[cfe-commits] r45062 - in /cfe/trunk/CodeGen: CGBuiltin.cpp CGExprScalar.cpp CodeGenFunction.h

[Chris Lattner]

On Dec 15, 2007, at 1:23 PM, Anders Carlsson wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=45062&view=rev
> Log:
> We now support all MMX intrinsics. SSE intrinsics are next.

Hi Anders,

> +++ cfe/trunk/CodeGen/CGExprScalar.cpp Sat Dec 15 15:23:30 2007
> @@ -1099,3 +1099,37 @@
>    return Builder.CreateShuffleVector(V1, V2, Mask, Name);
>  }
>
> +llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals,
> +                                         unsigned NumVals)
> +{
> +  bool AllConstElements = true;
> +
> +  for (unsigned i = 0; i < NumVals; i++) {
> +    if (!isa<llvm::Constant>(Vals[i])) {
> +      AllConstElements = false;
> +      break;
> +    }
> +  }
> +
> +  assert(!(NumVals & NumVals - 1) &&
> +         "Number of elements must be power of two!");

Please don't abort on non-power-2 vectors.  Nothing in this code  
depends on it, and we'd like to support them in time.

> +
> +  if (AllConstElements) {
> +    llvm::SmallVector<llvm::Constant*, 16> Constants;
> +
> +    for (unsigned i = 0, e = NumVals; i != e; ++i)
> +      Constants.push_back(cast<llvm::Constant>(Vals[i]));
> +
> +    return llvm::ConstantVector::get(&Constants[0], Constants.size 
> ());
> +  }

I don't think you need any of this code, doesn't the folding builder  
do this already?  (looks)  ah, the issue is that the folding builder  
doesn't fold insertelement instructions.  Can you add this to the  
LLVMFoldingBuilder instead of this code?

> +
> +  llvm::Value *Vec
> +  = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType 
> (), NumVals));
> +
> +  for (unsigned i = 0, e = NumVals ; i != e; ++i) {
> +    llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty,  
> i);
> +    Vec = Builder.CreateInsertElement(Vec, Vals[i], Idx, "tmp");
> +  }
> +
> +  return Vec;

This looks great :)

-Chris