src/share/vm/opto/output.cpp

Thu, 24 May 2018 19:24:53 +0800

author
aoqi
date
Thu, 24 May 2018 19:24:53 +0800
changeset 8861
2a33b32dd03c
parent 8856
ac27a9c85bea
child 8862
fd13a567f179
permissions
-rw-r--r--

#7046 Disable the compilation when branch offset is beyond short branch
Contributed-by: fujie, aoqi

     1 /*
     2  * Copyright (c) 1998, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 /*
    26  * This file has been modified by Loongson Technology in 2015. These
    27  * modifications are Copyright (c) 2015 Loongson Technology, and are made
    28  * available on the same license terms set forth above.
    29  */
    31 #include "precompiled.hpp"
    32 #include "asm/assembler.inline.hpp"
    33 #include "code/compiledIC.hpp"
    34 #include "code/debugInfo.hpp"
    35 #include "code/debugInfoRec.hpp"
    36 #include "compiler/compileBroker.hpp"
    37 #include "compiler/oopMap.hpp"
    38 #include "memory/allocation.inline.hpp"
    39 #include "opto/callnode.hpp"
    40 #include "opto/cfgnode.hpp"
    41 #include "opto/locknode.hpp"
    42 #include "opto/machnode.hpp"
    43 #include "opto/output.hpp"
    44 #include "opto/regalloc.hpp"
    45 #include "opto/runtime.hpp"
    46 #include "opto/subnode.hpp"
    47 #include "opto/type.hpp"
    48 #include "runtime/handles.inline.hpp"
    49 #include "utilities/xmlstream.hpp"
    51 #ifndef PRODUCT
    52 #define DEBUG_ARG(x) , x
    53 #else
    54 #define DEBUG_ARG(x)
    55 #endif
    57 // Convert Nodes to instruction bits and pass off to the VM
    58 void Compile::Output() {
    59   // RootNode goes
    60   assert( _cfg->get_root_block()->number_of_nodes() == 0, "" );
    62   // The number of new nodes (mostly MachNop) is proportional to
    63   // the number of java calls and inner loops which are aligned.
    64   if ( C->check_node_count((NodeLimitFudgeFactor + C->java_calls()*3 +
    65                             C->inner_loops()*(OptoLoopAlignment-1)),
    66                            "out of nodes before code generation" ) ) {
    67     return;
    68   }
    69   // Make sure I can find the Start Node
    70   Block *entry = _cfg->get_block(1);
    71   Block *broot = _cfg->get_root_block();
    73   const StartNode *start = entry->head()->as_Start();
    75   // Replace StartNode with prolog
    76   MachPrologNode *prolog = new (this) MachPrologNode();
    77   entry->map_node(prolog, 0);
    78   _cfg->map_node_to_block(prolog, entry);
    79   _cfg->unmap_node_from_block(start); // start is no longer in any block
    81   // Virtual methods need an unverified entry point
    83   if( is_osr_compilation() ) {
    84     if( PoisonOSREntry ) {
    85       // TODO: Should use a ShouldNotReachHereNode...
    86       _cfg->insert( broot, 0, new (this) MachBreakpointNode() );
    87     }
    88   } else {
    89     if( _method && !_method->flags().is_static() ) {
    90       // Insert unvalidated entry point
    91       _cfg->insert( broot, 0, new (this) MachUEPNode() );
    92     }
    94   }
    97   // Break before main entry point
    98   if( (_method && _method->break_at_execute())
    99 #ifndef PRODUCT
   100     ||(OptoBreakpoint && is_method_compilation())
   101     ||(OptoBreakpointOSR && is_osr_compilation())
   102     ||(OptoBreakpointC2R && !_method)
   103 #endif
   104     ) {
   105     // checking for _method means that OptoBreakpoint does not apply to
   106     // runtime stubs or frame converters
   107     _cfg->insert( entry, 1, new (this) MachBreakpointNode() );
   108   }
   110   // Insert epilogs before every return
   111   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
   112     Block* block = _cfg->get_block(i);
   113     if (!block->is_connector() && block->non_connector_successor(0) == _cfg->get_root_block()) { // Found a program exit point?
   114       Node* m = block->end();
   115       if (m->is_Mach() && m->as_Mach()->ideal_Opcode() != Op_Halt) {
   116         MachEpilogNode* epilog = new (this) MachEpilogNode(m->as_Mach()->ideal_Opcode() == Op_Return);
   117         block->add_inst(epilog);
   118         _cfg->map_node_to_block(epilog, block);
   119       }
   120     }
   121   }
   123 # ifdef ENABLE_ZAP_DEAD_LOCALS
   124   if (ZapDeadCompiledLocals) {
   125     Insert_zap_nodes();
   126   }
   127 # endif
   129   uint* blk_starts = NEW_RESOURCE_ARRAY(uint, _cfg->number_of_blocks() + 1);
   130   blk_starts[0] = 0;
   132   // Initialize code buffer and process short branches.
   133   CodeBuffer* cb = init_buffer(blk_starts);
   135   if (cb == NULL || failing()) {
   136     return;
   137   }
   139   ScheduleAndBundle();
   141 #ifndef PRODUCT
   142   if (trace_opto_output()) {
   143     tty->print("\n---- After ScheduleAndBundle ----\n");
   144     for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
   145       tty->print("\nBB#%03d:\n", i);
   146       Block* block = _cfg->get_block(i);
   147       for (uint j = 0; j < block->number_of_nodes(); j++) {
   148         Node* n = block->get_node(j);
   149         OptoReg::Name reg = _regalloc->get_reg_first(n);
   150         tty->print(" %-6s ", reg >= 0 && reg < REG_COUNT ? Matcher::regName[reg] : "");
   151         n->dump();
   152       }
   153     }
   154   }
   155 #endif
   157   if (failing()) {
   158     return;
   159   }
   161   BuildOopMaps();
   163   if (failing())  {
   164     return;
   165   }
   167   fill_buffer(cb, blk_starts);
   168 }
   170 bool Compile::need_stack_bang(int frame_size_in_bytes) const {
   171   // Determine if we need to generate a stack overflow check.
   172   // Do it if the method is not a stub function and
   173   // has java calls or has frame size > vm_page_size/8.
   174   // The debug VM checks that deoptimization doesn't trigger an
   175   // unexpected stack overflow (compiled method stack banging should
   176   // guarantee it doesn't happen) so we always need the stack bang in
   177   // a debug VM.
   178   return (UseStackBanging && stub_function() == NULL &&
   179           (has_java_calls() || frame_size_in_bytes > os::vm_page_size()>>3
   180            DEBUG_ONLY(|| true)));
   181 }
   183 bool Compile::need_register_stack_bang() const {
   184   // Determine if we need to generate a register stack overflow check.
   185   // This is only used on architectures which have split register
   186   // and memory stacks (ie. IA64).
   187   // Bang if the method is not a stub function and has java calls
   188   return (stub_function() == NULL && has_java_calls());
   189 }
   191 # ifdef ENABLE_ZAP_DEAD_LOCALS
   194 // In order to catch compiler oop-map bugs, we have implemented
   195 // a debugging mode called ZapDeadCompilerLocals.
   196 // This mode causes the compiler to insert a call to a runtime routine,
   197 // "zap_dead_locals", right before each place in compiled code
   198 // that could potentially be a gc-point (i.e., a safepoint or oop map point).
   199 // The runtime routine checks that locations mapped as oops are really
   200 // oops, that locations mapped as values do not look like oops,
   201 // and that locations mapped as dead are not used later
   202 // (by zapping them to an invalid address).
   204 int Compile::_CompiledZap_count = 0;
   206 void Compile::Insert_zap_nodes() {
   207   bool skip = false;
   210   // Dink with static counts because code code without the extra
   211   // runtime calls is MUCH faster for debugging purposes
   213        if ( CompileZapFirst  ==  0  ) ; // nothing special
   214   else if ( CompileZapFirst  >  CompiledZap_count() )  skip = true;
   215   else if ( CompileZapFirst  == CompiledZap_count() )
   216     warning("starting zap compilation after skipping");
   218        if ( CompileZapLast  ==  -1  ) ; // nothing special
   219   else if ( CompileZapLast  <   CompiledZap_count() )  skip = true;
   220   else if ( CompileZapLast  ==  CompiledZap_count() )
   221     warning("about to compile last zap");
   223   ++_CompiledZap_count; // counts skipped zaps, too
   225   if ( skip )  return;
   228   if ( _method == NULL )
   229     return; // no safepoints/oopmaps emitted for calls in stubs,so we don't care
   231   // Insert call to zap runtime stub before every node with an oop map
   232   for( uint i=0; i<_cfg->number_of_blocks(); i++ ) {
   233     Block *b = _cfg->get_block(i);
   234     for ( uint j = 0;  j < b->number_of_nodes();  ++j ) {
   235       Node *n = b->get_node(j);
   237       // Determining if we should insert a zap-a-lot node in output.
   238       // We do that for all nodes that has oopmap info, except for calls
   239       // to allocation.  Calls to allocation passes in the old top-of-eden pointer
   240       // and expect the C code to reset it.  Hence, there can be no safepoints between
   241       // the inlined-allocation and the call to new_Java, etc.
   242       // We also cannot zap monitor calls, as they must hold the microlock
   243       // during the call to Zap, which also wants to grab the microlock.
   244       bool insert = n->is_MachSafePoint() && (n->as_MachSafePoint()->oop_map() != NULL);
   245       if ( insert ) { // it is MachSafePoint
   246         if ( !n->is_MachCall() ) {
   247           insert = false;
   248         } else if ( n->is_MachCall() ) {
   249           MachCallNode* call = n->as_MachCall();
   250           if (call->entry_point() == OptoRuntime::new_instance_Java() ||
   251               call->entry_point() == OptoRuntime::new_array_Java() ||
   252               call->entry_point() == OptoRuntime::multianewarray2_Java() ||
   253               call->entry_point() == OptoRuntime::multianewarray3_Java() ||
   254               call->entry_point() == OptoRuntime::multianewarray4_Java() ||
   255               call->entry_point() == OptoRuntime::multianewarray5_Java() ||
   256               call->entry_point() == OptoRuntime::slow_arraycopy_Java() ||
   257               call->entry_point() == OptoRuntime::complete_monitor_locking_Java()
   258               ) {
   259             insert = false;
   260           }
   261         }
   262         if (insert) {
   263           Node *zap = call_zap_node(n->as_MachSafePoint(), i);
   264           b->insert_node(zap, j);
   265           _cfg->map_node_to_block(zap, b);
   266           ++j;
   267         }
   268       }
   269     }
   270   }
   271 }
   274 Node* Compile::call_zap_node(MachSafePointNode* node_to_check, int block_no) {
   275   const TypeFunc *tf = OptoRuntime::zap_dead_locals_Type();
   276   CallStaticJavaNode* ideal_node =
   277     new (this) CallStaticJavaNode( tf,
   278          OptoRuntime::zap_dead_locals_stub(_method->flags().is_native()),
   279                        "call zap dead locals stub", 0, TypePtr::BOTTOM);
   280   // We need to copy the OopMap from the site we're zapping at.
   281   // We have to make a copy, because the zap site might not be
   282   // a call site, and zap_dead is a call site.
   283   OopMap* clone = node_to_check->oop_map()->deep_copy();
   285   // Add the cloned OopMap to the zap node
   286   ideal_node->set_oop_map(clone);
   287   return _matcher->match_sfpt(ideal_node);
   288 }
   290 bool Compile::is_node_getting_a_safepoint( Node* n) {
   291   // This code duplicates the logic prior to the call of add_safepoint
   292   // below in this file.
   293   if( n->is_MachSafePoint() ) return true;
   294   return false;
   295 }
   297 # endif // ENABLE_ZAP_DEAD_LOCALS
   299 // Compute the size of first NumberOfLoopInstrToAlign instructions at the top
   300 // of a loop. When aligning a loop we need to provide enough instructions
   301 // in cpu's fetch buffer to feed decoders. The loop alignment could be
   302 // avoided if we have enough instructions in fetch buffer at the head of a loop.
   303 // By default, the size is set to 999999 by Block's constructor so that
   304 // a loop will be aligned if the size is not reset here.
   305 //
   306 // Note: Mach instructions could contain several HW instructions
   307 // so the size is estimated only.
   308 //
   309 void Compile::compute_loop_first_inst_sizes() {
   310   // The next condition is used to gate the loop alignment optimization.
   311   // Don't aligned a loop if there are enough instructions at the head of a loop
   312   // or alignment padding is larger then MaxLoopPad. By default, MaxLoopPad
   313   // is equal to OptoLoopAlignment-1 except on new Intel cpus, where it is
   314   // equal to 11 bytes which is the largest address NOP instruction.
   315   if (MaxLoopPad < OptoLoopAlignment - 1) {
   316     uint last_block = _cfg->number_of_blocks() - 1;
   317     for (uint i = 1; i <= last_block; i++) {
   318       Block* block = _cfg->get_block(i);
   319       // Check the first loop's block which requires an alignment.
   320       if (block->loop_alignment() > (uint)relocInfo::addr_unit()) {
   321         uint sum_size = 0;
   322         uint inst_cnt = NumberOfLoopInstrToAlign;
   323         inst_cnt = block->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
   325         // Check subsequent fallthrough blocks if the loop's first
   326         // block(s) does not have enough instructions.
   327         Block *nb = block;
   328         while(inst_cnt > 0 &&
   329               i < last_block &&
   330               !_cfg->get_block(i + 1)->has_loop_alignment() &&
   331               !nb->has_successor(block)) {
   332           i++;
   333           nb = _cfg->get_block(i);
   334           inst_cnt  = nb->compute_first_inst_size(sum_size, inst_cnt, _regalloc);
   335         } // while( inst_cnt > 0 && i < last_block  )
   337         block->set_first_inst_size(sum_size);
   338       } // f( b->head()->is_Loop() )
   339     } // for( i <= last_block )
   340   } // if( MaxLoopPad < OptoLoopAlignment-1 )
   341 }
   343 // The architecture description provides short branch variants for some long
   344 // branch instructions. Replace eligible long branches with short branches.
   345 void Compile::shorten_branches(uint* blk_starts, int& code_size, int& reloc_size, int& stub_size) {
   346   // Compute size of each block, method size, and relocation information size
   347   uint nblocks  = _cfg->number_of_blocks();
   349   uint*      jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
   350   uint*      jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
   351   int*       jmp_nidx   = NEW_RESOURCE_ARRAY(int ,nblocks);
   353   // Collect worst case block paddings
   354   int* block_worst_case_pad = NEW_RESOURCE_ARRAY(int, nblocks);
   355   memset(block_worst_case_pad, 0, nblocks * sizeof(int));
   357   DEBUG_ONLY( uint *jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks); )
   358   DEBUG_ONLY( uint *jmp_rule = NEW_RESOURCE_ARRAY(uint,nblocks); )
   360   bool has_short_branch_candidate = false;
   362   // Initialize the sizes to 0
   363   code_size  = 0;          // Size in bytes of generated code
   364   stub_size  = 0;          // Size in bytes of all stub entries
   365   // Size in bytes of all relocation entries, including those in local stubs.
   366   // Start with 2-bytes of reloc info for the unvalidated entry point
   367   reloc_size = 1;          // Number of relocation entries
   369   // Make three passes.  The first computes pessimistic blk_starts,
   370   // relative jmp_offset and reloc_size information.  The second performs
   371   // short branch substitution using the pessimistic sizing.  The
   372   // third inserts nops where needed.
   374   // Step one, perform a pessimistic sizing pass.
   375   uint last_call_adr = max_uint;
   376   uint last_avoid_back_to_back_adr = max_uint;
   377   uint nop_size = (new (this) MachNopNode())->size(_regalloc);
   378   for (uint i = 0; i < nblocks; i++) { // For all blocks
   379     Block* block = _cfg->get_block(i);
   381     // During short branch replacement, we store the relative (to blk_starts)
   382     // offset of jump in jmp_offset, rather than the absolute offset of jump.
   383     // This is so that we do not need to recompute sizes of all nodes when
   384     // we compute correct blk_starts in our next sizing pass.
