1 /*
2 * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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24
25 #ifndef SHARE_VM_OPTO_MATCHER_HPP
26 #define SHARE_VM_OPTO_MATCHER_HPP
27
28 #include "libadt/vectset.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "opto/node.hpp"
31 #include "opto/phaseX.hpp"
32 #include "opto/regmask.hpp"
33
34 class Compile;
35 class Node;
36 class MachNode;
37 class MachTypeNode;
38 class MachOper;
39
40 //---------------------------Matcher-------------------------------------------
41 class Matcher : public PhaseTransform {
42 friend class VMStructs;
43 // Private arena of State objects
44 ResourceArea _states_arena;
45
46 VectorSet _visited; // Visit bits
47
48 // Used to control the Label pass
49 VectorSet _shared; // Shared Ideal Node
50 VectorSet _dontcare; // Nothing the matcher cares about
51
52 // Private methods which perform the actual matching and reduction
53 // Walks the label tree, generating machine nodes
54 MachNode *ReduceInst( State *s, int rule, Node *&mem);
55 void ReduceInst_Chain_Rule( State *s, int rule, Node *&mem, MachNode *mach);
56 uint ReduceInst_Interior(State *s, int rule, Node *&mem, MachNode *mach, uint num_opnds);
57 void ReduceOper( State *s, int newrule, Node *&mem, MachNode *mach );
58
59 // If this node already matched using "rule", return the MachNode for it.
60 MachNode* find_shared_node(Node* n, uint rule);
61
62 // Convert a dense opcode number to an expanded rule number
63 const int *_reduceOp;
64 const int *_leftOp;
65 const int *_rightOp;
66
67 // Map dense opcode number to info on when rule is swallowed constant.
68 const bool *_swallowed;
69
70 // Map dense rule number to determine if this is an instruction chain rule
71 const uint _begin_inst_chain_rule;
72 const uint _end_inst_chain_rule;
73
74 // We want to clone constants and possible CmpI-variants.
75 // If we do not clone CmpI, then we can have many instances of
76 // condition codes alive at once. This is OK on some chips and
77 // bad on others. Hence the machine-dependent table lookup.
78 const char *_must_clone;
79
80 // Find shared Nodes, or Nodes that otherwise are Matcher roots
81 void find_shared( Node *n );
82
83 // Debug and profile information for nodes in old space:
84 GrowableArray<Node_Notes*>* _old_node_note_array;
85
86 // Node labeling iterator for instruction selection
87 Node *Label_Root( const Node *n, State *svec, Node *control, const Node *mem );
88
89 Node *transform( Node *dummy );
90
91 Node_List &_proj_list; // For Machine nodes killing many values
92
93 Node_Array _shared_nodes;
94
95 debug_only(Node_Array _old2new_map;) // Map roots of ideal-trees to machine-roots
96 debug_only(Node_Array _new2old_map;) // Maps machine nodes back to ideal
97
98 // Accessors for the inherited field PhaseTransform::_nodes:
99 void grow_new_node_array(uint idx_limit) {
100 _nodes.map(idx_limit-1, NULL);
101 }
102 bool has_new_node(const Node* n) const {
103 return _nodes.at(n->_idx) != NULL;
104 }
105 Node* new_node(const Node* n) const {
106 assert(has_new_node(n), "set before get");
107 return _nodes.at(n->_idx);
108 }
109 void set_new_node(const Node* n, Node *nn) {
110 assert(!has_new_node(n), "set only once");
111 _nodes.map(n->_idx, nn);
112 }
113
114 #ifdef ASSERT
115 // Make sure only new nodes are reachable from this node
116 void verify_new_nodes_only(Node* root);
117
118 Node* _mem_node; // Ideal memory node consumed by mach node
119 #endif
120
121 // Mach node for ConP #NULL
122 MachNode* _mach_null;
123
124 public:
125 int LabelRootDepth;
126 static const int base2reg[]; // Map Types to machine register types
127 // Convert ideal machine register to a register mask for spill-loads
128 static const RegMask *idealreg2regmask[];
129 RegMask *idealreg2spillmask [_last_machine_leaf];
130 RegMask *idealreg2debugmask [_last_machine_leaf];
131 RegMask *idealreg2mhdebugmask[_last_machine_leaf];
132 void init_spill_mask( Node *ret );
133 // Convert machine register number to register mask
134 static uint mreg2regmask_max;
135 static RegMask mreg2regmask[];
136 static RegMask STACK_ONLY_mask;
137
138 MachNode* mach_null() const { return _mach_null; }
139
140 bool is_shared( Node *n ) { return _shared.test(n->_idx) != 0; }
141 void set_shared( Node *n ) { _shared.set(n->_idx); }
142 bool is_visited( Node *n ) { return _visited.test(n->_idx) != 0; }
143 void set_visited( Node *n ) { _visited.set(n->_idx); }
144 bool is_dontcare( Node *n ) { return _dontcare.test(n->_idx) != 0; }
145 void set_dontcare( Node *n ) { _dontcare.set(n->_idx); }
146
147 // Mode bit to tell DFA and expand rules whether we are running after
148 // (or during) register selection. Usually, the matcher runs before,
149 // but it will also get called to generate post-allocation spill code.
