[turbofan] Improve reduction of Word32And and Int32Add.

src/compiler/machine-operator-reducer.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/machine-operator-reducer.h"
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/codegen.h"
 #include "src/compiler/diamond.h"
@@ skipping 25 matching lines @@
 Node* MachineOperatorReducer::Int32Constant(int32_t value) {
   return jsgraph()->Int32Constant(value);
 }
 
 
 Node* MachineOperatorReducer::Int64Constant(int64_t value) {
   return graph()->NewNode(common()->Int64Constant(value));
 }
 
 
-Node* MachineOperatorReducer::Word32And(Node* lhs, uint32_t rhs) {
-  return graph()->NewNode(machine()->Word32And(), lhs, Uint32Constant(rhs));
+Node* MachineOperatorReducer::Word32And(Node* lhs, Node* rhs) {
+  Node* const node = graph()->NewNode(machine()->Word32And(), lhs, rhs);
+  Reduction const reduction = ReduceWord32And(node);
+  return reduction.Changed() ? reduction.replacement() : node;
 }
 
 
 Node* MachineOperatorReducer::Word32Sar(Node* lhs, uint32_t rhs) {
   if (rhs == 0) return lhs;
   return graph()->NewNode(machine()->Word32Sar(), lhs, Uint32Constant(rhs));
 }
 
 
 Node* MachineOperatorReducer::Word32Shr(Node* lhs, uint32_t rhs) {
   if (rhs == 0) return lhs;
   return graph()->NewNode(machine()->Word32Shr(), lhs, Uint32Constant(rhs));
 }
 
 
 Node* MachineOperatorReducer::Word32Equal(Node* lhs, Node* rhs) {
   return graph()->NewNode(machine()->Word32Equal(), lhs, rhs);
 }
 
 
 Node* MachineOperatorReducer::Int32Add(Node* lhs, Node* rhs) {
-  return graph()->NewNode(machine()->Int32Add(), lhs, rhs);
+  Node* const node = graph()->NewNode(machine()->Int32Add(), lhs, rhs);
+  Reduction const reduction = ReduceInt32Add(node);
+  return reduction.Changed() ? reduction.replacement() : node;
 }
 
 
 Node* MachineOperatorReducer::Int32Sub(Node* lhs, Node* rhs) {
   return graph()->NewNode(machine()->Int32Sub(), lhs, rhs);
 }
 
 
 Node* MachineOperatorReducer::Int32Mul(Node* lhs, Node* rhs) {
   return graph()->NewNode(machine()->Int32Mul(), lhs, rhs);
@@ skipping 123 matching lines @@
       if (m.left().IsInt64Sub() && m.right().Is(0)) {  // x - y == 0 => x == y
         Int64BinopMatcher msub(m.left().node());
         node->ReplaceInput(0, msub.left().node());
         node->ReplaceInput(1, msub.right().node());
         return Changed(node);
       }
       // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
       if (m.LeftEqualsRight()) return ReplaceBool(true);  // x == x => true
       break;
     }
-    case IrOpcode::kInt32Add: {
-      Int32BinopMatcher m(node);
-      if (m.right().Is(0)) return Replace(m.left().node());  // x + 0 => x
-      if (m.IsFoldable()) {                                  // K + K => K
-        return ReplaceInt32(static_cast<uint32_t>(m.left().Value()) +
-                            static_cast<uint32_t>(m.right().Value()));
-      }
-      break;
-    }
+    case IrOpcode::kInt32Add:
+      return ReduceInt32Add(node);
     case IrOpcode::kInt32Sub: {
       Int32BinopMatcher m(node);
       if (m.right().Is(0)) return Replace(m.left().node());  // x - 0 => x
       if (m.IsFoldable()) {                                  // K - K => K
         return ReplaceInt32(static_cast<uint32_t>(m.left().Value()) -
                             static_cast<uint32_t>(m.right().Value()));
       }
       if (m.LeftEqualsRight()) return ReplaceInt32(0);  // x - x => 0
       break;
     }
@@ skipping 227 matching lines @@
     }
     case IrOpcode::kStore:
       return ReduceStore(node);
     default:
       break;
   }
   return NoChange();
 }
 
