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

src/x64/disasm-x64.cc

Index: src/x64/disasm-x64.cc
===================================================================
--- src/x64/disasm-x64.cc	(revision 2669)
+++ src/x64/disasm-x64.cc	(working copy)
@@ -105,7 +105,6 @@
 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" },
@@ -1425,7 +1424,7 @@
           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;