src/hotspot/cpu/aarch64/aarch64.ad

@@ -5797,10 +5797,13 @@
  // All of the memory operands. For the pipeline description.
  opclass memory(indirect, indIndexScaled, indIndexScaledI2L, indIndexI2L, indIndex,
                 indOffI1, indOffL1, indOffI2, indOffL2, indOffI4, indOffL4, indOffI8, indOffL8,
                 indirectN, indIndexScaledN, indIndexScaledI2LN, indIndexI2LN, indIndexN, indOffIN, indOffLN, indirectX2P, indOffX2P);
  
+ opclass memory_noindex(indirect,
+                        indOffI1, indOffL1,indOffI2, indOffL2, indOffI4, indOffL4, indOffI8, indOffL8,
+                        indirectN, indOffIN, indOffLN, indirectX2P, indOffX2P);
  
  // iRegIorL2I is used for src inputs in rules for 32 bit int (I)
  // operations. it allows the src to be either an iRegI or a (ConvL2I
  // iRegL). in the latter case the l2i normally planted for a ConvL2I
  // can be elided because the 32-bit instruction will just employ the

@@ -6734,25 +6737,26 @@
    ins_encode(aarch64_enc_ldrw(dst, mem));
  
    ins_pipe(iload_reg_mem);
  %}
  
- instruct loadNKlassCompactHeaders(iRegNNoSp dst, memory4 mem)
+ instruct loadNKlassCompactHeaders(iRegNNoSp dst, memory_noindex mem)
  %{
    match(Set dst (LoadNKlass mem));
    predicate(!needs_acquiring_load(n) && UseCompactObjectHeaders);
  
    ins_cost(4 * INSN_COST);
    format %{
      "ldrw  $dst, $mem\t# compressed class ptr, shifted\n\t"
-     "lsrw  $dst, $dst, markWord::klass_shift_at_offset"
+     "lsrw  $dst, $dst, markWord::klass_shift"
    %}
    ins_encode %{
-     // inlined aarch64_enc_ldrw
-     loadStore(masm, &MacroAssembler::ldrw, $dst$$Register, $mem->opcode(),
-               as_Register($mem$$base), $mem$$index, $mem$$scale, $mem$$disp, 4);
-     __ lsrw($dst$$Register, $dst$$Register, markWord::klass_shift_at_offset);
+     assert($mem$$index$$Register == noreg, "must not have indexed address");
+     // The incoming address is pointing into obj-start + klass_offset_in_bytes. We need to extract
+     // obj-start, so that we can load from the object's mark-word instead.
+     __ ldrw($dst$$Register, Address($mem$$base$$Register, $mem$$disp - Type::klass_offset()));
+     __ lsrw($dst$$Register, $dst$$Register, markWord::klass_shift);
    %}
    ins_pipe(iload_reg_mem);
  %}
  
  // Load Float