Harmony: optimize Math.clz32.

src/x64/disasm-x64.cc

 // Copyright 2011 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 1308 matching lines @@
     // SHLD, SHRD (double-precision shift), BTS (bit set).
     AppendToBuffer("%s ", mnemonic);
     int mod, regop, rm;
     get_modrm(*current, &mod, &regop, &rm);
     current += PrintRightOperand(current);
     if (opcode == 0xAB) {
       AppendToBuffer(",%s", NameOfCPURegister(regop));
     } else {
       AppendToBuffer(",%s,cl", NameOfCPURegister(regop));
     }
+  } else if (opcode == 0xBD) {
+    AppendToBuffer("%s%c ", mnemonic, operand_size_code());
+    int mod, regop, rm;
+    get_modrm(*current, &mod, &regop, &rm);
+    AppendToBuffer("%s,", NameOfCPURegister(regop));
+    current += PrintRightOperand(current);
   } else {
     UnimplementedInstruction();
   }
   return static_cast<int>(current - data);
 }
 
 
 // Mnemonics for two-byte opcode instructions starting with 0x0F.
 // The argument is the second byte of the two-byte opcode.
 // Returns NULL if the instruction is not handled here.
@@ skipping 22 matching lines @@
     case 0xAB:
       return "bts";
     case 0xAD:
       return "shrd";
     case 0xAF:
       return "imul";
     case 0xB6:
       return "movzxb";
     case 0xB7:
       return "movzxw";
+    case 0xBD:
+      return "bsr";
     case 0xBE:
       return "movsxb";
     case 0xBF:
       return "movsxw";
     default:
       return NULL;
   }
 }
 
 
@@ skipping 538 matching lines @@
     for (int i = 6 - static_cast<int>(pc - prev_pc); i >= 0; i--) {
       fprintf(f, "  ");
     }
     fprintf(f, "  %s\n", buffer.start());
   }
 }
 
 }  // namespace disasm
 
 #endif  // V8_TARGET_ARCH_X64