[stubs] Fixing loads/stores from arrays by int32 offsets/indices. Step 2.

Review-Url: https://codereview.chromium.org/2319173002
Cr-Commit-Position: refs/heads/master@{#39271}

src/code-stub-assembler.h

@@ -233,10 +233,11 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   // Load the constructor of a Map (equivalent to Map::GetConstructor()).
   compiler::Node* LoadMapConstructor(compiler::Node* map);
 
-  // Load the hash field of a name.
+  // Load the hash field of a name as an uint32 value.
   compiler::Node* LoadNameHashField(compiler::Node* name);
-  // Load the hash value of a name. If {if_hash_not_computed} label
-  // is specified then it also checks if hash is actually computed.
+  // Load the hash value of a name as an uint32 value.
+  // If {if_hash_not_computed} label is specified then it also checks if
+  // hash is actually computed.
   compiler::Node* LoadNameHash(compiler::Node* name,
                                Label* if_hash_not_computed = nullptr);
 
@@ -380,12 +381,21 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* StringToNumber(compiler::Node* context,
                                  compiler::Node* input);
 
-  // Returns a node that is true if the given bit is set in |word32|.
+  // Returns a node that contains a decoded (unsigned!) value of a bit
+  // field |T| in |word32|. Returns result as an uint32 node.
   template <typename T>
   compiler::Node* BitFieldDecode(compiler::Node* word32) {
     return BitFieldDecode(word32, T::kShift, T::kMask);
   }
 
+  // Returns a node that contains a decoded (unsigned!) value of a bit
+  // field |T| in |word32|. Returns result as a word-size node.
+  template <typename T>
+  compiler::Node* BitFieldDecodeWord(compiler::Node* word32) {
+    return ChangeUint32ToWord(BitFieldDecode<T>(word32));
+  }
+
+  // Decodes an unsigned (!) value from |word32| to an uint32 node.
   compiler::Node* BitFieldDecode(compiler::Node* word32, uint32_t shift,
                                  uint32_t mask);
 

test/cctest/test-code-stub-assembler.cc

@@ -268,7 +268,7 @@ void TestNameDictionaryLookup() {
 
     Label passed(&m), failed(&m);
     Label if_found(&m), if_not_found(&m);
-    Variable var_name_index(&m, MachineRepresentation::kWord32);
+    Variable var_name_index(&m, MachineType::PointerRepresentation());
 
     m.NameDictionaryLookup<Dictionary>(dictionary, unique_name, &if_found,
                                        &var_name_index, &if_not_found);
@@ -374,7 +374,7 @@ void TestNumberDictionaryLookup() {
 
     Label passed(&m), failed(&m);
     Label if_found(&m), if_not_found(&m);
-    Variable var_entry(&m, MachineRepresentation::kWord32);
+    Variable var_entry(&m, MachineType::PointerRepresentation());
 
     m.NumberDictionaryLookup<Dictionary>(dictionary, key, &if_found, &var_entry,
                                          &if_not_found);