Mercurial > hg > truffle
diff src/share/vm/code/location.hpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
---|---|
date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | cecd8eb4e0ca |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/code/location.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,114 @@ +/* + * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// 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: +// Where: [15] +// Type: [14..12] +// Offset: [11..0] + +class Location VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; + public: + enum Where { + on_stack, + in_register + }; + + enum Type { + 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 + invalid // Invalid location + }; + + + private: + enum { + OFFSET_MASK = (jchar) 0x0FFF, + OFFSET_SHIFT = 0, + TYPE_MASK = (jchar) 0x7000, + TYPE_SHIFT = 12, + WHERE_MASK = (jchar) 0x8000, + WHERE_SHIFT = 15 + }; + + uint16_t _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 = (uint16_t) ((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,(unsigned) -1); } + + // 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); +};