8351997: AArch64: Interpreter volatile reference stores with G1 are not sequentially consistent

Reviewed-by: eosterlund, adinn
Backport-of: 83b15da2eb3cb6c8937f517c9b75eaa9eeece314

Author: shipilev

src/hotspot/cpu/aarch64/templateTable_aarch64.cpp

@@ -1136,6 +1136,7 @@ void TemplateTable::aastore() {
   // Get the value we will store
   __ ldr(r0, at_tos());
   // Now store using the appropriate barrier
+  // Clobbers: r10, r11, r3
   do_oop_store(_masm, element_address, r0, IS_ARRAY);
   __ b(done);
 
@@ -1144,6 +1145,7 @@ void TemplateTable::aastore() {
   __ profile_null_seen(r2);
 
   // Store a NULL
+  // Clobbers: r10, r11, r3
   do_oop_store(_masm, element_address, noreg, IS_ARRAY);
 
   // Pop stack arguments
@@ -2706,6 +2708,7 @@ void TemplateTable::putfield_or_static(int byte_no, bool is_static, RewriteContr
     __ pop(atos);
     if (!is_static) pop_and_check_object(obj);
     // Store into the field
+    // Clobbers: r10, r11, r3
     do_oop_store(_masm, field, r0, IN_HEAP);
     if (rc == may_rewrite) {
       patch_bytecode(Bytecodes::_fast_aputfield, bc, r1, true, byte_no);
@@ -2905,16 +2908,16 @@ void TemplateTable::fast_storefield(TosState state)
   // Must prevent reordering of the following cp cache loads with bytecode load
   __ membar(MacroAssembler::LoadLoad);
 
-  // test for volatile with r3
-  __ ldrw(r3, Address(r2, in_bytes(base +
+  // test for volatile with r5
+  __ ldrw(r5, Address(r2, in_bytes(base +
                                    ConstantPoolCacheEntry::flags_offset())));
 
   // replace index with field offset from cache entry
   __ ldr(r1, Address(r2, in_bytes(base + ConstantPoolCacheEntry::f2_offset())));
 
   {
     Label notVolatile;
-    __ tbz(r3, ConstantPoolCacheEntry::is_volatile_shift, notVolatile);
+    __ tbz(r5, ConstantPoolCacheEntry::is_volatile_shift, notVolatile);
     __ membar(MacroAssembler::StoreStore | MacroAssembler::LoadStore);
     __ bind(notVolatile);
   }
@@ -2930,6 +2933,7 @@ void TemplateTable::fast_storefield(TosState state)
   // access field
   switch (bytecode()) {
   case Bytecodes::_fast_aputfield:
+    // Clobbers: r10, r11, r3
     do_oop_store(_masm, field, r0, IN_HEAP);
     break;
   case Bytecodes::_fast_lputfield:
@@ -2962,7 +2966,7 @@ void TemplateTable::fast_storefield(TosState state)
 
   {
     Label notVolatile;
-    __ tbz(r3, ConstantPoolCacheEntry::is_volatile_shift, notVolatile);
+    __ tbz(r5, ConstantPoolCacheEntry::is_volatile_shift, notVolatile);
     __ membar(MacroAssembler::StoreLoad | MacroAssembler::StoreStore);
     __ bind(notVolatile);
   }