Fix int64 lowering on big-endian architectures.

src/compiler/int64-lowering.cc

Index: src/compiler/int64-lowering.cc
diff --git a/src/compiler/int64-lowering.cc b/src/compiler/int64-lowering.cc
index 71f500886b40afe101ff6a32ed570ead578d0bfa..5b2dad4488d2b7603ba7bef2ed8b9c500a43f74b 100644
--- a/src/compiler/int64-lowering.cc
+++ b/src/compiler/int64-lowering.cc
@@ -117,10 +117,17 @@ void Int64Lowering::LowerNode(Node* node) {
       if (load_rep.representation() == MachineRepresentation::kWord64) {
         Node* base = node->InputAt(0);
         Node* index = node->InputAt(1);
+#if defined(V8_TARGET_LITTLE_ENDIAN)

[titzer, 2016/06/21 21:22:59]

Can you factor this out into a common subroutine?

+        Node* index_low = index;
         Node* index_high =
             graph()->NewNode(machine()->Int32Add(), index,
                              graph()->NewNode(common()->Int32Constant(4)));
-
+#elif defined(V8_TARGET_BIG_ENDIAN)
+        Node* index_low =
+            graph()->NewNode(machine()->Int32Add(), index,
+                             graph()->NewNode(common()->Int32Constant(4)));
+        Node* index_high = index;
+#endif
         const Operator* load_op = machine()->Load(MachineType::Int32());
         Node* high_node;
         if (node->InputCount() > 2) {
@@ -134,6 +141,7 @@ void Int64Lowering::LowerNode(Node* node) {
         } else {
           high_node = graph()->NewNode(load_op, base, index_high);
         }
+        node->ReplaceInput(1, index_low);
         NodeProperties::ChangeOp(node, load_op);
         ReplaceNode(node, node, high_node);
       } else {
@@ -152,10 +160,17 @@ void Int64Lowering::LowerNode(Node* node) {
 
         Node* base = node->InputAt(0);
         Node* index = node->InputAt(1);
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+        Node* index_low = index;
         Node* index_high =
             graph()->NewNode(machine()->Int32Add(), index,
                              graph()->NewNode(common()->Int32Constant(4)));
-
+#elif defined(V8_TARGET_BIG_ENDIAN)
+        Node* index_low =
+            graph()->NewNode(machine()->Int32Add(), index,
+                             graph()->NewNode(common()->Int32Constant(4)));
+        Node* index_high = index;
+#endif
         Node* value = node->InputAt(2);
         DCHECK(HasReplacementLow(value));
         DCHECK(HasReplacementHigh(value));
@@ -177,6 +192,7 @@ void Int64Lowering::LowerNode(Node* node) {
                                        GetReplacementHigh(value));
         }
 
+        node->ReplaceInput(1, index_low);
         node->ReplaceInput(2, GetReplacementLow(value));
         NodeProperties::ChangeOp(node, store_op);
         ReplaceNode(node, node, high_node);
@@ -491,14 +507,16 @@ void Int64Lowering::LowerNode(Node* node) {
           machine()->Store(
               StoreRepresentation(MachineRepresentation::kWord32,
                                   WriteBarrierKind::kNoWriteBarrier)),
-          stack_slot, graph()->NewNode(common()->Int32Constant(4)),
+          stack_slot,
+          graph()->NewNode(common()->Int32Constant(GetHigherWordOffset())),
           GetReplacementHigh(input), graph()->start(), graph()->start());
 
       Node* store_low_word = graph()->NewNode(
           machine()->Store(
               StoreRepresentation(MachineRepresentation::kWord32,
                                   WriteBarrierKind::kNoWriteBarrier)),
-          stack_slot, graph()->NewNode(common()->Int32Constant(0)),
+          stack_slot,
+          graph()->NewNode(common()->Int32Constant(GetLowerWordOffset())),
           GetReplacementLow(input), store_high_word, graph()->start());
 
       Node* load =
@@ -524,15 +542,15 @@ void Int64Lowering::LowerNode(Node* node) {
           stack_slot, graph()->NewNode(common()->Int32Constant(0)), input,
           graph()->start(), graph()->start());
 
-      Node* high_node =
-          graph()->NewNode(machine()->Load(MachineType::Int32()), stack_slot,
-                           graph()->NewNode(common()->Int32Constant(4)), store,
-                           graph()->start());
+      Node* high_node = graph()->NewNode(
+          machine()->Load(MachineType::Int32()), stack_slot,
+          graph()->NewNode(common()->Int32Constant(GetHigherWordOffset())),
+          store, graph()->start());
 
-      Node* low_node =
-          graph()->NewNode(machine()->Load(MachineType::Int32()), stack_slot,
-                           graph()->NewNode(common()->Int32Constant(0)), store,
-                           graph()->start());
+      Node* low_node = graph()->NewNode(
+          machine()->Load(MachineType::Int32()), stack_slot,
+          graph()->NewNode(common()->Int32Constant(GetLowerWordOffset())),
+          store, graph()->start());
       ReplaceNode(node, low_node, high_node);
       break;
     }