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src/share/vm/opto/callGenerator.hpp@1bd45abaa507 (annotated)

src/share/vm/opto/callGenerator.hpp

Wed, 16 Nov 2011 09:13:57 -0800

author

kvn

date

Wed, 16 Nov 2011 09:13:57 -0800

changeset 3311

1bd45abaa507

parent 3050

fdb992d83a87

child 3313

a04a201f0f5a

permissions

-rw-r--r--

6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never

duke@435	1	/*
twisti@3050	2	* Copyright (c) 2000, 2011, 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
stefank@2314	25	#ifndef SHARE_VM_OPTO_CALLGENERATOR_HPP
stefank@2314	26	#define SHARE_VM_OPTO_CALLGENERATOR_HPP
stefank@2314	27
stefank@2314	28	#include "opto/callnode.hpp"
stefank@2314	29	#include "opto/compile.hpp"
stefank@2314	30	#include "opto/type.hpp"
stefank@2314	31	#include "runtime/deoptimization.hpp"
stefank@2314	32
duke@435	33	//---------------------------CallGenerator-------------------------------------
duke@435	34	// The subclasses of this class handle generation of ideal nodes for
duke@435	35	// call sites and method entry points.
duke@435	36
duke@435	37	class CallGenerator : public ResourceObj {
duke@435	38	public:
duke@435	39	enum {
duke@435	40	xxxunusedxxx
duke@435	41	};
duke@435	42
duke@435	43	private:
duke@435	44	ciMethod* _method; // The method being called.
duke@435	45
duke@435	46	protected:
duke@435	47	CallGenerator(ciMethod* method);
duke@435	48
duke@435	49	public:
duke@435	50	// Accessors
duke@435	51	ciMethod* method() const { return _method; }
duke@435	52
duke@435	53	// is_inline: At least some code implementing the method is copied here.
duke@435	54	virtual bool is_inline() const { return false; }
duke@435	55	// is_intrinsic: There's a method-specific way of generating the inline code.
duke@435	56	virtual bool is_intrinsic() const { return false; }
duke@435	57	// is_parse: Bytecodes implementing the specific method are copied here.
duke@435	58	virtual bool is_parse() const { return false; }
duke@435	59	// is_virtual: The call uses the receiver type to select or check the method.
duke@435	60	virtual bool is_virtual() const { return false; }
duke@435	61	// is_deferred: The decision whether to inline or not is deferred.
duke@435	62	virtual bool is_deferred() const { return false; }
duke@435	63	// is_predicted: Uses an explicit check against a predicted type.
duke@435	64	virtual bool is_predicted() const { return false; }
duke@435	65	// is_trap: Does not return to the caller. (E.g., uncommon trap.)
duke@435	66	virtual bool is_trap() const { return false; }
duke@435	67
never@1515	68	// is_late_inline: supports conversion of call into an inline
never@1515	69	virtual bool is_late_inline() const { return false; }
never@1515	70	// Replace the call with an inline version of the code
never@1515	71	virtual void do_late_inline() { ShouldNotReachHere(); }
never@1515	72
never@1515	73	virtual CallStaticJavaNode* call_node() const { ShouldNotReachHere(); return NULL; }
never@1515	74
duke@435	75	// Note: It is possible for a CG to be both inline and virtual.
duke@435	76	// (The hashCode intrinsic does a vtable check and an inlined fast path.)
duke@435	77
duke@435	78	// Utilities:
duke@435	79	const TypeFunc* tf() const;
duke@435	80
duke@435	81	// The given jvms has state and arguments for a call to my method.
duke@435	82	// Edges after jvms->argoff() carry all (pre-popped) argument values.
duke@435	83	//
duke@435	84	// Update the map with state and return values (if any) and return it.
duke@435	85	// The return values (0, 1, or 2) must be pushed on the map's stack,
duke@435	86	// and the sp of the jvms incremented accordingly.
duke@435	87	//
duke@435	88	// The jvms is returned on success. Alternatively, a copy of the
duke@435	89	// given jvms, suitably updated, may be returned, in which case the
