[wasm] Int64Lowering of I64Shl on ia32.

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/graph.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/node-properties.h"
@@ skipping 271 matching lines @@
       Node* low_node =
           graph()->NewNode(machine()->Word32Xor(), GetReplacementLow(left),
                            GetReplacementLow(right));
       Node* high_node =
           graph()->NewNode(machine()->Word32Xor(), GetReplacementHigh(left),
                            GetReplacementHigh(right));
       ReplaceNode(node, low_node, high_node);
       break;
     }
     // kExprI64Shl:
+    case IrOpcode::kWord64Shl: {
+      DCHECK(node->InputCount() == 2);

[titzer, 2016/03/02 22:32:53]

Can you drop in a TODO(turbofan) here for shift count >= 32? In that case we can
just make the low word 0 and then only deal with the high word of the input.

[ahaas, 2016/03/04 10:21:11]

Done.

+      Node* shift = node->InputAt(1);
+      if (HasReplacementLow(shift)) {
+        // We do not have to care about the high word replacement, because
+        // the shift can only be between 0 and 63 anyways.
+        node->ReplaceInput(1, GetReplacementLow(shift));
+      }
+
+      Node* value = node->InputAt(0);
+      node->ReplaceInput(0, GetReplacementLow(value));
+      node->InsertInput(zone(), 1, GetReplacementHigh(value));
+
+      NodeProperties::ChangeOp(node, machine()->WasmWord64Shl());
+      // We access the additional return values through projections.
+      Node* low_node = graph()->NewNode(common()->Projection(0), node);
+      Node* high_node = graph()->NewNode(common()->Projection(1), node);
+      ReplaceNode(node, low_node, high_node);
+      break;
+    }
     // kExprI64ShrU:
     // kExprI64ShrS:
     // kExprI64Eq:
     case IrOpcode::kWord64Equal: {
       DCHECK(node->InputCount() == 2);
       Node* left = node->InputAt(0);
       Node* right = node->InputAt(1);
 
       // TODO(wasm): Use explicit comparisons and && here?
       Node* replacement = graph()->NewNode(
@@ skipping 111 matching lines @@
 }
 
 Node* Int64Lowering::GetReplacementHigh(Node* node) {
   Node* result = replacements_[node->id()].high;
   DCHECK(result);
   return result;
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8