   385     jmp_offset[i] = 0;
   386     jmp_size[i]   = 0;
   387     jmp_nidx[i]   = -1;
   388     DEBUG_ONLY( jmp_target[i] = 0; )
   389     DEBUG_ONLY( jmp_rule[i]   = 0; )
   391     // Sum all instruction sizes to compute block size
   392     uint last_inst = block->number_of_nodes();
   393     uint blk_size = 0;
   394     for (uint j = 0; j < last_inst; j++) {
   395       Node* nj = block->get_node(j);
   396       // Handle machine instruction nodes
   397       if (nj->is_Mach()) {
   398         MachNode *mach = nj->as_Mach();
   399         blk_size += (mach->alignment_required() - 1) * relocInfo::addr_unit(); // assume worst case padding
   400         reloc_size += mach->reloc();
   401         if (mach->is_MachCall()) {
   402           // add size information for trampoline stub
   403           // class CallStubImpl is platform-specific and defined in the *.ad files.
   404           stub_size  += CallStubImpl::size_call_trampoline();
   405           reloc_size += CallStubImpl::reloc_call_trampoline();
   407           MachCallNode *mcall = mach->as_MachCall();
   408           // This destination address is NOT PC-relative
   410           mcall->method_set((intptr_t)mcall->entry_point());
   412           if (mcall->is_MachCallJava() && mcall->as_MachCallJava()->_method) {
   413             stub_size  += CompiledStaticCall::to_interp_stub_size();
   414             reloc_size += CompiledStaticCall::reloc_to_interp_stub();
   415           }
   416         } else if (mach->is_MachSafePoint()) {
   417           // If call/safepoint are adjacent, account for possible
   418           // nop to disambiguate the two safepoints.
   419           // ScheduleAndBundle() can rearrange nodes in a block,
   420           // check for all offsets inside this block.
   421           if (last_call_adr >= blk_starts[i]) {
   422             blk_size += nop_size;
   423           }
   424         }
   425         if (mach->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
   426           // Nop is inserted between "avoid back to back" instructions.
   427           // ScheduleAndBundle() can rearrange nodes in a block,
   428           // check for all offsets inside this block.
   429           if (last_avoid_back_to_back_adr >= blk_starts[i]) {
   430             blk_size += nop_size;
   431           }
   432         }
   433         if (mach->may_be_short_branch()) {
   434           if (!nj->is_MachBranch()) {
   435 #ifndef PRODUCT
   436             nj->dump(3);
   437 #endif
   438             Unimplemented();
   439           }
   440           assert(jmp_nidx[i] == -1, "block should have only one branch");
   441           jmp_offset[i] = blk_size;
   442           jmp_size[i]   = nj->size(_regalloc);
   443           jmp_nidx[i]   = j;
   444           has_short_branch_candidate = true;
   445         }
   446       }
   447       blk_size += nj->size(_regalloc);
   448       // Remember end of call offset
   449       if (nj->is_MachCall() && !nj->is_MachCallLeaf()) {
   450         last_call_adr = blk_starts[i]+blk_size;
   451       }
   452       // Remember end of avoid_back_to_back offset
   453       if (nj->is_Mach() && nj->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
   454         last_avoid_back_to_back_adr = blk_starts[i]+blk_size;
   455       }
   456     }
   458     // When the next block starts a loop, we may insert pad NOP
   459     // instructions.  Since we cannot know our future alignment,
   460     // assume the worst.
   461     if (i < nblocks - 1) {
   462       Block* nb = _cfg->get_block(i + 1);
   463       int max_loop_pad = nb->code_alignment()-relocInfo::addr_unit();
   464       if (max_loop_pad > 0) {
   465         assert(is_power_of_2(max_loop_pad+relocInfo::addr_unit()), "");
   466         // Adjust last_call_adr and/or last_avoid_back_to_back_adr.
   467         // If either is the last instruction in this block, bump by
   468         // max_loop_pad in lock-step with blk_size, so sizing
   469         // calculations in subsequent blocks still can conservatively
   470         // detect that it may the last instruction in this block.
   471         if (last_call_adr == blk_starts[i]+blk_size) {
   472           last_call_adr += max_loop_pad;
   473         }
   474         if (last_avoid_back_to_back_adr == blk_starts[i]+blk_size) {
   475           last_avoid_back_to_back_adr += max_loop_pad;
   476         }
   477         blk_size += max_loop_pad;
   478         block_worst_case_pad[i + 1] = max_loop_pad;
   479       }
   480     }
   482     // Save block size; update total method size
   483     blk_starts[i+1] = blk_starts[i]+blk_size;
   484   }
   486   // Step two, replace eligible long jumps.
   487   bool progress = true;
   488   uint last_may_be_short_branch_adr = max_uint;
   489   while (has_short_branch_candidate && progress) {
   490     progress = false;
   491     has_short_branch_candidate = false;
   492     int adjust_block_start = 0;
   493     for (uint i = 0; i < nblocks; i++) {
   494       Block* block = _cfg->get_block(i);
   495       int idx = jmp_nidx[i];
   496       MachNode* mach = (idx == -1) ? NULL: block->get_node(idx)->as_Mach();
   497       if (mach != NULL && mach->may_be_short_branch()) {
   498 #ifdef ASSERT
   499         assert(jmp_size[i] > 0 && mach->is_MachBranch(), "sanity");
   500         int j;
   501         // Find the branch; ignore trailing NOPs.
   502         for (j = block->number_of_nodes()-1; j>=0; j--) {
   503           Node* n = block->get_node(j);
   504           if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con)
   505             break;
   506         }
   507         assert(j >= 0 && j == idx && block->get_node(j) == (Node*)mach, "sanity");
   508 #endif
   509         int br_size = jmp_size[i];
   510         int br_offs = blk_starts[i] + jmp_offset[i];
   512         // This requires the TRUE branch target be in succs[0]
   513         uint bnum = block->non_connector_successor(0)->_pre_order;
   514         int offset = blk_starts[bnum] - br_offs;
   515         if (bnum > i) { // adjust following block's offset
   516           offset -= adjust_block_start;
   517         }
   519         // This block can be a loop header, account for the padding
   520         // in the previous block.
   521         int block_padding = block_worst_case_pad[i];
   522         assert(i == 0 || block_padding == 0 || br_offs >= block_padding, "Should have at least a padding on top");
   523         // In the following code a nop could be inserted before
   524         // the branch which will increase the backward distance.
   525         bool needs_padding = ((uint)(br_offs - block_padding) == last_may_be_short_branch_adr);
   526         assert(!needs_padding || jmp_offset[i] == 0, "padding only branches at the beginning of block");
   528         if (needs_padding && offset <= 0)
   529           offset -= nop_size;
   531         if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
   532           // We've got a winner.  Replace this branch.
   533           MachNode* replacement = mach->as_MachBranch()->short_branch_version(this);
   535           // Update the jmp_size.
   536           int new_size = replacement->size(_regalloc);
   537           int diff     = br_size - new_size;
   538           assert(diff >= (int)nop_size, "short_branch size should be smaller");
   539           // Conservatively take into account padding between
   540           // avoid_back_to_back branches. Previous branch could be
   541           // converted into avoid_back_to_back branch during next
   542           // rounds.
   543           if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
   544             jmp_offset[i] += nop_size;
   545             diff -= nop_size;
   546           }
   547           adjust_block_start += diff;
   548           block->map_node(replacement, idx);
   549           mach->subsume_by(replacement, C);
   550           mach = replacement;
   551           progress = true;
   553           jmp_size[i] = new_size;
   554           DEBUG_ONLY( jmp_target[i] = bnum; );
   555           DEBUG_ONLY( jmp_rule[i] = mach->rule(); );
   556         } else {
   557 #ifdef MIPS64
   558           env()->record_method_not_compilable("Branch out of range for MIPS");
   559           return;
   560 #endif
   561           // The jump distance is not short, try again during next iteration.
   562           has_short_branch_candidate = true;
   563         }
   564       } // (mach->may_be_short_branch())
   565       if (mach != NULL && (mach->may_be_short_branch() ||
   566                            mach->avoid_back_to_back(MachNode::AVOID_AFTER))) {
   567         last_may_be_short_branch_adr = blk_starts[i] + jmp_offset[i] + jmp_size[i];
   568       }
   569       blk_starts[i+1] -= adjust_block_start;
   570     }
   571   }
   573 #ifdef ASSERT
   574   for (uint i = 0; i < nblocks; i++) { // For all blocks
   575     if (jmp_target[i] != 0) {
   576       int br_size = jmp_size[i];
   577       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
   578       if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
   579         tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
   580       }
   581       assert(_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset), "Displacement too large for short jmp");
   582     }
   583   }
   584 #endif
   586   // Step 3, compute the offsets of all blocks, will be done in fill_buffer()
   587   // after ScheduleAndBundle().
   589   // ------------------
   590   // Compute size for code buffer
   591   code_size = blk_starts[nblocks];
   593   // Relocation records
   594   reloc_size += 1;              // Relo entry for exception handler
   596   // Adjust reloc_size to number of record of relocation info
   597   // Min is 2 bytes, max is probably 6 or 8, with a tax up to 25% for
   598   // a relocation index.
   599   // The CodeBuffer will expand the locs array if this estimate is too low.
   600   reloc_size *= 10 / sizeof(relocInfo);
   601 }
   603 //------------------------------FillLocArray-----------------------------------
   604 // Create a bit of debug info and append it to the array.  The mapping is from
   605 // Java local or expression stack to constant, register or stack-slot.  For
   606 // doubles, insert 2 mappings and return 1 (to tell the caller that the next
   607 // entry has been taken care of and caller should skip it).
   608 static LocationValue *new_loc_value( PhaseRegAlloc *ra, OptoReg::Name regnum, Location::Type l_type ) {
   609   // This should never have accepted Bad before
   610   assert(OptoReg::is_valid(regnum), "location must be valid");
   611   return (OptoReg::is_reg(regnum))
   612     ? new LocationValue(Location::new_reg_loc(l_type, OptoReg::as_VMReg(regnum)) )
   613     : new LocationValue(Location::new_stk_loc(l_type,  ra->reg2offset(regnum)));
   614 }
   617 ObjectValue*
   618 Compile::sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id) {
   619   for (int i = 0; i < objs->length(); i++) {
   620     assert(objs->at(i)->is_object(), "corrupt object cache");
   621     ObjectValue* sv = (ObjectValue*) objs->at(i);
   622     if (sv->id() == id) {
   623       return sv;
   624     }
   625   }
   626   // Otherwise..
   627   return NULL;
   628 }
   630 void Compile::set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,
   631                                      ObjectValue* sv ) {
   632   assert(sv_for_node_id(objs, sv->id()) == NULL, "Precondition");
   633   objs->append(sv);
   634 }
   637 void Compile::FillLocArray( int idx, MachSafePointNode* sfpt, Node *local,
   638                             GrowableArray<ScopeValue*> *array,
   639                             GrowableArray<ScopeValue*> *objs ) {
   640   assert( local, "use _top instead of null" );
   641   if (array->length() != idx) {
   642     assert(array->length() == idx + 1, "Unexpected array count");
   643     // Old functionality:
   644     //   return
   645     // New functionality:
   646     //   Assert if the local is not top. In product mode let the new node
   647     //   override the old entry.
   648     assert(local == top(), "LocArray collision");
   649     if (local == top()) {
   650       return;
   651     }
   652     array->pop();
   653   }
   654   const Type *t = local->bottom_type();
   656   // Is it a safepoint scalar object node?
   657   if (local->is_SafePointScalarObject()) {
   658     SafePointScalarObjectNode* spobj = local->as_SafePointScalarObject();
   660     ObjectValue* sv = Compile::sv_for_node_id(objs, spobj->_idx);
   661     if (sv == NULL) {
   662       ciKlass* cik = t->is_oopptr()->klass();
   663       assert(cik->is_instance_klass() ||
   664              cik->is_array_klass(), "Not supported allocation.");
   665       sv = new ObjectValue(spobj->_idx,
   666                            new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
   667       Compile::set_sv_for_object_node(objs, sv);
   669       uint first_ind = spobj->first_index(sfpt->jvms());
   670       for (uint i = 0; i < spobj->n_fields(); i++) {
   671         Node* fld_node = sfpt->in(first_ind+i);
   672         (void)FillLocArray(sv->field_values()->length(), sfpt, fld_node, sv->field_values(), objs);
   673       }
   674     }
   675     array->append(sv);
   676     return;
   677   }
   679   // Grab the register number for the local
   680   OptoReg::Name regnum = _regalloc->get_reg_first(local);
   681   if( OptoReg::is_valid(regnum) ) {// Got a register/stack?
   682     // Record the double as two float registers.
   683     // The register mask for such a value always specifies two adjacent
   684     // float registers, with the lower register number even.
   685     // Normally, the allocation of high and low words to these registers
   686     // is irrelevant, because nearly all operations on register pairs
   687     // (e.g., StoreD) treat them as a single unit.
   688     // Here, we assume in addition that the words in these two registers
   689     // stored "naturally" (by operations like StoreD and double stores
   690     // within the interpreter) such that the lower-numbered register
   691     // is written to the lower memory address.  This may seem like
   692     // a machine dependency, but it is not--it is a requirement on
   693     // the author of the <arch>.ad file to ensure that, for every
   694     // even/odd double-register pair to which a double may be allocated,
   695     // the word in the even single-register is stored to the first
   696     // memory word.  (Note that register numbers are completely
   697     // arbitrary, and are not tied to any machine-level encodings.)
   698 #ifdef _LP64
   699     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon ) {
   700       array->append(new ConstantIntValue(0));
   701       array->append(new_loc_value( _regalloc, regnum, Location::dbl ));
   702     } else if ( t->base() == Type::Long ) {
   703       array->append(new ConstantIntValue(0));
   704       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
   705     } else if ( t->base() == Type::RawPtr ) {
   706       // jsr/ret return address which must be restored into a the full
   707       // width 64-bit stack slot.
   708       array->append(new_loc_value( _regalloc, regnum, Location::lng ));
   709     }
   710 #else //_LP64
   711 #ifdef SPARC
   712     if (t->base() == Type::Long && OptoReg::is_reg(regnum)) {
   713       // For SPARC we have to swap high and low words for
   714       // long values stored in a single-register (g0-g7).
   715       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
   716       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
   717     } else
   718 #endif //SPARC
   719     if( t->base() == Type::DoubleBot || t->base() == Type::DoubleCon || t->base() == Type::Long ) {
   720       // Repack the double/long as two jints.
   721       // The convention the interpreter uses is that the second local
   722       // holds the first raw word of the native double representation.
   723       // This is actually reasonable, since locals and stack arrays
   724       // grow downwards in all implementations.
   725       // (If, on some machine, the interpreter's Java locals or stack
   726       // were to grow upwards, the embedded doubles would be word-swapped.)
   727       array->append(new_loc_value( _regalloc, OptoReg::add(regnum,1), Location::normal ));
   728       array->append(new_loc_value( _regalloc,              regnum   , Location::normal ));
   729     }
   730 #endif //_LP64
   731     else if( (t->base() == Type::FloatBot || t->base() == Type::FloatCon) &&
   732                OptoReg::is_reg(regnum) ) {
   733       array->append(new_loc_value( _regalloc, regnum, Matcher::float_in_double()
   734                                    ? Location::float_in_dbl : Location::normal ));
   735     } else if( t->base() == Type::Int && OptoReg::is_reg(regnum) ) {
   736       array->append(new_loc_value( _regalloc, regnum, Matcher::int_in_long
   737                                    ? Location::int_in_long : Location::normal ));
   738     } else if( t->base() == Type::NarrowOop ) {
   739       array->append(new_loc_value( _regalloc, regnum, Location::narrowoop ));
   740     } else {
   741       array->append(new_loc_value( _regalloc, regnum, _regalloc->is_oop(local) ? Location::oop : Location::normal ));
   742     }
   743     return;
   744   }
   746   // No register.  It must be constant data.