duke@435	90	// caller should discard the original jvms.
duke@435	91	//
duke@435	92	// The non-Parm edges of the returned map will contain updated global state,
duke@435	93	// and one or two edges before jvms->sp() will carry any return values.
duke@435	94	// Other map edges may contain locals or monitors, and should not
duke@435	95	// be changed in meaning.
duke@435	96	//
duke@435	97	// If the call traps, the returned map must have a control edge of top.
duke@435	98	// If the call can throw, the returned map must report has_exceptions().
duke@435	99	//
duke@435	100	// If the result is NULL, it means that this CallGenerator was unable
duke@435	101	// to handle the given call, and another CallGenerator should be consulted.
duke@435	102	virtual JVMState* generate(JVMState* jvms) = 0;
duke@435	103
duke@435	104	// How to generate a call site that is inlined:
duke@435	105	static CallGenerator* for_inline(ciMethod* m, float expected_uses = -1);
duke@435	106	// How to generate code for an on-stack replacement handler.
duke@435	107	static CallGenerator* for_osr(ciMethod* m, int osr_bci);
duke@435	108
duke@435	109	// How to generate vanilla out-of-line call sites:
never@1515	110	static CallGenerator* for_direct_call(ciMethod* m, bool separate_io_projs = false); // static, special
twisti@1572	111	static CallGenerator* for_dynamic_call(ciMethod* m); // invokedynamic
duke@435	112	static CallGenerator* for_virtual_call(ciMethod* m, int vtable_index); // virtual, interface
duke@435	113
twisti@3050	114	static CallGenerator* for_method_handle_inline(Node* method_handle, JVMState* jvms, ciMethod* caller, ciMethod* callee, ciCallProfile profile);
twisti@3050	115	static CallGenerator* for_invokedynamic_inline(ciCallSite* call_site, JVMState* jvms, ciMethod* caller, ciMethod* callee, ciCallProfile profile);
never@2949	116
never@1515	117	// How to generate a replace a direct call with an inline version
never@1515	118	static CallGenerator* for_late_inline(ciMethod* m, CallGenerator* inline_cg);
never@1515	119
duke@435	120	// How to make a call but defer the decision whether to inline or not.
duke@435	121	static CallGenerator* for_warm_call(WarmCallInfo* ci,
duke@435	122	CallGenerator* if_cold,
duke@435	123	CallGenerator* if_hot);
duke@435	124
duke@435	125	// How to make a call that optimistically assumes a receiver type:
duke@435	126	static CallGenerator* for_predicted_call(ciKlass* predicted_receiver,
duke@435	127	CallGenerator* if_missed,
duke@435	128	CallGenerator* if_hit,
duke@435	129	float hit_prob);
duke@435	130
twisti@1573	131	// How to make a call that optimistically assumes a MethodHandle target:
twisti@1573	132	static CallGenerator* for_predicted_dynamic_call(ciMethodHandle* predicted_method_handle,
twisti@1573	133	CallGenerator* if_missed,
twisti@1573	134	CallGenerator* if_hit,
twisti@1573	135	float hit_prob);
twisti@1573	136
duke@435	137	// How to make a call that gives up and goes back to the interpreter:
duke@435	138	static CallGenerator* for_uncommon_trap(ciMethod* m,
duke@435	139	Deoptimization::DeoptReason reason,
duke@435	140	Deoptimization::DeoptAction action);
duke@435	141
duke@435	142	// Registry for intrinsics:
duke@435	143	static CallGenerator* for_intrinsic(ciMethod* m);
duke@435	144	static void register_intrinsic(ciMethod* m, CallGenerator* cg);
duke@435	145	};
duke@435	146
duke@435	147	class InlineCallGenerator : public CallGenerator {
duke@435	148	virtual bool is_inline() const { return true; }
duke@435	149
duke@435	150	protected:
duke@435	151	InlineCallGenerator(ciMethod* method) : CallGenerator(method) { }
duke@435	152	};
duke@435	153
duke@435	154
duke@435	155	//---------------------------WarmCallInfo--------------------------------------
duke@435	156	// A struct to collect information about a given call site.
duke@435	157	// Helps sort call sites into "hot", "medium", and "cold".
