Add optimized version of memcpy on ia32.

src/ia32/disasm-ia32.cc

Index: src/ia32/disasm-ia32.cc
diff --git a/src/ia32/disasm-ia32.cc b/src/ia32/disasm-ia32.cc
index 58c22afcd376ea10e47b5222b557c43e3372e350..e1b5a88b51506aae1d70b0924124bf99dbfc741d 100644
--- a/src/ia32/disasm-ia32.cc
+++ b/src/ia32/disasm-ia32.cc
@@ -817,6 +817,7 @@ int DisassemblerIA32::RegisterFPUInstruction(int escape_opcode,
 // Returns NULL if the instruction is not handled here.
 static const char* F0Mnem(byte f0byte) {
   switch (f0byte) {
+    case 0x18: return "prefetch";

[Erik Corry, 2010/06/04 07:07:40]

What about the other instructions?  Can they already be disassembled?

[Lasse Reichstein, 2010/06/04 11:52:13]

movntdq[a] can't, but they aren't used yet either.
Still, someone might start using them, so they should be disassemblable. 

     case 0xA2: return "cpuid";
     case 0x31: return "rdtsc";
     case 0xBE: return "movsx_b";
@@ -942,7 +943,13 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
       case 0x0F:
         { byte f0byte = *(data+1);
           const char* f0mnem = F0Mnem(f0byte);
-          if (f0byte == 0xA2 || f0byte == 0x31) {
+          if (f0byte == 0x18) {
+            int mod, regop, rm;
+            get_modrm(*data, &mod, &regop, &rm);
+            const char* suffix[] = {"nta", "1", "2", "3"};
+            AppendToBuffer("%s%s ", f0mnem, suffix[regop & 0x03]);
+            data += PrintRightOperand(data);
+          } else if (f0byte == 0xA2 || f0byte == 0x31) {
             AppendToBuffer("%s", f0mnem);
             data += 2;
           } else if ((f0byte & 0xF0) == 0x80) {