Tag length of FixedArrayBase and smi-array[x] as smi representation

src/ia32/lithium-ia32.cc

 // Copyright 2012 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 1892 matching lines @@
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
   if (from.IsSmi()) {
     if (to.IsTagged()) {
       LOperand* value = UseRegister(instr->value());
-      return DefineSameAsFirst(new(zone()) LDummyUse(value));
+      // For now, always deopt on hole.
+      if (instr->value()->IsLoadKeyed() &&
+          HLoadKeyed::cast(instr->value())->UsesMustHandleHole()) {
+        return AssignEnvironment(
+            DefineSameAsFirst(new(zone()) LCheckSmiAndReturn(value)));
+      } else {
+        return DefineSameAsFirst(new(zone()) LDummyUse(value));
+      }
     }
     from = Representation::Tagged();
   }
   // Only mark conversions that might need to allocate as calling rather than
   // all changes. This makes simple, non-allocating conversion not have to force
   // building a stack frame.
   if (from.IsTagged()) {
     if (to.IsDouble()) {
       info()->MarkAsDeferredCalling();
       LOperand* value = UseRegister(instr->value());
       // Temp register only necessary for minus zero check.
       LOperand* temp = instr->deoptimize_on_minus_zero()
                        ? TempRegister()
                        : NULL;
       LNumberUntagD* res = new(zone()) LNumberUntagD(value, temp);
       if (CpuFeatures::IsSafeForSnapshot(SSE2)) {
         return AssignEnvironment(DefineAsRegister(res));
       } else {
         return AssignEnvironment(DefineX87TOS(res));
       }
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
-      LOperand* value = UseRegisterAtStart(val);
+      LOperand* value = UseRegister(val);
       return AssignEnvironment(
-          DefineSameAsFirst(new(zone()) LCheckSmi(value)));
+          DefineSameAsFirst(new(zone()) LCheckSmiAndReturn(value)));
     } else {
       ASSERT(to.IsInteger32());
       if (instr->value()->type().IsSmi()) {
         LOperand* value = UseRegister(instr->value());
         LInstruction* result =
             DefineSameAsFirst(new(zone()) LSmiUntag(value, false));
         if (instr->value()->IsLoadKeyed()) {
           HLoadKeyed* load_keyed = HLoadKeyed::cast(instr->value());
           if (load_keyed->UsesMustHandleHole() &&
               load_keyed->hole_mode() == NEVER_RETURN_HOLE) {
@@ skipping 102 matching lines @@
 
 LInstruction* LChunkBuilder::DoCheckPrototypeMaps(HCheckPrototypeMaps* instr) {
   LUnallocated* temp = TempRegister();
   LCheckPrototypeMaps* result = new(zone()) LCheckPrototypeMaps(temp);
   return AssignEnvironment(result);
 }
 
 
 LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
   LOperand* value = UseAtStart(instr->value());
-  return AssignEnvironment(DefineSameAsFirst(new(zone()) LCheckSmi(value)));
+  return AssignEnvironment(new(zone()) LCheckSmi(value));
 }
 
 
 LInstruction* LChunkBuilder::DoCheckSmiOrInt32(HCheckSmiOrInt32* instr) {
   LOperand* value = UseAtStart(instr->value());
-  return AssignEnvironment(DefineSameAsFirst(new(zone()) LCheckSmi(value)));
+  return AssignEnvironment(new(zone()) LCheckSmi(value));
 }
 
 
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   // If the target is in new space, we'll emit a global cell compare and so
   // want the value in a register.  If the target gets promoted before we
   // emit code, we will still get the register but will do an immediate
   // compare instead of the cell compare.  This is safe.
   LOperand* value = instr->target_in_new_space()
       ? UseRegisterAtStart(instr->value()) : UseAtStart(instr->value());
@@ skipping 714 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32