< prev index next >

src/hotspot/cpu/aarch64/c1_MacroAssembler_aarch64.cpp

Print this page
*** 1,7 ***
  /*
!  * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2014, 2021, Red Hat Inc. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
--- 1,7 ---
  /*
!  * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2014, 2021, Red Hat Inc. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as

*** 78,16 ***
      ldrw(hdr, Address(hdr, Klass::access_flags_offset()));
      tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS);
      br(Assembler::NE, slow_case);
    }
  
-   // Load object header
-   ldr(hdr, Address(obj, hdr_offset));
    if (LockingMode == LM_LIGHTWEIGHT) {
      lightweight_lock(obj, hdr, temp, rscratch2, slow_case);
    } else if (LockingMode == LM_LEGACY) {
      Label done;
      // and mark it as unlocked
      orr(hdr, hdr, markWord::unlocked_value);
      // save unlocked object header into the displaced header location on the stack
      str(hdr, Address(disp_hdr, 0));
      // test if object header is still the same (i.e. unlocked), and if so, store the
--- 78,16 ---
      ldrw(hdr, Address(hdr, Klass::access_flags_offset()));
      tstw(hdr, JVM_ACC_IS_VALUE_BASED_CLASS);
      br(Assembler::NE, slow_case);
    }
  
    if (LockingMode == LM_LIGHTWEIGHT) {
      lightweight_lock(obj, hdr, temp, rscratch2, slow_case);
    } else if (LockingMode == LM_LEGACY) {
      Label done;
+     // Load object header
+     ldr(hdr, Address(obj, hdr_offset));
      // and mark it as unlocked
      orr(hdr, hdr, markWord::unlocked_value);
      // save unlocked object header into the displaced header location on the stack
      str(hdr, Address(disp_hdr, 0));
      // test if object header is still the same (i.e. unlocked), and if so, store the

*** 142,15 ***
    // load object
    ldr(obj, Address(disp_hdr, BasicObjectLock::obj_offset()));
    verify_oop(obj);
  
    if (LockingMode == LM_LIGHTWEIGHT) {
-     ldr(hdr, Address(obj, oopDesc::mark_offset_in_bytes()));
-     // We cannot use tbnz here, the target might be too far away and cannot
-     // be encoded.
-     tst(hdr, markWord::monitor_value);
-     br(Assembler::NE, slow_case);
      lightweight_unlock(obj, hdr, temp, rscratch2, 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
      // the displaced header, get the object header instead
--- 142,10 ---

*** 178,24 ***
    }
  }
  
  void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
    assert_different_registers(obj, klass, len);
!   // This assumes that all prototype bits fit in an int32_t
!   mov(t1, (int32_t)(intptr_t)markWord::prototype().value());
!   str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
- 
-   if (UseCompressedClassPointers) { // Take care not to kill klass
-     encode_klass_not_null(t1, klass);
-     strw(t1, Address(obj, oopDesc::klass_offset_in_bytes()));
    } else {
!     str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));
    }
  
    if (len->is_valid()) {
      strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
!   } else if (UseCompressedClassPointers) {
      store_klass_gap(obj, zr);
    }
  }
  
  // preserves obj, destroys len_in_bytes
--- 173,29 ---
    }
  }
  
  void C1_MacroAssembler::initialize_header(Register obj, Register klass, Register len, Register t1, Register t2) {
    assert_different_registers(obj, klass, len);
!   if (UseCompactObjectHeaders) {
!     ldr(t1, Address(klass, Klass::prototype_header_offset()));
!     str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
    } else {
!     // This assumes that all prototype bits fit in an int32_t
+     mov(t1, (int32_t)(intptr_t)markWord::prototype().value());
+     str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
+ 
+     if (UseCompressedClassPointers) { // Take care not to kill klass
+       encode_klass_not_null(t1, klass);
+       strw(t1, Address(obj, oopDesc::klass_offset_in_bytes()));
+     } else {
+       str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));
+     }
    }
  
    if (len->is_valid()) {
      strw(len, Address(obj, arrayOopDesc::length_offset_in_bytes()));
!   } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
      store_klass_gap(obj, zr);
    }
  }
  
