jdk8-mips64-public/hotspot: src/share/vm/asm/assembler.cpp@f90c822e73f8 (annotated)

src/share/vm/asm/assembler.cpp@f90c822e73f8 (annotated)

src/share/vm/asm/assembler.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "asm/macroAssembler.hpp"
 #include "asm/macroAssembler.inline.hpp"
 #include "asm/codeBuffer.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/atomic.inline.hpp"
 #include "runtime/icache.hpp"
 #include "runtime/os.hpp"
 // Implementation of AbstractAssembler
 //
 // The AbstractAssembler is generating code into a CodeBuffer. To make code generation faster,
 // the assembler keeps a copy of the code buffers boundaries & modifies them when
 // emitting bytes rather than using the code buffers accessor functions all the time.
 // The code buffer is updated via set_code_end(...) after emitting a whole instruction.
 AbstractAssembler::AbstractAssembler(CodeBuffer* code) {
   if (code == NULL)  return;
   CodeSection* cs = code->insts();
   cs->clear_mark();   // new assembler kills old mark
   if (cs->start() == NULL)  {
     vm_exit_out_of_memory(0, OOM_MMAP_ERROR, err_msg("CodeCache: no room for %s",
                                      code->name()));
   }
   _code_section = cs;
   _oop_recorder= code->oop_recorder();
   DEBUG_ONLY( _short_branch_delta = 0; )
 }
 void AbstractAssembler::set_code_section(CodeSection* cs) {
   assert(cs->outer() == code_section()->outer(), "sanity");
   assert(cs->is_allocated(), "need to pre-allocate this section");
   cs->clear_mark();  // new assembly into this section kills old mark
   _code_section = cs;
 }
 // Inform CodeBuffer that incoming code and relocation will be for stubs
 address AbstractAssembler::start_a_stub(int required_space) {
   CodeBuffer*  cb = code();
   CodeSection* cs = cb->stubs();
   assert(_code_section == cb->insts(), "not in insts?");
   if (cs->maybe_expand_to_ensure_remaining(required_space)
       && cb->blob() == NULL) {
     return NULL;
   }
   set_code_section(cs);
   return pc();
 }
 // Inform CodeBuffer that incoming code and relocation will be code
 // Should not be called if start_a_stub() returned NULL
 void AbstractAssembler::end_a_stub() {
   assert(_code_section == code()->stubs(), "not in stubs?");
   set_code_section(code()->insts());
 }
 // Inform CodeBuffer that incoming code and relocation will be for stubs
 address AbstractAssembler::start_a_const(int required_space, int required_align) {
   CodeBuffer*  cb = code();
   CodeSection* cs = cb->consts();
   assert(_code_section == cb->insts() || _code_section == cb->stubs(), "not in insts/stubs?");
   address end = cs->end();
   int pad = -(intptr_t)end & (required_align-1);
   if (cs->maybe_expand_to_ensure_remaining(pad + required_space)) {
     if (cb->blob() == NULL)  return NULL;
     end = cs->end();  // refresh pointer
   }
   if (pad > 0) {
     while (--pad >= 0) { *end++ = 0; }
     cs->set_end(end);
   }
   set_code_section(cs);
   return end;
 }
 // Inform CodeBuffer that incoming code and relocation will be code
 // in section cs (insts or stubs).
 void AbstractAssembler::end_a_const(CodeSection* cs) {
   assert(_code_section == code()->consts(), "not in consts?");
   set_code_section(cs);
 }
 void AbstractAssembler::flush() {
   ICache::invalidate_range(addr_at(0), offset());
 }
 void AbstractAssembler::bind(Label& L) {
   if (L.is_bound()) {
     // Assembler can bind a label more than once to the same place.
     guarantee(L.loc() == locator(), "attempt to redefine label");
     return;
   }
   L.bind_loc(locator());
   L.patch_instructions((MacroAssembler*)this);
 }
 void AbstractAssembler::generate_stack_overflow_check( int frame_size_in_bytes) {
   if (UseStackBanging) {
     // Each code entry causes one stack bang n pages down the stack where n
     // is configurable by StackShadowPages.  The setting depends on the maximum
     // depth of VM call stack or native before going back into java code,
     // since only java code can raise a stack overflow exception using the
     // stack banging mechanism.  The VM and native code does not detect stack
     // overflow.