   747   switch (t->base()) {
   748   case Type::Half:              // Second half of a double
   749     ShouldNotReachHere();       // Caller should skip 2nd halves
   750     break;
   751   case Type::AnyPtr:
   752     array->append(new ConstantOopWriteValue(NULL));
   753     break;
   754   case Type::AryPtr:
   755   case Type::InstPtr:          // fall through
   756     array->append(new ConstantOopWriteValue(t->isa_oopptr()->const_oop()->constant_encoding()));
   757     break;
   758   case Type::NarrowOop:
   759     if (t == TypeNarrowOop::NULL_PTR) {
   760       array->append(new ConstantOopWriteValue(NULL));
   761     } else {
   762       array->append(new ConstantOopWriteValue(t->make_ptr()->isa_oopptr()->const_oop()->constant_encoding()));
   763     }
   764     break;
   765   case Type::Int:
   766     array->append(new ConstantIntValue(t->is_int()->get_con()));
   767     break;
   768   case Type::RawPtr:
   769     // A return address (T_ADDRESS).
   770     assert((intptr_t)t->is_ptr()->get_con() < (intptr_t)0x10000, "must be a valid BCI");
   771 #ifdef _LP64
   772     // Must be restored to the full-width 64-bit stack slot.
   773     array->append(new ConstantLongValue(t->is_ptr()->get_con()));
   774 #else
   775     array->append(new ConstantIntValue(t->is_ptr()->get_con()));
   776 #endif
   777     break;
   778   case Type::FloatCon: {
   779     float f = t->is_float_constant()->getf();
   780     array->append(new ConstantIntValue(jint_cast(f)));
   781     break;
   782   }
   783   case Type::DoubleCon: {
   784     jdouble d = t->is_double_constant()->getd();
   785 #ifdef _LP64
   786     array->append(new ConstantIntValue(0));
   787     array->append(new ConstantDoubleValue(d));
   788 #else
   789     // Repack the double as two jints.
   790     // The convention the interpreter uses is that the second local
   791     // holds the first raw word of the native double representation.
   792     // This is actually reasonable, since locals and stack arrays
   793     // grow downwards in all implementations.
   794     // (If, on some machine, the interpreter's Java locals or stack
   795     // were to grow upwards, the embedded doubles would be word-swapped.)
   796     jlong_accessor acc;
   797     acc.long_value = jlong_cast(d);
   798     array->append(new ConstantIntValue(acc.words[1]));
   799     array->append(new ConstantIntValue(acc.words[0]));
   800 #endif
   801     break;
   802   }
   803   case Type::Long: {
   804     jlong d = t->is_long()->get_con();
   805 #ifdef _LP64
   806     array->append(new ConstantIntValue(0));
   807     array->append(new ConstantLongValue(d));
   808 #else
   809     // Repack the long as two jints.
   810     // The convention the interpreter uses is that the second local
   811     // holds the first raw word of the native double representation.
   812     // This is actually reasonable, since locals and stack arrays
   813     // grow downwards in all implementations.
   814     // (If, on some machine, the interpreter's Java locals or stack
   815     // were to grow upwards, the embedded doubles would be word-swapped.)
   816     jlong_accessor acc;
   817     acc.long_value = d;
   818     array->append(new ConstantIntValue(acc.words[1]));
   819     array->append(new ConstantIntValue(acc.words[0]));
   820 #endif
   821     break;
   822   }
   823   case Type::Top:               // Add an illegal value here
   824     array->append(new LocationValue(Location()));
   825     break;
   826   default:
   827     ShouldNotReachHere();
   828     break;
   829   }
   830 }
   832 // Determine if this node starts a bundle
   833 bool Compile::starts_bundle(const Node *n) const {
   834   return (_node_bundling_limit > n->_idx &&
   835           _node_bundling_base[n->_idx].starts_bundle());
   836 }
   838 //--------------------------Process_OopMap_Node--------------------------------
   839 void Compile::Process_OopMap_Node(MachNode *mach, int current_offset) {
   841   // Handle special safepoint nodes for synchronization
   842   MachSafePointNode *sfn   = mach->as_MachSafePoint();
   843   MachCallNode      *mcall;
   845 #ifdef ENABLE_ZAP_DEAD_LOCALS
   846   assert( is_node_getting_a_safepoint(mach),  "logic does not match; false negative");
   847 #endif
   849   int safepoint_pc_offset = current_offset;
   850   bool is_method_handle_invoke = false;
   851   bool return_oop = false;
   853   // Add the safepoint in the DebugInfoRecorder
   854   if( !mach->is_MachCall() ) {
   855     mcall = NULL;
   856 #ifdef MIPS64
   857 /*
   858         2013/10/30 Jin: safepoint_pc_offset should point to tha last instruction in safePoint.
   859                 In X86 and sparc, their safePoints only contain one instruction.
   860                 However, we should add current_offset with the size of safePoint in MIPS.
   861           0x2d6ff22c: lw s2, 0x14(s2)
   862         last_pd->pc_offset()=308, pc_offset=304, bci=64
   863         last_pd->pc_offset()=312, pc_offset=312, bci=64
   864         /mnt/openjdk6/hotspot/src/share/vm/code/debugInfoRec.cpp, 289 , assert(last_pd->pc_offset() == pc_offset,"must be last pc")
   866           ;; Safepoint:
   867         ---> pc_offset=304
   868           0x2d6ff230: lui at, 0x2b7a            ; OopMap{s2=Oop s5=Oop t4=Oop off=308}
   869                                                 ;*goto
   870                                                 ; - java.util.Hashtable::get@64 (line 353)
   871         ---> last_pd(308)
   872           0x2d6ff234: lw at, 0xffffc100(at)     ;*goto
   873                                                 ; - java.util.Hashtable::get@64 (line 353)
   874                                                 ;   {poll}
   875           0x2d6ff238: addiu s0, zero, 0x0
   876 */
   877     safepoint_pc_offset += sfn->size(_regalloc) - 4;
   878 #endif
   879     debug_info()->add_safepoint(safepoint_pc_offset, sfn->_oop_map);
   880   } else {
   881     mcall = mach->as_MachCall();
   883     // Is the call a MethodHandle call?
   884     if (mcall->is_MachCallJava()) {
   885       if (mcall->as_MachCallJava()->_method_handle_invoke) {
   886         assert(has_method_handle_invokes(), "must have been set during call generation");
   887         is_method_handle_invoke = true;
   888       }
   889     }
   891     // Check if a call returns an object.
   892     if (mcall->returns_pointer()) {
   893       return_oop = true;
   894     }
   895     safepoint_pc_offset += mcall->ret_addr_offset();
   896     debug_info()->add_safepoint(safepoint_pc_offset, mcall->_oop_map);
   897   }
   899   // Loop over the JVMState list to add scope information
   900   // Do not skip safepoints with a NULL method, they need monitor info
   901   JVMState* youngest_jvms = sfn->jvms();
   902   int max_depth = youngest_jvms->depth();
   904   // Allocate the object pool for scalar-replaced objects -- the map from
   905   // small-integer keys (which can be recorded in the local and ostack
   906   // arrays) to descriptions of the object state.
   907   GrowableArray<ScopeValue*> *objs = new GrowableArray<ScopeValue*>();
   909   // Visit scopes from oldest to youngest.
   910   for (int depth = 1; depth <= max_depth; depth++) {
   911     JVMState* jvms = youngest_jvms->of_depth(depth);
   912     int idx;
   913     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
   914     // Safepoints that do not have method() set only provide oop-map and monitor info
   915     // to support GC; these do not support deoptimization.
   916     int num_locs = (method == NULL) ? 0 : jvms->loc_size();
   917     int num_exps = (method == NULL) ? 0 : jvms->stk_size();
   918     int num_mon  = jvms->nof_monitors();
   919     assert(method == NULL || jvms->bci() < 0 || num_locs == method->max_locals(),
   920            "JVMS local count must match that of the method");
   922     // Add Local and Expression Stack Information
   924     // Insert locals into the locarray
   925     GrowableArray<ScopeValue*> *locarray = new GrowableArray<ScopeValue*>(num_locs);
   926     for( idx = 0; idx < num_locs; idx++ ) {
   927       FillLocArray( idx, sfn, sfn->local(jvms, idx), locarray, objs );
   928     }
   930     // Insert expression stack entries into the exparray
   931     GrowableArray<ScopeValue*> *exparray = new GrowableArray<ScopeValue*>(num_exps);
   932     for( idx = 0; idx < num_exps; idx++ ) {
   933       FillLocArray( idx,  sfn, sfn->stack(jvms, idx), exparray, objs );
   934     }
   936     // Add in mappings of the monitors
   937     assert( !method ||
   938             !method->is_synchronized() ||
   939             method->is_native() ||
   940             num_mon > 0 ||
   941             !GenerateSynchronizationCode,
   942             "monitors must always exist for synchronized methods");
   944     // Build the growable array of ScopeValues for exp stack
   945     GrowableArray<MonitorValue*> *monarray = new GrowableArray<MonitorValue*>(num_mon);
   947     // Loop over monitors and insert into array
   948     for (idx = 0; idx < num_mon; idx++) {
   949       // Grab the node that defines this monitor
   950       Node* box_node = sfn->monitor_box(jvms, idx);
   951       Node* obj_node = sfn->monitor_obj(jvms, idx);
   953       // Create ScopeValue for object
   954       ScopeValue *scval = NULL;
   956       if (obj_node->is_SafePointScalarObject()) {
   957         SafePointScalarObjectNode* spobj = obj_node->as_SafePointScalarObject();
   958         scval = Compile::sv_for_node_id(objs, spobj->_idx);
   959         if (scval == NULL) {
   960           const Type *t = spobj->bottom_type();
   961           ciKlass* cik = t->is_oopptr()->klass();
   962           assert(cik->is_instance_klass() ||
   963                  cik->is_array_klass(), "Not supported allocation.");
   964           ObjectValue* sv = new ObjectValue(spobj->_idx,
   965                                             new ConstantOopWriteValue(cik->java_mirror()->constant_encoding()));
   966           Compile::set_sv_for_object_node(objs, sv);
   968           uint first_ind = spobj->first_index(youngest_jvms);
   969           for (uint i = 0; i < spobj->n_fields(); i++) {
   970             Node* fld_node = sfn->in(first_ind+i);
   971             (void)FillLocArray(sv->field_values()->length(), sfn, fld_node, sv->field_values(), objs);
   972           }
   973           scval = sv;
   974         }
   975       } else if (!obj_node->is_Con()) {
   976         OptoReg::Name obj_reg = _regalloc->get_reg_first(obj_node);
   977         if( obj_node->bottom_type()->base() == Type::NarrowOop ) {
   978           scval = new_loc_value( _regalloc, obj_reg, Location::narrowoop );
   979         } else {
   980           scval = new_loc_value( _regalloc, obj_reg, Location::oop );
   981         }
   982       } else {
   983         const TypePtr *tp = obj_node->get_ptr_type();
   984         scval = new ConstantOopWriteValue(tp->is_oopptr()->const_oop()->constant_encoding());
   985       }
   987       OptoReg::Name box_reg = BoxLockNode::reg(box_node);
   988       Location basic_lock = Location::new_stk_loc(Location::normal,_regalloc->reg2offset(box_reg));
   989       bool eliminated = (box_node->is_BoxLock() && box_node->as_BoxLock()->is_eliminated());
   990       monarray->append(new MonitorValue(scval, basic_lock, eliminated));
   991     }
   993     // We dump the object pool first, since deoptimization reads it in first.
   994     debug_info()->dump_object_pool(objs);
   996     // Build first class objects to pass to scope
   997     DebugToken *locvals = debug_info()->create_scope_values(locarray);
   998     DebugToken *expvals = debug_info()->create_scope_values(exparray);
   999     DebugToken *monvals = debug_info()->create_monitor_values(monarray);
  1001     // Make method available for all Safepoints
  1002     ciMethod* scope_method = method ? method : _method;
  1003     // Describe the scope here
  1004     assert(jvms->bci() >= InvocationEntryBci && jvms->bci() <= 0x10000, "must be a valid or entry BCI");
  1005     assert(!jvms->should_reexecute() || depth == max_depth, "reexecute allowed only for the youngest");
  1006     // Now we can describe the scope.
  1007     debug_info()->describe_scope(safepoint_pc_offset, scope_method, jvms->bci(), jvms->should_reexecute(), is_method_handle_invoke, return_oop, locvals, expvals, monvals);
  1008   } // End jvms loop
  1010   // Mark the end of the scope set.
  1011   debug_info()->end_safepoint(safepoint_pc_offset);
  1016 // A simplified version of Process_OopMap_Node, to handle non-safepoints.
  1017 class NonSafepointEmitter {
  1018   Compile*  C;
  1019   JVMState* _pending_jvms;
  1020   int       _pending_offset;
  1022   void emit_non_safepoint();
  1024  public:
  1025   NonSafepointEmitter(Compile* compile) {
  1026     this->C = compile;
  1027     _pending_jvms = NULL;
  1028     _pending_offset = 0;
  1031   void observe_instruction(Node* n, int pc_offset) {
  1032     if (!C->debug_info()->recording_non_safepoints())  return;
  1034     Node_Notes* nn = C->node_notes_at(n->_idx);
  1035     if (nn == NULL || nn->jvms() == NULL)  return;
  1036     if (_pending_jvms != NULL &&
  1037         _pending_jvms->same_calls_as(nn->jvms())) {
  1038       // Repeated JVMS?  Stretch it up here.
  1039       _pending_offset = pc_offset;
  1040     } else {
  1041       if (_pending_jvms != NULL &&
  1042           _pending_offset < pc_offset) {
  1043         emit_non_safepoint();
  1045       _pending_jvms = NULL;
  1046       if (pc_offset > C->debug_info()->last_pc_offset()) {
  1047         // This is the only way _pending_jvms can become non-NULL:
  1048         _pending_jvms = nn->jvms();
  1049         _pending_offset = pc_offset;
  1054   // Stay out of the way of real safepoints:
  1055   void observe_safepoint(JVMState* jvms, int pc_offset) {
  1056     if (_pending_jvms != NULL &&
  1057         !_pending_jvms->same_calls_as(jvms) &&
  1058         _pending_offset < pc_offset) {
  1059       emit_non_safepoint();
  1061     _pending_jvms = NULL;
  1064   void flush_at_end() {
  1065     if (_pending_jvms != NULL) {
  1066       emit_non_safepoint();
  1068     _pending_jvms = NULL;
  1070 };
  1072 void NonSafepointEmitter::emit_non_safepoint() {
  1073   JVMState* youngest_jvms = _pending_jvms;
  1074   int       pc_offset     = _pending_offset;
  1076   // Clear it now:
  1077   _pending_jvms = NULL;
  1079   DebugInformationRecorder* debug_info = C->debug_info();
  1080   assert(debug_info->recording_non_safepoints(), "sanity");
  1082   debug_info->add_non_safepoint(pc_offset);
  1083   int max_depth = youngest_jvms->depth();
  1085   // Visit scopes from oldest to youngest.
  1086   for (int depth = 1; depth <= max_depth; depth++) {
  1087     JVMState* jvms = youngest_jvms->of_depth(depth);
  1088     ciMethod* method = jvms->has_method() ? jvms->method() : NULL;
  1089     assert(!jvms->should_reexecute() || depth==max_depth, "reexecute allowed only for the youngest");
  1090     debug_info->describe_scope(pc_offset, method, jvms->bci(), jvms->should_reexecute());
  1093   // Mark the end of the scope set.
  1094   debug_info->end_non_safepoint(pc_offset);
  1097 //------------------------------init_buffer------------------------------------
  1098 CodeBuffer* Compile::init_buffer(uint* blk_starts) {
  1100   // Set the initially allocated size
  1101   int  code_req   = initial_code_capacity;
  1102   int  locs_req   = initial_locs_capacity;
  1103   int  stub_req   = TraceJumps ? initial_stub_capacity * 10 : initial_stub_capacity;
  1104   int  const_req  = initial_const_capacity;
  1106   int  pad_req    = NativeCall::instruction_size;
  1107   // The extra spacing after the code is necessary on some platforms.
  1108   // Sometimes we need to patch in a jump after the last instruction,
  1109   // if the nmethod has been deoptimized.  (See 4932387, 4894843.)
