[turbofan] Push JSToNumber conversions into Phis.

src/compiler/js-typed-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/access-builder.h"
 #include "src/compiler/graph-inl.h"
 #include "src/compiler/js-builtin-reducer.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/node-aux-data-inl.h"
 #include "src/compiler/node-properties-inl.h"
@@ skipping 448 matching lines @@
     return r.ChangeToPureOperator(simplified()->NumberEqual(), invert);
   }
   // TODO(turbofan): js-typed-lowering of StrictEqual(mixed types)
   return NoChange();
 }
 
 
 Reduction JSTypedLowering::ReduceJSToNumberInput(Node* input) {
   if (input->opcode() == IrOpcode::kJSToNumber) {
     // Recursively try to reduce the input first.
-    Reduction result = ReduceJSToNumberInput(input->InputAt(0));
-    if (result.Changed()) {
-      RelaxEffects(input);
-      return result;
-    }
+    Reduction result = ReduceJSToNumber(input);
+    if (result.Changed()) return result;
     return Changed(input);  // JSToNumber(JSToNumber(x)) => JSToNumber(x)
   }
   Type* input_type = NodeProperties::GetBounds(input).upper;
   if (input_type->Is(Type::Number())) {
     // JSToNumber(x:number) => x
     return Changed(input);
   }
   if (input_type->Is(Type::Undefined())) {
     // JSToNumber(undefined) => #NaN
     return ReplaceWith(jsgraph()->NaNConstant());
   }
   if (input_type->Is(Type::Null())) {
     // JSToNumber(null) => #0
     return ReplaceWith(jsgraph()->ZeroConstant());
   }
   if (input_type->Is(Type::Boolean())) {
     // JSToNumber(x:boolean) => BooleanToNumber(x)
     return ReplaceWith(
         graph()->NewNode(simplified()->BooleanToNumber(), input));
   }
   // TODO(turbofan): js-typed-lowering of ToNumber(x:string)
   return NoChange();
 }
 
