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8064457: Introduce compressed oops mode disjoint base and improve compressed heap handling

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Introduce compressed oops mode disjoint base and improve compressed heap handling.

Reviewed-by: kvn, coleenp
This commit is contained in:
Goetz Lindenmaier 2015-01-05 12:07:37 -05:00
parent 5b8ee4c102
commit 1c18aef92c
13 changed files with 530 additions and 296 deletions
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33
hotspot/src/share/vm/memory/universe.hpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2015, 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
@ -102,8 +102,8 @@ class Universe: AllStatic {
friend class MarkSweep;
friend class oopDesc;
friend class ClassLoader;
friend class Arguments;
friend class SystemDictionary;
friend class ReservedHeapSpace;
friend class VMStructs;
friend class VM_PopulateDumpSharedSpace;
friend class Metaspace;
@ -351,17 +351,40 @@ class Universe: AllStatic {
// NarrowOopHeapBaseMin + heap_size < 4Gb
// 1 - Use zero based compressed oops with encoding when
// NarrowOopHeapBaseMin + heap_size < 32Gb
// 2 - Use compressed oops with heap base + encoding.
// 2 - Use compressed oops with disjoint heap base if
// base is 32G-aligned and base > 0. This allows certain
// optimizations in encoding/decoding.
// Disjoint: Bits used in base are disjoint from bits used
// for oops ==> oop = (cOop << 3) | base. One can disjoint
// the bits of an oop into base and compressed oop.
// 3 - Use compressed oops with heap base + encoding.
enum NARROW_OOP_MODE {
UnscaledNarrowOop = 0,
ZeroBasedNarrowOop = 1,
HeapBasedNarrowOop = 2
DisjointBaseNarrowOop = 2,
HeapBasedNarrowOop = 3,
AnyNarrowOopMode = 4
};
static NARROW_OOP_MODE narrow_oop_mode();
static const char* narrow_oop_mode_to_string(NARROW_OOP_MODE mode);
static char* preferred_heap_base(size_t heap_size, size_t alignment, NARROW_OOP_MODE mode);
static char* preferred_metaspace_base(size_t heap_size, NARROW_OOP_MODE mode);
static address narrow_oop_base() { return _narrow_oop._base; }
static address narrow_oop_base() { return _narrow_oop._base; }
// Test whether bits of addr and possible offsets into the heap overlap.
static bool is_disjoint_heap_base_address(address addr) {
return (((uint64_t)(intptr_t)addr) &
(((uint64_t)UCONST64(0xFFFFffffFFFFffff)) >> (32-LogMinObjAlignmentInBytes))) == 0;
}
// Check for disjoint base compressed oops.
static bool narrow_oop_base_disjoint() {
return _narrow_oop._base != NULL && is_disjoint_heap_base_address(_narrow_oop._base);
}
// Check for real heapbased compressed oops.
// We must subtract the base as the bits overlap.
// If we negate above function, we also get unscaled and zerobased.
static bool narrow_oop_base_overlaps() {
return _narrow_oop._base != NULL && !is_disjoint_heap_base_address(_narrow_oop._base);
}
static bool is_narrow_oop_base(void* addr) { return (narrow_oop_base() == (address)addr); }
static int narrow_oop_shift() { return _narrow_oop._shift; }
static bool narrow_oop_use_implicit_null_checks() { return _narrow_oop._use_implicit_null_checks; }