Address(rsp, RegisterSaver::rax_offset_in_bytes()), rax);
@@ -3661,7 +3660,7 @@ RuntimeStub* SharedRuntime::generate_jfr_write_checkpoint() {
   __ reset_last_Java_frame(true);
 
   // rax is jobject handle result, unpack and process it through a barrier.
-  __ resolve_global_jobject(rax, r15_thread, c_rarg0);
+  __ resolve_global_jobject(rax, c_rarg0);
 
   __ leave();
   __ ret(0);
diff --git a/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp b/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp
index 7e63e6fb49b..9fcb044b09a 100644
--- a/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp
+++ b/src/hotspot/cpu/x86/stubGenerator_x86_64.cpp
@@ -339,7 +339,7 @@ address StubGenerator::generate_call_stub(address& return_address) {
     __ jcc(Assembler::equal, L1);
     __ stop("StubRoutines::call_stub: r15_thread is corrupted");
     __ bind(L1);
-    __ get_thread(rbx);
+    __ get_thread_slow(rbx);
     __ cmpptr(r15_thread, thread);
     __ jcc(Assembler::equal, L2);
     __ stop("StubRoutines::call_stub: r15_thread is modified by call");
@@ -426,7 +426,7 @@ address StubGenerator::generate_catch_exception() {
     __ jcc(Assembler::equal, L1);
     __ stop("StubRoutines::catch_exception: r15_thread is corrupted");
     __ bind(L1);
-    __ get_thread(rbx);
+    __ get_thread_slow(rbx);
     __ cmpptr(r15_thread, thread);
     __ jcc(Assembler::equal, L2);
     __ stop("StubRoutines::catch_exception: r15_thread is modified by call");
@@ -1313,7 +1313,7 @@ void StubGenerator::setup_arg_regs_using_thread(int nargs) {
     __ mov(rax, r9);       // r9 is also saved_r15
   }
   __ mov(saved_r15, r15);  // r15 is callee saved and needs to be restored
-  __ get_thread(r15_thread);
+  __ get_thread_slow(r15_thread);
   assert(c_rarg0 == rcx && c_rarg1 == rdx && c_rarg2 == r8 && c_rarg3 == r9,
          "unexpected argument registers");
   __ movptr(Address(r15_thread, in_bytes(JavaThread::windows_saved_rdi_offset())), rdi);
@@ -1337,7 +1337,7 @@ void StubGenerator::restore_arg_regs_using_thread() {
   assert(_regs_in_thread, "wrong call to restore_arg_regs");
   const Register saved_r15 = r9;
 #ifdef _WIN64
-  __ get_thread(r15_thread);
+  __ get_thread_slow(r15_thread);
   __ movptr(rsi, Address(r15_thread, in_bytes(JavaThread::windows_saved_rsi_offset())));
   __ movptr(rdi, Address(r15_thread, in_bytes(JavaThread::windows_saved_rdi_offset())));
   __ mov(r15, saved_r15);  // r15 is callee saved and needs to be restored
@@ -3974,7 +3974,7 @@ address StubGenerator::generate_upcall_stub_load_target() {
   StubCodeMark mark(this, stub_id);
   address start = __ pc();
 
-  __ resolve_global_jobject(j_rarg0, r15_thread, rscratch1);
+  __ resolve_global_jobject(j_rarg0, rscratch1);
     // Load target method from receiver
   __ load_heap_oop(rbx, Address(j_rarg0, java_lang_invoke_MethodHandle::form_offset()), rscratch1);
   __ load_heap_oop(rbx, Address(rbx, java_lang_invoke_LambdaForm::vmentry_offset()), rscratch1);
diff --git a/src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp b/src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp
index ccc8e456d57..1e056f15213 100644
--- a/src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp
+++ b/src/hotspot/cpu/x86/stubGenerator_x86_64_arraycopy.cpp
@@ -2476,7 +2476,7 @@ address StubGenerator::generate_checkcast_copy(StubGenStubId stub_id, address *e
 
