MIPS: Add rotate-right instruction to hydrogen and use it instead of bitwise operations of the form…

src/mips/lithium-codegen-mips.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 1122 matching lines @@
   // Both 'left' and 'right' are "used at start" (see LCodeGen::DoShift), so
   // result may alias either of them.
   LOperand* right_op = instr->right();
   Register left = ToRegister(instr->left());
   Register result = ToRegister(instr->result());
 
   if (right_op->IsRegister()) {
     // No need to mask the right operand on MIPS, it is built into the variable
     // shift instructions.
     switch (instr->op()) {
+      case Token::ROR:
+        __ Ror(result, left, Operand(ToRegister(right_op)));
+        break;
       case Token::SAR:
         __ srav(result, left, ToRegister(right_op));
         break;
       case Token::SHR:
         __ srlv(result, left, ToRegister(right_op));
         if (instr->can_deopt()) {
           DeoptimizeIf(lt, instr->environment(), result, Operand(zero_reg));
         }
         break;
       case Token::SHL:
         __ sllv(result, left, ToRegister(right_op));
         break;
       default:
         UNREACHABLE();
         break;
     }
   } else {
     // Mask the right_op operand.
     int value = ToInteger32(LConstantOperand::cast(right_op));
     uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
     switch (instr->op()) {
+      case Token::ROR:
+          if (shift_count != 0) {
+          __ Ror(result, left, Operand(shift_count));
+        } else {
+          __ Move(result, left);
+        }
+        break;
       case Token::SAR:
         if (shift_count != 0) {
           __ sra(result, left, shift_count);
         } else {
           __ Move(result, left);
         }
         break;
       case Token::SHR:
         if (shift_count != 0) {
           __ srl(result, left, shift_count);
@@ skipping 4286 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal