Re: [PATCH 0/3] MR487: vkd3d-shader/hlsl: Fix infinite loops when applying copy-prop to swizzles, version 3.

[Zebediah Figura (＠zfigura)]

Zebediah Figura (@zfigura) commented about libs/vkd3d-shader/hlsl_codegen.c:
> for (i = 0; i < 4; ++i)
>      {
>          if (writemask & (1u << i))
> -            var_def->values[comp + i].state = VALUE_STATE_DYNAMICALLY_WRITTEN;
> +        {
> +            struct copy_propagation_trace *trace = &var_def->traces[comp + i];
> +
> +            /* Don't add an invalidate record if it is already invalidated. */
> +            if (trace->record_count && trace->records[trace->record_count - 1].timestamp == time)
> +            {
> +                assert(!trace->records[trace->record_count - 1].statically_written);
> +                continue;
> +            }

Having this as an optimization is fine, if perhaps unnecessary, but why compare the timestamp here? Why would that cause problems?

-- 
https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/487#note_53362