 #ifdef ASSERT
     Label L2;
-    __ get_thread(r14);
+    __ get_thread_slow(r14);
     __ cmpptr(r15_thread, r14);
     __ jcc(Assembler::equal, L2);
     __ stop("StubRoutines::call_stub: r15_thread is modified by call");
diff --git a/src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp b/src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp
index efbdac8244d..fecc804a044 100644
--- a/src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp
+++ b/src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp
@@ -204,10 +204,10 @@ address TemplateInterpreterGenerator::generate_return_entry_for(TosState state,
   }
 
    if (JvmtiExport::can_pop_frame()) {
-     __ check_and_handle_popframe(r15_thread);
+     __ check_and_handle_popframe();
    }
    if (JvmtiExport::can_force_early_return()) {
-     __ check_and_handle_earlyret(r15_thread);
+     __ check_and_handle_earlyret();
    }
 
   __ dispatch_next(state, step);
@@ -991,7 +991,7 @@ address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
     Label Continue;
     Label slow_path;
 
-    __ safepoint_poll(slow_path, thread, true /* at_return */, false /* in_nmethod */);
+    __ safepoint_poll(slow_path, true /* at_return */, false /* in_nmethod */);
 
     __ cmpl(Address(thread, JavaThread::suspend_flags_offset()), 0);
     __ jcc(Assembler::equal, Continue);
@@ -1034,7 +1034,7 @@ address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
   }
 
   // reset_last_Java_frame
-  __ reset_last_Java_frame(thread, true);
+  __ reset_last_Java_frame(true);
 
   if (CheckJNICalls) {
     // clear_pending_jni_exception_check
@@ -1057,7 +1057,6 @@ address TemplateInterpreterGenerator::generate_native_entry(bool synchronized) {
     __ pop(ltos);
     // Unbox oop result, e.g. JNIHandles::resolve value.
     __ resolve_jobject(rax /* value */,
-                       thread /* thread */,
                        t /* tmp */);
     __ movptr(Address(rbp, frame::interpreter_frame_oop_temp_offset*wordSize), rax);
     // keep stack depth as expected by pushing oop which will eventually be discarded
@@ -1495,7 +1494,7 @@ void TemplateInterpreterGenerator::generate_throw_exception() {
   // PC must point into interpreter here
   __ set_last_Java_frame(noreg, rbp, __ pc(), rscratch1);
   __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::popframe_move_outgoing_args), r15_thread, c_rarg1, c_rarg2);
-  __ reset_last_Java_frame(thread, true);
+  __ reset_last_Java_frame(true);
 
   // Restore the last_sp and null it out
   __ movptr(rcx, Address(rbp, frame::interpreter_frame_last_sp_offset * wordSize));
@@ -1548,7 +1547,7 @@ void TemplateInterpreterGenerator::generate_throw_exception() {
   // remove the activation (without doing throws on illegalMonitorExceptions)
   __ remove_activation(vtos, rdx, false, true, false);
   // restore exception
-  __ get_vm_result(rax, thread);
+  __ get_vm_result(rax);
 
   // In between activations - previous activation type unknown yet
   // compute continuation point - the continuation point expects the
diff --git a/src/hotspot/cpu/x86/templateInterpreterGenerator_x86_64.cpp b/src/hotspot/cpu/x86/templateInterpreterGenerator_x86_64.cpp
index f4ed1081c3b..6be702f2699 100644
--- a/src/hotspot/cpu/x86/templateInterpreterGenerator_x86_64.cpp
+++ b/src/hotspot/cpu/x86/templateInterpreterGenerator_x86_64.cpp
@@ -190,7 +190,7 @@ address TemplateInterpreterGenerator::generate_CRC32_update_entry() {
   // c_rarg1: scratch (rsi on non-Win64, rdx on Win64)
 
   Label slow_path;
-  __ safepoint_poll(slow_path, r15_thread, true /* at_return */, false /* in_nmethod */);
+  __ safepoint_poll(slow_path, true /* at_return */, false /* in_nmethod */);
 
   // We don't generate local frame and don't align stack because
   // we call stub code and there is no safepoint on this path.
@@ -234,7 +234,7 @@ address TemplateInterpreterGenerator::generate_CRC32_updateBytes_entry(AbstractI
   // r13: senderSP must preserved for slow path, set SP to it on fast path
 
   Label slow_path;
-  __ safepoint_poll(slow_path, r15_thread, false /* at_return */, false /* in_nmethod */);
+  __ safepoint_poll(slow_path, false /* at_return */, false /* in_nmethod */);
 
