[compiler] Allow matcher to work on arch without scaling capability

src/compiler/node-matchers.h

 // 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.
 
 #ifndef V8_COMPILER_NODE_MATCHERS_H_
 #define V8_COMPILER_NODE_MATCHERS_H_
 
 #include <cmath>
 
 // TODO(turbofan): Move ExternalReference out of assembler.h
@@ skipping 378 matching lines @@
                    IrOpcode::kInt32Mul, IrOpcode::kWord32Shl>
     Int32AddMatcher;
 typedef AddMatcher<Int64BinopMatcher, IrOpcode::kInt64Add, IrOpcode::kInt64Sub,
                    IrOpcode::kInt64Mul, IrOpcode::kWord64Shl>
     Int64AddMatcher;
 
 enum DisplacementMode { kPositiveDisplacement, kNegativeDisplacement };
 
 template <class AddMatcher>
 struct BaseWithIndexAndDisplacementMatcher {
-  BaseWithIndexAndDisplacementMatcher(Node* node, bool allow_input_swap)
+  BaseWithIndexAndDisplacementMatcher(Node* node, bool allow_input_swap,

[Benedikt Meurer, 2016/08/12 17:57:06]

Can you turn these two booleans into flags? Using an enum (class) + base::Flags?

+                                      bool allow_scale = true)
       : matches_(false),
         index_(nullptr),
         scale_(0),
         base_(nullptr),
         displacement_(nullptr),
         displacement_mode_(kPositiveDisplacement) {
-    Initialize(node, allow_input_swap);
+    Initialize(node, allow_input_swap, allow_scale);
   }
 
   explicit BaseWithIndexAndDisplacementMatcher(Node* node)
       : matches_(false),
         index_(nullptr),
         scale_(0),
         base_(nullptr),
         displacement_(nullptr),
         displacement_mode_(kPositiveDisplacement) {
-    Initialize(node, node->op()->HasProperty(Operator::kCommutative));
+    Initialize(node, node->op()->HasProperty(Operator::kCommutative), true);
   }
 
   bool matches() const { return matches_; }
   Node* index() const { return index_; }
   int scale() const { return scale_; }
   Node* base() const { return base_; }
   Node* displacement() const { return displacement_; }
   DisplacementMode displacement_mode() const { return displacement_mode_; }
 
  private:
   bool matches_;
   Node* index_;
   int scale_;
   Node* base_;
   Node* displacement_;
   DisplacementMode displacement_mode_;
 
-  void Initialize(Node* node, bool allow_input_swap) {
+  void Initialize(Node* node, bool allow_input_swap, bool allow_scale) {
     // The BaseWithIndexAndDisplacementMatcher canonicalizes the order of
     // displacements and scale factors that are used as inputs, so instead of
     // enumerating all possible patterns by brute force, checking for node
     // clusters using the following templates in the following order suffices to
     // find all of the interesting cases (S = index * scale, B = base input, D =
     // displacement input):
     // (S + (B + D))
     // (S + (B + B))
     // (S + D)
     // (S + B)
@@ skipping 156 matching lines @@
         // If the scale requires explicitly using the index as the base, but a
         // base is already part of the match, then the (1 << N + 1) scale factor
         // can't be folded into the match and the entire index * scale
         // calculation must be computed separately.
         index = scale_expression;
         scale = 0;
       } else {
         base = index;
       }
     }
+    if (!allow_scale && scale != 0) {
+      index = scale_expression;
+      scale = 0;
+    }
     base_ = base;
     displacement_ = displacement;
     displacement_mode_ = displacement_mode;
     index_ = index;
     scale_ = scale;
     matches_ = true;
   }
 };
 
 typedef BaseWithIndexAndDisplacementMatcher<Int32AddMatcher>
@@ skipping 47 matching lines @@
   Node* branch_;
   Node* if_true_;
   Node* if_false_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_NODE_MATCHERS_H_