[wasm] Int64Lowering of Word64Clz.

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"
 #include "src/compiler/node-properties.h"
 
 #include "src/compiler/node.h"
 #include "src/wasm/wasm-module.h"
 #include "src/zone.h"
 
 namespace v8 {
@@ skipping 480 matching lines @@
                            graph()->start());
 
       Node* low_node =
           graph()->NewNode(machine()->Load(MachineType::Int32()), stack_slot,
                            graph()->NewNode(common()->Int32Constant(0)), store,
                            graph()->start());
       ReplaceNode(node, low_node, high_node);
       break;
     }
     // kExprI64Clz:
+    case IrOpcode::kWord64Clz: {
+      DCHECK(node->InputCount() == 1);
+      Node* input = node->InputAt(0);
+      Diamond d(
+          graph(), common(),
+          graph()->NewNode(machine()->Word32Equal(), GetReplacementHigh(input),
+                           graph()->NewNode(common()->Int32Constant(0))));
+
+      Node* low_node = d.Phi(
+          MachineRepresentation::kWord32,
+          graph()->NewNode(machine()->Int32Add(),
+                           graph()->NewNode(machine()->Word32Clz(),
+                                            GetReplacementLow(input)),
+                           graph()->NewNode(common()->Int32Constant(32))),
+          graph()->NewNode(machine()->Word32Clz(), GetReplacementHigh(input)));
+      ReplaceNode(node, low_node, graph()->NewNode(common()->Int32Constant(0)));
+      break;
+    }
     // kExprI64Ctz:
     case IrOpcode::kWord64Popcnt: {
       DCHECK(node->InputCount() == 1);
       Node* input = node->InputAt(0);
       // We assume that a Word64Popcnt node only has been created if
       // Word32Popcnt is actually supported.
       DCHECK(machine()->Word32Popcnt().IsSupported());
       ReplaceNode(node, graph()->NewNode(
                             machine()->Int32Add(),
                             graph()->NewNode(machine()->Word32Popcnt().op(),
@@ skipping 66 matching lines @@
 }
 
 Node* Int64Lowering::GetReplacementHigh(Node* node) {
   Node* result = replacements_[node->id()].high;
   DCHECK(result);
   return result;
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8