Add signed/unsigned 8-bit and 16-bit Representations

src/hydrogen-load-elimination.cc

 // Copyright 2013 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 255 matching lines @@
     if (access.IsInobject()) {
       int offset = access.offset();
       if ((offset % kPointerSize) != 0) {
         // Kill the field containing the first word of the access.
         HValue* object = instr->object()->ActualValue();
         int field = offset / kPointerSize;
         KillFieldInternal(object, field, NULL);
 
         // Kill the next field in case of overlap.
         int size = kPointerSize;
-        if (access.representation().IsByte()) size = 1;
+        if (access.representation().IsInteger8() ||
+            access.representation().IsUInteger8()) size = 1;

[Yang, 2013/11/08 08:45:59]

I favor adding brackets for readability.

[Sven Panne, 2013/11/08 09:09:30]

I would favor something actually OO-like: Adding a method to Representation.
This is plain old imperative C code here...

[danno, 2013/11/08 10:49:12]

Done.

[danno, 2013/11/08 10:49:12]

Done.

+        if (access.representation().IsInteger16() ||
+            access.representation().IsUInteger16()) size = 2;
         else if (access.representation().IsInteger32()) size = 4;
         int next_field = (offset + size - 1) / kPointerSize;
         if (next_field != field) KillFieldInternal(object, next_field, NULL);
       }
     }
     return instr;
   }
 
   // Find an entry for the given object and field pair.
   HFieldApproximation* Find(HValue* object, int field) {
@@ skipping 214 matching lines @@
   } else {
     // Perform only local analysis.
     for (int i = 0; i < graph()->blocks()->length(); i++) {
       table->Kill();
       engine.AnalyzeOneBlock(graph()->blocks()->at(i), table);
     }
   }
 }
 
 } }  // namespace v8::internal