X87: [crankshaft] [ia32] Remove dynamic frame alignment optimization.

src/crankshaft/x87/lithium-x87.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/crankshaft/x87/lithium-x87.h"
 
 #include <sstream>
 
 #if V8_TARGET_ARCH_X87
 
@@ skipping 406 matching lines @@
   stream->Add(" %p -> %p", *original_map(), *transitioned_map());
 }
 
 
 LPlatformChunk* LChunkBuilder::Build() {
   DCHECK(is_unused());
   chunk_ = new(zone()) LPlatformChunk(info(), graph());
   LPhase phase("L_Building chunk", chunk_);
   status_ = BUILDING;
 
-  // Reserve the first spill slot for the state of dynamic alignment.
-  if (info()->IsOptimizing()) {
-    int alignment_state_index = chunk_->GetNextSpillIndex(GENERAL_REGISTERS);
-    DCHECK_EQ(alignment_state_index, 4);
-    USE(alignment_state_index);
-  }
-
   // If compiling for OSR, reserve space for the unoptimized frame,
   // which will be subsumed into this frame.
   if (graph()->has_osr()) {
     for (int i = graph()->osr()->UnoptimizedFrameSlots(); i > 0; i--) {
       chunk_->GetNextSpillIndex(GENERAL_REGISTERS);
     }
   }
 
   const ZoneList<HBasicBlock*>* blocks = graph()->blocks();
   for (int i = 0; i < blocks->length(); i++) {
@@ skipping 2014 matching lines @@
   int env_index = instr->index();
   int spill_index = 0;
   if (instr->environment()->is_parameter_index(env_index)) {
     spill_index = chunk()->GetParameterStackSlot(env_index);
   } else {
     spill_index = env_index - instr->environment()->first_local_index();
     if (spill_index > LUnallocated::kMaxFixedSlotIndex) {
       Retry(kNotEnoughSpillSlotsForOsr);
       spill_index = 0;
     }
-    if (spill_index == 0) {
-      // The dynamic frame alignment state overwrites the first local.
-      // The first local is saved at the end of the unoptimized frame.
-      spill_index = graph()->osr()->UnoptimizedFrameSlots();
-    }
     spill_index += StandardFrameConstants::kFixedSlotCount;
   }
   return DefineAsSpilled(new(zone()) LUnknownOSRValue, spill_index);
 }
 
 
 LInstruction* LChunkBuilder::DoArgumentsObject(HArgumentsObject* instr) {
   // There are no real uses of the arguments object.
   // arguments.length and element access are supported directly on
   // stack arguments, and any real arguments object use causes a bailout.
@@ skipping 139 matching lines @@
 LInstruction* LChunkBuilder::DoStoreFrameContext(HStoreFrameContext* instr) {
   LOperand* context = UseRegisterAtStart(instr->context());
   return new(zone()) LStoreFrameContext(context);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X87