[PATCH vkd3d 1/6] vkd3d-shader/hlsl: Write SM4 sample instructions.

[Giovanni Mascellani]

Signed-off-by: Giovanni Mascellani <gmascellani at codeweavers.com>
---
This patch looks fine, but it makes me wonder that where is probably 
something to fix in an earlier commit...

On 23/11/21 02:45, Zebediah Figura wrote:
> @@ -1238,6 +1248,34 @@ static void write_sm4_ld(struct hlsl_ctx *ctx, struct vkd3d_bytecode_buffer *buf
>       write_sm4_instruction(buffer, &instr);
>   }
>   
> +static void write_sm4_sample(struct hlsl_ctx *ctx, struct vkd3d_bytecode_buffer *buffer,
> +        const struct hlsl_type *resource_type, const struct hlsl_ir_node *dst,
> +        const struct hlsl_deref *resource, const struct hlsl_deref *sampler, const struct hlsl_ir_node *coords)
> +{
> +    struct sm4_instruction instr;
> +    unsigned int writemask;
> +
> +    memset(&instr, 0, sizeof(instr));
> +    instr.opcode = VKD3D_SM4_OP_SAMPLE;
> +
> +    sm4_register_from_node(&instr.dsts[0].reg, &instr.dsts[0].writemask, NULL, dst);
> +    instr.dst_count = 1;
> +
> +    sm4_register_from_node(&instr.srcs[0].reg, &writemask, &instr.srcs[0].swizzle_type, coords);
> +    instr.srcs[0].swizzle = hlsl_swizzle_from_writemask(writemask);
> +
> +    sm4_register_from_deref(ctx, &instr.srcs[1].reg, &writemask,
> +            &instr.srcs[1].swizzle_type, resource, resource_type);
> +    instr.srcs[1].swizzle = hlsl_map_swizzle(hlsl_swizzle_from_writemask(writemask), instr.dsts[0].writemask);

Here you pass the swizzle_type field to sm4_register_from_deref, as 
write_sm4_ld already does. However, it seems that 
sm4_register_from_deref currently ignores swizzle_type in its texture 
branch, so that's going to remain uninitialized (swizzle_type is also 
ignored in another branch of sm4_register_from_deref).

I guess the patch that introduced swizzle_type missed a few cases, I 
doubt there is a reason why textures should not have the swizzle_type 
field set, right?

Thanks, Giovanni.