[cfe-dev] Adding new data type

Olaf Krzikalla Olaf.Krzikalla at tu-dresden.de
Fri Apr 30 00:48:38 PDT 2010


kalyan ponnala schrieb:
> Thanks for the replies. I am trying to add support to a new 
> architecture called Line Associative Registers. It has vector 
> registers in it. I would like to add a vector data type such as int[4] 
> which could access a register with a width of 4 integers in it (max). 
> Since it has to be mentioned in the source as
> int[4] = {1, 2, 3, 4}
> I am not sure about how to proceed. This form looks like an array with 
> 4 elements but I want it to be a datatype.
I had a similiar problem when I wanted to add SSE data types. First I 
tried adding a new type to the type system too, but this was clearly the 
wrong way. I recommend adding just a typedef, which then can act like a 
built-in type. See my source code below (vecType should be int, float, 
double or the like).

QualType StmtCollector::getSimdType(const QualType& vecType, unsigned 
  // Ctx is a ASTContext
  BuiltinType *baseType = 
  assert(baseType != 0 && "getVectorType(): Expecting a built-in type");

  TypedefDecl*& simdTypedef = 
m_SimdTypedefDecl[tSimdTypedefDeclKey(baseType, NumElts)];
  if (simdTypedef == 0)
    const char* pTypeName;
    if (baseType == Ctx.FloatTy.getTypePtr() && NumElts == 4)
      pTypeName = "__m128";
    else if (baseType == Ctx.DoubleTy.getTypePtr() && NumElts == 2)
      pTypeName = "__m128d";
      assert(0 && "simd type unsupported"); 

    simdTypedef = TypedefDecl::Create(Ctx,
      Ctx.CreateTypeSourceInfo(Ctx.getVectorType(vecType, NumElts, 
false, false)));

  return Ctx.getTypedefType(simdTypedef);

Olaf Krzikalla

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