Subzero. x8664. Resurrects the Target.

src/IceAssemblerX86Base.h

Index: src/IceAssemblerX86Base.h
diff --git a/src/IceAssemblerX86Base.h b/src/IceAssemblerX86Base.h
index b064365c262a90f9499cb10ac7be4a218b193aa5..49c8ea02e5fa5d606c2275289f7b54fa64d572a0 100644
--- a/src/IceAssemblerX86Base.h
+++ b/src/IceAssemblerX86Base.h
@@ -918,6 +918,16 @@ private:
 
   Label *getOrCreateLabel(SizeT Number, LabelVector &Labels);
 
+  template <typename T = Traits>

[Jim Stichnoth, 2015/12/20 19:27:37]

Could you do something like this instead?

void emitAddrSizeOverridePrefix() {
  if (Traits::Is64Bit) {
    static constexpr uint8_t AddrSizeOverridePrefix = 0x67;
    emitUint8(AddrSizeOverridePrefix);
  }
}

[John, 2015/12/21 13:41:31]

Done.

+  typename std::enable_if<T::Is64Bit, void>::type emitAddrSizeOverridePrefix() {
+    static constexpr uint8_t AddrSizeOverridePrefix = 0x67;
+    emitUint8(AddrSizeOverridePrefix);
+  }
+
+  template <typename T = Traits>
+  typename std::enable_if<!T::Is64Bit, void>::type
+  emitAddrSizeOverridePrefix() {}
+
   // The arith_int() methods factor out the commonality between the encodings
   // of add(), Or(), adc(), sbb(), And(), sub(), Xor(), and cmp(). The Tag
   // parameter is statically asserted to be less than 8.
@@ -965,8 +975,13 @@ private:
         std::is_same<typename std::decay<RegType>::type,
                      typename Traits::GPRRegister>::value;
 
+    // At this point in the assembler, we have encoded regs, so it is not
+    // possible to distinguish between the the "new" low byte registers

[Jim Stichnoth, 2015/12/20 19:27:37]

the the

[John, 2015/12/21 13:41:31]

Done.

+    // introduced in x86-64 and the legacy [abcd]h registers. Because x86,
+    // we may still see ah (div) in the assembler, so we whitelist it here.
+    static uint32_t Encoded_ah = 0x04;

[Jim Stichnoth, 2015/12/20 19:27:37]

constexpr

[John, 2015/12/21 13:41:31]

Done.

     return IsGPR && (Reg & 0x04) != 0 && (Reg & 0x08) == 0 &&
-           isByteSizedType(Ty);
+           isByteSizedType(Ty) && (Reg != Encoded_ah);

[Jim Stichnoth, 2015/12/20 19:27:37]

Could you use something like Traits::RegisterSet::Encoded_ah instead?

[John, 2015/12/21 13:41:31]

Sure. I still needed the local Encoded_ah (which I renamed to Encoded_Reg_ah)
because Traits::RegisterSet::Encoded_Reg_ah's type might be different than
RegType.

   }
 
   // assembleAndEmitRex is used for determining which (if any) rex prefix