jdk8-mips64-public/hotspot: src/share/vm/asm/assembler.hpp@c89f86385056 (annotated)

src/share/vm/asm/assembler.hpp@c89f86385056 (annotated)

src/share/vm/asm/assembler.hpp

Fri, 20 Mar 2009 23:19:36 -0700

author: jrose
date: Fri, 20 Mar 2009 23:19:36 -0700
changeset 1100: c89f86385056
parent 1057: 56aae7be60d4
child 1907: c18cbe5936b8
permissions: -rw-r--r--

6814659: separable cleanups and subroutines for 6655638
Summary: preparatory but separable changes for method handles
Reviewed-by: kvn, never

 /*
  * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 // This file contains platform-independent assembler declarations.
 class CodeBuffer;
 class MacroAssembler;
 class AbstractAssembler;
 class Label;
 /**
  * Labels represent destinations for control transfer instructions.  Such
  * instructions can accept a Label as their target argument.  A Label is
  * bound to the current location in the code stream by calling the
  * MacroAssembler's 'bind' method, which in turn calls the Label's 'bind'
  * method.  A Label may be referenced by an instruction before it's bound
  * (i.e., 'forward referenced').  'bind' stores the current code offset
  * in the Label object.
  *
  * If an instruction references a bound Label, the offset field(s) within
  * the instruction are immediately filled in based on the Label's code
  * offset.  If an instruction references an unbound label, that
  * instruction is put on a list of instructions that must be patched
  * (i.e., 'resolved') when the Label is bound.
  *
  * 'bind' will call the platform-specific 'patch_instruction' method to
  * fill in the offset field(s) for each unresolved instruction (if there
  * are any).  'patch_instruction' lives in one of the
  * cpu/<arch>/vm/assembler_<arch>* files.
  *
  * Instead of using a linked list of unresolved instructions, a Label has
  * an array of unresolved instruction code offsets.  _patch_index
  * contains the total number of forward references.  If the Label's array
  * overflows (i.e., _patch_index grows larger than the array size), a
  * GrowableArray is allocated to hold the remaining offsets.  (The cache
  * size is 4 for now, which handles over 99.5% of the cases)
  *
  * Labels may only be used within a single CodeSection.  If you need
  * to create references between code sections, use explicit relocations.
  */
 class Label VALUE_OBJ_CLASS_SPEC {
  private:
   enum { PatchCacheSize = 4 };
   // _loc encodes both the binding state (via its sign)
   // and the binding locator (via its value) of a label.
   //
   // _loc >= 0   bound label, loc() encodes the target (jump) position
   // _loc == -1  unbound label
   int _loc;
   // References to instructions that jump to this unresolved label.
   // These instructions need to be patched when the label is bound
   // using the platform-specific patchInstruction() method.
   //
   // To avoid having to allocate from the C-heap each time, we provide
   // a local cache and use the overflow only if we exceed the local cache
   int _patches[PatchCacheSize];
   int _patch_index;
   GrowableArray<int>* _patch_overflow;
   Label(const Label&) { ShouldNotReachHere(); }
  public:
   /**
    * After binding, be sure 'patch_instructions' is called later to link
    */
   void bind_loc(int loc) {
     assert(loc >= 0, "illegal locator");
     assert(_loc == -1, "already bound");
     _loc = loc;
   }
   void bind_loc(int pos, int sect);  // = bind_loc(locator(pos, sect))
 #ifndef PRODUCT
   // Iterates over all unresolved instructions for printing
   void print_instructions(MacroAssembler* masm) const;
 #endif // PRODUCT
   /**
    * Returns the position of the the Label in the code buffer
    * The position is a 'locator', which encodes both offset and section.
    */
   int loc() const {
     assert(_loc >= 0, "unbound label");
     return _loc;
   }
   int loc_pos() const;   // == locator_pos(loc())
   int loc_sect() const;  // == locator_sect(loc())
   bool is_bound() const    { return _loc >=  0; }
   bool is_unbound() const  { return _loc == -1 && _patch_index > 0; }
   bool is_unused() const   { return _loc == -1 && _patch_index == 0; }
   /**
    * Adds a reference to an unresolved displacement instruction to
    * this unbound label
    *
