Crankshaft: Recognize (i >>> 0) === i for integer32 inputs and replace

src/ia32/lithium-codegen-ia32.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 1674 matching lines @@
         break;
       default:
         UNREACHABLE();
         break;
     }
   } else {
     int value = ToInteger32(LConstantOperand::cast(right));
     uint8_t shift_count = static_cast<uint8_t>(value & 0x1F);
     switch (instr->op()) {
       case Token::ROR:
-        if (shift_count == 0 && instr->can_deopt()) {
+        if (shift_count != 0) {
+          __ ror(ToRegister(left), shift_count);
+        } else if (instr->can_deopt()) {
           __ test(ToRegister(left), Immediate(0x80000000));
           DeoptimizeIf(not_zero, instr->environment());
-        } else {
-          __ ror(ToRegister(left), shift_count);
         }
         break;
       case Token::SAR:
         if (shift_count != 0) {
           __ sar(ToRegister(left), shift_count);
         }
         break;
       case Token::SHR:
-        if (shift_count == 0 && instr->can_deopt()) {
+        if (shift_count != 0) {
+          __ shr(ToRegister(left), shift_count);
+        } else if (instr->can_deopt()) {
           __ test(ToRegister(left), Immediate(0x80000000));
           DeoptimizeIf(not_zero, instr->environment());
-        } else {
-          __ shr(ToRegister(left), shift_count);
         }
         break;
       case Token::SHL:
         if (shift_count != 0) {
           __ shl(ToRegister(left), shift_count);
         }
         break;
       default:
         UNREACHABLE();
         break;
@@ skipping 4853 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32