Fwd: Re: [PATCH 2/5] d3dx9_36: Implemented ID3DXConstantTable_SetIntArray and ID3DXConstantTable_SetInt (Try 5)

[Rico Schüller]

Forwarding to the list.

Am 28.03.2011 20:47, schrieb David Laight:
> > Ints and floats are represented differently and so, if we want to put
> >  an integer array into floating point registers, we need to have casts.
> >  If you were to simply call SetFloatArray, you would get nonsense
> >  values in the floating point registers.
>
> Even using casts will fall foul of the C aliasing rules - which
>  mean that the compiler can assume that a read of type will not be
>  modified by a write to a different type so can be reorderd (unless
>  one of the types is 'char').
>
> Not only that, but there are systems that will fault is an invalid
>  FP bit pattern is loaded into an FP register.
>
> David

My example wasn't very well chosen. So conversation (casts) between the
different types is necessary. It was meant the way to reuse some of the
code. Because I think ID3DXConstantTable_SetIntArray and
ID3DXConstantTable_SetFloatArray could share a lot of code. This will
probably be the same for ID3DXConstantTable_SetBoolArray.

Cheers
Rico