X64: Add an SHL optimization, fix a floating-point bug, fix xchg rax,r8 and p...

src/x64/disasm-x64.cc

 // Copyright 2009 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 87 matching lines @@
   { 0x8A, BYTE_REG_OPER_OP_ORDER, "mov" },
   { 0x8B, REG_OPER_OP_ORDER,      "mov" },
   { 0x8D, REG_OPER_OP_ORDER,      "lea" },
   { -1, UNSET_OP_ORDER, "" }
 };
 
 
 static ByteMnemonic zero_operands_instr[] = {
   { 0xC3, UNSET_OP_ORDER, "ret" },
   { 0xC9, UNSET_OP_ORDER, "leave" },
-  { 0x90, UNSET_OP_ORDER, "nop" },

[Erik Corry, 2009/08/12 20:03:37]

Was this deliberate?

[William Hesse, 2009/08/13 07:59:36]

Yes.  This instruction is handled by code, because one 64-bit case of it is no
longer NOP, but xchg rax, r8.

   { 0xF4, UNSET_OP_ORDER, "hlt" },
   { 0xCC, UNSET_OP_ORDER, "int3" },
   { 0x60, UNSET_OP_ORDER, "pushad" },
   { 0x61, UNSET_OP_ORDER, "popad" },
   { 0x9C, UNSET_OP_ORDER, "pushfd" },
   { 0x9D, UNSET_OP_ORDER, "popfd" },
   { 0x9E, UNSET_OP_ORDER, "sahf" },
   { 0x99, UNSET_OP_ORDER, "cdq" },
   { 0x9B, UNSET_OP_ORDER, "fwait" },
   { -1, UNSET_OP_ORDER, "" }
@@ skipping 1299 matching lines @@
             value = *reinterpret_cast<uint32_t*>(data + 1);
             data += 5;
             break;
           case QUADWORD_SIZE:
             value = *reinterpret_cast<int32_t*>(data + 1);
             data += 5;
             break;
           default:
             UNREACHABLE();
         }
-        AppendToBuffer("test%c rax,0x%"V8_PTR_PREFIX"ux",
+        AppendToBuffer("test%c rax,0x%"V8_PTR_PREFIX"x",
                        operand_size_code(),
                        value);
         break;
       }
       case 0xD1:  // fall through
       case 0xD3:  // fall through
       case 0xC1:
         data += ShiftInstruction(data);
         break;
       case 0xD0:  // fall through
@@ skipping 144 matching lines @@
       fprintf(f, "%02x", *bp);
     }
     for (int i = 6 - (pc - prev_pc); i >= 0; i--) {
       fprintf(f, "  ");
     }
     fprintf(f, "  %s\n", buffer.start());
   }
 }
 
 }  // namespace disasm