    * @param cb         the code buffer being patched
    * @param branch_loc the locator of the branch instruction in the code buffer
    */
   void add_patch_at(CodeBuffer* cb, int branch_loc);
   /**
    * Iterate over the list of patches, resolving the instructions
    * Call patch_instruction on each 'branch_loc' value
    */
   void patch_instructions(MacroAssembler* masm);
   void init() {
     _loc = -1;
     _patch_index = 0;
     _patch_overflow = NULL;
   }
   Label() {
     init();
   }
 };
 // A union type for code which has to assemble both constant and
 // non-constant operands, when the distinction cannot be made
 // statically.
 class RegisterOrConstant VALUE_OBJ_CLASS_SPEC {
  private:
   Register _r;
   intptr_t _c;
  public:
   RegisterOrConstant(): _r(noreg), _c(0) {}
   RegisterOrConstant(Register r): _r(r), _c(0) {}
   RegisterOrConstant(intptr_t c): _r(noreg), _c(c) {}
   Register as_register() const { assert(is_register(),""); return _r; }
   intptr_t as_constant() const { assert(is_constant(),""); return _c; }
   Register register_or_noreg() const { return _r; }
   intptr_t constant_or_zero() const  { return _c; }
   bool is_register() const { return _r != noreg; }
   bool is_constant() const { return _r == noreg; }
 };
 // The Abstract Assembler: Pure assembler doing NO optimizations on the
 // instruction level; i.e., what you write is what you get.
 // The Assembler is generating code into a CodeBuffer.
 class AbstractAssembler : public ResourceObj  {
   friend class Label;
  protected:
   CodeSection* _code_section;          // section within the code buffer
   address      _code_begin;            // first byte of code buffer
   address      _code_limit;            // first byte after code buffer
   address      _code_pos;              // current code generation position
   OopRecorder* _oop_recorder;          // support for relocInfo::oop_type
   // Code emission & accessing
   address addr_at(int pos) const       { return _code_begin + pos; }
   // This routine is called with a label is used for an address.
   // Labels and displacements truck in offsets, but target must return a PC.
   address target(Label& L);            // return _code_section->target(L)
   bool is8bit(int x) const             { return -0x80 <= x && x < 0x80; }
   bool isByte(int x) const             { return 0 <= x && x < 0x100; }
   bool isShiftCount(int x) const       { return 0 <= x && x < 32; }
   void emit_byte(int x);  // emit a single byte
   void emit_word(int x);  // emit a 16-bit word (not a wordSize word!)
   void emit_long(jint x); // emit a 32-bit word (not a longSize word!)
   void emit_address(address x); // emit an address (not a longSize word!)
   // Instruction boundaries (required when emitting relocatable values).
   class InstructionMark: public StackObj {
    private:
     AbstractAssembler* _assm;
    public:
     InstructionMark(AbstractAssembler* assm) : _assm(assm) {
       assert(assm->inst_mark() == NULL, "overlapping instructions");
       _assm->set_inst_mark();
     }
     ~InstructionMark() {
       _assm->clear_inst_mark();
     }
   };
   friend class InstructionMark;
   #ifdef ASSERT
   // Make it return true on platforms which need to verify
   // instruction boundaries for some operations.
   inline static bool pd_check_instruction_mark();
   #endif
   // Label functions
   void print(Label& L);
  public:
   // Creation
   AbstractAssembler(CodeBuffer* code);
   // save end pointer back to code buf.
   void sync();
   // ensure buf contains all code (call this before using/copying the code)
   void flush();
   // Accessors
   CodeBuffer*   code() const;          // _code_section->outer()
   CodeSection*  code_section() const   { return _code_section; }
   int           sect() const;          // return _code_section->index()
   address       pc() const             { return _code_pos; }
   int           offset() const         { return _code_pos - _code_begin; }
   int           locator() const;       // CodeBuffer::locator(offset(), sect())
   OopRecorder*  oop_recorder() const   { return _oop_recorder; }
   void      set_oop_recorder(OopRecorder* r) { _oop_recorder = r; }
   address  inst_mark() const;
   void set_inst_mark();
   void clear_inst_mark();