 
+Reduction MachineOperatorReducer::ReduceInt32Add(Node* node) {
+  DCHECK_EQ(IrOpcode::kInt32Add, node->opcode());
+  Int32BinopMatcher m(node);
+  if (m.right().Is(0)) return Replace(m.left().node());  // x + 0 => x
+  if (m.IsFoldable()) {                                  // K + K => K
+    return ReplaceUint32(bit_cast<uint32_t>(m.left().Value()) +
+                         bit_cast<uint32_t>(m.right().Value()));
+  }
+  return NoChange();
+}
+
+
 Reduction MachineOperatorReducer::ReduceInt32Div(Node* node) {
   Int32BinopMatcher m(node);
   if (m.left().Is(0)) return Replace(m.left().node());    // 0 / x => 0
   if (m.right().Is(0)) return Replace(m.right().node());  // x / 0 => 0
   if (m.right().Is(1)) return Replace(m.left().node());   // x / 1 => x
   if (m.IsFoldable()) {                                   // K / K => K
     return ReplaceInt32(
         base::bits::SignedDiv32(m.left().Value(), m.right().Value()));
   }
   if (m.LeftEqualsRight()) {  // x / x => x != 0
@@ skipping 285 matching lines @@
   if (m.IsFoldable()) {                                   // K & K  => K
     return ReplaceInt32(m.left().Value() & m.right().Value());
   }
   if (m.LeftEqualsRight()) return Replace(m.left().node());  // x & x => x
   if (m.left().IsWord32And() && m.right().HasValue()) {
     Int32BinopMatcher mleft(m.left().node());
     if (mleft.right().HasValue()) {  // (x & K) & K => x & K
       node->ReplaceInput(0, mleft.left().node());
       node->ReplaceInput(
           1, Int32Constant(m.right().Value() & mleft.right().Value()));
-      Reduction reduction = ReduceWord32And(node);
+      Reduction const reduction = ReduceWord32And(node);
       return reduction.Changed() ? reduction : Changed(node);
     }
   }
   if (m.left().IsInt32Add() && m.right().IsNegativePowerOf2()) {
     Int32BinopMatcher mleft(m.left().node());
     if (mleft.right().HasValue() &&
         (mleft.right().Value() & m.right().Value()) == mleft.right().Value()) {
       // (x + (K << L)) & (-1 << L) => (x & (-1 << L)) + (K << L)
-      return Replace(graph()->NewNode(
-          machine()->Int32Add(),
-          graph()->NewNode(machine()->Word32And(), mleft.left().node(),
-                           m.right().node()),
-          mleft.right().node()));
+      node->set_op(machine()->Int32Add());
+      node->ReplaceInput(0, Word32And(mleft.left().node(), m.right().node()));
+      node->ReplaceInput(1, mleft.right().node());
+      Reduction const reduction = ReduceInt32Add(node);
+      return reduction.Changed() ? reduction : Changed(node);
     }
     if (mleft.left().IsWord32Shl()) {
       Int32BinopMatcher mleftleft(mleft.left().node());
       if (mleftleft.right().Is(
               base::bits::CountTrailingZeros32(m.right().Value()))) {
         // (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
-        return Replace(graph()->NewNode(
-            machine()->Int32Add(),
-            graph()->NewNode(machine()->Word32And(), mleft.right().node(),
-                             m.right().node()),
-            mleftleft.node()));
+        node->set_op(machine()->Int32Add());
+        node->ReplaceInput(0,
+                           Word32And(mleft.right().node(), m.right().node()));
+        node->ReplaceInput(1, mleftleft.node());
+        Reduction const reduction = ReduceInt32Add(node);
+        return reduction.Changed() ? reduction : Changed(node);
       }
     }
     if (mleft.right().IsWord32Shl()) {
       Int32BinopMatcher mleftright(mleft.right().node());
       if (mleftright.right().Is(
               base::bits::CountTrailingZeros32(m.right().Value()))) {
         // (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L
-        return Replace(graph()->NewNode(
-            machine()->Int32Add(),
-            graph()->NewNode(machine()->Word32And(), mleft.left().node(),
-                             m.right().node()),
-            mleftright.node()));
+        node->set_op(machine()->Int32Add());
+        node->ReplaceInput(0, Word32And(mleft.left().node(), m.right().node()));
+        node->ReplaceInput(1, mleftright.node());
+        Reduction const reduction = ReduceInt32Add(node);
+        return reduction.Changed() ? reduction : Changed(node);
       }
     }
   }
   return NoChange();
 }
 
 
 Reduction MachineOperatorReducer::ReduceWord32Or(Node* node) {
   DCHECK_EQ(IrOpcode::kWord32Or, node->opcode());
   Int32BinopMatcher m(node);
@@ skipping 59 matching lines @@
 MachineOperatorBuilder* MachineOperatorReducer::machine() const {
   return jsgraph()->machine();
 }
 
 
 Graph* MachineOperatorReducer::graph() const { return jsgraph()->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8