Make guard_cid and nullable_cid half words.

runtime/vm/intermediate_language_mips.cc

 // 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 1632 matching lines @@
   if (emit_full_guard) {
     __ LoadObject(field_reg, Field::ZoneHandle(field().raw()));
 
     FieldAddress field_cid_operand(field_reg, Field::guarded_cid_offset());
     FieldAddress field_nullability_operand(
         field_reg, Field::is_nullable_offset());
 
     if (value_cid == kDynamicCid) {
       LoadValueCid(compiler, value_cid_reg, value_reg);
 
-      __ lw(CMPRES1, field_cid_operand);
+      __ lhu(CMPRES1, field_cid_operand);
       __ beq(value_cid_reg, CMPRES1, &ok);
-      __ lw(TMP, field_nullability_operand);
+      __ lhu(TMP, field_nullability_operand);
       __ subu(CMPRES1, value_cid_reg, TMP);
     } else if (value_cid == kNullCid) {
-      __ lw(TMP, field_nullability_operand);
+      __ lhu(TMP, field_nullability_operand);
       __ LoadImmediate(CMPRES1, value_cid);
       __ subu(CMPRES1, TMP, CMPRES1);
     } else {
-      __ lw(TMP, field_cid_operand);
+      __ lhu(TMP, field_cid_operand);
       __ LoadImmediate(CMPRES1, value_cid);
       __ subu(CMPRES1, TMP, CMPRES1);
     }
     __ beq(CMPRES1, ZR, &ok);
 
     // Check if the tracked state of the guarded field can be initialized
     // inline. If the field needs length check we fall through to runtime
     // which is responsible for computing offset of the length field
     // based on the class id.
     // Length guard will be emitted separately when needed via GuardFieldLength
     // instruction after GuardFieldClass.
     if (!field().needs_length_check()) {
       // Uninitialized field can be handled inline. Check if the
       // field is still unitialized.
-      __ lw(CMPRES1, field_cid_operand);
+      __ lhu(CMPRES1, field_cid_operand);
       __ BranchNotEqual(CMPRES1, Immediate(kIllegalCid), fail);
 
       if (value_cid == kDynamicCid) {
-        __ sw(value_cid_reg, field_cid_operand);
-        __ sw(value_cid_reg, field_nullability_operand);
+        __ sh(value_cid_reg, field_cid_operand);
+        __ sh(value_cid_reg, field_nullability_operand);
       } else {
         __ LoadImmediate(TMP, value_cid);
-        __ sw(TMP, field_cid_operand);
-        __ sw(TMP, field_nullability_operand);
+        __ sh(TMP, field_cid_operand);
+        __ sh(TMP, field_nullability_operand);
       }
 
       if (deopt == NULL) {
         ASSERT(!compiler->is_optimizing());
         __ b(&ok);
       }
     }
 
     if (deopt == NULL) {
       ASSERT(!compiler->is_optimizing());
       __ Bind(fail);
 
-      __ lw(CMPRES1, FieldAddress(field_reg, Field::guarded_cid_offset()));
+      __ lhu(CMPRES1, FieldAddress(field_reg, Field::guarded_cid_offset()));
       __ BranchEqual(CMPRES1, Immediate(kDynamicCid), &ok);
 
       __ addiu(SP, SP, Immediate(-2 * kWordSize));
       __ sw(field_reg, Address(SP, 1 * kWordSize));
       __ sw(value_reg, Address(SP, 0 * kWordSize));
       __ CallRuntime(kUpdateFieldCidRuntimeEntry, 2);
       __ Drop(2);  // Drop the field and the value.
     }
   } else {
     ASSERT(compiler->is_optimizing());
@@ skipping 283 matching lines @@
       // Value input is a writable register and should be manually preserved
       // across allocation slow-path.
       locs()->live_registers()->Add(locs()->in(1), kTagged);
     }
 
     Label store_pointer;
     Label store_double;
 
     __ LoadObject(temp, Field::ZoneHandle(field().raw()));
 
-    __ lw(temp2, FieldAddress(temp, Field::is_nullable_offset()));
+    __ lhu(temp2, FieldAddress(temp, Field::is_nullable_offset()));
     __ BranchEqual(temp2, Immediate(kNullCid), &store_pointer);
 
     __ lbu(temp2, FieldAddress(temp, Field::kind_bits_offset()));
     __ andi(CMPRES1, temp2, Immediate(1 << Field::kUnboxingCandidateBit));
     __ beq(CMPRES1, ZR, &store_pointer);
 
-    __ lw(temp2, FieldAddress(temp, Field::guarded_cid_offset()));
+    __ lhu(temp2, FieldAddress(temp, Field::guarded_cid_offset()));
     __ BranchEqual(temp2, Immediate(kDoubleCid), &store_double);
 
     // Fall through.
     __ b(&store_pointer);
 
     if (!compiler->is_optimizing()) {
       locs()->live_registers()->Add(locs()->in(0));
       locs()->live_registers()->Add(locs()->in(1));
     }
 
@@ skipping 289 matching lines @@
 
     Label load_pointer;
     Label load_double;
 
     __ LoadObject(result_reg, Field::ZoneHandle(field()->raw()));
 
     FieldAddress field_cid_operand(result_reg, Field::guarded_cid_offset());
     FieldAddress field_nullability_operand(result_reg,
                                            Field::is_nullable_offset());
 
-    __ lw(temp, field_nullability_operand);
+    __ lhu(temp, field_nullability_operand);
     __ BranchEqual(temp, Immediate(kNullCid), &load_pointer);
 
-    __ lw(temp, field_cid_operand);
+    __ lhu(temp, field_cid_operand);
     __ BranchEqual(temp, Immediate(kDoubleCid), &load_double);
 
     // Fall through.
     __ b(&load_pointer);
 
     if (!compiler->is_optimizing()) {
       locs()->live_registers()->Add(locs()->in(0));
     }
 
     {
@@ skipping 3288 matching lines @@
                                 1,
                                 locs());
   __ lw(result, Address(SP, 1 * kWordSize));
   __ addiu(SP, SP, Immediate(2 * kWordSize));
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS