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?