[Mesa-dev] [PATCH v4 (part2) 29/59] nir: Implement __intrinsic_store_ssbo

[Connor Abbott]

On Thu, Aug 6, 2015 at 12:30 AM, Iago Toral <itoral at igalia.com> wrote:
> On Wed, 2015-08-05 at 12:17 -0700, Connor Abbott wrote:
>> On Wed, Aug 5, 2015 at 1:30 AM, Iago Toral Quiroga <itoral at igalia.com> wrote:
>> > ---
>> >  src/glsl/nir/glsl_to_nir.cpp  | 36 ++++++++++++++++++++++++++++++++++++
>> >  src/glsl/nir/nir_intrinsics.h | 12 ++++++------
>> >  2 files changed, 42 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/src/glsl/nir/glsl_to_nir.cpp b/src/glsl/nir/glsl_to_nir.cpp
>> > index 642affd..cbec2df 100644
>> > --- a/src/glsl/nir/glsl_to_nir.cpp
>> > +++ b/src/glsl/nir/glsl_to_nir.cpp
>> > @@ -641,6 +641,8 @@ nir_visitor::visit(ir_call *ir)
>> >           op = nir_intrinsic_image_atomic_comp_swap;
>> >        } else if (strcmp(ir->callee_name(), "__intrinsic_memory_barrier") == 0) {
>> >           op = nir_intrinsic_memory_barrier;
>> > +      } else if (strcmp(ir->callee_name(), "__intrinsic_store_ssbo") == 0) {
>> > +         op = nir_intrinsic_store_ssbo;
>> >        } else {
>> >           unreachable("not reached");
>> >        }
>> > @@ -730,6 +732,40 @@ nir_visitor::visit(ir_call *ir)
>> >        }
>> >        case nir_intrinsic_memory_barrier:
>> >           break;
>> > +      case nir_intrinsic_store_ssbo: {
>> > +         exec_node *param = ir->actual_parameters.get_head();
>> > +         ir_rvalue *block = ((ir_instruction *)param)->as_rvalue();
>> > +
>> > +         param = param->get_next();
>> > +         ir_rvalue *offset = ((ir_instruction *)param)->as_rvalue();
>> > +
>> > +         param = param->get_next();
>> > +         ir_rvalue *val = ((ir_instruction *)param)->as_rvalue();
>> > +
>> > +         param = param->get_next();
>> > +         ir_constant *write_mask = ((ir_instruction *)param)->as_constant();
>> > +         assert(write_mask);
>> > +
>> > +         /* Check if we need the indirect version */
>> > +         ir_constant *const_offset = offset->as_constant();
>> > +         if (!const_offset) {
>> > +            op = nir_intrinsic_store_ssbo_indirect;
>> > +            ralloc_free(instr);
>> > +            instr = nir_intrinsic_instr_create(shader, op);
>> > +            instr->src[2] = evaluate_rvalue(offset);
>> > +            instr->const_index[0] = 0;
>> > +         } else {
>> > +            instr->const_index[0] = const_offset->value.u[0];
>> > +         }
>> > +
>> > +         instr->const_index[1] = write_mask->value.u[0];
>> > +
>> > +         instr->src[0] = evaluate_rvalue(val);
>> > +         instr->num_components = val->type->vector_elements;
>> > +
>> > +         instr->src[1] = evaluate_rvalue(block);
>> > +         break;
>> > +      }
>> >        default:
>> >           unreachable("not reached");
>> >        }
>> > diff --git a/src/glsl/nir/nir_intrinsics.h b/src/glsl/nir/nir_intrinsics.h
>> > index f264f55..83eeecd 100644
>> > --- a/src/glsl/nir/nir_intrinsics.h
>> > +++ b/src/glsl/nir/nir_intrinsics.h
>> > @@ -176,12 +176,12 @@ LOAD(input, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
>> >   * offset.
>> >   */
>> >
>> > -#define STORE(name, num_indices, flags) \
>> > -   INTRINSIC(store_##name, 1, ARR(0), false, 0, 0, num_indices, flags) \
>> > -   INTRINSIC(store_##name##_indirect, 2, ARR(0, 1), false, 0, 0, \
>> > +#define STORE(name, extra_srcs, num_indices, flags) \
>> > +   INTRINSIC(store_##name, extra_srcs, ARR(0, 1), false, 0, 0, num_indices, flags) \
>> > +   INTRINSIC(store_##name##_indirect, extra_srcs + 1, ARR(0, 1, 1), false, 0, 0, \
>> >               num_indices, flags) \
>> >
>> > -STORE(output, 1, 0)
>> > -/* STORE(ssbo, 2, 0) */
>> > +STORE(output, 1, 2, 0)
>> > +STORE(ssbo, 2, 2, 0)
>>
>> I don't think outputs should have any extra sources, since they only
>> take a constant index, plus possibly an indirect source that's already
>> covered by the STORE macro. SSBO stores should only have one extra
>> source for the block index. Also, we should update the comment above
>> to explain this similarly to the paragraph above the loads.
>
> SSBO stores need an extra source for the block index and an extra index
> for a writemask.
>
> I'll leave the STORE() macro as it was and just define SSBO stores using
> INTRINSIC() directly then.

Ok, I see. I don't think you need a separate INTRINSIC(), but right
now calling the parameter you added "extra_srcs" is confusing, since
you're counting the value to be stored, which isn't really "extra" at
all -- every store should have one! How about instead, we change the
STORE macro to have:

- An "extra_srcs" parameter that contains only sources that are
actually extra, not counting the value to be stored -- direct stores
have "extra_srcs + 1" sources, and indirect sources have "extra_srcs +
2" sources
- An "extra_indices" parameter that contains the extra indices, and
replace "num_indices" with "extra_indices + 1"

Then normal stores have both set to 0, and SSBO stores have both set
to 1 to indicate the extra block index and writemask.

>
>> >
>> > -LAST_INTRINSIC(store_output_indirect)
>> > +LAST_INTRINSIC(store_ssbo_indirect)
>> > --
>> > 1.9.1
>> >
>> > _______________________________________________
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>> > mesa-dev at lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>
>