src/share/vm/opto/matcher.hpp

Fri, 27 Feb 2009 13:27:09 -0800

author
twisti
date
Fri, 27 Feb 2009 13:27:09 -0800
changeset 1040
98cb887364d3
parent 850
4d9884b01ba6
child 1164
04fa5affa478
permissions
-rw-r--r--

6810672: Comment typos
Summary: I have collected some typos I have found while looking at the code.
Reviewed-by: kvn, never

     1 /*
     2  * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 class Compile;
    26 class Node;
    27 class MachNode;
    28 class MachTypeNode;
    29 class MachOper;
    31 //---------------------------Matcher-------------------------------------------
    32 class Matcher : public PhaseTransform {
    33   friend class VMStructs;
    34   // Private arena of State objects
    35   ResourceArea _states_arena;
    37   VectorSet   _visited;         // Visit bits
    39   // Used to control the Label pass
    40   VectorSet   _shared;          // Shared Ideal Node
    41   VectorSet   _dontcare;        // Nothing the matcher cares about
    43   // Private methods which perform the actual matching and reduction
    44   // Walks the label tree, generating machine nodes
    45   MachNode *ReduceInst( State *s, int rule, Node *&mem);
    46   void ReduceInst_Chain_Rule( State *s, int rule, Node *&mem, MachNode *mach);
    47   uint ReduceInst_Interior(State *s, int rule, Node *&mem, MachNode *mach, uint num_opnds);
    48   void ReduceOper( State *s, int newrule, Node *&mem, MachNode *mach );
    50   // If this node already matched using "rule", return the MachNode for it.
    51   MachNode* find_shared_node(Node* n, uint rule);
    53   // Convert a dense opcode number to an expanded rule number
    54   const int *_reduceOp;
    55   const int *_leftOp;
    56   const int *_rightOp;
    58   // Map dense opcode number to info on when rule is swallowed constant.
    59   const bool *_swallowed;
    61   // Map dense rule number to determine if this is an instruction chain rule
    62   const uint _begin_inst_chain_rule;
    63   const uint _end_inst_chain_rule;
    65   // We want to clone constants and possible CmpI-variants.
    66   // If we do not clone CmpI, then we can have many instances of
    67   // condition codes alive at once.  This is OK on some chips and
    68   // bad on others.  Hence the machine-dependent table lookup.
    69   const char *_must_clone;
    71   // Find shared Nodes, or Nodes that otherwise are Matcher roots
    72   void find_shared( Node *n );
    74   // Debug and profile information for nodes in old space:
    75   GrowableArray<Node_Notes*>* _old_node_note_array;
    77   // Node labeling iterator for instruction selection
    78   Node *Label_Root( const Node *n, State *svec, Node *control, const Node *mem );
    80   Node *transform( Node *dummy );
    82   Node_List &_proj_list;        // For Machine nodes killing many values
    84   Node_Array _shared_nodes;
    86   debug_only(Node_Array _old2new_map;)   // Map roots of ideal-trees to machine-roots
    87   debug_only(Node_Array _new2old_map;)   // Maps machine nodes back to ideal
    89   // Accessors for the inherited field PhaseTransform::_nodes:
    90   void   grow_new_node_array(uint idx_limit) {
    91     _nodes.map(idx_limit-1, NULL);
    92   }
    93   bool    has_new_node(const Node* n) const {
    94     return _nodes.at(n->_idx) != NULL;
    95   }
    96   Node*       new_node(const Node* n) const {
    97     assert(has_new_node(n), "set before get");
    98     return _nodes.at(n->_idx);
    99   }
   100   void    set_new_node(const Node* n, Node *nn) {
   101     assert(!has_new_node(n), "set only once");
   102     _nodes.map(n->_idx, nn);
   103   }
   105 #ifdef ASSERT
   106   // Make sure only new nodes are reachable from this node
   107   void verify_new_nodes_only(Node* root);
   109   Node* _mem_node;   // Ideal memory node consumed by mach node
   110 #endif
   112 public:
   113   int LabelRootDepth;
   114   static const int base2reg[];        // Map Types to machine register types
   115   // Convert ideal machine register to a register mask for spill-loads
   116   static const RegMask *idealreg2regmask[];
   117   RegMask *idealreg2spillmask[_last_machine_leaf];
   118   RegMask *idealreg2debugmask[_last_machine_leaf];
   119   void init_spill_mask( Node *ret );
   120   // Convert machine register number to register mask
   121   static uint mreg2regmask_max;
   122   static RegMask mreg2regmask[];
   123   static RegMask STACK_ONLY_mask;
   125   bool    is_shared( Node *n ) { return _shared.test(n->_idx) != 0; }
   126   void   set_shared( Node *n ) {  _shared.set(n->_idx); }
   127   bool   is_visited( Node *n ) { return _visited.test(n->_idx) != 0; }
   128   void  set_visited( Node *n ) { _visited.set(n->_idx); }
   129   bool  is_dontcare( Node *n ) { return _dontcare.test(n->_idx) != 0; }
   130   void set_dontcare( Node *n ) {  _dontcare.set(n->_idx); }
   132   // Mode bit to tell DFA and expand rules whether we are running after
   133   // (or during) register selection.  Usually, the matcher runs before,
   134   // but it will also get called to generate post-allocation spill code.
   135   // In this situation, it is a deadly error to attempt to allocate more
   136   // temporary registers.
   137   bool _allocation_started;
   139   // Machine register names
   140   static const char *regName[];
   141   // Machine register encodings
   142   static const unsigned char _regEncode[];
   143   // Machine Node names
   144   const char **_ruleName;
   145   // Rules that are cheaper to rematerialize than to spill
   146   static const uint _begin_rematerialize;
   147   static const uint _end_rematerialize;
   149   // An array of chars, from 0 to _last_Mach_Reg.
   150   // No Save       = 'N' (for register windows)
   151   // Save on Entry = 'E'
   152   // Save on Call  = 'C'
   153   // Always Save   = 'A' (same as SOE + SOC)
   154   const char *_register_save_policy;
   155   const char *_c_reg_save_policy;
   156   // Convert a machine register to a machine register type, so-as to
   157   // properly match spill code.
   158   const int *_register_save_type;
   159   // Maps from machine register to boolean; true if machine register can
   160   // be holding a call argument in some signature.
   161   static bool can_be_java_arg( int reg );
   162   // Maps from machine register to boolean; true if machine register holds
   163   // a spillable argument.
   164   static bool is_spillable_arg( int reg );
   166   // List of IfFalse or IfTrue Nodes that indicate a taken null test.
   167   // List is valid in the post-matching space.
   168   Node_List _null_check_tests;
   169   void collect_null_checks( Node *proj, Node *orig_proj );
   170   void validate_null_checks( );
   172   Matcher( Node_List &proj_list );
   174   // Select instructions for entire method
   175   void  match( );
   176   // Helper for match
   177   OptoReg::Name warp_incoming_stk_arg( VMReg reg );
   179   // Transform, then walk.  Does implicit DCE while walking.
   180   // Name changed from "transform" to avoid it being virtual.
   181   Node *xform( Node *old_space_node, int Nodes );
   183   // Match a single Ideal Node - turn it into a 1-Node tree; Label & Reduce.
   184   MachNode *match_tree( const Node *n );
   185   MachNode *match_sfpt( SafePointNode *sfpt );
   186   // Helper for match_sfpt
   187   OptoReg::Name warp_outgoing_stk_arg( VMReg reg, OptoReg::Name begin_out_arg_area, OptoReg::Name &out_arg_limit_per_call );
   189   // Initialize first stack mask and related masks.
   190   void init_first_stack_mask();
   192   // If we should save-on-entry this register
   193   bool is_save_on_entry( int reg );
   195   // Fixup the save-on-entry registers
   196   void Fixup_Save_On_Entry( );
   198   // --- Frame handling ---
   200   // Register number of the stack slot corresponding to the incoming SP.
   201   // Per the Big Picture in the AD file, it is:
   202   //   SharedInfo::stack0 + locks + in_preserve_stack_slots + pad2.
   203   OptoReg::Name _old_SP;
   205   // Register number of the stack slot corresponding to the highest incoming
   206   // argument on the stack.  Per the Big Picture in the AD file, it is:
   207   //   _old_SP + out_preserve_stack_slots + incoming argument size.
   208   OptoReg::Name _in_arg_limit;
   210   // Register number of the stack slot corresponding to the new SP.
   211   // Per the Big Picture in the AD file, it is:
   212   //   _in_arg_limit + pad0
   213   OptoReg::Name _new_SP;
   215   // Register number of the stack slot corresponding to the highest outgoing
   216   // argument on the stack.  Per the Big Picture in the AD file, it is:
   217   //   _new_SP + max outgoing arguments of all calls
   218   OptoReg::Name _out_arg_limit;
   220   OptoRegPair *_parm_regs;        // Array of machine registers per argument
   221   RegMask *_calling_convention_mask; // Array of RegMasks per argument
   223   // Does matcher support this ideal node?
   224   static const bool has_match_rule(int opcode);
   225   static const bool _hasMatchRule[_last_opcode];
   227   // Used to determine if we have fast l2f conversion
   228   // USII has it, USIII doesn't
   229   static const bool convL2FSupported(void);
   231   // Vector width in bytes
   232   static const uint vector_width_in_bytes(void);
   234   // Vector ideal reg
   235   static const uint vector_ideal_reg(void);
   237   // Used to determine a "low complexity" 64-bit constant.  (Zero is simple.)
   238   // The standard of comparison is one (StoreL ConL) vs. two (StoreI ConI).
   239   // Depends on the details of 64-bit constant generation on the CPU.
   240   static const bool isSimpleConstant64(jlong con);
   242   // These calls are all generated by the ADLC
   244   // TRUE - grows up, FALSE - grows down (Intel)
   245   virtual bool stack_direction() const;
   247   // Java-Java calling convention
   248   // (what you use when Java calls Java)
   250   // Alignment of stack in bytes, standard Intel word alignment is 4.
   251   // Sparc probably wants at least double-word (8).
   252   static uint stack_alignment_in_bytes();
   253   // Alignment of stack, measured in stack slots.
   254   // The size of stack slots is defined by VMRegImpl::stack_slot_size.
   255   static uint stack_alignment_in_slots() {
   256     return stack_alignment_in_bytes() / (VMRegImpl::stack_slot_size);
   257   }
   259   // Array mapping arguments to registers.  Argument 0 is usually the 'this'
   260   // pointer.  Registers can include stack-slots and regular registers.
   261   static void calling_convention( BasicType *, VMRegPair *, uint len, bool is_outgoing );
   263   // Convert a sig into a calling convention register layout
   264   // and find interesting things about it.
   265   static OptoReg::Name  find_receiver( bool is_outgoing );
   266   // Return address register.  On Intel it is a stack-slot.  On PowerPC
   267   // it is the Link register.  On Sparc it is r31?
   268   virtual OptoReg::Name return_addr() const;
   269   RegMask              _return_addr_mask;
   270   // Return value register.  On Intel it is EAX.  On Sparc i0/o0.
   271   static OptoRegPair   return_value(int ideal_reg, bool is_outgoing);
   272   static OptoRegPair c_return_value(int ideal_reg, bool is_outgoing);
   273   RegMask                     _return_value_mask;
   274   // Inline Cache Register
   275   static OptoReg::Name  inline_cache_reg();
   276   static const RegMask &inline_cache_reg_mask();
   277   static int            inline_cache_reg_encode();
   279   // Register for DIVI projection of divmodI
   280   static RegMask divI_proj_mask();
   281   // Register for MODI projection of divmodI
   282   static RegMask modI_proj_mask();
   284   // Register for DIVL projection of divmodL
   285   static RegMask divL_proj_mask();
   286   // Register for MODL projection of divmodL
   287   static RegMask modL_proj_mask();
   289   // Java-Interpreter calling convention
   290   // (what you use when calling between compiled-Java and Interpreted-Java
   292   // Number of callee-save + always-save registers
   293   // Ignores frame pointer and "special" registers
   294   static int  number_of_saved_registers();
   296   // The Method-klass-holder may be passed in the inline_cache_reg
   297   // and then expanded into the inline_cache_reg and a method_oop register
   299   static OptoReg::Name  interpreter_method_oop_reg();
   300   static const RegMask &interpreter_method_oop_reg_mask();
   301   static int            interpreter_method_oop_reg_encode();
   303   static OptoReg::Name  compiler_method_oop_reg();
   304   static const RegMask &compiler_method_oop_reg_mask();
   305   static int            compiler_method_oop_reg_encode();
   307   // Interpreter's Frame Pointer Register
   308   static OptoReg::Name  interpreter_frame_pointer_reg();
   309   static const RegMask &interpreter_frame_pointer_reg_mask();
   311   // Java-Native calling convention
   312   // (what you use when intercalling between Java and C++ code)
   314   // Array mapping arguments to registers.  Argument 0 is usually the 'this'
   315   // pointer.  Registers can include stack-slots and regular registers.