   // Constants in code
   void a_byte(int x);
   void a_long(jint x);
   void relocate(RelocationHolder const& rspec, int format = 0);
   void relocate(   relocInfo::relocType rtype, int format = 0) {
     if (rtype != relocInfo::none)
       relocate(Relocation::spec_simple(rtype), format);
   }
   static int code_fill_byte();         // used to pad out odd-sized code buffers
   // Associate a comment with the current offset.  It will be printed
   // along with the disassembly when printing nmethods.  Currently
   // only supported in the instruction section of the code buffer.
   void block_comment(const char* comment);
   // Label functions
   void bind(Label& L); // binds an unbound label L to the current code position
   // Move to a different section in the same code buffer.
   void set_code_section(CodeSection* cs);
   // Inform assembler when generating stub code and relocation info
   address    start_a_stub(int required_space);
   void       end_a_stub();
   // Ditto for constants.
   address    start_a_const(int required_space, int required_align = sizeof(double));
   void       end_a_const();
   // fp constants support
   address double_constant(jdouble c) {
     address ptr = start_a_const(sizeof(c), sizeof(c));
     if (ptr != NULL) {
       *(jdouble*)ptr = c;
       _code_pos = ptr + sizeof(c);
       end_a_const();
     }
     return ptr;
   }
   address float_constant(jfloat c) {
     address ptr = start_a_const(sizeof(c), sizeof(c));
     if (ptr != NULL) {
       *(jfloat*)ptr = c;
       _code_pos = ptr + sizeof(c);
       end_a_const();
     }
     return ptr;
   }
   address address_constant(address c, RelocationHolder const& rspec) {
     address ptr = start_a_const(sizeof(c), sizeof(c));
     if (ptr != NULL) {
       relocate(rspec);
       *(address*)ptr = c;
       _code_pos = ptr + sizeof(c);
       end_a_const();
     }
     return ptr;
   }
   inline address address_constant(Label& L);
   inline address address_table_constant(GrowableArray<Label*> label);
   // Bootstrapping aid to cope with delayed determination of constants.
   // Returns a static address which will eventually contain the constant.
   // The value zero (NULL) stands instead of a constant which is still uncomputed.
   // Thus, the eventual value of the constant must not be zero.
   // This is fine, since this is designed for embedding object field
   // offsets in code which must be generated before the object class is loaded.
   // Field offsets are never zero, since an object's header (mark word)
   // is located at offset zero.
   RegisterOrConstant delayed_value(int(*value_fn)(), Register tmp, int offset = 0) {
     return delayed_value_impl(delayed_value_addr(value_fn), tmp, offset);
   }
   RegisterOrConstant delayed_value(address(*value_fn)(), Register tmp, int offset = 0) {
     return delayed_value_impl(delayed_value_addr(value_fn), tmp, offset);
   }
   virtual RegisterOrConstant delayed_value_impl(intptr_t* delayed_value_addr, Register tmp, int offset) = 0;
   // Last overloading is platform-dependent; look in assembler_<arch>.cpp.
   static intptr_t* delayed_value_addr(int(*constant_fn)());
   static intptr_t* delayed_value_addr(address(*constant_fn)());
   static void update_delayed_values();
   // Bang stack to trigger StackOverflowError at a safe location
   // implementation delegates to machine-specific bang_stack_with_offset
   void generate_stack_overflow_check( int frame_size_in_bytes );
   virtual void bang_stack_with_offset(int offset) = 0;
   /**
    * A platform-dependent method to patch a jump instruction that refers
    * to this label.
    *
    * @param branch the location of the instruction to patch
    * @param masm the assembler which generated the branch
    */
   void pd_patch_instruction(address branch, address target);
 #ifndef PRODUCT
   /**
    * Platform-dependent method of printing an instruction that needs to be
    * patched.
    *
    * @param branch the instruction to be patched in the buffer.
    */
   static void pd_print_patched_instruction(address branch);
 #endif // PRODUCT
 };
 #include "incls/_assembler_pd.hpp.incl"

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/asm/assembler.hpp@c89f86385056 (annotated)

src/share/vm/asm/assembler.hpp