150 lines
5.5 KiB
C++
150 lines
5.5 KiB
C++
/*
|
|
* Copyright (c) 2017, 2020, 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
|
|
* or visit www.oracle.com if you need additional information or have any
|
|
* questions.
|
|
*
|
|
*/
|
|
|
|
#ifndef SHARE_OOPS_COMPRESSEDOOPS_INLINE_HPP
|
|
#define SHARE_OOPS_COMPRESSEDOOPS_INLINE_HPP
|
|
|
|
#include "gc/shared/collectedHeap.hpp"
|
|
#include "memory/universe.hpp"
|
|
#include "oops/compressedOops.hpp"
|
|
#include "oops/oop.hpp"
|
|
#include "utilities/align.hpp"
|
|
|
|
// Functions for encoding and decoding compressed oops.
|
|
// If the oops are compressed, the type passed to these overloaded functions
|
|
// is narrowOop. All functions are overloaded so they can be called by
|
|
// template functions without conditionals (the compiler instantiates via
|
|
// the right type and inlines the appropriate code).
|
|
|
|
// Algorithm for encoding and decoding oops from 64 bit pointers to 32 bit
|
|
// offset from the heap base. Saving the check for null can save instructions
|
|
// in inner GC loops so these are separated.
|
|
|
|
inline oop CompressedOops::decode_raw_not_null(narrowOop v) {
|
|
assert(!is_null(v), "narrow oop value can never be zero");
|
|
return decode_raw(v);
|
|
}
|
|
|
|
inline oop CompressedOops::decode_raw(narrowOop v) {
|
|
return (oop)(void*)((uintptr_t)base() + ((uintptr_t)v << shift()));
|
|
}
|
|
|
|
inline oop CompressedOops::decode_not_null(narrowOop v) {
|
|
assert(!is_null(v), "narrow oop value can never be zero");
|
|
oop result = decode_raw(v);
|
|
assert(is_object_aligned(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
|
|
assert(Universe::heap()->is_in(result), "object not in heap " PTR_FORMAT, p2i((void*) result));
|
|
return result;
|
|
}
|
|
|
|
inline oop CompressedOops::decode(narrowOop v) {
|
|
return is_null(v) ? (oop)NULL : decode_not_null(v);
|
|
}
|
|
|
|
inline narrowOop CompressedOops::encode_not_null(oop v) {
|
|
assert(!is_null(v), "oop value can never be zero");
|
|
assert(is_object_aligned(v), "address not aligned: " PTR_FORMAT, p2i((void*)v));
|
|
assert(is_in(v), "address not in heap range: " PTR_FORMAT, p2i((void*)v));
|
|
uint64_t pd = (uint64_t)(pointer_delta((void*)v, (void*)base(), 1));
|
|
assert(OopEncodingHeapMax > pd, "change encoding max if new encoding");
|
|
narrowOop result = narrow_oop_cast(pd >> shift());
|
|
assert(decode_raw(result) == v, "reversibility");
|
|
return result;
|
|
}
|
|
|
|
inline narrowOop CompressedOops::encode(oop v) {
|
|
return is_null(v) ? narrowOop::null : encode_not_null(v);
|
|
}
|
|
|
|
inline oop CompressedOops::decode_not_null(oop v) {
|
|
assert(Universe::heap()->is_in(v), "object not in heap " PTR_FORMAT, p2i((void*) v));
|
|
return v;
|
|
}
|
|
|
|
inline oop CompressedOops::decode(oop v) {
|
|
assert(Universe::heap()->is_in_or_null(v), "object not in heap " PTR_FORMAT, p2i((void*) v));
|
|
return v;
|
|
}
|
|
|
|
inline narrowOop CompressedOops::encode_not_null(narrowOop v) {
|
|
return v;
|
|
}
|
|
|
|
inline narrowOop CompressedOops::encode(narrowOop v) {
|
|
return v;
|
|
}
|
|
|
|
inline uint32_t CompressedOops::narrow_oop_value(oop o) {
|
|
return narrow_oop_value(encode(o));
|
|
}
|
|
|
|
inline uint32_t CompressedOops::narrow_oop_value(narrowOop o) {
|
|
return static_cast<uint32_t>(o);
|
|
}
|
|
|
|
template<typename T>
|
|
inline narrowOop CompressedOops::narrow_oop_cast(T i) {
|
|
static_assert(std::is_integral<T>::value, "precondition");
|
|
uint32_t narrow_value = static_cast<uint32_t>(i);
|
|
// Ensure no bits lost in conversion to uint32_t.
|
|
assert(i == static_cast<T>(narrow_value), "narrowOop overflow");
|
|
return static_cast<narrowOop>(narrow_value);
|
|
}
|
|
|
|
static inline bool check_alignment(Klass* v) {
|
|
return (intptr_t)v % KlassAlignmentInBytes == 0;
|
|
}
|
|
|
|
inline Klass* CompressedKlassPointers::decode_raw(narrowKlass v) {
|
|
return (Klass*)(void*)((uintptr_t)base() +((uintptr_t)v << shift()));
|
|
}
|
|
|
|
inline Klass* CompressedKlassPointers::decode_not_null(narrowKlass v) {
|
|
assert(!is_null(v), "narrow klass value can never be zero");
|
|
Klass* result = decode_raw(v);
|
|
assert(check_alignment(result), "address not aligned: " INTPTR_FORMAT, p2i((void*) result));
|
|
return result;
|
|
}
|
|
|
|
inline Klass* CompressedKlassPointers::decode(narrowKlass v) {
|
|
return is_null(v) ? (Klass*)NULL : decode_not_null(v);
|
|
}
|
|
|
|
inline narrowKlass CompressedKlassPointers::encode_not_null(Klass* v) {
|
|
assert(!is_null(v), "klass value can never be zero");
|
|
assert(check_alignment(v), "Address not aligned");
|
|
uint64_t pd = (uint64_t)(pointer_delta((void*)v, 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(result) == v, "reversibility");
|
|
return (narrowKlass)result;
|
|
}
|
|
|
|
inline narrowKlass CompressedKlassPointers::encode(Klass* v) {
|
|
return is_null(v) ? (narrowKlass)0 : encode_not_null(v);
|
|
}
|
|
|
|
#endif // SHARE_OOPS_COMPRESSEDOOPS_INLINE_HPP
|