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/*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * 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
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;
+ // 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
// 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
}
}
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()));
+ if (UseCompactObjectHeaders) {
+ ldr(t1, Address(klass, Klass::prototype_header_offset()));
+ str(t1, Address(obj, oopDesc::mark_offset_in_bytes()));
} else {
- str(klass, Address(obj, oopDesc::klass_offset_in_bytes()));
+ // 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) {
+ } else if (UseCompressedClassPointers && !UseCompactObjectHeaders) {
store_klass_gap(obj, zr);
}
}
// preserves obj, destroys len_in_bytes
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) {
+ 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");
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);
+ 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, header_size * BytesPerWord, t1, t2);
+ initialize_body(obj, arr_size, base_offset, t1, t2);
if (Compilation::current()->bailed_out()) {
return;
}
membar(StoreStore);
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");
-
+ // 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) {
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