Simplifies MIPS LoadWordFromPoolOffset

runtime/vm/instructions_mips.cc

Index: runtime/vm/instructions_mips.cc
===================================================================
--- runtime/vm/instructions_mips.cc	(revision 20527)
+++ runtime/vm/instructions_mips.cc	(working copy)
@@ -60,20 +60,14 @@
     instr = Instr::At(reinterpret_cast<uword>(&i));
     if (instr->OpcodeField() == LUI) {
       ASSERT(instr->RtField() == *reg);
-      offset |= (instr->UImmField() << 16);
+      // Offset is signed, so add the upper 16 bits.
+      offset += (instr->UImmField() << 16);
     } else {
       ASSERT(instr->OpcodeField() == ORI);
       ASSERT(instr->RtField() == *reg);
+      ASSERT(offset == 0);
+      // Offset is 0 here, so just grab the lower offset bits.
       offset |= instr->UImmField();
-
-      if (instr->RsField() != ZR) {
-        ASSERT(instr->RsField() == *reg);
-        i = Back(++end);
-        instr = Instr::At(reinterpret_cast<uword>(&i));
-        ASSERT(instr->OpcodeField() == LUI);
-        ASSERT(instr->RtField() == *reg);
-        offset |= (instr->UImmField() << 16);
-      }
     }
   }
   offset += kHeapObjectTag;