  1111   // Compute the byte offset where we can store the deopt pc.
  1112   if (fixed_slots() != 0) {
  1113     _orig_pc_slot_offset_in_bytes = _regalloc->reg2offset(OptoReg::stack2reg(_orig_pc_slot));
  1116   // Compute prolog code size
  1117   _method_size = 0;
  1118   _frame_slots = OptoReg::reg2stack(_matcher->_old_SP)+_regalloc->_framesize;
  1119 #if defined(IA64) && !defined(AIX)
  1120   if (save_argument_registers()) {
  1121     // 4815101: this is a stub with implicit and unknown precision fp args.
  1122     // The usual spill mechanism can only generate stfd's in this case, which
  1123     // doesn't work if the fp reg to spill contains a single-precision denorm.
  1124     // Instead, we hack around the normal spill mechanism using stfspill's and
  1125     // ldffill's in the MachProlog and MachEpilog emit methods.  We allocate
  1126     // space here for the fp arg regs (f8-f15) we're going to thusly spill.
  1127     //
  1128     // If we ever implement 16-byte 'registers' == stack slots, we can
  1129     // get rid of this hack and have SpillCopy generate stfspill/ldffill
  1130     // instead of stfd/stfs/ldfd/ldfs.
  1131     _frame_slots += 8*(16/BytesPerInt);
  1133 #endif
  1134   assert(_frame_slots >= 0 && _frame_slots < 1000000, "sanity check");
  1136   if (has_mach_constant_base_node()) {
  1137     uint add_size = 0;
  1138     // Fill the constant table.
  1139     // Note:  This must happen before shorten_branches.
  1140     for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  1141       Block* b = _cfg->get_block(i);
  1143       for (uint j = 0; j < b->number_of_nodes(); j++) {
  1144         Node* n = b->get_node(j);
  1146         // If the node is a MachConstantNode evaluate the constant
  1147         // value section.
  1148         if (n->is_MachConstant()) {
  1149           MachConstantNode* machcon = n->as_MachConstant();
  1150           machcon->eval_constant(C);
  1151         } else if (n->is_Mach()) {
  1152           // On Power there are more nodes that issue constants.
  1153           add_size += (n->as_Mach()->ins_num_consts() * 8);
  1158     // Calculate the offsets of the constants and the size of the
  1159     // constant table (including the padding to the next section).
  1160     constant_table().calculate_offsets_and_size();
  1161     const_req = constant_table().size() + add_size;
  1164   // Initialize the space for the BufferBlob used to find and verify
  1165   // instruction size in MachNode::emit_size()
  1166   init_scratch_buffer_blob(const_req);
  1167   if (failing())  return NULL; // Out of memory
  1169   // Pre-compute the length of blocks and replace
  1170   // long branches with short if machine supports it.
  1171   shorten_branches(blk_starts, code_req, locs_req, stub_req);
  1172 #ifdef MIPS64
  1173   if (failing())  return NULL; // Branch out of range for MIPS
  1174 #endif
  1176   // nmethod and CodeBuffer count stubs & constants as part of method's code.
  1177   // class HandlerImpl is platform-specific and defined in the *.ad files.
  1178   int exception_handler_req = HandlerImpl::size_exception_handler() + MAX_stubs_size; // add marginal slop for handler
  1179   int deopt_handler_req     = HandlerImpl::size_deopt_handler()     + MAX_stubs_size; // add marginal slop for handler
  1180   stub_req += MAX_stubs_size;   // ensure per-stub margin
  1181   code_req += MAX_inst_size;    // ensure per-instruction margin
  1183   if (StressCodeBuffers)
  1184     code_req = const_req = stub_req = exception_handler_req = deopt_handler_req = 0x10;  // force expansion
  1186   int total_req =
  1187     const_req +
  1188     code_req +
  1189     pad_req +
  1190     stub_req +
  1191     exception_handler_req +
  1192     deopt_handler_req;               // deopt handler
  1194   if (has_method_handle_invokes())
  1195     total_req += deopt_handler_req;  // deopt MH handler
  1197   CodeBuffer* cb = code_buffer();
  1198   cb->initialize(total_req, locs_req);
  1200   // Have we run out of code space?
  1201   if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
  1202     C->record_failure("CodeCache is full");
  1203     return NULL;
  1205   // Configure the code buffer.
  1206   cb->initialize_consts_size(const_req);
  1207   cb->initialize_stubs_size(stub_req);
  1208   cb->initialize_oop_recorder(env()->oop_recorder());
  1210   // fill in the nop array for bundling computations
  1211   MachNode *_nop_list[Bundle::_nop_count];
  1212   Bundle::initialize_nops(_nop_list, this);
  1214   return cb;
  1217 //------------------------------fill_buffer------------------------------------
  1218 void Compile::fill_buffer(CodeBuffer* cb, uint* blk_starts) {
  1219   // blk_starts[] contains offsets calculated during short branches processing,
  1220   // offsets should not be increased during following steps.
  1222   // Compute the size of first NumberOfLoopInstrToAlign instructions at head
  1223   // of a loop. It is used to determine the padding for loop alignment.
  1224   compute_loop_first_inst_sizes();
  1226   // Create oopmap set.
  1227   _oop_map_set = new OopMapSet();
  1229   // !!!!! This preserves old handling of oopmaps for now
  1230   debug_info()->set_oopmaps(_oop_map_set);
  1232   uint nblocks  = _cfg->number_of_blocks();
  1233   // Count and start of implicit null check instructions
  1234   uint inct_cnt = 0;
  1235   uint *inct_starts = NEW_RESOURCE_ARRAY(uint, nblocks+1);
  1237   // Count and start of calls
  1238   uint *call_returns = NEW_RESOURCE_ARRAY(uint, nblocks+1);
  1240   uint  return_offset = 0;
  1241   int nop_size = (new (this) MachNopNode())->size(_regalloc);
  1243   int previous_offset = 0;
  1244   int current_offset  = 0;
  1245   int last_call_offset = -1;
  1246   int last_avoid_back_to_back_offset = -1;
  1247 #ifdef ASSERT
  1248   uint* jmp_target = NEW_RESOURCE_ARRAY(uint,nblocks);
  1249   uint* jmp_offset = NEW_RESOURCE_ARRAY(uint,nblocks);
  1250   uint* jmp_size   = NEW_RESOURCE_ARRAY(uint,nblocks);
  1251   uint* jmp_rule   = NEW_RESOURCE_ARRAY(uint,nblocks);
  1252 #endif
  1254   // Create an array of unused labels, one for each basic block, if printing is enabled
  1255 #ifndef PRODUCT
  1256   int *node_offsets      = NULL;
  1257   uint node_offset_limit = unique();
  1259   if (print_assembly())
  1260     node_offsets         = NEW_RESOURCE_ARRAY(int, node_offset_limit);
  1261 #endif
  1263   NonSafepointEmitter non_safepoints(this);  // emit non-safepoints lazily
  1265   // Emit the constant table.
  1266   if (has_mach_constant_base_node()) {
  1267     constant_table().emit(*cb);
  1270   // Create an array of labels, one for each basic block
  1271   Label *blk_labels = NEW_RESOURCE_ARRAY(Label, nblocks+1);
  1272   for (uint i=0; i <= nblocks; i++) {
  1273     blk_labels[i].init();
  1276   // ------------------
  1277   // Now fill in the code buffer
  1278   Node *delay_slot = NULL;
  1280   for (uint i = 0; i < nblocks; i++) {
  1281     Block* block = _cfg->get_block(i);
  1282     Node* head = block->head();
  1284     // If this block needs to start aligned (i.e, can be reached other
  1285     // than by falling-thru from the previous block), then force the
  1286     // start of a new bundle.
  1287     if (Pipeline::requires_bundling() && starts_bundle(head)) {
  1288       cb->flush_bundle(true);
  1291 #ifdef ASSERT
  1292     if (!block->is_connector()) {
  1293       stringStream st;
  1294       block->dump_head(_cfg, &st);
  1295       MacroAssembler(cb).block_comment(st.as_string());
  1297     jmp_target[i] = 0;
  1298     jmp_offset[i] = 0;
  1299     jmp_size[i]   = 0;
  1300     jmp_rule[i]   = 0;
  1301 #endif
  1302     int blk_offset = current_offset;
  1304     // Define the label at the beginning of the basic block
  1305     MacroAssembler(cb).bind(blk_labels[block->_pre_order]);
  1307     uint last_inst = block->number_of_nodes();
  1309     // Emit block normally, except for last instruction.
  1310     // Emit means "dump code bits into code buffer".
  1311     for (uint j = 0; j<last_inst; j++) {
  1313       // Get the node
  1314       Node* n = block->get_node(j);
  1316       // See if delay slots are supported
  1317       if (valid_bundle_info(n) &&
  1318           node_bundling(n)->used_in_unconditional_delay()) {
  1319         assert(delay_slot == NULL, "no use of delay slot node");
  1320         assert(n->size(_regalloc) == Pipeline::instr_unit_size(), "delay slot instruction wrong size");
  1322         delay_slot = n;
  1323         continue;
  1326       // If this starts a new instruction group, then flush the current one
  1327       // (but allow split bundles)
  1328       if (Pipeline::requires_bundling() && starts_bundle(n))
  1329         cb->flush_bundle(false);
  1331       // The following logic is duplicated in the code ifdeffed for
  1332       // ENABLE_ZAP_DEAD_LOCALS which appears above in this file.  It
  1333       // should be factored out.  Or maybe dispersed to the nodes?
  1335       // Special handling for SafePoint/Call Nodes
  1336       bool is_mcall = false;
  1337       if (n->is_Mach()) {
  1338         MachNode *mach = n->as_Mach();
  1339         is_mcall = n->is_MachCall();
  1340         bool is_sfn = n->is_MachSafePoint();
  1342         // If this requires all previous instructions be flushed, then do so
  1343         if (is_sfn || is_mcall || mach->alignment_required() != 1) {
  1344           cb->flush_bundle(true);
  1345           current_offset = cb->insts_size();
  1348         // A padding may be needed again since a previous instruction
  1349         // could be moved to delay slot.
  1351         // align the instruction if necessary
  1352         int padding = mach->compute_padding(current_offset);
  1353         // Make sure safepoint node for polling is distinct from a call's
  1354         // return by adding a nop if needed.
  1355         if (is_sfn && !is_mcall && padding == 0 && current_offset == last_call_offset) {
  1356           padding = nop_size;
  1358         if (padding == 0 && mach->avoid_back_to_back(MachNode::AVOID_BEFORE) &&
  1359             current_offset == last_avoid_back_to_back_offset) {
  1360           // Avoid back to back some instructions.
  1361           padding = nop_size;
  1364         if(padding > 0) {
  1365           assert((padding % nop_size) == 0, "padding is not a multiple of NOP size");
  1366           int nops_cnt = padding / nop_size;
  1367           MachNode *nop = new (this) MachNopNode(nops_cnt);
  1368           block->insert_node(nop, j++);
  1369           last_inst++;
  1370           _cfg->map_node_to_block(nop, block);
  1371           nop->emit(*cb, _regalloc);
  1372           cb->flush_bundle(true);
  1373           current_offset = cb->insts_size();
  1376         // Remember the start of the last call in a basic block
  1377         if (is_mcall) {
  1378           MachCallNode *mcall = mach->as_MachCall();
  1380           // This destination address is NOT PC-relative
  1381           mcall->method_set((intptr_t)mcall->entry_point());
  1383           // Save the return address
  1384           call_returns[block->_pre_order] = current_offset + mcall->ret_addr_offset();
  1386           if (mcall->is_MachCallLeaf()) {
  1387             is_mcall = false;
  1388             is_sfn = false;
  1392         // sfn will be valid whenever mcall is valid now because of inheritance
  1393         if (is_sfn || is_mcall) {
  1395           // Handle special safepoint nodes for synchronization
  1396           if (!is_mcall) {
  1397             MachSafePointNode *sfn = mach->as_MachSafePoint();
  1398             // !!!!! Stubs only need an oopmap right now, so bail out
  1399             if (sfn->jvms()->method() == NULL) {
  1400               // Write the oopmap directly to the code blob??!!
  1401 #             ifdef ENABLE_ZAP_DEAD_LOCALS
  1402               assert( !is_node_getting_a_safepoint(sfn),  "logic does not match; false positive");
  1403 #             endif
  1404               continue;
  1406           } // End synchronization
  1408           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
  1409                                            current_offset);
  1410           Process_OopMap_Node(mach, current_offset);
  1411         } // End if safepoint
  1413         // If this is a null check, then add the start of the previous instruction to the list
  1414         else if( mach->is_MachNullCheck() ) {
  1415           inct_starts[inct_cnt++] = previous_offset;
  1418         // If this is a branch, then fill in the label with the target BB's label
  1419         else if (mach->is_MachBranch()) {
  1420           // This requires the TRUE branch target be in succs[0]
  1421           uint block_num = block->non_connector_successor(0)->_pre_order;
  1423           // Try to replace long branch if delay slot is not used,
  1424           // it is mostly for back branches since forward branch's
  1425           // distance is not updated yet.
  1426           bool delay_slot_is_used = valid_bundle_info(n) &&
  1427                                     node_bundling(n)->use_unconditional_delay();
  1428           if (!delay_slot_is_used && mach->may_be_short_branch()) {
  1429            assert(delay_slot == NULL, "not expecting delay slot node");
  1430            int br_size = n->size(_regalloc);
  1431             int offset = blk_starts[block_num] - current_offset;
  1432             if (block_num >= i) {
  1433               // Current and following block's offset are not
  1434               // finalized yet, adjust distance by the difference
  1435               // between calculated and final offsets of current block.
  1436               offset -= (blk_starts[i] - blk_offset);
  1438             // In the following code a nop could be inserted before
  1439             // the branch which will increase the backward distance.
  1440             bool needs_padding = (current_offset == last_avoid_back_to_back_offset);
  1441             if (needs_padding && offset <= 0)
  1442               offset -= nop_size;
  1444             if (_matcher->is_short_branch_offset(mach->rule(), br_size, offset)) {
  1445               // We've got a winner.  Replace this branch.
  1446               MachNode* replacement = mach->as_MachBranch()->short_branch_version(this);
  1448               // Update the jmp_size.
  1449               int new_size = replacement->size(_regalloc);
  1450               assert((br_size - new_size) >= (int)nop_size, "short_branch size should be smaller");
  1451               // Insert padding between avoid_back_to_back branches.
  1452               if (needs_padding && replacement->avoid_back_to_back(MachNode::AVOID_BEFORE)) {
  1453                 MachNode *nop = new (this) MachNopNode();
  1454                 block->insert_node(nop, j++);
  1455                 _cfg->map_node_to_block(nop, block);
  1456                 last_inst++;
  1457                 nop->emit(*cb, _regalloc);
  1458                 cb->flush_bundle(true);
  1459                 current_offset = cb->insts_size();
  1461 #ifdef ASSERT
  1462               jmp_target[i] = block_num;
  1463               jmp_offset[i] = current_offset - blk_offset;
  1464               jmp_size[i]   = new_size;
  1465               jmp_rule[i]   = mach->rule();
  1466 #endif
  1467               block->map_node(replacement, j);
  1468               mach->subsume_by(replacement, C);
  1469               n    = replacement;
  1470               mach = replacement;
  1473           mach->as_MachBranch()->label_set( &blk_labels[block_num], block_num );
  1474         } else if (mach->ideal_Opcode() == Op_Jump) {
  1475           for (uint h = 0; h < block->_num_succs; h++) {
  1476             Block* succs_block = block->_succs[h];
  1477             for (uint j = 1; j < succs_block->num_preds(); j++) {
  1478               Node* jpn = succs_block->pred(j);
  1479               if (jpn->is_JumpProj() && jpn->in(0) == mach) {
  1480                 uint block_num = succs_block->non_connector()->_pre_order;
  1481                 Label *blkLabel = &blk_labels[block_num];
  1482                 mach->add_case_label(jpn->as_JumpProj()->proj_no(), blkLabel);
  1487 #ifdef ASSERT
  1488         // Check that oop-store precedes the card-mark
  1489         else if (mach->ideal_Opcode() == Op_StoreCM) {
  1490           uint storeCM_idx = j;
  1491           int count = 0;
  1492           for (uint prec = mach->req(); prec < mach->len(); prec++) {
  1493             Node *oop_store = mach->in(prec);  // Precedence edge
  1494             if (oop_store == NULL) continue;
  1495             count++;
  1496             uint i4;
  1497             for (i4 = 0; i4 < last_inst; ++i4) {
  1498               if (block->get_node(i4) == oop_store) {
  1499                 break;
  1502             // Note: This test can provide a false failure if other precedence
  1503             // edges have been added to the storeCMNode.
  1504             assert(i4 == last_inst || i4 < storeCM_idx, "CM card-mark executes before oop-store");
  1506           assert(count > 0, "storeCM expects at least one precedence edge");
  1508 #endif
  1509         else if (!n->is_Proj()) {
  1510           // Remember the beginning of the previous instruction, in case
  1511           // it's followed by a flag-kill and a null-check.  Happens on
  1512           // Intel all the time, with add-to-memory kind of opcodes.
  1513           previous_offset = current_offset;
  1516         // Not an else-if!
  1517         // If this is a trap based cmp then add its offset to the list.
  1518         if (mach->is_TrapBasedCheckNode()) {
  1519           inct_starts[inct_cnt++] = current_offset;
  1523       // Verify that there is sufficient space remaining
  1524       cb->insts()->maybe_expand_to_ensure_remaining(MAX_inst_size);
  1525       if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
  1526         C->record_failure("CodeCache is full");
  1527         return;
  1530       // Save the offset for the listing
  1531 #ifndef PRODUCT
  1532       if (node_offsets && n->_idx < node_offset_limit)
  1533         node_offsets[n->_idx] = cb->insts_size();
  1534 #endif
  1536       // "Normal" instruction case
  1537       DEBUG_ONLY( uint instr_offset = cb->insts_size(); )
  1538       n->emit(*cb, _regalloc);
  1539       current_offset  = cb->insts_size();
  1540 #ifdef MIPS64
  1541       if (!n->is_Proj()) {
  1542         // For MIPS, the first instruction of the previous node (usually a instruction sequence) sometime
  1543         // is not the instruction which access memory. adjust is needed. previous_offset points to the
  1544         // instruction which access memory. Instruction size is 4. cb->insts_size() and
  1545         // cb->insts()->end() are the location of current instruction.
  1546         int adjust = 4;
  1547         NativeInstruction* inst = (NativeInstruction*) (cb->insts()->end() - 4);
  1548         if (inst->is_sync()) {
  1549           // a sync may be the last instruction, see store_B_immI_enc_sync
  1550           adjust += 4;
  1551           inst = (NativeInstruction*) (cb->insts()->end() - 8);
  1553         previous_offset = current_offset - adjust;
  1555 #endif
  1557       // Above we only verified that there is enough space in the instruction section.
  1558       // However, the instruction may emit stubs that cause code buffer expansion.
  1559       // Bail out here if expansion failed due to a lack of code cache space.
  1560       if (failing()) {
  1561         return;
  1564 #ifdef ASSERT
  1565       if (n->size(_regalloc) < (current_offset-instr_offset)) {
  1566         n->dump();
  1567         assert(false, "wrong size of mach node");
  1569 #endif
  1570       non_safepoints.observe_instruction(n, current_offset);
  1572       // mcall is last "call" that can be a safepoint
  1573       // record it so we can see if a poll will directly follow it
  1574       // in which case we'll need a pad to make the PcDesc sites unique
  1575       // see  5010568. This can be slightly inaccurate but conservative
  1576       // in the case that return address is not actually at current_offset.
  1577       // This is a small price to pay.
  1579       if (is_mcall) {
  1580         last_call_offset = current_offset;
  1583       if (n->is_Mach() && n->as_Mach()->avoid_back_to_back(MachNode::AVOID_AFTER)) {
  1584         // Avoid back to back some instructions.
  1585         last_avoid_back_to_back_offset = current_offset;
  1588       // See if this instruction has a delay slot
  1589       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  1590         assert(delay_slot != NULL, "expecting delay slot node");
  1592         // Back up 1 instruction
  1593         cb->set_insts_end(cb->insts_end() - Pipeline::instr_unit_size());
  1595         // Save the offset for the listing
  1596 #ifndef PRODUCT
  1597         if (node_offsets && delay_slot->_idx < node_offset_limit)
  1598           node_offsets[delay_slot->_idx] = cb->insts_size();
  1599 #endif
  1601         // Support a SafePoint in the delay slot
  1602         if (delay_slot->is_MachSafePoint()) {
  1603           MachNode *mach = delay_slot->as_Mach();
  1604           // !!!!! Stubs only need an oopmap right now, so bail out
  1605           if (!mach->is_MachCall() && mach->as_MachSafePoint()->jvms()->method() == NULL) {
  1606             // Write the oopmap directly to the code blob??!!
  1607 #           ifdef ENABLE_ZAP_DEAD_LOCALS
  1608             assert( !is_node_getting_a_safepoint(mach),  "logic does not match; false positive");
  1609 #           endif
  1610             delay_slot = NULL;
  1611             continue;
  1614           int adjusted_offset = current_offset - Pipeline::instr_unit_size();
  1615           non_safepoints.observe_safepoint(mach->as_MachSafePoint()->jvms(),
  1616                                            adjusted_offset);
  1617           // Generate an OopMap entry
  1618           Process_OopMap_Node(mach, adjusted_offset);
  1621         // Insert the delay slot instruction
  1622         delay_slot->emit(*cb, _regalloc);
  1624         // Don't reuse it
  1625         delay_slot = NULL;
  1628     } // End for all instructions in block
  1630     // If the next block is the top of a loop, pad this block out to align
  1631     // the loop top a little. Helps prevent pipe stalls at loop back branches.
  1632     if (i < nblocks-1) {
  1633       Block *nb = _cfg->get_block(i + 1);
  1634       int padding = nb->alignment_padding(current_offset);
  1635       if( padding > 0 ) {
  1636         MachNode *nop = new (this) MachNopNode(padding / nop_size);
  1637         block->insert_node(nop, block->number_of_nodes());
  1638         _cfg->map_node_to_block(nop, block);
  1639         nop->emit(*cb, _regalloc);
  1640         current_offset = cb->insts_size();
  1643     // Verify that the distance for generated before forward
  1644     // short branches is still valid.
  1645     guarantee((int)(blk_starts[i+1] - blk_starts[i]) >= (current_offset - blk_offset), "shouldn't increase block size");
  1647     // Save new block start offset
  1648     blk_starts[i] = blk_offset;
  1649   } // End of for all blocks
  1650   blk_starts[nblocks] = current_offset;
  1652   non_safepoints.flush_at_end();
  1654   // Offset too large?
  1655   if (failing())  return;
  1657   // Define a pseudo-label at the end of the code
  1658   MacroAssembler(cb).bind( blk_labels[nblocks] );
  1660   // Compute the size of the first block
  1661   _first_block_size = blk_labels[1].loc_pos() - blk_labels[0].loc_pos();
  1663   assert(cb->insts_size() < 500000, "method is unreasonably large");
  1665 #ifdef ASSERT
  1666   for (uint i = 0; i < nblocks; i++) { // For all blocks
  1667     if (jmp_target[i] != 0) {
  1668       int br_size = jmp_size[i];
  1669       int offset = blk_starts[jmp_target[i]]-(blk_starts[i] + jmp_offset[i]);
  1670       if (!_matcher->is_short_branch_offset(jmp_rule[i], br_size, offset)) {
  1671         tty->print_cr("target (%d) - jmp_offset(%d) = offset (%d), jump_size(%d), jmp_block B%d, target_block B%d", blk_starts[jmp_target[i]], blk_starts[i] + jmp_offset[i], offset, br_size, i, jmp_target[i]);
  1672         assert(false, "Displacement too large for short jmp");
  1676 #endif
  1678 #ifndef PRODUCT
  1679   // Information on the size of the method, without the extraneous code
  1680   Scheduling::increment_method_size(cb->insts_size());
  1681 #endif
  1683   // ------------------
  1684   // Fill in exception table entries.
  1685   FillExceptionTables(inct_cnt, call_returns, inct_starts, blk_labels);
  1687   // Only java methods have exception handlers and deopt handlers
  1688   // class HandlerImpl is platform-specific and defined in the *.ad files.
  1689   if (_method) {
  1690     // Emit the exception handler code.
  1691     _code_offsets.set_value(CodeOffsets::Exceptions, HandlerImpl::emit_exception_handler(*cb));
  1692     if (failing()) {
  1693       return; // CodeBuffer::expand failed
  1695     // Emit the deopt handler code.
  1696     _code_offsets.set_value(CodeOffsets::Deopt, HandlerImpl::emit_deopt_handler(*cb));
  1698     // Emit the MethodHandle deopt handler code (if required).
  1699     if (has_method_handle_invokes() && !failing()) {
  1700       // We can use the same code as for the normal deopt handler, we
  1701       // just need a different entry point address.
  1702       _code_offsets.set_value(CodeOffsets::DeoptMH, HandlerImpl::emit_deopt_handler(*cb));
  1706   // One last check for failed CodeBuffer::expand:
  1707   if ((cb->blob() == NULL) || (!CompileBroker::should_compile_new_jobs())) {
  1708     C->record_failure("CodeCache is full");
  1709     return;
  1712 #ifndef PRODUCT
  1713   // Dump the assembly code, including basic-block numbers
  1714   if (print_assembly()) {
  1715     ttyLocker ttyl;  // keep the following output all in one block
  1716     if (!VMThread::should_terminate()) {  // test this under the tty lock
  1717       // This output goes directly to the tty, not the compiler log.
  1718       // To enable tools to match it up with the compilation activity,
  1719       // be sure to tag this tty output with the compile ID.
  1720       if (xtty != NULL) {
  1721         xtty->head("opto_assembly compile_id='%d'%s", compile_id(),
  1722                    is_osr_compilation()    ? " compile_kind='osr'" :
  1723                    "");
  1725       if (method() != NULL) {
  1726         method()->print_metadata();
  1728       dump_asm(node_offsets, node_offset_limit);
  1729       if (xtty != NULL) {
  1730         xtty->tail("opto_assembly");
  1734 #endif
  1738 void Compile::FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels) {
  1739   _inc_table.set_size(cnt);
  1741   uint inct_cnt = 0;
  1742   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  1743     Block* block = _cfg->get_block(i);
  1744     Node *n = NULL;
  1745     int j;
  1747     // Find the branch; ignore trailing NOPs.
  1748     for (j = block->number_of_nodes() - 1; j >= 0; j--) {
  1749       n = block->get_node(j);
  1750       if (!n->is_Mach() || n->as_Mach()->ideal_Opcode() != Op_Con) {
  1751         break;
  1755     // If we didn't find anything, continue
  1756     if (j < 0) {
  1757       continue;
  1760     // Compute ExceptionHandlerTable subtable entry and add it
  1761     // (skip empty blocks)
  1762     if (n->is_Catch()) {
  1764       // Get the offset of the return from the call
  1765       uint call_return = call_returns[block->_pre_order];
  1766 #ifdef ASSERT
  1767       assert( call_return > 0, "no call seen for this basic block" );
  1768       while (block->get_node(--j)->is_MachProj()) ;
  1769       assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call");
  1770 #endif
  1771       // last instruction is a CatchNode, find it's CatchProjNodes
  1772       int nof_succs = block->_num_succs;
  1773       // allocate space
  1774       GrowableArray<intptr_t> handler_bcis(nof_succs);
  1775       GrowableArray<intptr_t> handler_pcos(nof_succs);
  1776       // iterate through all successors
  1777       for (int j = 0; j < nof_succs; j++) {
  1778         Block* s = block->_succs[j];
  1779         bool found_p = false;
  1780         for (uint k = 1; k < s->num_preds(); k++) {
  1781           Node* pk = s->pred(k);
  1782           if (pk->is_CatchProj() && pk->in(0) == n) {
  1783             const CatchProjNode* p = pk->as_CatchProj();
  1784             found_p = true;
  1785             // add the corresponding handler bci & pco information
  1786             if (p->_con != CatchProjNode::fall_through_index) {
  1787               // p leads to an exception handler (and is not fall through)
  1788               assert(s == _cfg->get_block(s->_pre_order), "bad numbering");
  1789               // no duplicates, please
  1790               if (!handler_bcis.contains(p->handler_bci())) {
  1791                 uint block_num = s->non_connector()->_pre_order;
  1792                 handler_bcis.append(p->handler_bci());
  1793                 handler_pcos.append(blk_labels[block_num].loc_pos());
  1798         assert(found_p, "no matching predecessor found");
  1799         // Note:  Due to empty block removal, one block may have
  1800         // several CatchProj inputs, from the same Catch.
  1803       // Set the offset of the return from the call
  1804       _handler_table.add_subtable(call_return, &handler_bcis, NULL, &handler_pcos);
  1805       continue;
  1808     // Handle implicit null exception table updates
  1809     if (n->is_MachNullCheck()) {
  1810       uint block_num = block->non_connector_successor(0)->_pre_order;
  1811       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
  1812       continue;
  1814     // Handle implicit exception table updates: trap instructions.
  1815     if (n->is_Mach() && n->as_Mach()->is_TrapBasedCheckNode()) {
  1816       uint block_num = block->non_connector_successor(0)->_pre_order;
  1817       _inc_table.append(inct_starts[inct_cnt++], blk_labels[block_num].loc_pos());
  1818       continue;
  1820   } // End of for all blocks fill in exception table entries
  1823 // Static Variables
  1824 #ifndef PRODUCT
  1825 uint Scheduling::_total_nop_size = 0;
  1826 uint Scheduling::_total_method_size = 0;
  1827 uint Scheduling::_total_branches = 0;
  1828 uint Scheduling::_total_unconditional_delays = 0;
  1829 uint Scheduling::_total_instructions_per_bundle[Pipeline::_max_instrs_per_cycle+1];
  1830 #endif
  1832 // Initializer for class Scheduling
  1834 Scheduling::Scheduling(Arena *arena, Compile &compile)
  1835   : _arena(arena),
  1836     _cfg(compile.cfg()),
  1837     _regalloc(compile.regalloc()),
  1838     _reg_node(arena),
  1839     _bundle_instr_count(0),
  1840     _bundle_cycle_number(0),
  1841     _scheduled(arena),
  1842     _available(arena),
  1843     _next_node(NULL),
  1844     _bundle_use(0, 0, resource_count, &_bundle_use_elements[0]),
  1845     _pinch_free_list(arena)
  1846 #ifndef PRODUCT
  1847   , _branches(0)
  1848   , _unconditional_delays(0)
  1849 #endif
  1851   // Create a MachNopNode
  1852   _nop = new (&compile) MachNopNode();
  1854   // Now that the nops are in the array, save the count
  1855   // (but allow entries for the nops)
  1856   _node_bundling_limit = compile.unique();
  1857   uint node_max = _regalloc->node_regs_max_index();
  1859   compile.set_node_bundling_limit(_node_bundling_limit);
  1861   // This one is persistent within the Compile class
  1862   _node_bundling_base = NEW_ARENA_ARRAY(compile.comp_arena(), Bundle, node_max);
  1864   // Allocate space for fixed-size arrays
  1865   _node_latency    = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
  1866   _uses            = NEW_ARENA_ARRAY(arena, short,          node_max);
  1867   _current_latency = NEW_ARENA_ARRAY(arena, unsigned short, node_max);
  1869   // Clear the arrays
  1870   memset(_node_bundling_base, 0, node_max * sizeof(Bundle));
  1871   memset(_node_latency,       0, node_max * sizeof(unsigned short));
  1872   memset(_uses,               0, node_max * sizeof(short));
  1873   memset(_current_latency,    0, node_max * sizeof(unsigned short));
  1875   // Clear the bundling information
  1876   memcpy(_bundle_use_elements, Pipeline_Use::elaborated_elements, sizeof(Pipeline_Use::elaborated_elements));
  1878   // Get the last node
  1879   Block* block = _cfg->get_block(_cfg->number_of_blocks() - 1);
  1881   _next_node = block->get_node(block->number_of_nodes() - 1);
  1884 #ifndef PRODUCT
  1885 // Scheduling destructor
  1886 Scheduling::~Scheduling() {
  1887   _total_branches             += _branches;
  1888   _total_unconditional_delays += _unconditional_delays;
  1890 #endif
  1892 // Step ahead "i" cycles
  1893 void Scheduling::step(uint i) {
  1895   Bundle *bundle = node_bundling(_next_node);
  1896   bundle->set_starts_bundle();
  1898   // Update the bundle record, but leave the flags information alone
  1899   if (_bundle_instr_count > 0) {
  1900     bundle->set_instr_count(_bundle_instr_count);
  1901     bundle->set_resources_used(_bundle_use.resourcesUsed());
  1904   // Update the state information
  1905   _bundle_instr_count = 0;
  1906   _bundle_cycle_number += i;
  1907   _bundle_use.step(i);
  1910 void Scheduling::step_and_clear() {
  1911   Bundle *bundle = node_bundling(_next_node);
  1912   bundle->set_starts_bundle();
  1914   // Update the bundle record
  1915   if (_bundle_instr_count > 0) {
  1916     bundle->set_instr_count(_bundle_instr_count);
  1917     bundle->set_resources_used(_bundle_use.resourcesUsed());
  1919     _bundle_cycle_number += 1;
  1922   // Clear the bundling information
  1923   _bundle_instr_count = 0;
  1924   _bundle_use.reset();
  1926   memcpy(_bundle_use_elements,
  1927     Pipeline_Use::elaborated_elements,
  1928     sizeof(Pipeline_Use::elaborated_elements));
  1931 // Perform instruction scheduling and bundling over the sequence of
  1932 // instructions in backwards order.
