Revert of [turbofan] Reduces x << y ^ x >>> (32 - y) to x ror (32 - y).

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/base/ieee754.h"
 #include "src/codegen.h"
@@ skipping 132 matching lines @@
 
 // Perform constant folding and strength reduction on machine operators.
 Reduction MachineOperatorReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kProjection:
       return ReduceProjection(ProjectionIndexOf(node->op()), node->InputAt(0));
     case IrOpcode::kWord32And:
       return ReduceWord32And(node);
     case IrOpcode::kWord32Or:
       return ReduceWord32Or(node);
-    case IrOpcode::kWord32Xor:
-      return ReduceWord32Xor(node);
+    case IrOpcode::kWord32Xor: {
+      Int32BinopMatcher m(node);
+      if (m.right().Is(0)) return Replace(m.left().node());  // x ^ 0 => x
+      if (m.IsFoldable()) {                                  // K ^ K => K
+        return ReplaceInt32(m.left().Value() ^ m.right().Value());
+      }
+      if (m.LeftEqualsRight()) return ReplaceInt32(0);  // x ^ x => 0
+      if (m.left().IsWord32Xor() && m.right().Is(-1)) {
+        Int32BinopMatcher mleft(m.left().node());
+        if (mleft.right().Is(-1)) {  // (x ^ -1) ^ -1 => x
+          return Replace(mleft.left().node());
+        }
+      }
+      break;
+    }
     case IrOpcode::kWord32Shl:
       return ReduceWord32Shl(node);
     case IrOpcode::kWord32Shr:
       return ReduceWord32Shr(node);
     case IrOpcode::kWord32Sar:
       return ReduceWord32Sar(node);
     case IrOpcode::kWord32Ror: {
       Int32BinopMatcher m(node);
       if (m.right().Is(0)) return Replace(m.left().node());  // x ror 0 => x
       if (m.IsFoldable()) {                                  // K ror K => K
@@ skipping 921 matching lines @@
       Int32BinopMatcher mleft(m.left().node());
       if (mleft.right().IsMultipleOf(-mask)) {
         // (x * (K << L)) & (-1 << L) => x * (K << L)
         return Replace(mleft.node());
       }
     }
   }
   return NoChange();
 }
 
-Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node) {
-  DCHECK(IrOpcode::kWord32Or == node->opcode() ||
-         IrOpcode::kWord32Xor == node->opcode());
+
+Reduction MachineOperatorReducer::ReduceWord32Or(Node* node) {
+  DCHECK_EQ(IrOpcode::kWord32Or, node->opcode());
   Int32BinopMatcher m(node);
+  if (m.right().Is(0)) return Replace(m.left().node());    // x | 0  => x
+  if (m.right().Is(-1)) return Replace(m.right().node());  // x | -1 => -1
+  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
+
   Node* shl = nullptr;
   Node* shr = nullptr;
-  // Recognize rotation, we are matching:
+  // Recognize rotation, we are matching either:
   //  * x << y | x >>> (32 - y) => x ror (32 - y), i.e  x rol y
   //  * x << (32 - y) | x >>> y => x ror y
-  //  * x << y ^ x >>> (32 - y) => x ror (32 - y), i.e. x rol y
-  //  * x << (32 - y) ^ x >>> y => x ror y
   // as well as their commuted form.
   if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
     shl = m.left().node();
     shr = m.right().node();
   } else if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) {
     shl = m.right().node();
     shr = m.left().node();
   } else {
     return NoChange();
   }
@@ skipping 21 matching lines @@
     Int32BinopMatcher msub(sub);
     if (!msub.left().Is(32) || msub.right().node() != y) return NoChange();
   }
 
   node->ReplaceInput(0, mshl.left().node());
   node->ReplaceInput(1, mshr.right().node());
   NodeProperties::ChangeOp(node, machine()->Word32Ror());
   return Changed(node);
 }
 
-Reduction MachineOperatorReducer::ReduceWord32Or(Node* node) {
-  DCHECK_EQ(IrOpcode::kWord32Or, node->opcode());
-  Int32BinopMatcher m(node);
-  if (m.right().Is(0)) return Replace(m.left().node());    // x | 0  => x
-  if (m.right().Is(-1)) return Replace(m.right().node());  // x | -1 => -1
-  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
-
-  return TryMatchWord32Ror(node);
-}
-
-Reduction MachineOperatorReducer::ReduceWord32Xor(Node* node) {
-  DCHECK_EQ(IrOpcode::kWord32Xor, 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 ReplaceInt32(m.left().Value() ^ m.right().Value());
-  }
-  if (m.LeftEqualsRight()) return ReplaceInt32(0);  // x ^ x => 0
-  if (m.left().IsWord32Xor() && m.right().Is(-1)) {
-    Int32BinopMatcher mleft(m.left().node());
-    if (mleft.right().Is(-1)) {  // (x ^ -1) ^ -1 => x
-      return Replace(mleft.left().node());
-    }
-  }
-
-  return TryMatchWord32Ror(node);
-}
 
 Reduction MachineOperatorReducer::ReduceFloat64InsertLowWord32(Node* node) {
   DCHECK_EQ(IrOpcode::kFloat64InsertLowWord32, node->opcode());
   Float64Matcher mlhs(node->InputAt(0));
   Uint32Matcher mrhs(node->InputAt(1));
   if (mlhs.HasValue() && mrhs.HasValue()) {
     return ReplaceFloat64(bit_cast<double>(
         (bit_cast<uint64_t>(mlhs.Value()) & V8_UINT64_C(0xFFFFFFFF00000000)) |
         mrhs.Value()));
   }
@@ skipping 79 matching lines @@
 MachineOperatorBuilder* MachineOperatorReducer::machine() const {
   return jsgraph()->machine();
 }
 
 
 Graph* MachineOperatorReducer::graph() const { return jsgraph()->graph(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8