[Mesa-dev] [PATCH] intel: Fix 3DSTATE_CONSTANT buffer decoding.

[Kenneth Graunke]

On Wednesday, May 2, 2018 9:50:33 AM PDT Lionel Landwerlin wrote:
> On 02/05/18 17:45, Kenneth Graunke wrote:
> > First, this was iterating over the 3DSTATE_CONSTANT_* instruction
> > but trying to process fields of the 3DSTATE_CONSTANT_BODY substructure.
> >
> > Secondly, the fields have been called Buffer[0] and Read Length[0],
> > for a while now, and we were not handling the subscripts correctly.
> > ---
> >   src/intel/common/gen_batch_decoder.c | 40 +++++++++++++++++-----------
> >   1 file changed, 25 insertions(+), 15 deletions(-)
> >
> > diff --git a/src/intel/common/gen_batch_decoder.c b/src/intel/common/gen_batch_decoder.c
> > index dd78e07827e..c059b194974 100644
> > --- a/src/intel/common/gen_batch_decoder.c
> > +++ b/src/intel/common/gen_batch_decoder.c
> > @@ -543,31 +543,41 @@ static void
> >   decode_3dstate_constant(struct gen_batch_decode_ctx *ctx, const uint32_t *p)
> >   {
> >      struct gen_group *inst = gen_spec_find_instruction(ctx->spec, p);
> > +   struct gen_group *body =
> > +      gen_spec_find_struct(ctx->spec, "3DSTATE_CONSTANT_BODY");
> >   
> >      uint32_t read_length[4];
> >      struct gen_batch_decode_bo buffer[4];
> >      memset(buffer, 0, sizeof(buffer));
> >   
> > -   int rlidx = 0, bidx = 0;
> > +   struct gen_field_iterator outer;
> > +   gen_field_iterator_init(&outer, inst, p, 0, false);
> > +   while (gen_field_iterator_next(&outer)) {
> > +      if (outer.struct_desc != body)
> > +         continue;
> >   
> > -   struct gen_field_iterator iter;
> > -   gen_field_iterator_init(&iter, inst, p, 0, false);
> > -   while (gen_field_iterator_next(&iter)) {
> > -      if (strcmp(iter.name, "Read Length") == 0) {
> > -         read_length[rlidx++] = iter.raw_value;
> > -      } else if (strcmp(iter.name, "Buffer") == 0) {
> > -         buffer[bidx++] = ctx_get_bo(ctx, iter.raw_value);
> > +      struct gen_field_iterator iter;
> > +      gen_field_iterator_init(&iter, body, &outer.p[outer.start_bit / 32],
> > +                              0, false);
> > +
> > +      while (gen_field_iterator_next(&iter)) {
> > +         int idx;
> > +         if (sscanf(iter.name, "Read Length[%d]", &idx) == 1) {
> > +            read_length[idx] = iter.raw_value;
> > +         } else if (sscanf(iter.name, "Buffer[%d]", &idx) == 1) {
> > +            buffer[idx] = ctx_get_bo(ctx, iter.raw_value);
> > +         }
> >         }
> > -   }
> >   
> > -   for (int i = 0; i < 4; i++) {
> > -      if (read_length[i] == 0 || buffer[i].map == NULL)
> > -         continue;
> 
> I'm kind of thinking we could get rid of the read_length[4] buffer[4] 
> arrays and just put that into the outer loop.
> What do you think?
> 
> Either way this is :
> 
> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

FTR, I was confused by this suggestion so I talked to Lionel on IRC, he
was thinking was that we could print them out as we fetch the buffers...

But the iteration order is

   - Read Length[0]
   - Read Length[1]
   - Read Length[2]
   - Read Length[3]
   - Buffer[0]
   - Buffer[1]
   - Buffer[2]
   - Buffer[3]

So we'd at least need the read_length array, still.  We decided to
just leave it as it is.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part.
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20180502/9464bd2e/attachment.sig>