  1933 void Compile::ScheduleAndBundle() {
  1935   // Don't optimize this if it isn't a method
  1936   if (!_method)
  1937     return;
  1939   // Don't optimize this if scheduling is disabled
  1940   if (!do_scheduling())
  1941     return;
  1943   // Scheduling code works only with pairs (8 bytes) maximum.
  1944   if (max_vector_size() > 8)
  1945     return;
  1947   NOT_PRODUCT( TracePhase t2("isched", &_t_instrSched, TimeCompiler); )
  1949   // Create a data structure for all the scheduling information
  1950   Scheduling scheduling(Thread::current()->resource_area(), *this);
  1952   // Walk backwards over each basic block, computing the needed alignment
  1953   // Walk over all the basic blocks
  1954   scheduling.DoScheduling();
  1957 // Compute the latency of all the instructions.  This is fairly simple,
  1958 // because we already have a legal ordering.  Walk over the instructions
  1959 // from first to last, and compute the latency of the instruction based
  1960 // on the latency of the preceding instruction(s).
  1961 void Scheduling::ComputeLocalLatenciesForward(const Block *bb) {
  1962 #ifndef PRODUCT
  1963   if (_cfg->C->trace_opto_output())
  1964     tty->print("# -> ComputeLocalLatenciesForward\n");
  1965 #endif
  1967   // Walk over all the schedulable instructions
  1968   for( uint j=_bb_start; j < _bb_end; j++ ) {
  1970     // This is a kludge, forcing all latency calculations to start at 1.
  1971     // Used to allow latency 0 to force an instruction to the beginning
  1972     // of the bb
  1973     uint latency = 1;
  1974     Node *use = bb->get_node(j);
  1975     uint nlen = use->len();
  1977     // Walk over all the inputs
  1978     for ( uint k=0; k < nlen; k++ ) {
  1979       Node *def = use->in(k);
  1980       if (!def)
  1981         continue;
  1983       uint l = _node_latency[def->_idx] + use->latency(k);
  1984       if (latency < l)
  1985         latency = l;
  1988     _node_latency[use->_idx] = latency;
  1990 #ifndef PRODUCT
  1991     if (_cfg->C->trace_opto_output()) {
  1992       tty->print("# latency %4d: ", latency);
  1993       use->dump();
  1995 #endif
  1998 #ifndef PRODUCT
  1999   if (_cfg->C->trace_opto_output())
  2000     tty->print("# <- ComputeLocalLatenciesForward\n");
  2001 #endif
  2003 } // end ComputeLocalLatenciesForward
  2005 // See if this node fits into the present instruction bundle
  2006 bool Scheduling::NodeFitsInBundle(Node *n) {
  2007   uint n_idx = n->_idx;
  2009   // If this is the unconditional delay instruction, then it fits
  2010   if (n == _unconditional_delay_slot) {
  2011 #ifndef PRODUCT
  2012     if (_cfg->C->trace_opto_output())
  2013       tty->print("#     NodeFitsInBundle [%4d]: TRUE; is in unconditional delay slot\n", n->_idx);
  2014 #endif
  2015     return (true);
  2018   // If the node cannot be scheduled this cycle, skip it
  2019   if (_current_latency[n_idx] > _bundle_cycle_number) {
  2020 #ifndef PRODUCT
  2021     if (_cfg->C->trace_opto_output())
  2022       tty->print("#     NodeFitsInBundle [%4d]: FALSE; latency %4d > %d\n",
  2023         n->_idx, _current_latency[n_idx], _bundle_cycle_number);
  2024 #endif
  2025     return (false);
  2028   const Pipeline *node_pipeline = n->pipeline();
  2030   uint instruction_count = node_pipeline->instructionCount();
  2031   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
  2032     instruction_count = 0;
  2033   else if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
  2034     instruction_count++;
  2036   if (_bundle_instr_count + instruction_count > Pipeline::_max_instrs_per_cycle) {
  2037 #ifndef PRODUCT
  2038     if (_cfg->C->trace_opto_output())
  2039       tty->print("#     NodeFitsInBundle [%4d]: FALSE; too many instructions: %d > %d\n",
  2040         n->_idx, _bundle_instr_count + instruction_count, Pipeline::_max_instrs_per_cycle);
  2041 #endif
  2042     return (false);
  2045   // Don't allow non-machine nodes to be handled this way
  2046   if (!n->is_Mach() && instruction_count == 0)
  2047     return (false);
  2049   // See if there is any overlap
  2050   uint delay = _bundle_use.full_latency(0, node_pipeline->resourceUse());
  2052   if (delay > 0) {
  2053 #ifndef PRODUCT
  2054     if (_cfg->C->trace_opto_output())
  2055       tty->print("#     NodeFitsInBundle [%4d]: FALSE; functional units overlap\n", n_idx);
  2056 #endif
  2057     return false;
  2060 #ifndef PRODUCT
  2061   if (_cfg->C->trace_opto_output())
  2062     tty->print("#     NodeFitsInBundle [%4d]:  TRUE\n", n_idx);
  2063 #endif
  2065   return true;
  2068 Node * Scheduling::ChooseNodeToBundle() {
  2069   uint siz = _available.size();
  2071   if (siz == 0) {
  2073 #ifndef PRODUCT
  2074     if (_cfg->C->trace_opto_output())
  2075       tty->print("#   ChooseNodeToBundle: NULL\n");
  2076 #endif
  2077     return (NULL);
  2080   // Fast path, if only 1 instruction in the bundle
  2081   if (siz == 1) {
  2082 #ifndef PRODUCT
  2083     if (_cfg->C->trace_opto_output()) {
  2084       tty->print("#   ChooseNodeToBundle (only 1): ");
  2085       _available[0]->dump();
  2087 #endif
  2088     return (_available[0]);
  2091   // Don't bother, if the bundle is already full
  2092   if (_bundle_instr_count < Pipeline::_max_instrs_per_cycle) {
  2093     for ( uint i = 0; i < siz; i++ ) {
  2094       Node *n = _available[i];
  2096       // Skip projections, we'll handle them another way
  2097       if (n->is_Proj())
  2098         continue;
  2100       // This presupposed that instructions are inserted into the
  2101       // available list in a legality order; i.e. instructions that
  2102       // must be inserted first are at the head of the list
  2103       if (NodeFitsInBundle(n)) {
  2104 #ifndef PRODUCT
  2105         if (_cfg->C->trace_opto_output()) {
  2106           tty->print("#   ChooseNodeToBundle: ");
  2107           n->dump();
  2109 #endif
  2110         return (n);
  2115   // Nothing fits in this bundle, choose the highest priority
  2116 #ifndef PRODUCT
  2117   if (_cfg->C->trace_opto_output()) {
  2118     tty->print("#   ChooseNodeToBundle: ");
  2119     _available[0]->dump();
  2121 #endif
  2123   return _available[0];
  2126 void Scheduling::AddNodeToAvailableList(Node *n) {
  2127   assert( !n->is_Proj(), "projections never directly made available" );
  2128 #ifndef PRODUCT
  2129   if (_cfg->C->trace_opto_output()) {
  2130     tty->print("#   AddNodeToAvailableList: ");
  2131     n->dump();
  2133 #endif
  2135   int latency = _current_latency[n->_idx];
  2137   // Insert in latency order (insertion sort)
  2138   uint i;
  2139   for ( i=0; i < _available.size(); i++ )
  2140     if (_current_latency[_available[i]->_idx] > latency)
  2141       break;
  2143   // Special Check for compares following branches
  2144   if( n->is_Mach() && _scheduled.size() > 0 ) {
  2145     int op = n->as_Mach()->ideal_Opcode();
  2146     Node *last = _scheduled[0];
  2147     if( last->is_MachIf() && last->in(1) == n &&
  2148         ( op == Op_CmpI ||
  2149           op == Op_CmpU ||
  2150           op == Op_CmpUL ||
  2151           op == Op_CmpP ||
  2152           op == Op_CmpF ||
  2153           op == Op_CmpD ||
  2154           op == Op_CmpL ) ) {
  2156       // Recalculate position, moving to front of same latency
  2157       for ( i=0 ; i < _available.size(); i++ )
  2158         if (_current_latency[_available[i]->_idx] >= latency)
  2159           break;
  2163   // Insert the node in the available list
  2164   _available.insert(i, n);
  2166 #ifndef PRODUCT
  2167   if (_cfg->C->trace_opto_output())
  2168     dump_available();
  2169 #endif
  2172 void Scheduling::DecrementUseCounts(Node *n, const Block *bb) {
  2173   for ( uint i=0; i < n->len(); i++ ) {
  2174     Node *def = n->in(i);
  2175     if (!def) continue;
  2176     if( def->is_Proj() )        // If this is a machine projection, then
  2177       def = def->in(0);         // propagate usage thru to the base instruction
  2179     if(_cfg->get_block_for_node(def) != bb) { // Ignore if not block-local
  2180       continue;
  2183     // Compute the latency
  2184     uint l = _bundle_cycle_number + n->latency(i);
  2185     if (_current_latency[def->_idx] < l)
  2186       _current_latency[def->_idx] = l;
  2188     // If this does not have uses then schedule it
  2189     if ((--_uses[def->_idx]) == 0)
  2190       AddNodeToAvailableList(def);
  2194 void Scheduling::AddNodeToBundle(Node *n, const Block *bb) {
  2195 #ifndef PRODUCT
  2196   if (_cfg->C->trace_opto_output()) {
  2197     tty->print("#   AddNodeToBundle: ");
  2198     n->dump();
  2200 #endif
  2202   // Remove this from the available list
  2203   uint i;
  2204   for (i = 0; i < _available.size(); i++)
  2205     if (_available[i] == n)
  2206       break;
  2207   assert(i < _available.size(), "entry in _available list not found");
  2208   _available.remove(i);
  2210   // See if this fits in the current bundle
  2211   const Pipeline *node_pipeline = n->pipeline();
  2212   const Pipeline_Use& node_usage = node_pipeline->resourceUse();
  2214   // Check for instructions to be placed in the delay slot. We
  2215   // do this before we actually schedule the current instruction,
  2216   // because the delay slot follows the current instruction.
  2217   if (Pipeline::_branch_has_delay_slot &&
  2218       node_pipeline->hasBranchDelay() &&
  2219       !_unconditional_delay_slot) {
  2221     uint siz = _available.size();
  2223     // Conditional branches can support an instruction that
  2224     // is unconditionally executed and not dependent by the
  2225     // branch, OR a conditionally executed instruction if
  2226     // the branch is taken.  In practice, this means that
  2227     // the first instruction at the branch target is
  2228     // copied to the delay slot, and the branch goes to
  2229     // the instruction after that at the branch target
  2230     if ( n->is_MachBranch() ) {
  2232       assert( !n->is_MachNullCheck(), "should not look for delay slot for Null Check" );
  2233       assert( !n->is_Catch(),         "should not look for delay slot for Catch" );
  2235 #ifndef PRODUCT
  2236       _branches++;
  2237 #endif
  2239       // At least 1 instruction is on the available list
  2240       // that is not dependent on the branch
  2241       for (uint i = 0; i < siz; i++) {
  2242         Node *d = _available[i];
  2243         const Pipeline *avail_pipeline = d->pipeline();
  2245         // Don't allow safepoints in the branch shadow, that will
  2246         // cause a number of difficulties
  2247         if ( avail_pipeline->instructionCount() == 1 &&
  2248             !avail_pipeline->hasMultipleBundles() &&
  2249             !avail_pipeline->hasBranchDelay() &&
  2250             Pipeline::instr_has_unit_size() &&
  2251             d->size(_regalloc) == Pipeline::instr_unit_size() &&
  2252             NodeFitsInBundle(d) &&
  2253             !node_bundling(d)->used_in_delay()) {
  2255           if (d->is_Mach() && !d->is_MachSafePoint()) {
  2256             // A node that fits in the delay slot was found, so we need to
  2257             // set the appropriate bits in the bundle pipeline information so
  2258             // that it correctly indicates resource usage.  Later, when we
  2259             // attempt to add this instruction to the bundle, we will skip
  2260             // setting the resource usage.
  2261             _unconditional_delay_slot = d;
  2262             node_bundling(n)->set_use_unconditional_delay();
  2263             node_bundling(d)->set_used_in_unconditional_delay();
  2264             _bundle_use.add_usage(avail_pipeline->resourceUse());
  2265             _current_latency[d->_idx] = _bundle_cycle_number;
  2266             _next_node = d;
  2267             ++_bundle_instr_count;
  2268 #ifndef PRODUCT
  2269             _unconditional_delays++;
  2270 #endif
  2271             break;
  2277     // No delay slot, add a nop to the usage
  2278     if (!_unconditional_delay_slot) {
  2279       // See if adding an instruction in the delay slot will overflow
  2280       // the bundle.
