jdk/src/hotspot/share/oops/compressedKlass.inline.hpp
2023-07-12 09:06:53 +00:00

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/*
* Copyright (c) 2017, 2023, Oracle and/or its affiliates. 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
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
#ifndef SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP
#define SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP
#include "oops/compressedKlass.hpp"
#include "memory/universe.hpp"
#include "oops/oop.hpp"
#include "utilities/align.hpp"
#include "utilities/globalDefinitions.hpp"
static inline bool check_alignment(Klass* v) {
return (intptr_t)v % KlassAlignmentInBytes == 0;
}
inline Klass* CompressedKlassPointers::decode_raw(narrowKlass v) {
return decode_raw(v, base(), shift());
}
inline Klass* CompressedKlassPointers::decode_raw(narrowKlass v, address narrow_base, int shift) {
return (Klass*)((uintptr_t)narrow_base +((uintptr_t)v << shift));
}
inline Klass* CompressedKlassPointers::decode_not_null(narrowKlass v) {
return decode_not_null(v, base(), shift());
}
inline Klass* CompressedKlassPointers::decode_not_null(narrowKlass v, address narrow_base, int shift) {
assert(!is_null(v), "narrow klass value can never be zero");
Klass* result = decode_raw(v, narrow_base, shift);
assert(check_alignment(result), "address not aligned: " PTR_FORMAT, p2i(result));
return result;
}
inline Klass* CompressedKlassPointers::decode(narrowKlass v) {
return is_null(v) ? nullptr : decode_not_null(v);
}
inline narrowKlass CompressedKlassPointers::encode_not_null(Klass* v) {
return encode_not_null(v, base(), shift());
}
inline narrowKlass CompressedKlassPointers::encode_not_null(Klass* v, address narrow_base, int shift) {
assert(!is_null(v), "klass value can never be zero");
assert(check_alignment(v), "Address not aligned");
uint64_t pd = (uint64_t)(pointer_delta(v, narrow_base, 1));
assert(KlassEncodingMetaspaceMax > pd, "change encoding max if new encoding");
uint64_t result = pd >> shift;
assert((result & CONST64(0xffffffff00000000)) == 0, "narrow klass pointer overflow");
assert(decode_not_null((narrowKlass)result, narrow_base, shift) == v, "reversibility");
return (narrowKlass)result;
}
inline narrowKlass CompressedKlassPointers::encode(Klass* v) {
return is_null(v) ? (narrowKlass)0 : encode_not_null(v);
}
#endif // SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP