Remove the unused support for jump-table switch statements.

src/ia32/codegen-ia32.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2402 matching lines @@
   ASSERT(!in_spilled_code());
   Comment cmnt(masm_, "[ WithExitStatement");
   CodeForStatementPosition(node);
   // Pop context.
   __ mov(esi, ContextOperand(esi, Context::PREVIOUS_INDEX));
   // Update context local.
   frame_->SaveContextRegister();
 }
 
 
-int CodeGenerator::FastCaseSwitchMaxOverheadFactor() {
-    return kFastSwitchMaxOverheadFactor;
-}
-
-
-int CodeGenerator::FastCaseSwitchMinCaseCount() {
-    return kFastSwitchMinCaseCount;
-}
-
-
-// Generate a computed jump to a switch case.
-void CodeGenerator::GenerateFastCaseSwitchJumpTable(
-    SwitchStatement* node,
-    int min_index,
-    int range,
-    Label* default_label,
-    Vector<Label*> case_targets,
-    Vector<Label> case_labels) {
-  // Notice: Internal references, used by both the jmp instruction and
-  // the table entries, need to be relocated if the buffer grows. This
-  // prevents the forward use of Labels, since a displacement cannot
-  // survive relocation, and it also cannot safely be distinguished
-  // from a real address.  Instead we put in zero-values as
-  // placeholders, and fill in the addresses after the labels have been
-  // bound.
-
-  JumpTarget setup_default;
-  JumpTarget is_smi;
-
-  // A non-null default label pointer indicates a default case among
-  // the case labels.  Otherwise we use the break target as a
-  // "default".
-  JumpTarget* default_target =
-      (default_label == NULL) ? node->break_target() : &setup_default;
-
-  // Test whether input is a smi.
-  ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
-  Result switch_value = frame_->Pop();
-  switch_value.ToRegister();
-  __ test(switch_value.reg(), Immediate(kSmiTagMask));
-  is_smi.Branch(equal, &switch_value, taken);
-
-  // It's a heap object, not a smi or a failure.  Check if it is a
-  // heap number.
-  Result temp = allocator()->Allocate();
-  ASSERT(temp.is_valid());
-  __ CmpObjectType(switch_value.reg(), HEAP_NUMBER_TYPE, temp.reg());
-  temp.Unuse();
-  default_target->Branch(not_equal);
-
-  // The switch value is a heap number.  Convert it to a smi.
-  frame_->Push(&switch_value);
-  Result smi_value = frame_->CallRuntime(Runtime::kNumberToSmi, 1);
-
-  is_smi.Bind(&smi_value);
-  smi_value.ToRegister();
-  // Convert the switch value to a 0-based table index.
-  if (min_index != 0) {
-    frame_->Spill(smi_value.reg());
-    __ sub(Operand(smi_value.reg()), Immediate(min_index << kSmiTagSize));
-  }
-  // Go to the default case if the table index is negative or not a smi.
-  __ test(smi_value.reg(), Immediate(0x80000000 | kSmiTagMask));
-  default_target->Branch(not_equal, not_taken);
-  __ cmp(smi_value.reg(), range << kSmiTagSize);
-  default_target->Branch(greater_equal, not_taken);
-
-  // The expected frame at all the case labels is a version of the
-  // current one (the bidirectional entry frame, which an arbitrary
-  // frame of the correct height can be merged to).  Keep a copy to
-  // restore at the start of every label.  Create a jump target and
-  // bind it to set its entry frame properly.
-  JumpTarget entry_target(JumpTarget::BIDIRECTIONAL);
-  entry_target.Bind(&smi_value);
-  VirtualFrame* start_frame = new VirtualFrame(frame_);
-
-  // 0 is placeholder.
-  // Jump to the address at table_address + 2 * smi_value.reg().
-  // The target of the jump is read from table_address + 4 * switch_value.
-  // The Smi encoding of smi_value.reg() is 2 * switch_value.
-  smi_value.ToRegister();
-  __ jmp(Operand(smi_value.reg(), smi_value.reg(),
-                 times_1, 0x0, RelocInfo::INTERNAL_REFERENCE));
-  smi_value.Unuse();
-  // Calculate address to overwrite later with actual address of table.
-  int32_t jump_table_ref = masm_->pc_offset() - sizeof(int32_t);
-  __ Align(4);
-  Label table_start;
-  __ bind(&table_start);
-  __ WriteInternalReference(jump_table_ref, table_start);
-
-  for (int i = 0; i < range; i++) {
-    // These are the table entries. 0x0 is the placeholder for case address.
-    __ dd(0x0, RelocInfo::INTERNAL_REFERENCE);
-  }
-
-  GenerateFastCaseSwitchCases(node, case_labels, start_frame);
-
-  // If there was a default case, we need to emit the code to match it.
-  if (default_label != NULL) {
-    if (has_valid_frame()) {
-      node->break_target()->Jump();
-    }
-    setup_default.Bind();
-    frame_->MergeTo(start_frame);
-    __ jmp(default_label);
-    DeleteFrame();
-  }
-  if (node->break_target()->is_linked()) {
-    node->break_target()->Bind();
-  }
-
-  for (int i = 0, entry_pos = table_start.pos();
-       i < range;
-       i++, entry_pos += sizeof(uint32_t)) {
-    if (case_targets[i] == NULL) {
-      __ WriteInternalReference(entry_pos,
-                                *node->break_target()->entry_label());
-    } else {
-      __ WriteInternalReference(entry_pos, *case_targets[i]);
-    }
-  }
-}
-
-
 void CodeGenerator::VisitSwitchStatement(SwitchStatement* node) {
   ASSERT(!in_spilled_code());
   Comment cmnt(masm_, "[ SwitchStatement");
   CodeForStatementPosition(node);
   node->break_target()->set_direction(JumpTarget::FORWARD_ONLY);
 
   // Compile the switch value.
   Load(node->tag());
 
-  if (TryGenerateFastCaseSwitchStatement(node)) {
-    return;
-  }
-
   ZoneList<CaseClause*>* cases = node->cases();
   int length = cases->length();
   CaseClause* default_clause = NULL;
 
   JumpTarget next_test;
   // Compile the case label expressions and comparisons.  Exit early
   // if a comparison is unconditionally true.  The target next_test is
   // bound before the loop in order to indicate control flow to the
   // first comparison.
   next_test.Bind();
@@ skipping 5040 matching lines @@
 
   // Slow-case: Go through the JavaScript implementation.
   __ bind(&slow);
   __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal