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src/share/vm/code/location.hpp@a61af66fc99e (annotated)

src/share/vm/code/location.hpp

Sat, 01 Dec 2007 00:00:00 +0000

author

duke

date

Sat, 01 Dec 2007 00:00:00 +0000

changeset 435

a61af66fc99e

child 766

cecd8eb4e0ca

permissions

-rw-r--r--

Initial load

duke@435	1	/*
duke@435	2	* Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	// A Location describes a concrete machine variable location
duke@435	26	// (such as integer or floating point register or a stack-held
duke@435	27	// variable). Used when generating debug-information for nmethods.
duke@435	28	//
duke@435	29	// Encoding:
duke@435	30	//
duke@435	31	// bits:
duke@435	32	// Where: [15]
duke@435	33	// Type: [14..12]
duke@435	34	// Offset: [11..0]
duke@435	35
duke@435	36	class Location VALUE_OBJ_CLASS_SPEC {
duke@435	37	friend class VMStructs;
duke@435	38	public:
duke@435	39	enum Where {
duke@435	40	on_stack,
duke@435	41	in_register
duke@435	42	};
duke@435	43
duke@435	44	enum Type {
duke@435	45	normal, // Ints, floats, double halves
duke@435	46	oop, // Oop (please GC me!)
duke@435	47	int_in_long, // Integer held in long register
duke@435	48	lng, // Long held in one register
duke@435	49	float_in_dbl, // Float held in double register
duke@435	50	dbl, // Double held in one register
duke@435	51	addr, // JSR return address
duke@435	52	invalid // Invalid location
duke@435	53	};
duke@435	54
duke@435	55
duke@435	56	private:
duke@435	57	enum {
duke@435	58	OFFSET_MASK = (jchar) 0x0FFF,
duke@435	59	OFFSET_SHIFT = 0,
duke@435	60	TYPE_MASK = (jchar) 0x7000,
duke@435	61	TYPE_SHIFT = 12,
duke@435	62	WHERE_MASK = (jchar) 0x8000,
duke@435	63	WHERE_SHIFT = 15
duke@435	64	};
duke@435	65
duke@435	66	uint16_t _value;
duke@435	67
duke@435	68	// Create a bit-packed Location
duke@435	69	Location(Where where_, Type type_, unsigned offset_) {
duke@435	70	set(where_, type_, offset_);
duke@435	71	assert( where () == where_ , "" );
duke@435	72	assert( type () == type_ , "" );
duke@435	73	assert( offset() == offset_, "" );
duke@435	74	}
duke@435	75
duke@435	76	inline void set(Where where_, Type type_, unsigned offset_) {
duke@435	77	_value = (uint16_t) ((where_ << WHERE_SHIFT) |
duke@435	78	(type_ << TYPE_SHIFT) |
duke@435	79	((offset_ << OFFSET_SHIFT) & OFFSET_MASK));
duke@435	80	}
duke@435	81
duke@435	82	public:
duke@435	83
duke@435	84	// Stack location Factory. Offset is 4-byte aligned; remove low bits
duke@435	85	static Location new_stk_loc( Type t, int offset ) { return Location(on_stack,t,offset>>LogBytesPerInt); }
duke@435	86	// Register location Factory
duke@435	87	static Location new_reg_loc( Type t, VMReg reg ) { return Location(in_register, t, reg->value()); }
duke@435	88	// Default constructor
duke@435	89	Location() { set(on_stack,invalid,(unsigned) -1); }
duke@435	90
duke@435	91	// Bit field accessors
duke@435	92	Where where() const { return (Where) ((_value & WHERE_MASK) >> WHERE_SHIFT);}
duke@435	93	Type type() const { return (Type) ((_value & TYPE_MASK) >> TYPE_SHIFT); }
duke@435	94	unsigned offset() const { return (unsigned) ((_value & OFFSET_MASK) >> OFFSET_SHIFT); }
duke@435	95
duke@435	96	// Accessors
duke@435	97	bool is_register() const { return where() == in_register; }
duke@435	98	bool is_stack() const { return where() == on_stack; }
duke@435	99
duke@435	100	int stack_offset() const { assert(where() == on_stack, "wrong Where"); return offset()<<LogBytesPerInt; }
duke@435	101	int register_number() const { assert(where() == in_register, "wrong Where"); return offset() ; }
duke@435	102
duke@435	103	VMReg reg() const { assert(where() == in_register, "wrong Where"); return VMRegImpl::as_VMReg(offset()) ; }
duke@435	104
duke@435	105	// Printing
duke@435	106	void print_on(outputStream* st) const;
duke@435	107
duke@435	108	// Serialization of debugging information
duke@435	109	Location(DebugInfoReadStream* stream);
duke@435	110	void write_on(DebugInfoWriteStream* stream);
duke@435	111
duke@435	112	// check
duke@435	113	static bool legal_offset_in_bytes(int offset_in_bytes);
duke@435	114	};