duke@435	158	// Participates in the queueing of "medium" call sites for possible inlining.
duke@435	159	class WarmCallInfo : public ResourceObj {
duke@435	160	private:
duke@435	161
duke@435	162	CallNode* _call; // The CallNode which may be inlined.
duke@435	163	CallGenerator* _hot_cg;// CG for expanding the call node
duke@435	164
duke@435	165	// These are the metrics we use to evaluate call sites:
duke@435	166
duke@435	167	float _count; // How often do we expect to reach this site?
duke@435	168	float _profit; // How much time do we expect to save by inlining?
duke@435	169	float _work; // How long do we expect the average call to take?
duke@435	170	float _size; // How big do we expect the inlined code to be?
duke@435	171
duke@435	172	float _heat; // Combined score inducing total order on call sites.
duke@435	173	WarmCallInfo* _next; // Next cooler call info in pending queue.
duke@435	174
duke@435	175	// Count is the number of times this call site is expected to be executed.
duke@435	176	// Large count is favorable for inlining, because the extra compilation
duke@435	177	// work will be amortized more completely.
duke@435	178
duke@435	179	// Profit is a rough measure of the amount of time we expect to save
duke@435	180	// per execution of this site if we inline it. (1.0 == call overhead)
duke@435	181	// Large profit favors inlining. Negative profit disables inlining.
duke@435	182
duke@435	183	// Work is a rough measure of the amount of time a typical out-of-line
duke@435	184	// call from this site is expected to take. (1.0 == call, no-op, return)
duke@435	185	// Small work is somewhat favorable for inlining, since methods with
duke@435	186	// short "hot" traces are more likely to inline smoothly.
duke@435	187
duke@435	188	// Size is the number of graph nodes we expect this method to produce,
duke@435	189	// not counting the inlining of any further warm calls it may include.
duke@435	190	// Small size favors inlining, since small methods are more likely to
duke@435	191	// inline smoothly. The size is estimated by examining the native code
duke@435	192	// if available. The method bytecodes are also examined, assuming
duke@435	193	// empirically observed node counts for each kind of bytecode.
duke@435	194
duke@435	195	// Heat is the combined "goodness" of a site's inlining. If we were
duke@435	196	// omniscient, it would be the difference of two sums of future execution
duke@435	197	// times of code emitted for this site (amortized across multiple sites if
duke@435	198	// sharing applies). The two sums are for versions of this call site with
duke@435	199	// and without inlining.
duke@435	200
duke@435	201	// We approximate this mythical quantity by playing with averages,
duke@435	202	// rough estimates, and assumptions that history repeats itself.
duke@435	203	// The basic formula count * profit is heuristically adjusted
duke@435	204	// by looking at the expected compilation and execution times of
duke@435	205	// of the inlined call.
duke@435	206
duke@435	207	// Note: Some of these metrics may not be present in the final product,
duke@435	208	// but exist in development builds to experiment with inline policy tuning.
duke@435	209
duke@435	210	// This heuristic framework does not model well the very significant
duke@435	211	// effects of multiple-level inlining. It is possible to see no immediate
duke@435	212	// profit from inlining X->Y, but to get great profit from a subsequent
duke@435	213	// inlining X->Y->Z.
duke@435	214
duke@435	215	// This framework does not take well into account the problem of N**2 code
duke@435	216	// size in a clique of mutually inlinable methods.
duke@435	217
duke@435	218	WarmCallInfo* next() const { return _next; }
duke@435	219	void set_next(WarmCallInfo* n) { _next = n; }
duke@435	220
