Fix int64 lowering on big-endian architectures.

src/compiler/int64-lowering.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/compiler/int64-lowering.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 82 matching lines @@
     Signature<MachineRepresentation>* signature) {
   int result = static_cast<int>(signature->return_count());
   for (int i = 0; i < static_cast<int>(signature->return_count()); i++) {
     if (signature->GetReturn(i) == MachineRepresentation::kWord64) {
       result++;
     }
   }
   return result;
 }
 
+void Int64Lowering::GetIndexNodes(Node* index, Node*& index_low,
+                                  Node*& index_high) {
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  index_low = index;
+  index_high = graph()->NewNode(machine()->Int32Add(), index,
+                                graph()->NewNode(common()->Int32Constant(4)));
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  index_low = graph()->NewNode(machine()->Int32Add(), index,
+                               graph()->NewNode(common()->Int32Constant(4)));
+  index_high = index;
+#endif
+}
+
+int Int64Lowering::GetLowerWordOffset() {

[titzer, 2016/06/22 16:03:09]

Can you go all the way and make these simple static constants in this file?

[ivica.bogosavljevic, 2016/06/23 10:56:54]

Acknowledged.

+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  return 0;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  return 4;
+#endif
+}
+
+int Int64Lowering::GetHigherWordOffset() {
+#if defined(V8_TARGET_LITTLE_ENDIAN)
+  return 4;
+#elif defined(V8_TARGET_BIG_ENDIAN)
+  return 0;
+#endif
+}
+
 void Int64Lowering::LowerNode(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kInt64Constant: {
       int64_t value = OpParameter<int64_t>(node);
       Node* low_node = graph()->NewNode(
           common()->Int32Constant(static_cast<int32_t>(value & 0xFFFFFFFF)));
       Node* high_node = graph()->NewNode(
           common()->Int32Constant(static_cast<int32_t>(value >> 32)));
       ReplaceNode(node, low_node, high_node);
       break;
     }
     case IrOpcode::kLoad: {
       LoadRepresentation load_rep = LoadRepresentationOf(node->op());
 
       if (load_rep.representation() == MachineRepresentation::kWord64) {
         Node* base = node->InputAt(0);
         Node* index = node->InputAt(1);
-        Node* index_high =
-            graph()->NewNode(machine()->Int32Add(), index,
-                             graph()->NewNode(common()->Int32Constant(4)));
-
+        Node* index_low;
+        Node* index_high;
+        GetIndexNodes(index, index_low, index_high);
         const Operator* load_op = machine()->Load(MachineType::Int32());
         Node* high_node;
         if (node->InputCount() > 2) {
           Node* effect_high = node->InputAt(2);
           Node* control_high = node->InputAt(3);
           high_node = graph()->NewNode(load_op, base, index_high, effect_high,
                                        control_high);
           // change the effect change from old_node --> old_effect to
           // old_node --> high_node --> old_effect.
           node->ReplaceInput(2, high_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 {
         DefaultLowering(node);
       }
       break;
     }
     case IrOpcode::kStore: {
       StoreRepresentation store_rep = StoreRepresentationOf(node->op());
       if (store_rep.representation() == MachineRepresentation::kWord64) {
         // We change the original store node to store the low word, and create
         // a new store node to store the high word. The effect and control edges
         // are copied from the original store to the new store node, the effect
         // edge of the original store is redirected to the new store.
         WriteBarrierKind write_barrier_kind = store_rep.write_barrier_kind();
 
         Node* base = node->InputAt(0);
         Node* index = node->InputAt(1);
-        Node* index_high =
-            graph()->NewNode(machine()->Int32Add(), index,
-                             graph()->NewNode(common()->Int32Constant(4)));
-
+        Node* index_low;
+        Node* index_high;
+        GetIndexNodes(index, index_low, index_high);
         Node* value = node->InputAt(2);
         DCHECK(HasReplacementLow(value));
         DCHECK(HasReplacementHigh(value));
 
         const Operator* store_op = machine()->Store(StoreRepresentation(
             MachineRepresentation::kWord32, write_barrier_kind));
 
         Node* high_node;
         if (node->InputCount() > 3) {
           Node* effect_high = node->InputAt(3);
           Node* control_high = node->InputAt(4);
           high_node = graph()->NewNode(store_op, base, index_high,
                                        GetReplacementHigh(value), effect_high,
                                        control_high);
           node->ReplaceInput(3, high_node);
 
         } else {
           high_node = graph()->NewNode(store_op, base, index_high,
                                        GetReplacementHigh(value));
         }
 
+        node->ReplaceInput(1, index_low);
         node->ReplaceInput(2, GetReplacementLow(value));
         NodeProperties::ChangeOp(node, store_op);
         ReplaceNode(node, node, high_node);
       } else {
         if (HasReplacementLow(node->InputAt(2))) {
           node->ReplaceInput(2, GetReplacementLow(node->InputAt(2)));
         }
       }
       break;
     }
@@ skipping 294 matching lines @@
     case IrOpcode::kBitcastInt64ToFloat64: {
       DCHECK(node->InputCount() == 1);
       Node* input = node->InputAt(0);
       Node* stack_slot = graph()->NewNode(
           machine()->StackSlot(MachineRepresentation::kWord64));
 
       Node* store_high_word = graph()->NewNode(
           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 =
           graph()->NewNode(machine()->Load(MachineType::Float64()), stack_slot,
                            graph()->NewNode(common()->Int32Constant(0)),
                            store_low_word, graph()->start());
 
       ReplaceNode(node, load, nullptr);
       break;
     }
     case IrOpcode::kBitcastFloat64ToInt64: {
       DCHECK(node->InputCount() == 1);
       Node* input = node->InputAt(0);
       if (HasReplacementLow(input)) {
         input = GetReplacementLow(input);
       }
       Node* stack_slot = graph()->NewNode(
           machine()->StackSlot(MachineRepresentation::kWord64));
       Node* store = graph()->NewNode(
           machine()->Store(
               StoreRepresentation(MachineRepresentation::kFloat64,
                                   WriteBarrierKind::kNoWriteBarrier)),
           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;
     }
     case IrOpcode::kWord64Ror: {
       DCHECK(node->InputCount() == 2);
       Node* input = node->InputAt(0);
       Node* shift = HasReplacementLow(node->InputAt(1))
                         ? GetReplacementLow(node->InputAt(1))
                         : node->InputAt(1);
       Int32Matcher m(shift);
@@ skipping 254 matching lines @@
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_low, false),
                 graph()->NewNode(
                     common()->Phi(MachineRepresentation::kWord32, value_count),
                     value_count + 1, inputs_high, false));
   }
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8