Support unaligned integer loads on ARM and MIPS.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 3829 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(StoreStaticFieldInstr);
 };
 
 
 class LoadIndexedInstr : public TemplateDefinition<2, NoThrow> {
  public:
   LoadIndexedInstr(Value* array,
                    Value* index,
                    intptr_t index_scale,
                    intptr_t class_id,
+                   bool aligned,

[Cutch, 2016/10/26 09:00:29]

Consider defining an enum:

enum MemoryAccessKind {
  kAlignedMemoryAccess,
  kUnalignedMemoryAccess,
}

instead of passing true / false.

                    intptr_t deopt_id,
-                   TokenPosition token_pos)
-      : TemplateDefinition(deopt_id),
-        index_scale_(index_scale),
-        class_id_(class_id),
-        token_pos_(token_pos) {
-    SetInputAt(0, array);
-    SetInputAt(1, index);
-  }
+                   TokenPosition token_pos);
 
   TokenPosition token_pos() const { return token_pos_; }
 
   DECLARE_INSTRUCTION(LoadIndexed)
   virtual CompileType ComputeType() const;
 
   virtual Representation RequiredInputRepresentation(intptr_t idx) const {
     ASSERT(idx == 0 || idx == 1);
     // The array may be tagged or untagged (for external arrays).
     if (idx == 0) return kNoRepresentation;
     return kTagged;
   }
 
   bool IsExternal() const {
     return array()->definition()->representation() == kUntagged;
   }
 
   Value* array() const { return inputs_[0]; }
   Value* index() const { return inputs_[1]; }
   intptr_t index_scale() const { return index_scale_; }
   intptr_t class_id() const { return class_id_; }
+  bool aligned() const { return aligned_; }
 
   virtual bool CanDeoptimize() const {
     return GetDeoptId() != Thread::kNoDeoptId;
   }
 
   virtual Representation representation() const;
   virtual void InferRange(RangeAnalysis* analysis, Range* range);
 
   virtual EffectSet Effects() const { return EffectSet::None(); }
 
  private:
   const intptr_t index_scale_;
   const intptr_t class_id_;
+  intptr_t aligned_;
   const TokenPosition token_pos_;
 
   DISALLOW_COPY_AND_ASSIGN(LoadIndexedInstr);
 };
 
 
 // Loads the specified number of code units from the given string, packing
 // multiple code units into a single datatype. In essence, this is a specialized
 // version of LoadIndexedInstr which accepts only string targets and can load
 // multiple elements at once. The result datatype differs depending on the
@@ skipping 143 matching lines @@
 
 
 class StoreIndexedInstr : public TemplateDefinition<3, NoThrow> {
  public:
   StoreIndexedInstr(Value* array,
                     Value* index,
                     Value* value,
                     StoreBarrierType emit_store_barrier,
                     intptr_t index_scale,
                     intptr_t class_id,
+                    bool aligned,
                     intptr_t deopt_id,
-                    TokenPosition token_pos)
-      : TemplateDefinition(deopt_id),
-        emit_store_barrier_(emit_store_barrier),
-        index_scale_(index_scale),
-        class_id_(class_id),
-        token_pos_(token_pos) {
-    SetInputAt(kArrayPos, array);
-    SetInputAt(kIndexPos, index);
-    SetInputAt(kValuePos, value);
-  }
-
+                    TokenPosition token_pos);
   DECLARE_INSTRUCTION(StoreIndexed)
 
   enum {
     kArrayPos = 0,
     kIndexPos = 1,
     kValuePos = 2
   };
 
   Value* array() const { return inputs_[kArrayPos]; }
   Value* index() const { return inputs_[kIndexPos]; }
   Value* value() const { return inputs_[kValuePos]; }
 
   intptr_t index_scale() const { return index_scale_; }
   intptr_t class_id() const { return class_id_; }
+  bool aligned() const { return aligned_; }
 
   bool ShouldEmitStoreBarrier() const {
     return value()->NeedsStoreBuffer()
         && (emit_store_barrier_ == kEmitStoreBarrier);
   }
 
   virtual bool CanDeoptimize() const { return false; }
 
   virtual Representation RequiredInputRepresentation(intptr_t idx) const;
 
   bool IsExternal() const {
     return array()->definition()->representation() == kUntagged;
   }
 
   virtual intptr_t DeoptimizationTarget() const {
     // Direct access since this instruction cannot deoptimize, and the deopt-id
     // was inherited from another instruction that could deoptimize.
     return GetDeoptId();
   }
 
   virtual EffectSet Effects() const { return EffectSet::None(); }
 
  private:
   const StoreBarrierType emit_store_barrier_;
   const intptr_t index_scale_;
   const intptr_t class_id_;
+  bool aligned_;
   const TokenPosition token_pos_;
 
   DISALLOW_COPY_AND_ASSIGN(StoreIndexedInstr);
 };
 
 
 // Note overrideable, built-in: value ? false : true.
 class BooleanNegateInstr : public TemplateDefinition<1, NoThrow> {
  public:
   explicit BooleanNegateInstr(Value* value) {
@@ skipping 4265 matching lines @@
   LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {    \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_