Fix the hole loading optimization.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index aed649291e15b350dfdab040dc1966c245812bc3..d15fe7ae2828a7c51271b6fc6a59f4d77f2b4a47 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -4963,7 +4963,9 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
 
   Label load_smi, heap_number, done;
 
-  if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED) {
+  STATIC_ASSERT(NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE >
+                NUMBER_CANDIDATE_IS_ANY_TAGGED);
+  if (mode >= NUMBER_CANDIDATE_IS_ANY_TAGGED) {
     // Smi check.
     __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
 
@@ -4974,14 +4976,20 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
     if (deoptimize_on_undefined) {
       DeoptimizeIf(ne, env);
     } else {
-      Label heap_number;
+      Label heap_number, convert;
       __ b(eq, &heap_number);
 
+      // Convert undefined (and hole) to NaN.
       __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
       __ cmp(input_reg, Operand(ip));
+      if (mode == NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE) {
+        __ b(eq, &convert);
+        __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
+        __ cmp(input_reg, Operand(ip));
+      }
       DeoptimizeIf(ne, env);
 
-      // Convert undefined to NaN.
+      __ bind(&convert);
       __ LoadRoot(ip, Heap::kNanValueRootIndex);
       __ sub(ip, ip, Operand(kHeapObjectTag));
       __ vldr(result_reg, ip, HeapNumber::kValueOffset);
@@ -5001,15 +5009,6 @@ void LCodeGen::EmitNumberUntagD(Register input_reg,
       DeoptimizeIf(eq, env);
     }
     __ jmp(&done);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_OR_HOLE) {
-    __ SmiUntag(scratch, input_reg, SetCC);
-    DeoptimizeIf(cs, env);
-  } else if (mode == NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE) {
-    __ UntagAndJumpIfSmi(scratch, input_reg, &load_smi);
-    __ Vmov(result_reg,
-            FixedDoubleArray::hole_nan_as_double(),
-            no_reg);
-    __ b(&done);
   } else {
     __ SmiUntag(scratch, input_reg);
     ASSERT(mode == NUMBER_CANDIDATE_IS_SMI);
@@ -5133,19 +5132,13 @@ void LCodeGen::DoNumberUntagD(LNumberUntagD* instr) {
   NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED;
   HValue* value = instr->hydrogen()->value();
   if (value->type().IsSmi()) {
-    if (value->IsLoadKeyed()) {
-      HLoadKeyed* load = HLoadKeyed::cast(value);
-      if (load->UsesMustHandleHole()) {
-        if (load->hole_mode() == ALLOW_RETURN_HOLE) {
-          mode = NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE;
-        } else {
-          mode = NUMBER_CANDIDATE_IS_SMI_OR_HOLE;
-        }
-      } else {
-        mode = NUMBER_CANDIDATE_IS_SMI;
+    mode = NUMBER_CANDIDATE_IS_SMI;
+  } else if (value->IsLoadKeyed()) {
+    HLoadKeyed* load = HLoadKeyed::cast(value);
+    if (load->UsesMustHandleHole()) {
+      if (load->hole_mode() == ALLOW_RETURN_HOLE) {
+        mode = NUMBER_CANDIDATE_IS_ANY_TAGGED_CONVERT_HOLE;
       }
-    } else {
-      mode = NUMBER_CANDIDATE_IS_SMI;
     }
   }