python3kgae wrote:
> > Could you explain more about can't put any vectors or matrices into the
> > cbuffer structure type?
>
> Consider this example (regardless of packoffset):
>
> ```hlsl
> cbuffer {
> float F;
> float2 V;
> }
> ```
>
> The layout for this is basically:
>
> ```c
> struct {
> float F;
> float Vx; // v.x
> float Vy; // v.y
> };
> ```
>
> These elements are all packed.
>
> If you translate this to an IR struct you get something like:
>
> ```llvm
> type { float, <2 x float>}
> ```
>
> The data layout will insert 4-bytes of padding between the float and the
> vector because the vector needs to be properly aligned.
This PR will not change this.
The padding will only be added when required.
```hlsl
cbuffer {
float F;
float2 V;
}
```
will still got
```llvm
type { float, <2 x float>}
```
But
```hlsl
cbuffer {
float3 F;
float2 V;
}
```
will got padding, because it crossed 4dword.
```llvm
type { <3 x float>, [4 x i8], <2 x float>}
```
https://github.com/llvm/llvm-project/pull/91999
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