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src/share/vm/code/location.hpp@e9ff18c4ace7 (annotated)

src/share/vm/code/location.hpp

Wed, 02 Jun 2010 22:45:42 -0700

author

jrose

date

Wed, 02 Jun 2010 22:45:42 -0700

changeset 1934

e9ff18c4ace7

parent 1907

c18cbe5936b8

child 2314

f95d63e2154a

permissions

-rw-r--r--

Merge

duke@435	1	/*
trims@1907	2	* Copyright (c) 1997, 2008, Oracle and/or its affiliates. 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	*
trims@1907	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907	20	* or visit www.oracle.com if you need additional information or have any
trims@1907	21	* 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	//
kvn@766	31	// bits (use low bits for best compression):
kvn@766	32	// Type: [3..0]
kvn@766	33	// Where: [4]
kvn@766	34	// Offset: [31..5]
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 {
kvn@766	45	invalid, // Invalid location
duke@435	46	normal, // Ints, floats, double halves
duke@435	47	oop, // Oop (please GC me!)
duke@435	48	int_in_long, // Integer held in long register
duke@435	49	lng, // Long held in one register
duke@435	50	float_in_dbl, // Float held in double register
duke@435	51	dbl, // Double held in one register
duke@435	52	addr, // JSR return address
kvn@766	53	narrowoop // Narrow Oop (please GC me!)
duke@435	54	};
duke@435	55
duke@435	56
duke@435	57	private:
duke@435	58	enum {
kvn@766	59	TYPE_MASK = (juint) 0x0F,
kvn@766	60	TYPE_SHIFT = 0,
kvn@766	61	WHERE_MASK = (juint) 0x10,
kvn@766	62	WHERE_SHIFT = 4,
kvn@766	63	OFFSET_MASK = (juint) 0xFFFFFFE0,
kvn@766	64	OFFSET_SHIFT = 5
duke@435	65	};
duke@435	66
kvn@766	67	juint _value;
duke@435	68
duke@435	69	// Create a bit-packed Location
duke@435	70	Location(Where where_, Type type_, unsigned offset_) {
duke@435	71	set(where_, type_, offset_);
duke@435	72	assert( where () == where_ , "" );
duke@435	73	assert( type () == type_ , "" );
duke@435	74	assert( offset() == offset_, "" );
duke@435	75	}
duke@435	76
duke@435	77	inline void set(Where where_, Type type_, unsigned offset_) {
kvn@766	78	_value = (juint) ((where_ << WHERE_SHIFT) |
kvn@766	79	(type_ << TYPE_SHIFT) |
kvn@766	80	((offset_ << OFFSET_SHIFT) & OFFSET_MASK));
duke@435	81	}
duke@435	82
duke@435	83	public:
duke@435	84
duke@435	85	// Stack location Factory. Offset is 4-byte aligned; remove low bits
duke@435	86	static Location new_stk_loc( Type t, int offset ) { return Location(on_stack,t,offset>>LogBytesPerInt); }
duke@435	87	// Register location Factory
duke@435	88	static Location new_reg_loc( Type t, VMReg reg ) { return Location(in_register, t, reg->value()); }
duke@435	89	// Default constructor
kvn@766	90	Location() { set(on_stack,invalid,0); }
duke@435	91
duke@435	92	// Bit field accessors
duke@435	93	Where where() const { return (Where) ((_value & WHERE_MASK) >> WHERE_SHIFT);}
duke@435	94	Type type() const { return (Type) ((_value & TYPE_MASK) >> TYPE_SHIFT); }
duke@435	95	unsigned offset() const { return (unsigned) ((_value & OFFSET_MASK) >> OFFSET_SHIFT); }
duke@435	96
duke@435	97	// Accessors
duke@435	98	bool is_register() const { return where() == in_register; }
duke@435	99	bool is_stack() const { return where() == on_stack; }
duke@435	100
duke@435	101	int stack_offset() const { assert(where() == on_stack, "wrong Where"); return offset()<<LogBytesPerInt; }
duke@435	102	int register_number() const { assert(where() == in_register, "wrong Where"); return offset() ; }
duke@435	103
duke@435	104	VMReg reg() const { assert(where() == in_register, "wrong Where"); return VMRegImpl::as_VMReg(offset()) ; }
duke@435	105
duke@435	106	// Printing
duke@435	107	void print_on(outputStream* st) const;
duke@435	108
duke@435	109	// Serialization of debugging information
duke@435	110	Location(DebugInfoReadStream* stream);
duke@435	111	void write_on(DebugInfoWriteStream* stream);
duke@435	112
duke@435	113	// check
duke@435	114	static bool legal_offset_in_bytes(int offset_in_bytes);
duke@435	115	};