[Mesa-dev] [PATCH 1/7] gallium: add CONSTBUF type to tgsi_file_type

Timothy Arceri tarceri at itsqueeze.com
Tue Aug 22 23:25:34 UTC 2017

On 23/08/17 09:08, Ilia Mirkin wrote:
> On Tue, Aug 22, 2017 at 6:55 PM, Timothy Arceri <tarceri at itsqueeze.com> wrote:
>> On 23/08/17 00:56, Ilia Mirkin wrote:
>>> On Tue, Aug 22, 2017 at 10:51 AM, Roland Scheidegger <sroland at vmware.com>
>>> wrote:
>>>> I am probably missing something here, but why do you need a new register
>>>> file? Since you couldn't use LOAD with TGSI_FILE_CONSTANT before, can't
>>>> you just allow LOAD with TGSI_FILE_CONSTANT and achieve the same thing?
>>>> Or do you need to know how it's going to be accessed in advance?
>>> With bindless, LOAD can take a CONST I believe [which contains the
>>> value of the bindless id]. I think it's nice to keep those concepts
>>> separate... having CONST sometimes mean the value and other times mean
>>> the address is a bit weird. This way CONSTBUF[0] is the address of the
>>> 0th constbuf.
>> Yeah. I think we also may need another type for bindless as I'm planning to
>> use TGSI_FILE_CONSTANT for regular uniforms. The plan is to use LOAD for
>> supporting packed uniforms rather than padding everything to vec4.
> Shouldn't be necessary... we can think of CONST (and TEMP and IMM) as
> "value" registers, and MEMORY/IMAGE/BUFFER/CONSTBUF as "address"
> registers. If LOAD receives a value, then it's a bindless image
> handle, otherwise it should work based on which of the address
> registers it receives.

But how do you tell the difference between a bindless image handle and a 
non-indirect uniform where the "value" is just the index of the uniform?

>    -ilia

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