PPC: Don't MISS if you read the hole from certain FastHoley arrays.

src/ppc/lithium-codegen-ppc.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/cpu-profiler.h"
@@ skipping 3475 matching lines @@
   // Check for the hole value.
   if (requires_hole_check) {
     if (IsFastSmiElementsKind(hinstr->elements_kind())) {
       __ TestIfSmi(result, r0);
       DeoptimizeIf(ne, instr, Deoptimizer::kNotASmi, cr0);
     } else {
       __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
       __ cmp(result, scratch);
       DeoptimizeIf(eq, instr, Deoptimizer::kHole);
     }
+  } else if (instr->hydrogen()->hole_mode() == CONVERT_HOLE_TO_UNDEFINED) {
+    DCHECK(instr->hydrogen()->elements_kind() == FAST_HOLEY_ELEMENTS);
+    Label done;
+    __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
+    __ cmp(result, scratch);
+    __ bne(&done);
+    if (info()->IsStub()) {
+      // A stub can safely convert the hole to undefined only if the array
+      // protector cell contains (Smi) Isolate::kArrayProtectorValid. Otherwise
+      // it needs to bail out.
+      __ LoadRoot(result, Heap::kArrayProtectorRootIndex);
+      __ LoadP(result, FieldMemOperand(result, Cell::kValueOffset));
+      __ CmpSmiLiteral(result, Smi::FromInt(Isolate::kArrayProtectorValid), r0);
+      DeoptimizeIf(ne, instr, Deoptimizer::kHole);
+    }
+    __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
+    __ bind(&done);
   }
 }
 
 
 void LCodeGen::DoLoadKeyed(LLoadKeyed* instr) {
   if (instr->is_typed_elements()) {
     DoLoadKeyedExternalArray(instr);
   } else if (instr->hydrogen()->representation().IsDouble()) {
     DoLoadKeyedFixedDoubleArray(instr);
   } else {
@@ skipping 2670 matching lines @@
   __ Push(scope_info);
   __ push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 }
 }  // namespace v8::internal