     // The code in JavaCalls::call() checks that there is at least n pages
     // available, so all entry code needs to do is bang once for the end of
     // this shadow zone.
     // The entry code may need to bang additional pages if the framesize
     // is greater than a page.
     const int page_size = os::vm_page_size();
     int bang_end = StackShadowPages*page_size;
     // This is how far the previous frame's stack banging extended.
     const int bang_end_safe = bang_end;
     if (frame_size_in_bytes > page_size) {
       bang_end += frame_size_in_bytes;
     }
     int bang_offset = bang_end_safe;
     while (bang_offset <= bang_end) {
       // Need at least one stack bang at end of shadow zone.
       bang_stack_with_offset(bang_offset);
       bang_offset += page_size;
     }
   } // end (UseStackBanging)
 }
 void Label::add_patch_at(CodeBuffer* cb, int branch_loc) {
   assert(_loc == -1, "Label is unbound");
   if (_patch_index < PatchCacheSize) {
     _patches[_patch_index] = branch_loc;
   } else {
     if (_patch_overflow == NULL) {
       _patch_overflow = cb->create_patch_overflow();
     }
     _patch_overflow->push(branch_loc);
   }
   ++_patch_index;
 }
 void Label::patch_instructions(MacroAssembler* masm) {
   assert(is_bound(), "Label is bound");
   CodeBuffer* cb = masm->code();
   int target_sect = CodeBuffer::locator_sect(loc());
   address target = cb->locator_address(loc());
   while (_patch_index > 0) {
     --_patch_index;
     int branch_loc;
     if (_patch_index >= PatchCacheSize) {
       branch_loc = _patch_overflow->pop();
     } else {
       branch_loc = _patches[_patch_index];
     }
     int branch_sect = CodeBuffer::locator_sect(branch_loc);
     address branch = cb->locator_address(branch_loc);
     if (branch_sect == CodeBuffer::SECT_CONSTS) {
       // The thing to patch is a constant word.
       *(address*)branch = target;
       continue;
     }
 #ifdef ASSERT
     // Cross-section branches only work if the
     // intermediate section boundaries are frozen.
     if (target_sect != branch_sect) {
       for (int n = MIN2(target_sect, branch_sect),
                nlimit = (target_sect + branch_sect) - n;
            n < nlimit; n++) {
         CodeSection* cs = cb->code_section(n);
         assert(cs->is_frozen(), "cross-section branch needs stable offsets");
       }
     }
 #endif //ASSERT
     // Push the target offset into the branch instruction.
     masm->pd_patch_instruction(branch, target);
   }
 }
 struct DelayedConstant {
   typedef void (*value_fn_t)();
   BasicType type;
   intptr_t value;
   value_fn_t value_fn;
   // This limit of 20 is generous for initial uses.
   // The limit needs to be large enough to store the field offsets
   // into classes which do not have statically fixed layouts.
   // (Initial use is for method handle object offsets.)
   // Look for uses of "delayed_value" in the source code
   // and make sure this number is generous enough to handle all of them.
