1 /*
2 * Copyright (c) 2017, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP
26 #define SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP
27
28 #include "oops/compressedKlass.hpp"
29
30 #include "memory/universe.hpp"
31 #include "oops/oop.hpp"
32 #include "utilities/align.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 inline Klass* CompressedKlassPointers::decode_not_null_without_asserts(narrowKlass v, address narrow_base_base, int shift) {
36 return (Klass*)((uintptr_t)narrow_base_base +((uintptr_t)v << shift));
37 }
38
39 inline Klass* CompressedKlassPointers::decode_not_null(narrowKlass v, address narrow_base, int shift) {
40 assert(!is_null(v), "narrow klass value can never be zero");
41 Klass* result = decode_not_null_without_asserts(v, narrow_base, shift);
42 DEBUG_ONLY(check_valid_klass(result, narrow_base, shift));
43 return result;
44 }
45
46 inline narrowKlass CompressedKlassPointers::encode_not_null_without_asserts(Klass* k, address narrow_base, int shift) {
47 return (narrowKlass)(pointer_delta(k, narrow_base, 1) >> shift);
48 }
49
50 inline narrowKlass CompressedKlassPointers::encode_not_null(Klass* v, address narrow_base, int shift) {
51 assert(!is_null(v), "klass value can never be zero");
52 DEBUG_ONLY(check_valid_klass(v);)
53 narrowKlass result = encode_not_null_without_asserts(v, narrow_base, shift);
54 assert(decode_not_null((narrowKlass)result, narrow_base, shift) == v, "reversibility");
55 return result;
56 }
57
58 inline Klass* CompressedKlassPointers::decode_not_null_without_asserts(narrowKlass v) {
59 return decode_not_null_without_asserts(v, base(), shift());
60 }
61
62 inline Klass* CompressedKlassPointers::decode_without_asserts(narrowKlass v) {
63 return is_null(v) ? nullptr : decode_not_null_without_asserts(v);
64 }
65
66 inline Klass* CompressedKlassPointers::decode_not_null(narrowKlass v) {
67 DEBUG_ONLY(check_valid_narrow_klass_id(v);)
68 return decode_not_null(v, base(), shift());
69 }
70
71 inline Klass* CompressedKlassPointers::decode(narrowKlass v) {
72 return is_null(v) ? nullptr : decode_not_null(v);
73 }
74
75 inline narrowKlass CompressedKlassPointers::encode_not_null(Klass* v) {
76 narrowKlass nk = encode_not_null(v, base(), shift());
77 DEBUG_ONLY(check_valid_narrow_klass_id(nk);)
78 return nk;
79 }
80
81 inline narrowKlass CompressedKlassPointers::encode(Klass* v) {
82 return is_null(v) ? (narrowKlass)0 : encode_not_null(v);
83 }
84
85 #ifdef ASSERT
86 inline void CompressedKlassPointers::check_valid_klass(const Klass* k, address base, int shift) {
87 const int log_alignment = MAX2(3, shift); // always at least 64-bit aligned
88 assert(is_aligned(k, nth_bit(log_alignment)), "Klass (" PTR_FORMAT ") not properly aligned to %zu",
89 p2i(k), nth_bit(shift));
90 const address encoding_end = base + nth_bit(narrow_klass_pointer_bits() + shift);
91 assert((address)k >= base && (address)k < encoding_end,
92 "Klass (" PTR_FORMAT ") falls outside of the valid encoding range [" PTR_FORMAT "-" PTR_FORMAT ")",
93 p2i(k), p2i(base), p2i(encoding_end));
94 }
95
96 inline void CompressedKlassPointers::check_valid_klass(const Klass* k) {
97 assert(UseCompressedClassPointers, "Only call for +UseCCP");
98 check_valid_klass(k, base(), shift());
99 // Also assert that k falls into what we know is the valid Klass range. This is usually smaller
100 // than the encoding range (e.g. encoding range covers 4G, but we only have 1G class space and a
101 // tiny bit of CDS => 1.1G)
102 const address klassrange_end = base() + range();
103 assert((address)k < klassrange_end,
104 "Klass (" PTR_FORMAT ") falls outside of the valid klass range [" PTR_FORMAT "-" PTR_FORMAT ")",
105 p2i(k), p2i(base()), p2i(klassrange_end));
106 }
107 inline void CompressedKlassPointers::check_valid_narrow_klass_id(narrowKlass nk) {
108 assert(UseCompressedClassPointers, "Only call for +UseCCP");
109 const uint64_t nk_mask = ~right_n_bits(narrow_klass_pointer_bits());
110 assert(((uint64_t)nk & nk_mask) == 0, "narrow klass id bit spillover (%u)", nk);
111 assert(nk >= _lowest_valid_narrow_klass_id &&
112 nk <= _highest_valid_narrow_klass_id, "narrowKlass ID out of range (%u)", nk);
113 }
114 #endif // ASSERT
115
116 #endif // SHARE_OOPS_COMPRESSEDKLASS_INLINE_HPP