Use one offsets table per generated irregexp matching function.

runtime/vm/regexp_assembler.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/regexp_assembler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 16 matching lines @@
         String::Handle(String::New("TAG: ")), \
         String::Handle(String::New(__FUNCTION__)), Heap::kOld))))));
 
 #define PRINT(arg) if (FLAG_trace_irregexp) { Print(arg); }
 
 namespace dart {
 
 DEFINE_FLAG(bool, trace_irregexp, false, "Trace irregexps");
 
 
 static const intptr_t kInvalidTryIndex = -1;

[Florian Schneider, 2014/11/12 11:38:56]

static const intptr_t kInvalidTryIndex = CatchClauseNode::kInvalidTryIndex

[zerny-google, 2014/11/12 11:58:47]

Done.

-static const intptr_t kNoTokenPos = -1;
+static const intptr_t kNoTokenPos = 0;

[Florian Schneider, 2014/11/12 11:38:56]

Define in terms of Scanner::kNoSourcePos which is also 0.

[zerny-google, 2014/11/12 11:58:47]

Done.

 
 
 void PrintUtf16(uint16_t c) {
   const char* format = (0x20 <= c && c <= 0x7F) ?
         "%c" : (c <= 0xff) ? "\\x%02x" : "\\u%04x";
   OS::Print(format, c);
 }
 
 
 /*
@@ skipping 67 matching lines @@
         Isolate::kNoDeoptId);
   start_block_ =
       new(isolate) JoinEntryInstr(block_id_.Alloc(), kInvalidTryIndex);
   success_block_ =
       new(isolate) JoinEntryInstr(block_id_.Alloc(), kInvalidTryIndex);
   backtrack_block_ =
       new(isolate) JoinEntryInstr(block_id_.Alloc(), kInvalidTryIndex);
   exit_block_ =
       new(isolate) JoinEntryInstr(block_id_.Alloc(), kInvalidTryIndex);
 
+  // Allocate offsets table mapping ids of backtracking blocks to addresses.
+  GrowableObjectArray& offsets = GrowableObjectArray::ZoneHandle(
+      isolate, GrowableObjectArray::New(Heap::kOld));
+  entry_block_->set_indirect_entry_offsets(&offsets);
+
   GenerateEntryBlock();
   GenerateSuccessBlock();
   GenerateBacktrackBlock();
   GenerateExitBlock();
 
   blocks_.Add(entry_block_);
   blocks_.Add(entry_block_->normal_entry());
   blocks_.Add(start_block_);
   blocks_.Add(success_block_);
   blocks_.Add(backtrack_block_);
@@ skipping 582 matching lines @@
     PushArgumentInstr* by_push = PushArgument(Bind(Int64Constant(by)));
     StoreLocal(position_register(reg), Bind(Add(reg_push, by_push)));
   }
 }
 
 
 void IRRegExpMacroAssembler::Backtrack() {
   TAG();
   CheckPreemption();
 
-  GrowableObjectArray& offsets = GrowableObjectArray::ZoneHandle(
-        I, GrowableObjectArray::New(Heap::kOld));
+  GrowableObjectArray& offsets = *entry_block_->indirect_entry_offsets();

[Florian Schneider, 2014/11/12 11:38:56]

const GrowableObjectArray&

[zerny-google, 2014/11/12 11:58:47]

Done.

 
   PushArgumentInstr* block_offsets_push =
       PushArgument(Bind(new(I) ConstantInstr(offsets)));
   PushArgumentInstr* block_id_push = PushArgument(PopStack());
 
   Value* offset_value =
       Bind(InstanceCall(InstanceCallDescriptor::FromToken(Token::kINDEX),
                         block_offsets_push,
                         block_id_push));
 
-  IndirectGotoInstr* igoto = new(I) IndirectGotoInstr(&offsets, offset_value);
+  IndirectGotoInstr* igoto = new(I) IndirectGotoInstr(offset_value);
   CloseBlockWith(igoto);
   igotos_.Add(igoto);
 }
 
