8346890: AArch64: Type profile counters generate suboptimal code

Reviewed-by: shade, adinn

Author: Andrew Haley

src/hotspot/cpu/aarch64/c1_LIRAssembler_aarch64.cpp

@@ -1217,31 +1217,37 @@ void LIR_Assembler::emit_alloc_array(LIR_OpAllocArray* op) {
 void LIR_Assembler::type_profile_helper(Register mdo,
                                         ciMethodData *md, ciProfileData *data,
                                         Register recv, Label* update_done) {
+
+  // Given a profile data offset, generate an Address which points to
+  // the corresponding slot in mdo->data().
+  // Clobbers rscratch2.
+  auto slot_at = [=](ByteSize offset) -> Address {
+    return __ form_address(rscratch2, mdo,
+                           md->byte_offset_of_slot(data, offset),
+                           LogBytesPerWord);
+  };
+
   for (uint i = 0; i < ReceiverTypeData::row_limit(); i++) {
     Label next_test;
     // See if the receiver is receiver[n].
-    __ lea(rscratch2, Address(mdo, md->byte_offset_of_slot(data, ReceiverTypeData::receiver_offset(i))));
-    __ ldr(rscratch1, Address(rscratch2));
+    __ ldr(rscratch1, slot_at(ReceiverTypeData::receiver_offset(i)));
     __ cmp(recv, rscratch1);
     __ br(Assembler::NE, next_test);
-    Address data_addr(mdo, md->byte_offset_of_slot(data, ReceiverTypeData::receiver_count_offset(i)));
-    __ addptr(data_addr, DataLayout::counter_increment);
+    __ addptr(slot_at(ReceiverTypeData::receiver_count_offset(i)),
+              DataLayout::counter_increment);
     __ b(*update_done);
     __ bind(next_test);
   }
 
   // Didn't find receiver; find next empty slot and fill it in
   for (uint i = 0; i < ReceiverTypeData::row_limit(); i++) {
     Label next_test;
-    __ lea(rscratch2,
-           Address(mdo, md->byte_offset_of_slot(data, ReceiverTypeData::receiver_offset(i))));
-    Address recv_addr(rscratch2);
+    Address recv_addr(slot_at(ReceiverTypeData::receiver_offset(i)));
     __ ldr(rscratch1, recv_addr);
     __ cbnz(rscratch1, next_test);
     __ str(recv, recv_addr);
     __ mov(rscratch1, DataLayout::counter_increment);
-    __ lea(rscratch2, Address(mdo, md->byte_offset_of_slot(data, ReceiverTypeData::receiver_count_offset(i))));
-    __ str(rscratch1, Address(rscratch2));
+    __ str(rscratch1, slot_at(ReceiverTypeData::receiver_count_offset(i)));
     __ b(*update_done);
     __ bind(next_test);
   }
@@ -1413,8 +1419,7 @@ void LIR_Assembler::emit_opTypeCheck(LIR_OpTypeCheck* op) {
       // Object is null; update MDO and exit
       Address data_addr
         = __ form_address(rscratch2, mdo,
-                          md->byte_offset_of_slot(data, DataLayout::flags_offset()),
-                          0);
+                          md->byte_offset_of_slot(data, DataLayout::flags_offset()), 0);
       __ ldrb(rscratch1, data_addr);
       __ orr(rscratch1, rscratch1, BitData::null_seen_byte_constant());
       __ strb(rscratch1, data_addr);
@@ -2565,10 +2570,12 @@ void LIR_Assembler::emit_profile_call(LIR_OpProfileCall* op) {
       for (i = 0; i < VirtualCallData::row_limit(); i++) {
         ciKlass* receiver = vc_data->receiver(i);
         if (receiver == nullptr) {
-          Address recv_addr(mdo, md->byte_offset_of_slot(data, VirtualCallData::receiver_offset(i)));
           __ mov_metadata(rscratch1, known_klass->constant_encoding());
-          __ lea(rscratch2, recv_addr);
-          __ str(rscratch1, Address(rscratch2));
+          Address recv_addr =
+            __ form_address(rscratch2, mdo,
+                            md->byte_offset_of_slot(data, VirtualCallData::receiver_offset(i)),
+                            LogBytesPerWord);
+          __ str(rscratch1, recv_addr);
           Address data_addr(mdo, md->byte_offset_of_slot(data, VirtualCallData::receiver_count_offset(i)));
           __ addptr(data_addr, DataLayout::counter_increment);
           return;

src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp

@@ -1173,7 +1173,10 @@ class MacroAssembler: public Assembler {
 
   // Arithmetics
 
+  // Clobber: rscratch1, rscratch2
   void addptr(const Address &dst, int32_t src);
+
+  // Clobber: rscratch1
   void cmpptr(Register src1, Address src2);
 
   void cmpoop(Register obj1, Register obj2);