150 // In this situation, it is a deadly error to attempt to allocate more
151 // temporary registers.
152 bool _allocation_started;
153
154 // Machine register names
155 static const char *regName[];
156 // Machine register encodings
157 static const unsigned char _regEncode[];
158 // Machine Node names
159 const char **_ruleName;
160 // Rules that are cheaper to rematerialize than to spill
161 static const uint _begin_rematerialize;
162 static const uint _end_rematerialize;
163
164 // An array of chars, from 0 to _last_Mach_Reg.
165 // No Save = 'N' (for register windows)
166 // Save on Entry = 'E'
167 // Save on Call = 'C'
168 // Always Save = 'A' (same as SOE + SOC)
169 const char *_register_save_policy;
170 const char *_c_reg_save_policy;
171 // Convert a machine register to a machine register type, so-as to
172 // properly match spill code.
173 const int *_register_save_type;
174 // Maps from machine register to boolean; true if machine register can
175 // be holding a call argument in some signature.
176 static bool can_be_java_arg( int reg );
177 // Maps from machine register to boolean; true if machine register holds
178 // a spillable argument.
179 static bool is_spillable_arg( int reg );
180
181 // List of IfFalse or IfTrue Nodes that indicate a taken null test.
182 // List is valid in the post-matching space.
183 Node_List _null_check_tests;
184 void collect_null_checks( Node *proj, Node *orig_proj );
185 void validate_null_checks( );
186
187 Matcher( Node_List &proj_list );
188
189 // Select instructions for entire method
190 void match( );
191 // Helper for match
192 OptoReg::Name warp_incoming_stk_arg( VMReg reg );
193
194 // Transform, then walk. Does implicit DCE while walking.
195 // Name changed from "transform" to avoid it being virtual.
196 Node *xform( Node *old_space_node, int Nodes );
197
198 // Match a single Ideal Node - turn it into a 1-Node tree; Label & Reduce.
199 MachNode *match_tree( const Node *n );
200 MachNode *match_sfpt( SafePointNode *sfpt );
201 // Helper for match_sfpt
202 OptoReg::Name warp_outgoing_stk_arg( VMReg reg, OptoReg::Name begin_out_arg_area, OptoReg::Name &out_arg_limit_per_call );
203
204 // Initialize first stack mask and related masks.
205 void init_first_stack_mask();
206
207 // If we should save-on-entry this register
208 bool is_save_on_entry( int reg );
209
210 // Fixup the save-on-entry registers
211 void Fixup_Save_On_Entry( );
212
213 // --- Frame handling ---
214
215 // Register number of the stack slot corresponding to the incoming SP.
216 // Per the Big Picture in the AD file, it is:
217 // SharedInfo::stack0 + locks + in_preserve_stack_slots + pad2.
218 OptoReg::Name _old_SP;
219
220 // Register number of the stack slot corresponding to the highest incoming
221 // argument on the stack. Per the Big Picture in the AD file, it is:
222 // _old_SP + out_preserve_stack_slots + incoming argument size.
223 OptoReg::Name _in_arg_limit;
224
225 // Register number of the stack slot corresponding to the new SP.
226 // Per the Big Picture in the AD file, it is:
227 // _in_arg_limit + pad0
228 OptoReg::Name _new_SP;
229
230 // Register number of the stack slot corresponding to the highest outgoing
231 // argument on the stack. Per the Big Picture in the AD file, it is:
232 // _new_SP + max outgoing arguments of all calls
233 OptoReg::Name _out_arg_limit;
234
235 OptoRegPair *_parm_regs; // Array of machine registers per argument
236 RegMask *_calling_convention_mask; // Array of RegMasks per argument
237
238 // Does matcher have a match rule for this ideal node?
239 static const bool has_match_rule(int opcode);
240 static const bool _hasMatchRule[_last_opcode];
241
242 // Does matcher have a match rule for this ideal node and is the
243 // predicate (if there is one) true?
244 // NOTE: If this function is used more commonly in the future, ADLC
245 // should generate this one.
