Update (2025.02.24)

35671: Fix -Wzero-as-null-pointer-constant warnings in loongarch code
35670: LA port of 8310691: [REDO] [vectorapi] Refactor VectorShuffle implementation
35669: LA port of 8345040: Clean up unused variables and code in generate_native_wrapper

src/hotspot/cpu/loongarch/c1_LIRAssembler_loongarch_64.cpp

@@ -557,7 +557,7 @@ void LIR_Assembler::const2mem(LIR_Opr src, LIR_Opr dest, BasicType type,
     break;
   case T_OBJECT:
   case T_ARRAY:
-    assert(c->as_jobject() == 0, "should be");
+    assert(c->as_jobject() == nullptr, "should be");
     if (UseCompressedOops && !wide) {
       insn = &Assembler::st_w;
     } else {

src/hotspot/cpu/loongarch/c1_Runtime1_loongarch_64.cpp

@@ -1063,7 +1063,4 @@ OopMapSet* Runtime1::generate_code_for(C1StubId id, StubAssembler* sasm) {
 
 #undef __
 
-const char *Runtime1::pd_name_for_address(address entry) {
-  Unimplemented();
-  return 0;
-}
+const char *Runtime1::pd_name_for_address(address entry) { Unimplemented(); }

src/hotspot/cpu/loongarch/frame_loongarch.cpp

@@ -272,7 +272,7 @@ void frame::patch_pc(Thread* thread, address pc) {
 
   // Either the return address is the original one or we are going to
   // patch in the same address that's already there.
-  assert(_pc == pc_old || pc == pc_old || pc_old == 0, "must be");
+  assert(_pc == pc_old || pc == pc_old || pc_old == nullptr, "must be");
   DEBUG_ONLY(address old_pc = _pc;)
   *pc_addr = pc;
   _pc = pc; // must be set before call to get_deopt_original_pc
@@ -499,10 +499,10 @@ frame frame::sender_for_interpreter_frame(RegisterMap* map) const {
 bool frame::is_interpreted_frame_valid(JavaThread* thread) const {
   assert(is_interpreted_frame(), "Not an interpreted frame");
   // These are reasonable sanity checks
-  if (fp() == 0 || (intptr_t(fp()) & (wordSize-1)) != 0) {
+  if (fp() == nullptr || (intptr_t(fp()) & (wordSize-1)) != 0) {
     return false;
   }
-  if (sp() == 0 || (intptr_t(sp()) & (wordSize-1)) != 0) {
+  if (sp() == nullptr || (intptr_t(sp()) & (wordSize-1)) != 0) {
     return false;
   }
   if (fp() + interpreter_frame_initial_sp_offset < sp()) {

src/hotspot/cpu/loongarch/loongarch_64.ad

@@ -1140,6 +1140,10 @@ bool Matcher::vector_needs_partial_operations(Node* node, const TypeVect* vt) {
   return false;
 }
 
+bool Matcher::vector_rearrange_requires_load_shuffle(BasicType elem_bt, int vlen) {
+  return false;
+}
+
 const RegMask* Matcher::predicate_reg_mask(void) {
   return nullptr;
 }
@@ -15209,36 +15213,6 @@ instruct populateIndexV(vReg dst, mRegI src1, immI_1 src2) %{
   ins_pipe( pipe_slow );
 %}
 
-// ---------------------------- LOAD_SHUFFLE ----------------------------------
-
-instruct loadShuffleVB(vReg dst) %{
-  predicate(Matcher::vector_element_basic_type(n) == T_BYTE);
-  match(Set dst (VectorLoadShuffle dst));
-  format %{ "(x)vld_shuffle    $dst\t# @loadShuffleVB" %}
-  ins_encode %{
-    // empty
-  %}
-  ins_pipe( pipe_slow );
-%}
-
-instruct loadShuffleV(vReg dst, vReg src) %{
-  predicate(Matcher::vector_element_basic_type(n) != T_BYTE);
-  match(Set dst (VectorLoadShuffle src));
-  format %{ "(x)vld_shuffle    $dst, $src\t# @loadShuffleV" %}
-  ins_encode %{
-    switch (Matcher::vector_element_basic_type(this)) {
-      case T_SHORT : __ vext2xv_hu_bu($dst$$FloatRegister, $src$$FloatRegister); break;
-      case T_FLOAT :
-      case T_INT   : __ vext2xv_wu_bu($dst$$FloatRegister, $src$$FloatRegister); break;
-      case T_DOUBLE:
-      case T_LONG  : __ vext2xv_du_bu($dst$$FloatRegister, $src$$FloatRegister); break;
-      default:
-        ShouldNotReachHere();
-    }
-  %}
-  ins_pipe( pipe_slow );
-%}
-
 // ---------------------------- Rearrange -------------------------------------
 
 instruct rearrangeV(vReg dst, vReg src, vReg tmp) %{

src/hotspot/cpu/loongarch/macroAssembler_loongarch.hpp

@@ -556,7 +556,7 @@ class MacroAssembler: public Assembler {
 
   void patchable_jump_far(Register ra, jlong offs);
   void patchable_jump(address target, bool force_patchable = false);
-  void patchable_call(address target, address call_size = 0);
+  void patchable_call(address target, address call_size = nullptr);
 
   // Floating
   void generate_dsin_dcos(bool isCos, address npio2_hw, address two_over_pi,

src/hotspot/cpu/loongarch/nativeInst_loongarch.hpp

@@ -163,7 +163,7 @@ class NativeCall: public NativeInstruction {
     return next_instruction_address();
   }
 
-  address target_addr_for_bl(address orig_addr = 0) const;
+  address target_addr_for_bl(address orig_addr = nullptr) const;
   address destination() const;
   void set_destination(address dest);
 
@@ -245,7 +245,7 @@ class NativeFarCall: public NativeInstruction {
   }
 
   // Returns the NativeFarCall's destination.
-  address destination(address orig_addr = 0) const;
+  address destination(address orig_addr = nullptr) const;
 
   // Sets the NativeFarCall's destination, not necessarily mt-safe.
   // Used when relocating code.
@@ -403,7 +403,7 @@ class NativeJump: public NativeInstruction {
   bool is_far();
 
   address instruction_address() const { return addr_at(instruction_offset); }
-  address jump_destination(address orig_addr = 0);
+  address jump_destination(address orig_addr = nullptr);
   void  set_jump_destination(address dest);
 
   // Creation

src/hotspot/cpu/loongarch/sharedRuntime_loongarch_64.cpp

@@ -1417,7 +1417,6 @@ nmethod *SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
 
   BasicType* out_sig_bt = NEW_RESOURCE_ARRAY(BasicType, total_c_args);
   VMRegPair* out_regs   = NEW_RESOURCE_ARRAY(VMRegPair, total_c_args);
-  BasicType* in_elem_bt = nullptr;
 
   int argc = 0;
   out_sig_bt[argc++] = T_ADDRESS;
@@ -1842,8 +1841,6 @@ nmethod *SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
     __ cast_primitive_type(ret_type, V0);
   }
 
-  Label after_transition;
-
   // Switch thread to "native transition" state before reading the synchronization state.
   // This additional state is necessary because reading and testing the synchronization
   // state is not atomic w.r.t. GC, as this scenario demonstrates:
@@ -1908,7 +1905,6 @@ nmethod *SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
   } else {
     __ st_w(AT, TREG, in_bytes(JavaThread::thread_state_offset()));
   }
-  __ bind(after_transition);
 
   if (LockingMode != LM_LEGACY && method->is_object_wait0()) {
     // Check preemption for Object.wait()