  2281       if (!NodeFitsInBundle(_nop)) {
  2282 #ifndef PRODUCT
  2283         if (_cfg->C->trace_opto_output())
  2284           tty->print("#  *** STEP(1 instruction for delay slot) ***\n");
  2285 #endif
  2286         step(1);
  2289       _bundle_use.add_usage(_nop->pipeline()->resourceUse());
  2290       _next_node = _nop;
  2291       ++_bundle_instr_count;
  2294     // See if the instruction in the delay slot requires a
  2295     // step of the bundles
  2296     if (!NodeFitsInBundle(n)) {
  2297 #ifndef PRODUCT
  2298         if (_cfg->C->trace_opto_output())
  2299           tty->print("#  *** STEP(branch won't fit) ***\n");
  2300 #endif
  2301         // Update the state information
  2302         _bundle_instr_count = 0;
  2303         _bundle_cycle_number += 1;
  2304         _bundle_use.step(1);
  2308   // Get the number of instructions
  2309   uint instruction_count = node_pipeline->instructionCount();
  2310   if (node_pipeline->mayHaveNoCode() && n->size(_regalloc) == 0)
  2311     instruction_count = 0;
  2313   // Compute the latency information
  2314   uint delay = 0;
  2316   if (instruction_count > 0 || !node_pipeline->mayHaveNoCode()) {
  2317     int relative_latency = _current_latency[n->_idx] - _bundle_cycle_number;
  2318     if (relative_latency < 0)
  2319       relative_latency = 0;
  2321     delay = _bundle_use.full_latency(relative_latency, node_usage);
  2323     // Does not fit in this bundle, start a new one
  2324     if (delay > 0) {
  2325       step(delay);
  2327 #ifndef PRODUCT
  2328       if (_cfg->C->trace_opto_output())
  2329         tty->print("#  *** STEP(%d) ***\n", delay);
  2330 #endif
  2334   // If this was placed in the delay slot, ignore it
  2335   if (n != _unconditional_delay_slot) {
  2337     if (delay == 0) {
  2338       if (node_pipeline->hasMultipleBundles()) {
  2339 #ifndef PRODUCT
  2340         if (_cfg->C->trace_opto_output())
  2341           tty->print("#  *** STEP(multiple instructions) ***\n");
  2342 #endif
  2343         step(1);
  2346       else if (instruction_count + _bundle_instr_count > Pipeline::_max_instrs_per_cycle) {
  2347 #ifndef PRODUCT
  2348         if (_cfg->C->trace_opto_output())
  2349           tty->print("#  *** STEP(%d >= %d instructions) ***\n",
  2350             instruction_count + _bundle_instr_count,
  2351             Pipeline::_max_instrs_per_cycle);
  2352 #endif
  2353         step(1);
  2357     if (node_pipeline->hasBranchDelay() && !_unconditional_delay_slot)
  2358       _bundle_instr_count++;
  2360     // Set the node's latency
  2361     _current_latency[n->_idx] = _bundle_cycle_number;
  2363     // Now merge the functional unit information
  2364     if (instruction_count > 0 || !node_pipeline->mayHaveNoCode())
  2365       _bundle_use.add_usage(node_usage);
  2367     // Increment the number of instructions in this bundle
  2368     _bundle_instr_count += instruction_count;
  2370     // Remember this node for later
  2371     if (n->is_Mach())
  2372       _next_node = n;
  2375   // It's possible to have a BoxLock in the graph and in the _bbs mapping but
  2376   // not in the bb->_nodes array.  This happens for debug-info-only BoxLocks.
  2377   // 'Schedule' them (basically ignore in the schedule) but do not insert them
  2378   // into the block.  All other scheduled nodes get put in the schedule here.
  2379   int op = n->Opcode();
  2380   if( (op == Op_Node && n->req() == 0) || // anti-dependence node OR
  2381       (op != Op_Node &&         // Not an unused antidepedence node and
  2382        // not an unallocated boxlock
  2383        (OptoReg::is_valid(_regalloc->get_reg_first(n)) || op != Op_BoxLock)) ) {
  2385     // Push any trailing projections
  2386     if( bb->get_node(bb->number_of_nodes()-1) != n ) {
  2387       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  2388         Node *foi = n->fast_out(i);
  2389         if( foi->is_Proj() )
  2390           _scheduled.push(foi);
  2394     // Put the instruction in the schedule list
  2395     _scheduled.push(n);
  2398 #ifndef PRODUCT
  2399   if (_cfg->C->trace_opto_output())
  2400     dump_available();
  2401 #endif
  2403   // Walk all the definitions, decrementing use counts, and
  2404   // if a definition has a 0 use count, place it in the available list.
  2405   DecrementUseCounts(n,bb);
  2408 // This method sets the use count within a basic block.  We will ignore all
  2409 // uses outside the current basic block.  As we are doing a backwards walk,
  2410 // any node we reach that has a use count of 0 may be scheduled.  This also
  2411 // avoids the problem of cyclic references from phi nodes, as long as phi
  2412 // nodes are at the front of the basic block.  This method also initializes
  2413 // the available list to the set of instructions that have no uses within this
  2414 // basic block.
  2415 void Scheduling::ComputeUseCount(const Block *bb) {
  2416 #ifndef PRODUCT
  2417   if (_cfg->C->trace_opto_output())
  2418     tty->print("# -> ComputeUseCount\n");
  2419 #endif
  2421   // Clear the list of available and scheduled instructions, just in case
  2422   _available.clear();
  2423   _scheduled.clear();
  2425   // No delay slot specified
  2426   _unconditional_delay_slot = NULL;
  2428 #ifdef ASSERT
  2429   for( uint i=0; i < bb->number_of_nodes(); i++ )
  2430     assert( _uses[bb->get_node(i)->_idx] == 0, "_use array not clean" );
  2431 #endif
  2433   // Force the _uses count to never go to zero for unscheduable pieces
  2434   // of the block
  2435   for( uint k = 0; k < _bb_start; k++ )
  2436     _uses[bb->get_node(k)->_idx] = 1;
  2437   for( uint l = _bb_end; l < bb->number_of_nodes(); l++ )
  2438     _uses[bb->get_node(l)->_idx] = 1;
  2440   // Iterate backwards over the instructions in the block.  Don't count the
  2441   // branch projections at end or the block header instructions.
  2442   for( uint j = _bb_end-1; j >= _bb_start; j-- ) {
  2443     Node *n = bb->get_node(j);
  2444     if( n->is_Proj() ) continue; // Projections handled another way
  2446     // Account for all uses
  2447     for ( uint k = 0; k < n->len(); k++ ) {
  2448       Node *inp = n->in(k);
  2449       if (!inp) continue;
  2450       assert(inp != n, "no cycles allowed" );
  2451       if (_cfg->get_block_for_node(inp) == bb) { // Block-local use?
  2452         if (inp->is_Proj()) { // Skip through Proj's
  2453           inp = inp->in(0);
  2455         ++_uses[inp->_idx];     // Count 1 block-local use
  2459     // If this instruction has a 0 use count, then it is available
  2460     if (!_uses[n->_idx]) {
  2461       _current_latency[n->_idx] = _bundle_cycle_number;
  2462       AddNodeToAvailableList(n);
  2465 #ifndef PRODUCT
  2466     if (_cfg->C->trace_opto_output()) {
  2467       tty->print("#   uses: %3d: ", _uses[n->_idx]);
  2468       n->dump();
  2470 #endif
  2473 #ifndef PRODUCT
  2474   if (_cfg->C->trace_opto_output())
  2475     tty->print("# <- ComputeUseCount\n");
  2476 #endif
  2479 // This routine performs scheduling on each basic block in reverse order,
  2480 // using instruction latencies and taking into account function unit
  2481 // availability.
  2482 void Scheduling::DoScheduling() {
  2483 #ifndef PRODUCT
  2484   if (_cfg->C->trace_opto_output())
  2485     tty->print("# -> DoScheduling\n");
  2486 #endif
  2488   Block *succ_bb = NULL;
  2489   Block *bb;
  2491   // Walk over all the basic blocks in reverse order
  2492   for (int i = _cfg->number_of_blocks() - 1; i >= 0; succ_bb = bb, i--) {
  2493     bb = _cfg->get_block(i);
  2495 #ifndef PRODUCT
  2496     if (_cfg->C->trace_opto_output()) {
  2497       tty->print("#  Schedule BB#%03d (initial)\n", i);
  2498       for (uint j = 0; j < bb->number_of_nodes(); j++) {
  2499         bb->get_node(j)->dump();
  2502 #endif
  2504     // On the head node, skip processing
  2505     if (bb == _cfg->get_root_block()) {
  2506       continue;
  2509     // Skip empty, connector blocks
  2510     if (bb->is_connector())
  2511       continue;
  2513     // If the following block is not the sole successor of
  2514     // this one, then reset the pipeline information
  2515     if (bb->_num_succs != 1 || bb->non_connector_successor(0) != succ_bb) {
  2516 #ifndef PRODUCT
  2517       if (_cfg->C->trace_opto_output()) {
  2518         tty->print("*** bundle start of next BB, node %d, for %d instructions\n",
  2519                    _next_node->_idx, _bundle_instr_count);
  2521 #endif
  2522       step_and_clear();
  2525     // Leave untouched the starting instruction, any Phis, a CreateEx node
  2526     // or Top.  bb->get_node(_bb_start) is the first schedulable instruction.
  2527     _bb_end = bb->number_of_nodes()-1;
  2528     for( _bb_start=1; _bb_start <= _bb_end; _bb_start++ ) {
  2529       Node *n = bb->get_node(_bb_start);
  2530       // Things not matched, like Phinodes and ProjNodes don't get scheduled.
  2531       // Also, MachIdealNodes do not get scheduled
  2532       if( !n->is_Mach() ) continue;     // Skip non-machine nodes
  2533       MachNode *mach = n->as_Mach();
  2534       int iop = mach->ideal_Opcode();
  2535       if( iop == Op_CreateEx ) continue; // CreateEx is pinned
  2536       if( iop == Op_Con ) continue;      // Do not schedule Top
  2537       if( iop == Op_Node &&     // Do not schedule PhiNodes, ProjNodes
  2538           mach->pipeline() == MachNode::pipeline_class() &&
  2539           !n->is_SpillCopy() && !n->is_MachMerge() )  // Breakpoints, Prolog, etc
  2540         continue;
  2541       break;                    // Funny loop structure to be sure...
  2543     // Compute last "interesting" instruction in block - last instruction we
  2544     // might schedule.  _bb_end points just after last schedulable inst.  We
  2545     // normally schedule conditional branches (despite them being forced last
  2546     // in the block), because they have delay slots we can fill.  Calls all
  2547     // have their delay slots filled in the template expansions, so we don't
  2548     // bother scheduling them.
  2549     Node *last = bb->get_node(_bb_end);
  2550     // Ignore trailing NOPs.
  2551     while (_bb_end > 0 && last->is_Mach() &&
  2552            last->as_Mach()->ideal_Opcode() == Op_Con) {
  2553       last = bb->get_node(--_bb_end);
  2555     assert(!last->is_Mach() || last->as_Mach()->ideal_Opcode() != Op_Con, "");
  2556     if( last->is_Catch() ||
  2557        // Exclude unreachable path case when Halt node is in a separate block.
  2558        (_bb_end > 1 && last->is_Mach() && last->as_Mach()->ideal_Opcode() == Op_Halt) ) {
  2559       // There must be a prior call.  Skip it.
  2560       while( !bb->get_node(--_bb_end)->is_MachCall() ) {
  2561         assert( bb->get_node(_bb_end)->is_MachProj(), "skipping projections after expected call" );
  2563     } else if( last->is_MachNullCheck() ) {
  2564       // Backup so the last null-checked memory instruction is
  2565       // outside the schedulable range. Skip over the nullcheck,
  2566       // projection, and the memory nodes.
  2567       Node *mem = last->in(1);
  2568       do {
  2569         _bb_end--;
  2570       } while (mem != bb->get_node(_bb_end));
  2571     } else {
  2572       // Set _bb_end to point after last schedulable inst.
  2573       _bb_end++;
  2576     assert( _bb_start <= _bb_end, "inverted block ends" );
  2578     // Compute the register antidependencies for the basic block
  2579     ComputeRegisterAntidependencies(bb);
  2580     if (_cfg->C->failing())  return;  // too many D-U pinch points
  2582     // Compute intra-bb latencies for the nodes
  2583     ComputeLocalLatenciesForward(bb);
  2585     // Compute the usage within the block, and set the list of all nodes
  2586     // in the block that have no uses within the block.
  2587     ComputeUseCount(bb);
  2589     // Schedule the remaining instructions in the block
  2590     while ( _available.size() > 0 ) {
  2591       Node *n = ChooseNodeToBundle();
  2592       guarantee(n != NULL, "no nodes available");
  2593       AddNodeToBundle(n,bb);
  2596     assert( _scheduled.size() == _bb_end - _bb_start, "wrong number of instructions" );
  2597 #ifdef ASSERT
  2598     for( uint l = _bb_start; l < _bb_end; l++ ) {
  2599       Node *n = bb->get_node(l);
  2600       uint m;
  2601       for( m = 0; m < _bb_end-_bb_start; m++ )
  2602         if( _scheduled[m] == n )
  2603           break;
  2604       assert( m < _bb_end-_bb_start, "instruction missing in schedule" );
  2606 #endif
  2608     // Now copy the instructions (in reverse order) back to the block
  2609     for ( uint k = _bb_start; k < _bb_end; k++ )
  2610       bb->map_node(_scheduled[_bb_end-k-1], k);
  2612 #ifndef PRODUCT
  2613     if (_cfg->C->trace_opto_output()) {
  2614       tty->print("#  Schedule BB#%03d (final)\n", i);
  2615       uint current = 0;
  2616       for (uint j = 0; j < bb->number_of_nodes(); j++) {
  2617         Node *n = bb->get_node(j);
  2618         if( valid_bundle_info(n) ) {
  2619           Bundle *bundle = node_bundling(n);
  2620           if (bundle->instr_count() > 0 || bundle->flags() > 0) {
  2621             tty->print("*** Bundle: ");
  2622             bundle->dump();
  2624           n->dump();
  2628 #endif
  2629 #ifdef ASSERT
  2630   verify_good_schedule(bb,"after block local scheduling");
  2631 #endif
  2634 #ifndef PRODUCT
  2635   if (_cfg->C->trace_opto_output())
  2636     tty->print("# <- DoScheduling\n");
  2637 #endif
  2639   // Record final node-bundling array location
  2640   _regalloc->C->set_node_bundling_base(_node_bundling_base);
  2642 } // end DoScheduling
  2644 // Verify that no live-range used in the block is killed in the block by a
  2645 // wrong DEF.  This doesn't verify live-ranges that span blocks.
  2647 // Check for edge existence.  Used to avoid adding redundant precedence edges.
  2648 static bool edge_from_to( Node *from, Node *to ) {
  2649   for( uint i=0; i<from->len(); i++ )
  2650     if( from->in(i) == to )
  2651       return true;
  2652   return false;
  2655 #ifdef ASSERT
  2656 void Scheduling::verify_do_def( Node *n, OptoReg::Name def, const char *msg ) {
  2657   // Check for bad kills
  2658   if( OptoReg::is_valid(def) ) { // Ignore stores & control flow
  2659     Node *prior_use = _reg_node[def];
  2660     if( prior_use && !edge_from_to(prior_use,n) ) {
  2661       tty->print("%s = ",OptoReg::as_VMReg(def)->name());
  2662       n->dump();
  2663       tty->print_cr("...");
  2664       prior_use->dump();
  2665       assert(edge_from_to(prior_use,n),msg);
  2667     _reg_node.map(def,NULL); // Kill live USEs
  2671 void Scheduling::verify_good_schedule( Block *b, const char *msg ) {
  2673   // Zap to something reasonable for the verify code
  2674   _reg_node.clear();
  2676   // Walk over the block backwards.  Check to make sure each DEF doesn't
  2677   // kill a live value (other than the one it's supposed to).  Add each
  2678   // USE to the live set.
  2679   for( uint i = b->number_of_nodes()-1; i >= _bb_start; i-- ) {
  2680     Node *n = b->get_node(i);
  2681     int n_op = n->Opcode();
  2682     if( n_op == Op_MachProj && n->ideal_reg() == MachProjNode::fat_proj ) {
  2683       // Fat-proj kills a slew of registers
  2684       RegMask rm = n->out_RegMask();// Make local copy
  2685       while( rm.is_NotEmpty() ) {
  2686         OptoReg::Name kill = rm.find_first_elem();
  2687         rm.Remove(kill);
  2688         verify_do_def( n, kill, msg );
  2690     } else if( n_op != Op_Node ) { // Avoid brand new antidependence nodes
  2691       // Get DEF'd registers the normal way
  2692       verify_do_def( n, _regalloc->get_reg_first(n), msg );
  2693       verify_do_def( n, _regalloc->get_reg_second(n), msg );
  2696     // Now make all USEs live
  2697     for( uint i=1; i<n->req(); i++ ) {
  2698       Node *def = n->in(i);
  2699       assert(def != 0, "input edge required");
  2700       OptoReg::Name reg_lo = _regalloc->get_reg_first(def);
  2701       OptoReg::Name reg_hi = _regalloc->get_reg_second(def);
  2702       if( OptoReg::is_valid(reg_lo) ) {
  2703         assert(!_reg_node[reg_lo] || edge_from_to(_reg_node[reg_lo],def), msg);
  2704         _reg_node.map(reg_lo,n);
  2706       if( OptoReg::is_valid(reg_hi) ) {
  2707         assert(!_reg_node[reg_hi] || edge_from_to(_reg_node[reg_hi],def), msg);
  2708         _reg_node.map(reg_hi,n);
  2714   // Zap to something reasonable for the Antidependence code
  2715   _reg_node.clear();
  2717 #endif
  2719 // Conditionally add precedence edges.  Avoid putting edges on Projs.
