Add support to load/store byte fields.

src/arm/lithium-codegen-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3024 matching lines @@
 }
 
 
 void LCodeGen::DoLoadNamedField(LLoadNamedField* instr) {
   HObjectAccess access = instr->hydrogen()->access();
   int offset = access.offset();
   Register object = ToRegister(instr->object());
 
   if (access.IsExternalMemory()) {
     Register result = ToRegister(instr->result());
-    __ ldr(result, MemOperand(object, offset));
+    MemOperand operand = MemOperand(object, offset);
+    if (access.representation().IsByte()) {
+      __ ldrb(result, operand);
+    } else {
+      __ ldr(result, operand);
+    }
     return;
   }
 
   if (instr->hydrogen()->representation().IsDouble()) {
     DwVfpRegister result = ToDoubleRegister(instr->result());
     __ vldr(result, FieldMemOperand(object, offset));
     return;
   }
 
   Register result = ToRegister(instr->result());
-  if (access.IsInobject()) {
-    __ ldr(result, FieldMemOperand(object, offset));
+  if (!access.IsInobject()) {
+    __ ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
+    object = result;
+  }
+  MemOperand operand = FieldMemOperand(object, offset);
+  if (access.representation().IsByte()) {
+    __ ldrb(result, operand);
   } else {
-    __ ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
-    __ ldr(result, FieldMemOperand(result, offset));
+    __ ldr(result, operand);
   }
 }
 
 
 void LCodeGen::DoLoadNamedGeneric(LLoadNamedGeneric* instr) {
   ASSERT(ToRegister(instr->context()).is(cp));
   ASSERT(ToRegister(instr->object()).is(r0));
   ASSERT(ToRegister(instr->result()).is(r0));
 
   // Name is always in r2.
@@ skipping 1085 matching lines @@
 void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
   Representation representation = instr->representation();
 
   Register object = ToRegister(instr->object());
   Register scratch = scratch0();
   HObjectAccess access = instr->hydrogen()->access();
   int offset = access.offset();
 
   if (access.IsExternalMemory()) {
     Register value = ToRegister(instr->value());
-    __ str(value, MemOperand(object, offset));
+    MemOperand operand = MemOperand(object, offset);
+    if (representation.IsByte()) {
+      __ strb(value, operand);
+    } else {
+      __ str(value, operand);
+    }
     return;
   }
 
   Handle<Map> transition = instr->transition();
 
   if (FLAG_track_heap_object_fields && representation.IsHeapObject()) {
     Register value = ToRegister(instr->value());
     if (!instr->hydrogen()->value()->type().IsHeapObject()) {
       __ SmiTst(value);
       DeoptimizeIf(eq, instr->environment());
@@ skipping 24 matching lines @@
     }
   }
 
   // Do the store.
   Register value = ToRegister(instr->value());
   ASSERT(!object.is(value));
   SmiCheck check_needed =
       instr->hydrogen()->value()->IsHeapObject()
           ? OMIT_SMI_CHECK : INLINE_SMI_CHECK;
   if (access.IsInobject()) {
-    __ str(value, FieldMemOperand(object, offset));
+    MemOperand operand = FieldMemOperand(object, offset);
+    if (representation.IsByte()) {
+      __ strb(value, operand);
+    } else {
+      __ str(value, operand);
+    }
     if (instr->hydrogen()->NeedsWriteBarrier()) {
       // Update the write barrier for the object for in-object properties.
       __ RecordWriteField(object,
                           offset,
                           value,
                           scratch,
                           GetLinkRegisterState(),
                           kSaveFPRegs,
                           EMIT_REMEMBERED_SET,
                           check_needed);
     }
   } else {
     __ ldr(scratch, FieldMemOperand(object, JSObject::kPropertiesOffset));
-    __ str(value, FieldMemOperand(scratch, offset));
+    MemOperand operand = FieldMemOperand(scratch, offset);
+    if (representation.IsByte()) {
+      __ strb(value, operand);
+    } else {
+      __ str(value, operand);
+    }
     if (instr->hydrogen()->NeedsWriteBarrier()) {
       // Update the write barrier for the properties array.
       // object is used as a scratch register.
       __ RecordWriteField(scratch,
                           offset,
                           value,
                           object,
                           GetLinkRegisterState(),
                           kSaveFPRegs,
                           EMIT_REMEMBERED_SET,
@@ skipping 1569 matching lines @@
   __ sub(scratch, result, Operand::PointerOffsetFromSmiKey(index));
   __ ldr(result, FieldMemOperand(scratch,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal