[LLVMdev] Misunderstanding vector

[Chris Lattner]

On Sep 21, 2008, at 11:45 AM, Jonathan S. Shapiro wrote:

> I was re-reading the specification for extractelement and friends,  
> and I
> notice that the index is restricted to i32. Since vectors might  
> clearly
> have a larger number of elements on 64-bit platforms, I wonder if I am
> misunderstanding the intended use of these instructions.
>
> Is this indeed intended for vector and structure access in general, or
> is intended to support (only) more specialized SIMD usage?

They are intended for SIMD usage.  You will get very poor performance  
if you try to use extremely large vectors with LLVM.  Use arrays  
instead.

-Chris