  2720 static void add_prec_edge_from_to( Node *from, Node *to ) {
  2721   if( from->is_Proj() ) {       // Put precedence edge on Proj's input
  2722     assert( from->req() == 1 && (from->len() == 1 || from->in(1)==0), "no precedence edges on projections" );
  2723     from = from->in(0);
  2725   if( from != to &&             // No cycles (for things like LD L0,[L0+4] )
  2726       !edge_from_to( from, to ) ) // Avoid duplicate edge
  2727     from->add_prec(to);
  2730 void Scheduling::anti_do_def( Block *b, Node *def, OptoReg::Name def_reg, int is_def ) {
  2731   if( !OptoReg::is_valid(def_reg) ) // Ignore stores & control flow
  2732     return;
  2734   Node *pinch = _reg_node[def_reg]; // Get pinch point
  2735   if ((pinch == NULL) || _cfg->get_block_for_node(pinch) != b || // No pinch-point yet?
  2736       is_def ) {    // Check for a true def (not a kill)
  2737     _reg_node.map(def_reg,def); // Record def/kill as the optimistic pinch-point
  2738     return;
  2741   Node *kill = def;             // Rename 'def' to more descriptive 'kill'
  2742   debug_only( def = (Node*)0xdeadbeef; )
  2744   // After some number of kills there _may_ be a later def
  2745   Node *later_def = NULL;
  2747   // Finding a kill requires a real pinch-point.
  2748   // Check for not already having a pinch-point.
  2749   // Pinch points are Op_Node's.
  2750   if( pinch->Opcode() != Op_Node ) { // Or later-def/kill as pinch-point?
  2751     later_def = pinch;            // Must be def/kill as optimistic pinch-point
  2752     if ( _pinch_free_list.size() > 0) {
  2753       pinch = _pinch_free_list.pop();
  2754     } else {
  2755       pinch = new (_cfg->C) Node(1); // Pinch point to-be
  2757     if (pinch->_idx >= _regalloc->node_regs_max_index()) {
  2758       _cfg->C->record_method_not_compilable("too many D-U pinch points");
  2759       return;
  2761     _cfg->map_node_to_block(pinch, b);      // Pretend it's valid in this block (lazy init)
  2762     _reg_node.map(def_reg,pinch); // Record pinch-point
  2763     //_regalloc->set_bad(pinch->_idx); // Already initialized this way.
  2764     if( later_def->outcnt() == 0 || later_def->ideal_reg() == MachProjNode::fat_proj ) { // Distinguish def from kill
  2765       pinch->init_req(0, _cfg->C->top());     // set not NULL for the next call
  2766       add_prec_edge_from_to(later_def,pinch); // Add edge from kill to pinch
  2767       later_def = NULL;           // and no later def
  2769     pinch->set_req(0,later_def);  // Hook later def so we can find it
  2770   } else {                        // Else have valid pinch point
  2771     if( pinch->in(0) )            // If there is a later-def
  2772       later_def = pinch->in(0);   // Get it
  2775   // Add output-dependence edge from later def to kill
  2776   if( later_def )               // If there is some original def
  2777     add_prec_edge_from_to(later_def,kill); // Add edge from def to kill
  2779   // See if current kill is also a use, and so is forced to be the pinch-point.
  2780   if( pinch->Opcode() == Op_Node ) {
  2781     Node *uses = kill->is_Proj() ? kill->in(0) : kill;
  2782     for( uint i=1; i<uses->req(); i++ ) {
  2783       if( _regalloc->get_reg_first(uses->in(i)) == def_reg ||
  2784           _regalloc->get_reg_second(uses->in(i)) == def_reg ) {
  2785         // Yes, found a use/kill pinch-point
  2786         pinch->set_req(0,NULL);  //
  2787         pinch->replace_by(kill); // Move anti-dep edges up
  2788         pinch = kill;
  2789         _reg_node.map(def_reg,pinch);
  2790         return;
  2795   // Add edge from kill to pinch-point
  2796   add_prec_edge_from_to(kill,pinch);
  2799 void Scheduling::anti_do_use( Block *b, Node *use, OptoReg::Name use_reg ) {
  2800   if( !OptoReg::is_valid(use_reg) ) // Ignore stores & control flow
  2801     return;
  2802   Node *pinch = _reg_node[use_reg]; // Get pinch point
  2803   // Check for no later def_reg/kill in block
  2804   if ((pinch != NULL) && _cfg->get_block_for_node(pinch) == b &&
  2805       // Use has to be block-local as well
  2806       _cfg->get_block_for_node(use) == b) {
  2807     if( pinch->Opcode() == Op_Node && // Real pinch-point (not optimistic?)
  2808         pinch->req() == 1 ) {   // pinch not yet in block?
  2809       pinch->del_req(0);        // yank pointer to later-def, also set flag
  2810       // Insert the pinch-point in the block just after the last use
  2811       b->insert_node(pinch, b->find_node(use) + 1);
  2812       _bb_end++;                // Increase size scheduled region in block
  2815     add_prec_edge_from_to(pinch,use);
  2819 // We insert antidependences between the reads and following write of
  2820 // allocated registers to prevent illegal code motion. Hopefully, the
  2821 // number of added references should be fairly small, especially as we
  2822 // are only adding references within the current basic block.
  2823 void Scheduling::ComputeRegisterAntidependencies(Block *b) {
  2825 #ifdef ASSERT
  2826   verify_good_schedule(b,"before block local scheduling");
  2827 #endif
  2829   // A valid schedule, for each register independently, is an endless cycle
  2830   // of: a def, then some uses (connected to the def by true dependencies),
  2831   // then some kills (defs with no uses), finally the cycle repeats with a new
  2832   // def.  The uses are allowed to float relative to each other, as are the
  2833   // kills.  No use is allowed to slide past a kill (or def).  This requires
  2834   // antidependencies between all uses of a single def and all kills that
  2835   // follow, up to the next def.  More edges are redundant, because later defs
  2836   // & kills are already serialized with true or antidependencies.  To keep
  2837   // the edge count down, we add a 'pinch point' node if there's more than
  2838   // one use or more than one kill/def.
  2840   // We add dependencies in one bottom-up pass.
  2842   // For each instruction we handle it's DEFs/KILLs, then it's USEs.
  2844   // For each DEF/KILL, we check to see if there's a prior DEF/KILL for this
  2845   // register.  If not, we record the DEF/KILL in _reg_node, the
  2846   // register-to-def mapping.  If there is a prior DEF/KILL, we insert a
  2847   // "pinch point", a new Node that's in the graph but not in the block.
  2848   // We put edges from the prior and current DEF/KILLs to the pinch point.
  2849   // We put the pinch point in _reg_node.  If there's already a pinch point
  2850   // we merely add an edge from the current DEF/KILL to the pinch point.
  2852   // After doing the DEF/KILLs, we handle USEs.  For each used register, we
  2853   // put an edge from the pinch point to the USE.
  2855   // To be expedient, the _reg_node array is pre-allocated for the whole
  2856   // compilation.  _reg_node is lazily initialized; it either contains a NULL,
  2857   // or a valid def/kill/pinch-point, or a leftover node from some prior
  2858   // block.  Leftover node from some prior block is treated like a NULL (no
  2859   // prior def, so no anti-dependence needed).  Valid def is distinguished by
  2860   // it being in the current block.
  2861   bool fat_proj_seen = false;
  2862   uint last_safept = _bb_end-1;
  2863   Node* end_node         = (_bb_end-1 >= _bb_start) ? b->get_node(last_safept) : NULL;
  2864   Node* last_safept_node = end_node;
  2865   for( uint i = _bb_end-1; i >= _bb_start; i-- ) {
  2866     Node *n = b->get_node(i);
  2867     int is_def = n->outcnt();   // def if some uses prior to adding precedence edges
  2868     if( n->is_MachProj() && n->ideal_reg() == MachProjNode::fat_proj ) {
  2869       // Fat-proj kills a slew of registers
  2870       // This can add edges to 'n' and obscure whether or not it was a def,
  2871       // hence the is_def flag.
  2872       fat_proj_seen = true;
  2873       RegMask rm = n->out_RegMask();// Make local copy
  2874       while( rm.is_NotEmpty() ) {
  2875         OptoReg::Name kill = rm.find_first_elem();
  2876         rm.Remove(kill);
  2877         anti_do_def( b, n, kill, is_def );
  2879     } else {
  2880       // Get DEF'd registers the normal way
  2881       anti_do_def( b, n, _regalloc->get_reg_first(n), is_def );
  2882       anti_do_def( b, n, _regalloc->get_reg_second(n), is_def );
  2885     // Kill projections on a branch should appear to occur on the
  2886     // branch, not afterwards, so grab the masks from the projections
  2887     // and process them.
  2888     if (n->is_MachBranch() || n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_Jump) {
  2889       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
  2890         Node* use = n->fast_out(i);
  2891         if (use->is_Proj()) {
  2892           RegMask rm = use->out_RegMask();// Make local copy
  2893           while( rm.is_NotEmpty() ) {
  2894             OptoReg::Name kill = rm.find_first_elem();
  2895             rm.Remove(kill);
  2896             anti_do_def( b, n, kill, false );
  2902     // Check each register used by this instruction for a following DEF/KILL
  2903     // that must occur afterward and requires an anti-dependence edge.
  2904     for( uint j=0; j<n->req(); j++ ) {
  2905       Node *def = n->in(j);
  2906       if( def ) {
  2907         assert( !def->is_MachProj() || def->ideal_reg() != MachProjNode::fat_proj, "" );
  2908         anti_do_use( b, n, _regalloc->get_reg_first(def) );
  2909         anti_do_use( b, n, _regalloc->get_reg_second(def) );
  2912     // Do not allow defs of new derived values to float above GC
  2913     // points unless the base is definitely available at the GC point.
  2915     Node *m = b->get_node(i);
  2917     // Add precedence edge from following safepoint to use of derived pointer
  2918     if( last_safept_node != end_node &&
  2919         m != last_safept_node) {
  2920       for (uint k = 1; k < m->req(); k++) {
  2921         const Type *t = m->in(k)->bottom_type();
  2922         if( t->isa_oop_ptr() &&
  2923             t->is_ptr()->offset() != 0 ) {
  2924           last_safept_node->add_prec( m );
  2925           break;
  2930     if( n->jvms() ) {           // Precedence edge from derived to safept
  2931       // Check if last_safept_node was moved by pinch-point insertion in anti_do_use()
  2932       if( b->get_node(last_safept) != last_safept_node ) {
  2933         last_safept = b->find_node(last_safept_node);
  2935       for( uint j=last_safept; j > i; j-- ) {
  2936         Node *mach = b->get_node(j);
  2937         if( mach->is_Mach() && mach->as_Mach()->ideal_Opcode() == Op_AddP )
  2938           mach->add_prec( n );
  2940       last_safept = i;
  2941       last_safept_node = m;
  2945   if (fat_proj_seen) {
  2946     // Garbage collect pinch nodes that were not consumed.
  2947     // They are usually created by a fat kill MachProj for a call.
  2948     garbage_collect_pinch_nodes();
  2952 // Garbage collect pinch nodes for reuse by other blocks.
  2953 //
  2954 // The block scheduler's insertion of anti-dependence
  2955 // edges creates many pinch nodes when the block contains
  2956 // 2 or more Calls.  A pinch node is used to prevent a
  2957 // combinatorial explosion of edges.  If a set of kills for a
  2958 // register is anti-dependent on a set of uses (or defs), rather
  2959 // than adding an edge in the graph between each pair of kill
  2960 // and use (or def), a pinch is inserted between them:
  2961 //
  2962 //            use1   use2  use3
  2963 //                \   |   /
  2964 //                 \  |  /
  2965 //                  pinch
  2966 //                 /  |  \
  2967 //                /   |   \
  2968 //            kill1 kill2 kill3
  2969 //
  2970 // One pinch node is created per register killed when
  2971 // the second call is encountered during a backwards pass
  2972 // over the block.  Most of these pinch nodes are never
  2973 // wired into the graph because the register is never
  2974 // used or def'ed in the block.
  2975 //
  2976 void Scheduling::garbage_collect_pinch_nodes() {
  2977 #ifndef PRODUCT
  2978     if (_cfg->C->trace_opto_output()) tty->print("Reclaimed pinch nodes:");
  2979 #endif
  2980     int trace_cnt = 0;
  2981     for (uint k = 0; k < _reg_node.Size(); k++) {
  2982       Node* pinch = _reg_node[k];
  2983       if ((pinch != NULL) && pinch->Opcode() == Op_Node &&
  2984           // no predecence input edges
  2985           (pinch->req() == pinch->len() || pinch->in(pinch->req()) == NULL) ) {
  2986         cleanup_pinch(pinch);
  2987         _pinch_free_list.push(pinch);
  2988         _reg_node.map(k, NULL);
  2989 #ifndef PRODUCT
  2990         if (_cfg->C->trace_opto_output()) {
  2991           trace_cnt++;
  2992           if (trace_cnt > 40) {
  2993             tty->print("\n");
  2994             trace_cnt = 0;
  2996           tty->print(" %d", pinch->_idx);
  2998 #endif
  3001 #ifndef PRODUCT
  3002     if (_cfg->C->trace_opto_output()) tty->print("\n");
  3003 #endif
  3006 // Clean up a pinch node for reuse.
  3007 void Scheduling::cleanup_pinch( Node *pinch ) {
  3008   assert (pinch && pinch->Opcode() == Op_Node && pinch->req() == 1, "just checking");
  3010   for (DUIterator_Last imin, i = pinch->last_outs(imin); i >= imin; ) {
  3011     Node* use = pinch->last_out(i);
  3012     uint uses_found = 0;
  3013     for (uint j = use->req(); j < use->len(); j++) {
  3014       if (use->in(j) == pinch) {
  3015         use->rm_prec(j);
  3016         uses_found++;
  3019     assert(uses_found > 0, "must be a precedence edge");
  3020     i -= uses_found;    // we deleted 1 or more copies of this edge
  3022   // May have a later_def entry
  3023   pinch->set_req(0, NULL);
  3026 #ifndef PRODUCT
  3028 void Scheduling::dump_available() const {
  3029   tty->print("#Availist  ");
  3030   for (uint i = 0; i < _available.size(); i++)
  3031     tty->print(" N%d/l%d", _available[i]->_idx,_current_latency[_available[i]->_idx]);
  3032   tty->cr();
  3035 // Print Scheduling Statistics
  3036 void Scheduling::print_statistics() {
  3037   // Print the size added by nops for bundling
  3038   tty->print("Nops added %d bytes to total of %d bytes",
  3039     _total_nop_size, _total_method_size);
  3040   if (_total_method_size > 0)
  3041     tty->print(", for %.2f%%",
  3042       ((double)_total_nop_size) / ((double) _total_method_size) * 100.0);
  3043   tty->print("\n");
  3045   // Print the number of branch shadows filled
  3046   if (Pipeline::_branch_has_delay_slot) {
  3047     tty->print("Of %d branches, %d had unconditional delay slots filled",
  3048       _total_branches, _total_unconditional_delays);
  3049     if (_total_branches > 0)
  3050       tty->print(", for %.2f%%",
  3051         ((double)_total_unconditional_delays) / ((double)_total_branches) * 100.0);
  3052     tty->print("\n");
  3055   uint total_instructions = 0, total_bundles = 0;
  3057   for (uint i = 1; i <= Pipeline::_max_instrs_per_cycle; i++) {
  3058     uint bundle_count   = _total_instructions_per_bundle[i];
  3059     total_instructions += bundle_count * i;
  3060     total_bundles      += bundle_count;
  3063   if (total_bundles > 0)
  3064     tty->print("Average ILP (excluding nops) is %.2f\n",
  3065       ((double)total_instructions) / ((double)total_bundles));
  3067 #endif

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