Inline memove for small constant sizes and refactor memcpy and memset.

src/IceAssemblerX86BaseImpl.h

 //===- subzero/src/IceAssemblerX86BaseImpl.h - base x86 assembler -*- C++ -*-=//
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        The Subzero Code Generator
@@ skipping 3081 matching lines @@
   emitUint8(0x0F);
   if (isByteSizedArithType(Ty))
     emitUint8(0xC0);
   else
     emitUint8(0xC1);
   emitOperand(gprEncoding(reg), addr);
 }
 
 template <class Machine>
 void AssemblerX86Base<Machine>::xchg(Type Ty,
+                                     typename Traits::GPRRegister reg0,
+                                     typename Traits::GPRRegister reg1) {
+  AssemblerBuffer::EnsureCapacity ensured(&Buffer);
+  if (Ty == IceType_i16)
+    emitOperandSizeOverride();
+  // Use short form if either register is EAX.
+  if (reg0 == Traits::Encoded_Reg_Accumulator) {
+    emitRexB(Ty, reg1);
+    emitUint8(0x90 + reg1);

[John, 2015/08/12 17:44:57]

emitUint8(0x90 + gprEncoding(reg1));

[ascull, 2015/08/17 22:18:52]

Done.

+  } else if (reg1 == Traits::Encoded_Reg_Accumulator) {
+    emitRexB(Ty, reg0);
+    emitUint8(0x90 + reg0);

[John, 2015/08/12 17:44:57]

emitUint8(0x90 + gprEncoding(reg0));

[ascull, 2015/08/17 22:18:52]

Done. Incl also only does `+ reg` is that a problem?

+  } else {
+    emitRexRB(Ty, reg0, reg1);
+    if (isByteSizedArithType(Ty))
+      emitUint8(0x86);
+    else
+      emitUint8(0x87);
+    emitRegisterOperand(gprEncoding(reg0), gprEncoding(reg1));
+  }
+}
+
+template <class Machine>
+void AssemblerX86Base<Machine>::xchg(Type Ty,
                                      const typename Traits::Address &addr,
                                      typename Traits::GPRRegister reg) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   if (Ty == IceType_i16)
     emitOperandSizeOverride();
   emitRex(Ty, addr, reg);
   if (isByteSizedArithType(Ty))
     emitUint8(0x86);
   else
     emitUint8(0x87);
@@ skipping 207 matching lines @@
   (void)shifter;
   if (Ty == IceType_i16)
     emitOperandSizeOverride();
   emitRexB(Ty, operand.rm());
   emitUint8(isByteSizedArithType(Ty) ? 0xD2 : 0xD3);
   emitOperand(rm, operand);
 }
 
 } // end of namespace X86Internal
 } // end of namespace Ice