[PATCH vkd3d v3 2/6] vkd3d-shader: Allocate temporary registers for variables.

[Zebediah Figura (she/her)]

On 4/9/21 1:31 PM, Matteo Bruni wrote:
> On Fri, Apr 9, 2021 at 6:38 AM Zebediah Figura <zfigura at codeweavers.com> wrote:
>>
>> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
>> ---
>>  libs/vkd3d-shader/hlsl.c         |   4 +-
>>  libs/vkd3d-shader/hlsl.h         |   9 ++
>>  libs/vkd3d-shader/hlsl_codegen.c | 187 +++++++++++++++++++++++++++++++
>>  3 files changed, 198 insertions(+), 2 deletions(-)
> 
> I keep finding nitpicks one at a time...
> 
>> +static struct hlsl_reg allocate_range(struct liveness *liveness,
>> +        unsigned int first_write, unsigned int last_read, unsigned int reg_count)
>> +{
>> +    const unsigned int component_count = reg_count * 4;
>> +    unsigned int i, component_idx;
>> +    struct hlsl_reg ret = {0};
>> +
>> +    for (component_idx = 0; component_idx < liveness->size; component_idx += 4)
>> +    {
>> +        if (is_range_available(liveness, first_write, component_idx,
>> +                min(component_count, liveness->size - component_idx)))
>> +            break;
>> +    }
>> +    if (!resize_liveness(liveness, component_idx + component_count))
>> +        return ret;
>> +
>> +    for (i = 0; i < component_count; ++i)
>> +        liveness->regs[component_idx + i].last_read = last_read;
>> +    ret.id = component_idx / 4;
>> +    ret.allocated = true;
>> +    return ret;
>> +}
> 
> This is slightly awkward in that it sets writemask to 0. That is
> arguably correct (more than 1 full register is allocated, in which
> case there is no partial register allocation) but we have to be
> careful with the users of struct hlsl_reg. At the moment there is not
> much of that, just the TRACE() in allocate_variable_temp_register()
> that prints something like "r0.". Speaking of which...
> 

I think I designed it this way on purpose. In a sense it allows us to be
more careful; I believe I've caught a few errors this way when a
register had an empty writemask.

I could have sworn I had fixed those traces, but oh well, I'll add an
extra patch for those...

>> +
>> +static const char *debug_register(char class, struct hlsl_reg reg, const struct hlsl_type *type)
>> +{
>> +    if (type->reg_size > 4)
>> +        return vkd3d_dbg_sprintf("%c%u-%c%u", class, reg.id, class,
>> +                reg.id + type->reg_size - 1);
>> +    return vkd3d_dbg_sprintf("%c%u%s", class, reg.id, debug_hlsl_writemask(reg.writemask));
>> +}
>> +
>> +static void allocate_variable_temp_register(struct hlsl_ir_var *var, struct liveness *liveness)
>> +{
>> +    if (var->is_input_varying || var->is_output_varying || var->is_uniform)
>> +        return;
>> +
>> +    if (!var->reg.allocated && var->last_read)
>> +    {
>> +        if (var->data_type->reg_size > 1)
>> +            var->reg = allocate_range(liveness, var->first_write,
>> +                    var->last_read, var->data_type->reg_size);
>> +        else
>> +            var->reg = allocate_register(liveness, var->first_write,
>> +                    var->last_read, var->data_type->dimx);
>> +        TRACE("Allocated %s to %s (liveness %u-%u).\n", var->name,
>> +                debug_register('r', var->reg, var->data_type), var->first_write, var->last_read);
> 
> This doesn't tell the whole story for register ranges, maybe we could
> print more info in that case.
> 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 495 bytes
Desc: OpenPGP digital signature
URL: <http://www.winehq.org/pipermail/wine-devel/attachments/20210413/14501699/attachment.sig>