never@2725	221	static WarmCallInfo _always_hot;
never@2725	222	static WarmCallInfo _always_cold;
never@2725	223
never@2725	224	// Constructor intitialization of always_hot and always_cold
never@2725	225	WarmCallInfo(float c, float p, float w, float s) {
never@2725	226	_call = NULL;
never@2725	227	_hot_cg = NULL;
never@2725	228	_next = NULL;
never@2725	229	_count = c;
never@2725	230	_profit = p;
never@2725	231	_work = w;
never@2725	232	_size = s;
never@2725	233	_heat = 0;
never@2725	234	}
duke@435	235
duke@435	236	public:
duke@435	237	// Because WarmInfo objects live over the entire lifetime of the
duke@435	238	// Compile object, they are allocated into the comp_arena, which
duke@435	239	// does not get resource marked or reset during the compile process
duke@435	240	void *operator new( size_t x, Compile* C ) { return C->comp_arena()->Amalloc(x); }
duke@435	241	void operator delete( void * ) { } // fast deallocation
duke@435	242
duke@435	243	static WarmCallInfo* always_hot();
duke@435	244	static WarmCallInfo* always_cold();
duke@435	245
duke@435	246	WarmCallInfo() {
duke@435	247	_call = NULL;
duke@435	248	_hot_cg = NULL;
duke@435	249	_next = NULL;
duke@435	250	_count = _profit = _work = _size = _heat = 0;
duke@435	251	}
duke@435	252
duke@435	253	CallNode* call() const { return _call; }
duke@435	254	float count() const { return _count; }
duke@435	255	float size() const { return _size; }
duke@435	256	float work() const { return _work; }
duke@435	257	float profit() const { return _profit; }
duke@435	258	float heat() const { return _heat; }
duke@435	259
duke@435	260	void set_count(float x) { _count = x; }
duke@435	261	void set_size(float x) { _size = x; }
duke@435	262	void set_work(float x) { _work = x; }
duke@435	263	void set_profit(float x) { _profit = x; }
duke@435	264	void set_heat(float x) { _heat = x; }
duke@435	265
duke@435	266	// Load initial heuristics from profiles, etc.
duke@435	267	// The heuristics can be tweaked further by the caller.
duke@435	268	void init(JVMState* call_site, ciMethod* call_method, ciCallProfile& profile, float prof_factor);
duke@435	269
duke@435	270	static float MAX_VALUE() { return +1.0e10; }
duke@435	271	static float MIN_VALUE() { return -1.0e10; }
duke@435	272
duke@435	273	float compute_heat() const;
duke@435	274
duke@435	275	void set_call(CallNode* call) { _call = call; }
duke@435	276	void set_hot_cg(CallGenerator* cg) { _hot_cg = cg; }
duke@435	277
duke@435	278	// Do not queue very hot or very cold calls.
duke@435	279	// Make very cold ones out of line immediately.
duke@435	280	// Inline very hot ones immediately.
duke@435	281	// These queries apply various tunable limits
duke@435	282	// to the above metrics in a systematic way.
duke@435	283	// Test for coldness before testing for hotness.
duke@435	284	bool is_cold() const;
duke@435	285	bool is_hot() const;
duke@435	286
duke@435	287	// Force a warm call to be hot. This worklists the call node for inlining.
duke@435	288	void make_hot();
duke@435	289
duke@435	290	// Force a warm call to be cold. This worklists the call node for out-of-lining.
duke@435	291	void make_cold();
duke@435	292
duke@435	293	// A reproducible total ordering, in which heat is the major key.
duke@435	294	bool warmer_than(WarmCallInfo* that);
duke@435	295
duke@435	296	// List management. These methods are called with the list head,
duke@435	297	// and return the new list head, inserting or removing the receiver.
duke@435	298	WarmCallInfo* insert_into(WarmCallInfo* head);
duke@435	299	WarmCallInfo* remove_from(WarmCallInfo* head);
duke@435	300
duke@435	301	#ifndef PRODUCT
duke@435	302	void print() const;
duke@435	303	void print_all() const;
duke@435	304	int count_all() const;
duke@435	305	#endif
duke@435	306	};
stefank@2314	307
stefank@2314	308	#endif // SHARE_VM_OPTO_CALLGENERATOR_HPP