   316   static void c_calling_convention( BasicType*, VMRegPair *, uint );
   317   // Frame pointer. The frame pointer is kept at the base of the stack
   318   // and so is probably the stack pointer for most machines.  On Intel
   319   // it is ESP.  On the PowerPC it is R1.  On Sparc it is SP.
   320   OptoReg::Name  c_frame_pointer() const;
   321   static RegMask c_frame_ptr_mask;
   323   // !!!!! Special stuff for building ScopeDescs
   324   virtual int      regnum_to_fpu_offset(int regnum);
   326   // Is this branch offset small enough to be addressed by a short branch?
   327   bool is_short_branch_offset(int rule, int offset);
   329   // Optional scaling for the parameter to the ClearArray/CopyArray node.
   330   static const bool init_array_count_is_in_bytes;
   332   // Threshold small size (in bytes) for a ClearArray/CopyArray node.
   333   // Anything this size or smaller may get converted to discrete scalar stores.
   334   static const int init_array_short_size;
   336   // Should the Matcher clone shifts on addressing modes, expecting them to
   337   // be subsumed into complex addressing expressions or compute them into
   338   // registers?  True for Intel but false for most RISCs
   339   static const bool clone_shift_expressions;
   341   // Is it better to copy float constants, or load them directly from memory?
   342   // Intel can load a float constant from a direct address, requiring no
   343   // extra registers.  Most RISCs will have to materialize an address into a
   344   // register first, so they may as well materialize the constant immediately.
   345   static const bool rematerialize_float_constants;
   347   // If CPU can load and store mis-aligned doubles directly then no fixup is
   348   // needed.  Else we split the double into 2 integer pieces and move it
   349   // piece-by-piece.  Only happens when passing doubles into C code or when
   350   // calling i2c adapters as the Java calling convention forces doubles to be
   351   // aligned.
   352   static const bool misaligned_doubles_ok;
   354   // Perform a platform dependent implicit null fixup.  This is needed
   355   // on windows95 to take care of some unusual register constraints.
   356   void pd_implicit_null_fixup(MachNode *load, uint idx);
   358   // Advertise here if the CPU requires explicit rounding operations
   359   // to implement the UseStrictFP mode.
   360   static const bool strict_fp_requires_explicit_rounding;
   362   // Do floats take an entire double register or just half?
   363   static const bool float_in_double;
   364   // Do ints take an entire long register or just half?
   365   static const bool int_in_long;
   367   // This routine is run whenever a graph fails to match.
   368   // If it returns, the compiler should bailout to interpreter without error.
   369   // In non-product mode, SoftMatchFailure is false to detect non-canonical
   370   // graphs.  Print a message and exit.
   371   static void soft_match_failure() {
   372     if( SoftMatchFailure ) return;
   373     else { fatal("SoftMatchFailure is not allowed except in product"); }
   374   }
   376   // Used by the DFA in dfa_sparc.cpp.  Check for a prior FastLock
   377   // acting as an Acquire and thus we don't need an Acquire here.  We
   378   // retain the Node to act as a compiler ordering barrier.
   379   static bool prior_fast_lock( const Node *acq );
   381   // Used by the DFA in dfa_sparc.cpp.  Check for a following
   382   // FastUnLock acting as a Release and thus we don't need a Release
   383   // here.  We retain the Node to act as a compiler ordering barrier.
   384   static bool post_fast_unlock( const Node *rel );
   386   // Check for a following volatile memory barrier without an
   387   // intervening load and thus we don't need a barrier here.  We
   388   // retain the Node to act as a compiler ordering barrier.
   389   static bool post_store_load_barrier(const Node* mb);
   392 #ifdef ASSERT
   393   void dump_old2new_map();      // machine-independent to machine-dependent
   395   Node* find_old_node(Node* new_node) {
   396     return _new2old_map[new_node->_idx];
   397   }
   398 #endif
   399 };

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