 
 // A BindBlock is analogous to assigning a label to a basic block.
 // If the BlockLabel does not yet contain a block, it is created.
 // If there is a current instruction, append a goto to the bound block.
 void IRRegExpMacroAssembler::BindBlock(BlockLabel* label) {
   ASSERT(!label->IsBound());
@@ skipping 21 matching lines @@
 LocalVariable* IRRegExpMacroAssembler::position_register(intptr_t index) {
   // Create position registers as needed.
   for (intptr_t i = position_registers_.length(); i < index + 1; i++) {
     position_registers_.Add(Local(Symbols::position_registers_()));
   }
 
   return position_registers_[index];
 }
 
 
-// TODO(zerny): Move the offset table outside to avoid having to keep
-// the assembler around until after code generation; both function or regexp
-// would work.
-void IRRegExpMacroAssembler::FinalizeBlockOffsetTable() {
-  for (intptr_t i = 0; i < igotos_.length(); i++) {
-    IndirectGotoInstr* igoto = igotos_[i];
-    igoto->SetOffsetCount(I, indirect_id_.Count());
-
-    for (intptr_t j = 0; j < igoto->SuccessorCount(); j++) {
-      TargetEntryInstr* target = igoto->SuccessorAt(j);
-
-      // Optimizations might have modified the immediate target block, but
-      // it must end with a goto to the indirect entry.
-      Instruction* instr = target;
-      while (instr != NULL && !instr->IsGoto()) {
-        instr = instr->next();
-      }
-      ASSERT(instr->IsGoto());
-
-      IndirectEntryInstr* ientry =
-          instr->AsGoto()->successor()->AsIndirectEntry();
-      ASSERT(ientry != NULL);
-
-      // The intermediate block was possibly compacted, check both it and the
-      // final indirect entry for a valid offset. If neither are valid, then
-      // the indirect entry is unreachable.
-      intptr_t offset =
-          (target->offset() > 0) ? target->offset() : ientry->offset();
-      if (offset > 0) {
-        intptr_t adjusted_offset =
-            offset - Assembler::EntryPointToPcMarkerOffset();
-        igoto->SetOffsetAt(I, ientry->indirect_id(), adjusted_offset);
-      }
+void IRRegExpMacroAssembler::FinalizeBlockOffsetTable(Isolate* isolate,
+                                                      GraphEntryInstr* graph) {
+  const GrowableArray<IndirectEntryInstr*>& entries = graph->indirect_entries();
+  const intptr_t count = entries.length();
+  if (!count) return;

[Florian Schneider, 2014/11/12 11:38:56]

Use count == 0 instead here.

[zerny-google, 2014/11/12 11:58:47]

Ok. But I rather removed the early return here.

+  GrowableObjectArray* offsets = graph->indirect_entry_offsets();
+  if (offsets->Capacity() < count) {
+    offsets->Grow(count, Heap::kOld);
+  }
+  if (offsets->Length() < count) {
+    offsets->SetLength(count);
+  }
+  for (intptr_t i = 0; i < count; ++i) {
+    IndirectEntryInstr* entry = entries[i];
+    if (entry->offset() <= 0) {
+      // An invalid offset signifies an unreachable block.
+      // TODO(zerny): We should guard against usage of an invalid index.
+      continue;
     }
+    intptr_t offset = entry->offset() - Assembler::EntryPointToPcMarkerOffset();
+    offsets->SetAt(i, Smi::ZoneHandle(isolate, Smi::New(offset)));
   }
 }
 
+
 void IRRegExpMacroAssembler::FinalizeIndirectGotos() {
   for (intptr_t i = 0; i < igotos_.length(); i++) {
     for (intptr_t j = 0; j < entry_block_->indirect_entries().length(); j++) {
       igotos_.At(i)->AddSuccessor(
             TargetWithJoinGoto(entry_block_->indirect_entries().At(j)));
     }
   }
 }
 
 
@@ skipping 1015 matching lines @@
       index,
       characters,
       specialization_cid_,
       Scanner::kNoSourcePos));
 }
 
 
 #undef __
 
 }  // namespace dart