   enum { DC_LIMIT = 20 };
   static DelayedConstant delayed_constants[DC_LIMIT];
   static DelayedConstant* add(BasicType type, value_fn_t value_fn);
   bool match(BasicType t, value_fn_t cfn) {
     return type == t && value_fn == cfn;
   }
   static void update_all();
 };
 DelayedConstant DelayedConstant::delayed_constants[DC_LIMIT];
 // Default C structure initialization rules have the following effect here:
 // = { { (BasicType)0, (intptr_t)NULL }, ... };
 DelayedConstant* DelayedConstant::add(BasicType type,
                                       DelayedConstant::value_fn_t cfn) {
   for (int i = 0; i < DC_LIMIT; i++) {
     DelayedConstant* dcon = &delayed_constants[i];
     if (dcon->match(type, cfn))
       return dcon;
     if (dcon->value_fn == NULL) {
       // (cmpxchg not because this is multi-threaded but because I'm paranoid)
       if (Atomic::cmpxchg_ptr(CAST_FROM_FN_PTR(void*, cfn), &dcon->value_fn, NULL) == NULL) {
         dcon->type = type;
         return dcon;
       }
     }
   }
   // If this assert is hit (in pre-integration testing!) then re-evaluate
   // the comment on the definition of DC_LIMIT.
   guarantee(false, "too many delayed constants");
   return NULL;
 }
 void DelayedConstant::update_all() {
   for (int i = 0; i < DC_LIMIT; i++) {
     DelayedConstant* dcon = &delayed_constants[i];
     if (dcon->value_fn != NULL && dcon->value == 0) {
       typedef int     (*int_fn_t)();
       typedef address (*address_fn_t)();
       switch (dcon->type) {
       case T_INT:     dcon->value = (intptr_t) ((int_fn_t)    dcon->value_fn)(); break;
       case T_ADDRESS: dcon->value = (intptr_t) ((address_fn_t)dcon->value_fn)(); break;
       }
     }
   }
 }
 RegisterOrConstant AbstractAssembler::delayed_value(int(*value_fn)(), Register tmp, int offset) {
   intptr_t val = (intptr_t) (*value_fn)();
   if (val != 0)  return val + offset;
   return delayed_value_impl(delayed_value_addr(value_fn), tmp, offset);
 }
 RegisterOrConstant AbstractAssembler::delayed_value(address(*value_fn)(), Register tmp, int offset) {
   intptr_t val = (intptr_t) (*value_fn)();
   if (val != 0)  return val + offset;
   return delayed_value_impl(delayed_value_addr(value_fn), tmp, offset);
 }
 intptr_t* AbstractAssembler::delayed_value_addr(int(*value_fn)()) {
   DelayedConstant* dcon = DelayedConstant::add(T_INT, (DelayedConstant::value_fn_t) value_fn);
   return &dcon->value;
 }
 intptr_t* AbstractAssembler::delayed_value_addr(address(*value_fn)()) {
   DelayedConstant* dcon = DelayedConstant::add(T_ADDRESS, (DelayedConstant::value_fn_t) value_fn);
   return &dcon->value;
 }
 void AbstractAssembler::update_delayed_values() {
   DelayedConstant::update_all();
 }
 void AbstractAssembler::block_comment(const char* comment) {
   if (sect() == CodeBuffer::SECT_INSTS) {
     code_section()->outer()->block_comment(offset(), comment);
   }
 }
 const char* AbstractAssembler::code_string(const char* str) {
   if (sect() == CodeBuffer::SECT_INSTS || sect() == CodeBuffer::SECT_STUBS) {
     return code_section()->outer()->code_string(str);
   }
   return NULL;
 }
 bool MacroAssembler::needs_explicit_null_check(intptr_t offset) {
   // Exception handler checks the nmethod's implicit null checks table
   // only when this method returns false.
 #ifdef _LP64
   if (UseCompressedOops && Universe::narrow_oop_base() != NULL) {
     assert (Universe::heap() != NULL, "java heap should be initialized");
     // The first page after heap_base is unmapped and
     // the 'offset' is equal to [heap_base + offset] for
     // narrow oop implicit null checks.
     uintptr_t base = (uintptr_t)Universe::narrow_oop_base();
     if ((uintptr_t)offset >= base) {
       // Normalize offset for the next check.
       offset = (intptr_t)(pointer_delta((void*)offset, (void*)base, 1));
     }
   }
 #endif
   return offset < 0 || os::vm_page_size() <= offset;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/asm/assembler.cpp@f90c822e73f8 (annotated)

src/share/vm/asm/assembler.cpp