 
+Reduction JSTypedLowering::ReduceJSToNumber(Node* node) {
+  // Try to reduce the input first.
+  Node* const input = node->InputAt(0);
+  Reduction reduction = ReduceJSToNumberInput(input);
+  if (reduction.Changed()) {
+    NodeProperties::ReplaceWithValue(node, reduction.replacement());
+    return reduction;
+  }
+  Type* const input_type = NodeProperties::GetBounds(input).upper;
+  if (input->opcode() == IrOpcode::kPhi && input_type->Is(Type::Primitive())) {
+    Node* const context = node->InputAt(1);
+    // JSToNumber(phi(x1,...,xn,control):primitive)
+    //   => phi(JSToNumber(x1),...,JSToNumber(xn),control):number
+    RelaxEffects(node);
+    int const input_count = input->InputCount() - 1;
+    Node* const control = input->InputAt(input_count);
+    DCHECK_LE(0, input_count);
+    DCHECK(NodeProperties::IsControl(control));
+    DCHECK(NodeProperties::GetBounds(node).upper->Is(Type::Number()));
+    DCHECK(!NodeProperties::GetBounds(input).upper->Is(Type::Number()));
+    node->set_op(common()->Phi(kMachAnyTagged, input_count));
+    for (int i = 0; i < input_count; ++i) {
+      Node* value = input->InputAt(i);
+      // Recursively try to reduce the value first.
+      Reduction reduction = ReduceJSToNumberInput(value);
+      if (reduction.Changed()) {
+        value = reduction.replacement();
+      } else {
+        value = graph()->NewNode(javascript()->ToNumber(), value, context,
+                                 graph()->start(), graph()->start());
+      }
+      if (i < node->InputCount()) {
+        node->ReplaceInput(i, value);
+      } else {
+        node->AppendInput(graph()->zone(), value);
+      }
+    }
+    if (input_count < node->InputCount()) {
+      node->ReplaceInput(input_count, control);
+    } else {
+      node->AppendInput(graph()->zone(), control);
+    }
+    node->TrimInputCount(input_count + 1);
+    return Changed(node);
+  }
+  return NoChange();
+}
+
+
 Reduction JSTypedLowering::ReduceJSToStringInput(Node* input) {
   if (input->opcode() == IrOpcode::kJSToString) {
     // Recursively try to reduce the input first.
     Reduction result = ReduceJSToStringInput(input->InputAt(0));
     if (result.Changed()) {
       RelaxEffects(input);
       return result;
     }
     return Changed(input);  // JSToString(JSToString(x)) => JSToString(x)
   }
@@ skipping 66 matching lines @@
 Reduction JSTypedLowering::ReduceJSToBoolean(Node* node) {
   // Try to reduce the input first.
   Node* const input = node->InputAt(0);
   Reduction reduction = ReduceJSToBooleanInput(input);
   if (reduction.Changed()) {
     NodeProperties::ReplaceWithValue(node, reduction.replacement());
     return reduction;
   }
   Type* const input_type = NodeProperties::GetBounds(input).upper;
   if (input->opcode() == IrOpcode::kPhi && input_type->Is(Type::Primitive())) {
+    Node* const context = node->InputAt(1);
     // JSToBoolean(phi(x1,...,xn,control):primitive)
     //   => phi(JSToBoolean(x1),...,JSToBoolean(xn),control):boolean
     RelaxEffects(node);
     int const input_count = input->InputCount() - 1;
     Node* const control = input->InputAt(input_count);
     DCHECK_LE(0, input_count);
     DCHECK(NodeProperties::IsControl(control));
     DCHECK(NodeProperties::GetBounds(node).upper->Is(Type::Boolean()));
     DCHECK(!NodeProperties::GetBounds(input).upper->Is(Type::Boolean()));
     node->set_op(common()->Phi(kMachAnyTagged, input_count));
     for (int i = 0; i < input_count; ++i) {
       Node* value = input->InputAt(i);
       // Recursively try to reduce the value first.
       Reduction reduction = ReduceJSToBooleanInput(value);
       if (reduction.Changed()) {
         value = reduction.replacement();
       } else {
-        value = graph()->NewNode(javascript()->ToBoolean(), value,
-                                 jsgraph()->ZeroConstant(), graph()->start(),
-                                 graph()->start());
+        value = graph()->NewNode(javascript()->ToBoolean(), value, context,
+                                 graph()->start(), graph()->start());
       }
       if (i < node->InputCount()) {
         node->ReplaceInput(i, value);
       } else {
         node->AppendInput(graph()->zone(), value);
       }
     }
     if (input_count < node->InputCount()) {
       node->ReplaceInput(input_count, control);
     } else {
@@ skipping 147 matching lines @@
         node->set_op(javascript()->ToBoolean());
         NodeProperties::ReplaceWithValue(node, value, node);
         // Note: ReplaceUses() smashes all uses, so smash it back here.
         value->ReplaceInput(0, node);
         return Changed(node);
       }
     }
     case IrOpcode::kJSToBoolean:
       return ReduceJSToBoolean(node);
     case IrOpcode::kJSToNumber:
-      return ReplaceWithReduction(node,
-                                  ReduceJSToNumberInput(node->InputAt(0)));
+      return ReduceJSToNumber(node);
     case IrOpcode::kJSToString:
       return ReplaceWithReduction(node,
                                   ReduceJSToStringInput(node->InputAt(0)));
     case IrOpcode::kJSLoadProperty:
       return ReduceJSLoadProperty(node);
     case IrOpcode::kJSStoreProperty:
       return ReduceJSStoreProperty(node);
     case IrOpcode::kJSCallFunction:
       return JSBuiltinReducer(jsgraph()).Reduce(node);
     default:
       break;
   }
   return NoChange();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8