  // preserves obj, destroys len_in_bytes

*** 269,11 ***
      far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
    }
  
    verify_oop(obj);
  }
! void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int header_size, int f, Register klass, Label& slow_case) {
    assert_different_registers(obj, len, t1, t2, klass);
  
    // determine alignment mask
    assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
  
--- 269,11 ---
      far_call(RuntimeAddress(Runtime1::entry_for(Runtime1::dtrace_object_alloc_id)));
    }
  
    verify_oop(obj);
  }
! void C1_MacroAssembler::allocate_array(Register obj, Register len, Register t1, Register t2, int base_offset_in_bytes, int f, Register klass, Label& slow_case) {
    assert_different_registers(obj, len, t1, t2, klass);
  
    // determine alignment mask
    assert(!(BytesPerWord & 1), "must be a multiple of 2 for masking code to work");
  

*** 282,20 ***
    cmp(len, rscratch1);
    br(Assembler::HS, slow_case);
  
    const Register arr_size = t2; // okay to be the same
    // align object end
!   mov(arr_size, (int32_t)header_size * BytesPerWord + MinObjAlignmentInBytesMask);
    add(arr_size, arr_size, len, ext::uxtw, f);
    andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask);
  
    try_allocate(obj, arr_size, 0, t1, t2, slow_case);
  
    initialize_header(obj, klass, len, t1, t2);
  
    // clear rest of allocated space
!   initialize_body(obj, arr_size, header_size * BytesPerWord, t1, t2);
    if (Compilation::current()->bailed_out()) {
      return;
    }
  
    membar(StoreStore);
--- 282,31 ---
    cmp(len, rscratch1);
    br(Assembler::HS, slow_case);
  
    const Register arr_size = t2; // okay to be the same
    // align object end
!   mov(arr_size, (int32_t)base_offset_in_bytes + MinObjAlignmentInBytesMask);
    add(arr_size, arr_size, len, ext::uxtw, f);
    andr(arr_size, arr_size, ~MinObjAlignmentInBytesMask);
  
    try_allocate(obj, arr_size, 0, t1, t2, slow_case);
  
    initialize_header(obj, klass, len, t1, t2);
  
+   // Clear leading 4 bytes, if necessary.
+   // TODO: This could perhaps go into initialize_body() and also clear the leading 4 bytes
+   // for non-array objects, thereby replacing the klass-gap clearing code in initialize_header().
+   int base_offset = base_offset_in_bytes;
+   if (!is_aligned(base_offset, BytesPerWord)) {
+     assert(is_aligned(base_offset, BytesPerInt), "must be 4-byte aligned");
+     strw(zr, Address(obj, base_offset));
+     base_offset += BytesPerInt;
+   }
+   assert(is_aligned(base_offset, BytesPerWord), "must be word-aligned");
+ 
    // clear rest of allocated space
!   initialize_body(obj, arr_size, base_offset, t1, t2);
    if (Compilation::current()->bailed_out()) {
      return;
    }
  
    membar(StoreStore);

*** 310,13 ***
  
  
  void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
    verify_oop(receiver);
    // explicit null check not needed since load from [klass_offset] causes a trap
!   // check against inline cache
-   assert(!MacroAssembler::needs_explicit_null_check(oopDesc::klass_offset_in_bytes()), "must add explicit null check");
- 
    cmp_klass(receiver, iCache, rscratch1);
  }
  
  
  void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes) {
--- 321,11 ---
  
  
  void C1_MacroAssembler::inline_cache_check(Register receiver, Register iCache) {
    verify_oop(receiver);
    // explicit null check not needed since load from [klass_offset] causes a trap
!   // check against inline cache. This is checked in Universe::genesis()..
    cmp_klass(receiver, iCache, rscratch1);
  }
  
  
  void C1_MacroAssembler::build_frame(int framesize, int bang_size_in_bytes) {
< prev index next >