[PATCH] Allow casts of mixed-size same-arity vectors

[Hal Finkel]

----- Original Message -----
> On Sep 11, 2013, at 3:29 PM, Hal Finkel < hfinkel at anl.gov > wrote:
> 
> 
> 
> 
> 
> ----- Original Message -----
> 
> 
> ----- Original Message -----
> 
> 
> Hal —
> 
> Am I understanding this correctly:
> 
> vector4float x;
> vector4int16 y = (vector4int16)x; // this is a conversion
> vector4int32 z = (vector4int32)x; // this is a bitcast
> 
> This seems confusing in the extreme.
> 
> On the other hand, I don't really like the implied int-to-float
> bitcast semantics. Maybe it would be better to just add a warning
> for this case. What do you think?
> 
> bitcast semantics for vector casts are an essential tool for SIMD
> programming. Essentially all warnings generated would be false
> positives.

Do you specifically mean in OpenCL, or generally? (I've worked on SIMD special function implementations, so I understand the utility).

 -Hal

> 
> 
> – Steve

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory