Mercurial > hg > truffle
annotate src/share/vm/code/location.hpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
| author | tschatzl |
|---|---|
| date | Fri, 10 Oct 2014 15:51:58 +0200 |
| parents | f95d63e2154a |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 1972 | 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_CODE_LOCATION_HPP |
| 26 #define SHARE_VM_CODE_LOCATION_HPP | |
| 27 | |
| 28 #include "asm/assembler.hpp" | |
| 29 #include "code/vmreg.hpp" | |
| 30 #include "memory/allocation.hpp" | |
| 31 | |
| 0 | 32 // A Location describes a concrete machine variable location |
| 33 // (such as integer or floating point register or a stack-held | |
| 34 // variable). Used when generating debug-information for nmethods. | |
| 35 // | |
| 36 // Encoding: | |
| 37 // | |
| 331 | 38 // bits (use low bits for best compression): |
| 39 // Type: [3..0] | |
| 40 // Where: [4] | |
| 41 // Offset: [31..5] | |
| 0 | 42 |
| 43 class Location VALUE_OBJ_CLASS_SPEC { | |
| 44 friend class VMStructs; | |
| 45 public: | |
| 46 enum Where { | |
| 47 on_stack, | |
| 48 in_register | |
| 49 }; | |
| 50 | |
| 51 enum Type { | |
| 331 | 52 invalid, // Invalid location |
| 0 | 53 normal, // Ints, floats, double halves |
| 54 oop, // Oop (please GC me!) | |
| 55 int_in_long, // Integer held in long register | |
| 56 lng, // Long held in one register | |
| 57 float_in_dbl, // Float held in double register | |
| 58 dbl, // Double held in one register | |
| 59 addr, // JSR return address | |
| 331 | 60 narrowoop // Narrow Oop (please GC me!) |
| 0 | 61 }; |
| 62 | |
| 63 | |
| 64 private: | |
| 65 enum { | |
| 331 | 66 TYPE_MASK = (juint) 0x0F, |
| 67 TYPE_SHIFT = 0, | |
| 68 WHERE_MASK = (juint) 0x10, | |
| 69 WHERE_SHIFT = 4, | |
| 70 OFFSET_MASK = (juint) 0xFFFFFFE0, | |
| 71 OFFSET_SHIFT = 5 | |
| 0 | 72 }; |
| 73 | |
| 331 | 74 juint _value; |
| 0 | 75 |
| 76 // Create a bit-packed Location | |
| 77 Location(Where where_, Type type_, unsigned offset_) { | |
| 78 set(where_, type_, offset_); | |
| 79 assert( where () == where_ , "" ); | |
| 80 assert( type () == type_ , "" ); | |
| 81 assert( offset() == offset_, "" ); | |
| 82 } | |
| 83 | |
| 84 inline void set(Where where_, Type type_, unsigned offset_) { | |
| 331 | 85 _value = (juint) ((where_ << WHERE_SHIFT) | |
| 86 (type_ << TYPE_SHIFT) | | |
| 87 ((offset_ << OFFSET_SHIFT) & OFFSET_MASK)); | |
| 0 | 88 } |
| 89 | |
| 90 public: | |
| 91 | |
| 92 // Stack location Factory. Offset is 4-byte aligned; remove low bits | |
| 93 static Location new_stk_loc( Type t, int offset ) { return Location(on_stack,t,offset>>LogBytesPerInt); } | |
| 94 // Register location Factory | |
| 95 static Location new_reg_loc( Type t, VMReg reg ) { return Location(in_register, t, reg->value()); } | |
| 96 // Default constructor | |
| 331 | 97 Location() { set(on_stack,invalid,0); } |
| 0 | 98 |
| 99 // Bit field accessors | |
| 100 Where where() const { return (Where) ((_value & WHERE_MASK) >> WHERE_SHIFT);} | |
| 101 Type type() const { return (Type) ((_value & TYPE_MASK) >> TYPE_SHIFT); } | |
| 102 unsigned offset() const { return (unsigned) ((_value & OFFSET_MASK) >> OFFSET_SHIFT); } | |
| 103 | |
| 104 // Accessors | |
| 105 bool is_register() const { return where() == in_register; } | |
| 106 bool is_stack() const { return where() == on_stack; } | |
| 107 | |
| 108 int stack_offset() const { assert(where() == on_stack, "wrong Where"); return offset()<<LogBytesPerInt; } | |
| 109 int register_number() const { assert(where() == in_register, "wrong Where"); return offset() ; } | |
| 110 | |
| 111 VMReg reg() const { assert(where() == in_register, "wrong Where"); return VMRegImpl::as_VMReg(offset()) ; } | |
| 112 | |
| 113 // Printing | |
| 114 void print_on(outputStream* st) const; | |
| 115 | |
| 116 // Serialization of debugging information | |
| 117 Location(DebugInfoReadStream* stream); | |
| 118 void write_on(DebugInfoWriteStream* stream); | |
| 119 | |
| 120 // check | |
| 121 static bool legal_offset_in_bytes(int offset_in_bytes); | |
| 122 }; | |
| 1972 | 123 |
| 124 #endif // SHARE_VM_CODE_LOCATION_HPP |