246 static const bool match_rule_supported(int opcode);
247
248 // Used to determine if we have fast l2f conversion
249 // USII has it, USIII doesn't
250 static const bool convL2FSupported(void);
251
252 // Vector width in bytes
253 static const int vector_width_in_bytes(BasicType bt);
254
255 // Limits on vector size (number of elements).
256 static const int max_vector_size(const BasicType bt);
257 static const int min_vector_size(const BasicType bt);
258 static const bool vector_size_supported(const BasicType bt, int size) {
259 return (Matcher::max_vector_size(bt) >= size &&
260 Matcher::min_vector_size(bt) <= size);
261 }
262
263 // Vector ideal reg
264 static const int vector_ideal_reg(int len);
265
266 // CPU supports misaligned vectors store/load.
267 static const bool misaligned_vectors_ok();
268
269 // Used to determine a "low complexity" 64-bit constant. (Zero is simple.)
270 // The standard of comparison is one (StoreL ConL) vs. two (StoreI ConI).
271 // Depends on the details of 64-bit constant generation on the CPU.
272 static const bool isSimpleConstant64(jlong con);
273
274 // These calls are all generated by the ADLC
275
276 // TRUE - grows up, FALSE - grows down (Intel)
277 virtual bool stack_direction() const;
278
279 // Java-Java calling convention
280 // (what you use when Java calls Java)
281
282 // Alignment of stack in bytes, standard Intel word alignment is 4.
283 // Sparc probably wants at least double-word (8).
284 static uint stack_alignment_in_bytes();
285 // Alignment of stack, measured in stack slots.
286 // The size of stack slots is defined by VMRegImpl::stack_slot_size.
287 static uint stack_alignment_in_slots() {
288 return stack_alignment_in_bytes() / (VMRegImpl::stack_slot_size);
289 }
290
291 // Array mapping arguments to registers. Argument 0 is usually the 'this'
292 // pointer. Registers can include stack-slots and regular registers.
293 static void calling_convention( BasicType *, VMRegPair *, uint len, bool is_outgoing );
294
295 // Convert a sig into a calling convention register layout
296 // and find interesting things about it.
297 static OptoReg::Name find_receiver( bool is_outgoing );
298 // Return address register. On Intel it is a stack-slot. On PowerPC
299 // it is the Link register. On Sparc it is r31?
300 virtual OptoReg::Name return_addr() const;
301 RegMask _return_addr_mask;
302 // Return value register. On Intel it is EAX. On Sparc i0/o0.
303 static OptoRegPair return_value(int ideal_reg, bool is_outgoing);
304 static OptoRegPair c_return_value(int ideal_reg, bool is_outgoing);
305 RegMask _return_value_mask;
306 // Inline Cache Register
307 static OptoReg::Name inline_cache_reg();
308 static int inline_cache_reg_encode();
309
310 // Register for DIVI projection of divmodI
311 static RegMask divI_proj_mask();
312 // Register for MODI projection of divmodI
313 static RegMask modI_proj_mask();
314
315 // Register for DIVL projection of divmodL
316 static RegMask divL_proj_mask();
317 // Register for MODL projection of divmodL
318 static RegMask modL_proj_mask();
319
320 // Use hardware DIV instruction when it is faster than
321 // a code which use multiply for division by constant.
322 static bool use_asm_for_ldiv_by_con( jlong divisor );
323
324 static const RegMask method_handle_invoke_SP_save_mask();
325
326 // Java-Interpreter calling convention
327 // (what you use when calling between compiled-Java and Interpreted-Java
328
329 // Number of callee-save + always-save registers
330 // Ignores frame pointer and "special" registers
331 static int number_of_saved_registers();
332
333 // The Method-klass-holder may be passed in the inline_cache_reg
334 // and then expanded into the inline_cache_reg and a method_oop register
335
336 static OptoReg::Name interpreter_method_oop_reg();
337 static int interpreter_method_oop_reg_encode();
338
339 static OptoReg::Name compiler_method_oop_reg();
340 static const RegMask &compiler_method_oop_reg_mask();
341 static int compiler_method_oop_reg_encode();
342
343 // Interpreter's Frame Pointer Register
344 static OptoReg::Name interpreter_frame_pointer_reg();
345
346 // Java-Native calling convention
347 // (what you use when intercalling between Java and C++ code)
348
349 // Array mapping arguments to registers. Argument 0 is usually the 'this'
350 // pointer. Registers can include stack-slots and regular registers.
351 static void c_calling_convention( BasicType*, VMRegPair *, uint );
352 // Frame pointer. The frame pointer is kept at the base of the stack
353 // and so is probably the stack pointer for most machines. On Intel
354 // it is ESP. On the PowerPC it is R1. On Sparc it is SP.
