Simplifies MIPS LoadWordFromPoolOffset

runtime/vm/instructions_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/constants_mips.h"
 #include "vm/instructions.h"
 #include "vm/object.h"
@@ skipping 42 matching lines @@
     ASSERT(instr->OpcodeField() == SPECIAL);
     ASSERT(instr->FunctionField() == ADDU);
     ASSERT(instr->RdField() == *reg);
     ASSERT(instr->RsField() == *reg);
     ASSERT(instr->RtField() == PP);
 
     i = Back(++end);
     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;
   ASSERT(Utils::IsAligned(offset, 4));
   *index = (offset - Array::data_offset())/4;
   return end;
 }
 
 
 RawICData* CallPattern::IcData() {
@@ skipping 39 matching lines @@
 
 
 void JumpPattern::SetTargetAddress(uword target_address) const {
   UNIMPLEMENTED();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS