| /* |
| * Copyright (c) 1997, 2010, 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_VM_CODE_LOCATION_HPP |
| #define SHARE_VM_CODE_LOCATION_HPP |
| |
| #include "asm/assembler.hpp" |
| #include "code/vmreg.hpp" |
| #include "memory/allocation.hpp" |
| |
| // A Location describes a concrete machine variable location |
| // (such as integer or floating point register or a stack-held |
| // variable). Used when generating debug-information for nmethods. |
| // |
| // Encoding: |
| // |
| // bits (use low bits for best compression): |
| // Type: [3..0] |
| // Where: [4] |
| // Offset: [31..5] |
| |
| class Location VALUE_OBJ_CLASS_SPEC { |
| friend class VMStructs; |
| public: |
| enum Where { |
| on_stack, |
| in_register |
| }; |
| |
| enum Type { |
| invalid, // Invalid location |
| normal, // Ints, floats, double halves |
| oop, // Oop (please GC me!) |
| int_in_long, // Integer held in long register |
| lng, // Long held in one register |
| float_in_dbl, // Float held in double register |
| dbl, // Double held in one register |
| addr, // JSR return address |
| narrowoop // Narrow Oop (please GC me!) |
| }; |
| |
| |
| private: |
| enum { |
| TYPE_MASK = (juint) 0x0F, |
| TYPE_SHIFT = 0, |
| WHERE_MASK = (juint) 0x10, |
| WHERE_SHIFT = 4, |
| OFFSET_MASK = (juint) 0xFFFFFFE0, |
| OFFSET_SHIFT = 5 |
| }; |
| |
| juint _value; |
| |
| // Create a bit-packed Location |
| Location(Where where_, Type type_, unsigned offset_) { |
| set(where_, type_, offset_); |
| assert( where () == where_ , "" ); |
| assert( type () == type_ , "" ); |
| assert( offset() == offset_, "" ); |
| } |
| |
| inline void set(Where where_, Type type_, unsigned offset_) { |
| _value = (juint) ((where_ << WHERE_SHIFT) | |
| (type_ << TYPE_SHIFT) | |
| ((offset_ << OFFSET_SHIFT) & OFFSET_MASK)); |
| } |
| |
| public: |
| |
| // Stack location Factory. Offset is 4-byte aligned; remove low bits |
| static Location new_stk_loc( Type t, int offset ) { return Location(on_stack,t,offset>>LogBytesPerInt); } |
| // Register location Factory |
| static Location new_reg_loc( Type t, VMReg reg ) { return Location(in_register, t, reg->value()); } |
| // Default constructor |
| Location() { set(on_stack,invalid,0); } |
| |
| // Bit field accessors |
| Where where() const { return (Where) ((_value & WHERE_MASK) >> WHERE_SHIFT);} |
| Type type() const { return (Type) ((_value & TYPE_MASK) >> TYPE_SHIFT); } |
| unsigned offset() const { return (unsigned) ((_value & OFFSET_MASK) >> OFFSET_SHIFT); } |
| |
| // Accessors |
| bool is_register() const { return where() == in_register; } |
| bool is_stack() const { return where() == on_stack; } |
| |
| int stack_offset() const { assert(where() == on_stack, "wrong Where"); return offset()<<LogBytesPerInt; } |
| int register_number() const { assert(where() == in_register, "wrong Where"); return offset() ; } |
| |
| VMReg reg() const { assert(where() == in_register, "wrong Where"); return VMRegImpl::as_VMReg(offset()) ; } |
| |
| // Printing |
| void print_on(outputStream* st) const; |
| |
| // Serialization of debugging information |
| Location(DebugInfoReadStream* stream); |
| void write_on(DebugInfoWriteStream* stream); |
| |
| // check |
| static bool legal_offset_in_bytes(int offset_in_bytes); |
| }; |
| |
| #endif // SHARE_VM_CODE_LOCATION_HPP |