Re: [PATCH v4 0/1] MR203: vkd3d-shader/hlsl: Fold constant integral abs().

[Francisco Casas (＠fcasas)]

Francisco Casas (@fcasas) commented about libs/vkd3d-shader/hlsl_constant_ops.c:
> - {
> -
>    switch (type)
> -
>    {
> -
>        case HLSL_TYPE_FLOAT:
> -
>        case HLSL_TYPE_HALF:
> -
>            dst->value.u[k].f = fabsf(src->value.u[k].f);
> -
>            break;
> -
> -
>        case HLSL_TYPE_DOUBLE:
> -
>            dst->value.u[k].d = fabs(src->value.u[k].d);
> -
>            break;
> -
> -
>        case HLSL_TYPE_INT:
> -
>            /* abs(INT_MIN) is undefined, leave this expression alone */
> -
>            if (src->value.u[k].i == INT_MIN)
> -
>                return false;

This won't get the absolute value of components that come after the component that is INT_MIN. 
Consider an int vector such as `(-1, INT_MIN, -1, -1)`; This would end up as `(1, INT_MIN, -1, -1)`.

I think it would be better to guard the assignment:
```c
            case HLSL_TYPE_INT:
                /* abs(INT_MIN) is undefined, leave this expression alone */
                if (src->value.u[k].i != INT_MIN)
                    dst->value.u[k].i = abs(src->value.u[k].i);
                break;
```