355 OptoReg::Name c_frame_pointer() const;
356 static RegMask c_frame_ptr_mask;
357
358 // !!!!! Special stuff for building ScopeDescs
359 virtual int regnum_to_fpu_offset(int regnum);
360
361 // Is this branch offset small enough to be addressed by a short branch?
362 bool is_short_branch_offset(int rule, int br_size, int offset);
363
364 // Optional scaling for the parameter to the ClearArray/CopyArray node.
365 static const bool init_array_count_is_in_bytes;
366
367 // Threshold small size (in bytes) for a ClearArray/CopyArray node.
368 // Anything this size or smaller may get converted to discrete scalar stores.
369 static const int init_array_short_size;
370
371 // Some hardware needs 2 CMOV's for longs.
372 static const int long_cmove_cost();
373
374 // Some hardware have expensive CMOV for float and double.
375 static const int float_cmove_cost();
376
377 // Should the Matcher clone shifts on addressing modes, expecting them to
378 // be subsumed into complex addressing expressions or compute them into
379 // registers? True for Intel but false for most RISCs
380 static const bool clone_shift_expressions;
381
382 static bool narrow_oop_use_complex_address();
383
384 // Generate implicit null check for narrow oops if it can fold
385 // into address expression (x64).
386 //
387 // [R12 + narrow_oop_reg<<3 + offset] // fold into address expression
388 // NullCheck narrow_oop_reg
389 //
390 // When narrow oops can't fold into address expression (Sparc) and
391 // base is not null use decode_not_null and normal implicit null check.
392 // Note, decode_not_null node can be used here since it is referenced
393 // only on non null path but it requires special handling, see
394 // collect_null_checks():
395 //
396 // decode_not_null narrow_oop_reg, oop_reg // 'shift' and 'add base'
397 // [oop_reg + offset]
398 // NullCheck oop_reg
399 //
400 // With Zero base and when narrow oops can not fold into address
401 // expression use normal implicit null check since only shift
402 // is needed to decode narrow oop.
403 //
404 // decode narrow_oop_reg, oop_reg // only 'shift'
405 // [oop_reg + offset]
406 // NullCheck oop_reg
407 //
408 inline static bool gen_narrow_oop_implicit_null_checks() {
409 return Universe::narrow_oop_use_implicit_null_checks() &&
410 (narrow_oop_use_complex_address() ||
411 Universe::narrow_oop_base() != NULL);
412 }
413
414 // Is it better to copy float constants, or load them directly from memory?
415 // Intel can load a float constant from a direct address, requiring no
416 // extra registers. Most RISCs will have to materialize an address into a
417 // register first, so they may as well materialize the constant immediately.
418 static const bool rematerialize_float_constants;
419
420 // If CPU can load and store mis-aligned doubles directly then no fixup is
421 // needed. Else we split the double into 2 integer pieces and move it
422 // piece-by-piece. Only happens when passing doubles into C code or when
423 // calling i2c adapters as the Java calling convention forces doubles to be
424 // aligned.
425 static const bool misaligned_doubles_ok;
426
427 // Perform a platform dependent implicit null fixup. This is needed
428 // on windows95 to take care of some unusual register constraints.
429 void pd_implicit_null_fixup(MachNode *load, uint idx);
430
431 // Advertise here if the CPU requires explicit rounding operations
432 // to implement the UseStrictFP mode.
433 static const bool strict_fp_requires_explicit_rounding;
434
435 // Are floats conerted to double when stored to stack during deoptimization?
436 static bool float_in_double();
437 // Do ints take an entire long register or just half?
438 static const bool int_in_long;
439
440 // Do the processor's shift instructions only use the low 5/6 bits
441 // of the count for 32/64 bit ints? If not we need to do the masking
442 // ourselves.
443 static const bool need_masked_shift_count;
444
445 // This routine is run whenever a graph fails to match.
446 // If it returns, the compiler should bailout to interpreter without error.
447 // In non-product mode, SoftMatchFailure is false to detect non-canonical
448 // graphs. Print a message and exit.
449 static void soft_match_failure() {
450 if( SoftMatchFailure ) return;
451 else { fatal("SoftMatchFailure is not allowed except in product"); }
452 }
453
454 // Check for a following volatile memory barrier without an
455 // intervening load and thus we don't need a barrier here. We
456 // retain the Node to act as a compiler ordering barrier.
457 static bool post_store_load_barrier(const Node* mb);
458
459
460 #ifdef ASSERT
461 void dump_old2new_map(); // machine-independent to machine-dependent
462
463 Node* find_old_node(Node* new_node) {
464 return _new2old_map[new_node->_idx];
465 }
466 #endif
467 };
468
469 #endif // SHARE_VM_OPTO_MATCHER_HPP