ARM optimize loading of immediates.

src/arm/simulator-arm.cc

 // Copyright 2010 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 921 matching lines @@
 
 // Addressing Mode 1 - Data-processing operands:
 // Get the value based on the shifter_operand with register.
 int32_t Simulator::GetShiftRm(Instr* instr, bool* carry_out) {
   Shift shift = instr->ShiftField();
   int shift_amount = instr->ShiftAmountField();
   int32_t result = get_register(instr->RmField());
   if (instr->Bit(4) == 0) {
     // by immediate
     if ((shift == ROR) && (shift_amount == 0)) {
+      // RRX.
       UNIMPLEMENTED();
       return result;
     } else if (((shift == LSR) || (shift == ASR)) && (shift_amount == 0)) {
       shift_amount = 32;
     }
     switch (shift) {
       case ASR: {
         if (shift_amount == 0) {
           if (result < 0) {
             result = 0xffffffff;
@@ skipping 29 matching lines @@
           uint32_t uresult = static_cast<uint32_t>(result);
           uresult >>= (shift_amount - 1);
           *carry_out = (uresult & 1) == 1;
           uresult >>= 1;
           result = static_cast<int32_t>(uresult);
         }
         break;
       }
 
       case ROR: {
-        UNIMPLEMENTED();
+        uint32_t uresult = static_cast<uint32_t>(result);
+        uresult =
+            (uresult >> shift_amount) | (uresult << (32 - shift_amount));
+        *carry_out = (uresult >> 31) != 0;
+        result = static_cast<int32_t>(uresult);
         break;
       }
 
       default: {
         UNREACHABLE();
         break;
       }
     }
   } else {
     // by register
@@ skipping 1301 matching lines @@
   uintptr_t* stack_slot = reinterpret_cast<uintptr_t*>(current_sp);
   uintptr_t address = *stack_slot;
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 
 
 } }  // namespace assembler::arm
 
 #endif  // !defined(__arm__)