   // We don't generate local frame and don't align stack because
   // we call stub code and there is no safepoint on this path.
diff --git a/src/hotspot/cpu/x86/templateTable_x86.cpp b/src/hotspot/cpu/x86/templateTable_x86.cpp
index b378bc431fa..1641abac923 100644
--- a/src/hotspot/cpu/x86/templateTable_x86.cpp
+++ b/src/hotspot/cpu/x86/templateTable_x86.cpp
@@ -478,7 +478,7 @@ void TemplateTable::condy_helper(Label& Done) {
   const Register rarg = c_rarg1;
   __ movl(rarg, (int)bytecode());
   call_VM(obj, CAST_FROM_FN_PTR(address, InterpreterRuntime::resolve_ldc), rarg);
-  __ get_vm_result_2(flags, r15_thread);
+  __ get_vm_result_2(flags);
   // VMr = obj = base address to find primitive value to push
   // VMr2 = flags = (tos, off) using format of CPCE::_flags
   __ movl(off, flags);
@@ -2263,12 +2263,10 @@ void TemplateTable::resolve_cache_and_index_for_method(int byte_no,
   if (VM_Version::supports_fast_class_init_checks() && bytecode() == Bytecodes::_invokestatic) {
     const Register method = temp;
     const Register klass  = temp;
-    const Register thread = r15_thread;
-    assert(thread != noreg, "x86_32 not supported");
 
     __ movptr(method, Address(cache, in_bytes(ResolvedMethodEntry::method_offset())));
     __ load_method_holder(klass, method);
-    __ clinit_barrier(klass, thread, nullptr /*L_fast_path*/, &L_clinit_barrier_slow);
+    __ clinit_barrier(klass, nullptr /*L_fast_path*/, &L_clinit_barrier_slow);
   }
 }
 
@@ -3572,7 +3570,7 @@ void TemplateTable::_new() {
   // make sure klass is initialized
   // init_state needs acquire, but x86 is TSO, and so we are already good.
   assert(VM_Version::supports_fast_class_init_checks(), "must support fast class initialization checks");
-  __ clinit_barrier(rcx, r15_thread, nullptr /*L_fast_path*/, &slow_case);
+  __ clinit_barrier(rcx, nullptr /*L_fast_path*/, &slow_case);
 
   // get instance_size in InstanceKlass (scaled to a count of bytes)
   __ movl(rdx, Address(rcx, Klass::layout_helper_offset()));
@@ -3712,7 +3710,7 @@ void TemplateTable::checkcast() {
   call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::quicken_io_cc));
 
   // vm_result_2 has metadata result
-  __ get_vm_result_2(rax, r15_thread);
+  __ get_vm_result_2(rax);
 
   __ pop_ptr(rdx); // restore receiver
   __ jmpb(resolved);
@@ -3767,9 +3765,9 @@ void TemplateTable::instanceof() {
 
   __ push(atos); // save receiver for result, and for GC
   call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::quicken_io_cc));
-  // vm_result_2 has metadata result
 
-  __ get_vm_result_2(rax, r15_thread);
+  // vm_result_2 has metadata result
+  __ get_vm_result_2(rax);
 
   __ pop_ptr(rdx); // restore receiver
   __ verify_oop(rdx);
diff --git a/src/hotspot/cpu/x86/x86_64.ad b/src/hotspot/cpu/x86/x86_64.ad
index b94ff7dbd9e..5781ffce4bd 100644
--- a/src/hotspot/cpu/x86/x86_64.ad
+++ b/src/hotspot/cpu/x86/x86_64.ad
@@ -845,7 +845,7 @@ void MachPrologNode::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {
     Register klass = rscratch1;
 
     __ mov_metadata(klass, C->method()->holder()->constant_encoding());
-    __ clinit_barrier(klass, r15_thread, &L_skip_barrier /*L_fast_path*/);
+    __ clinit_barrier(klass, &L_skip_barrier /*L_fast_path*/);
 
     __ jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub())); // slow path
 
@@ -943,7 +943,7 @@ void MachEpilogNode::emit(C2_MacroAssembler* masm, PhaseRegAlloc* ra_) const
       code_stub = &stub->entry();
     }
     __ relocate(relocInfo::poll_return_type);
-    __ safepoint_poll(*code_stub, r15_thread, true /* at_return */, true /* in_nmethod */);
+    __ safepoint_poll(*code_stub, true /* at_return */, true /* in_nmethod */);
   }
 }