[Mesa-dev] [PATCH 6/6] gallivm: implement breakc and implicit primitive flushing

[Brian Paul]

On 03/26/2013 10:38 AM, Zack Rusin wrote:
> we were missing implementation of the breakc instruction and our
> TGSI semantics currently require an implicit endprim at the end
> of GS if none is present - this implements both.

Maybe I'm dense, but off-hand I don't see the relationship between 
endprim and breakc.  Can you elaborate?


>
> Signed-off-by: Zack Rusin<zackr at vmware.com>
> ---
>   src/gallium/auxiliary/gallivm/lp_bld_tgsi.h        |    6 ++++
>   src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c |    1 +
>   src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c    |   38 ++++++++++++++++++++
>   3 files changed, 45 insertions(+)
>
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
> index 4c6456e..4acc592 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi.h
> @@ -392,6 +392,12 @@ struct lp_build_tgsi_soa_context
>      LLVMValueRef emitted_prims_vec;
>      LLVMValueRef total_emitted_vertices_vec;
>      LLVMValueRef emitted_vertices_vec;
> +   /* if a shader doesn't have ENDPRIM instruction but it has
> +    * a number of EMIT instructions it means the END instruction
> +    * implicitly invokes ENDPRIM. handle this via a flag here
> +    * in the future maybe we can enforce TGSI to always have
> +    * an explicit ENDPRIM */
> +   boolean pending_end_primitive;
>
>      LLVMValueRef consts_ptr;
>      const LLVMValueRef *pos;
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
> index 41ddd99..55bb8e3 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_action.c
> @@ -867,6 +867,7 @@ lp_set_default_actions(struct lp_build_tgsi_context * bld_base)
>      bld_base->op_actions[TGSI_OPCODE_COS].fetch_args = scalar_unary_fetch_args;
>      bld_base->op_actions[TGSI_OPCODE_EX2].fetch_args = scalar_unary_fetch_args;
>      bld_base->op_actions[TGSI_OPCODE_IF].fetch_args = scalar_unary_fetch_args;
> +   bld_base->op_actions[TGSI_OPCODE_BREAKC].fetch_args = scalar_unary_fetch_args;
>      bld_base->op_actions[TGSI_OPCODE_KIL].fetch_args = kil_fetch_args;
>      bld_base->op_actions[TGSI_OPCODE_KILP].fetch_args = kilp_fetch_args;
>      bld_base->op_actions[TGSI_OPCODE_RCP].fetch_args = scalar_unary_fetch_args;
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
> index 95633ab..36e49ac 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_tgsi_soa.c
> @@ -213,6 +213,23 @@ static void lp_exec_break(struct lp_exec_mask *mask)
>      lp_exec_mask_update(mask);
>   }
>
> +
> +static void lp_exec_break_condition(struct lp_exec_mask *mask, LLVMValueRef cond)
> +{
> +   LLVMBuilderRef builder = mask->bld->gallivm->builder;
> +   LLVMValueRef exec_mask = LLVMBuildNot(builder,
> +                                         mask->exec_mask,
> +                                         "break");
> +
> +   exec_mask = LLVMBuildAnd(builder, exec_mask, cond, "");
> +
> +   mask->break_mask = LLVMBuildAnd(builder,
> +                                   mask->break_mask,
> +                                   exec_mask, "break_full");
> +
> +   lp_exec_mask_update(mask);
> +}
> +
>   static void lp_exec_continue(struct lp_exec_mask *mask)
>   {
>      LLVMBuilderRef builder = mask->bld->gallivm->builder;
> @@ -2190,6 +2207,7 @@ emit_vertex(
>            LLVMBuildAdd(builder, bld->emitted_vertices_vec, masked_ones, "");
>         bld->total_emitted_vertices_vec =
>            LLVMBuildAdd(builder, bld->total_emitted_vertices_vec, masked_ones, "");
> +      bld->pending_end_primitive = TRUE;
>      }
>   }
>
> @@ -2212,6 +2230,7 @@ end_primitive(
>         bld->emitted_prims_vec =
>            LLVMBuildAdd(builder, bld->emitted_prims_vec, masked_ones, "");
>         bld->emitted_vertices_vec = bld_base->uint_bld.zero;
> +      bld->pending_end_primitive = FALSE;
>      }
>   }
>
> @@ -2250,6 +2269,17 @@ brk_emit(
>   }
>
>   static void
> +breakc_emit(
> +   const struct lp_build_tgsi_action * action,
> +   struct lp_build_tgsi_context * bld_base,
> +   struct lp_build_emit_data * emit_data)
> +{
> +   struct lp_build_tgsi_soa_context * bld = lp_soa_context(bld_base);
> +
> +   lp_exec_break_condition(&bld->exec_mask, emit_data->args[0]);
> +}
> +
> +static void
>   if_emit(
>      const struct lp_build_tgsi_action * action,
>      struct lp_build_tgsi_context * bld_base,
> @@ -2504,6 +2534,12 @@ static void emit_epilogue(struct lp_build_tgsi_context * bld_base)
>      /* If we have indirect addressing in outputs we need to copy our alloca array
>       * to the outputs slots specified by the caller */
>      if (bld->gs_args) {
> +      /* flush the accumulated vertices as a primitive */
> +      if (bld->pending_end_primitive) {
> +         end_primitive(NULL, bld_base, NULL);
> +         bld->pending_end_primitive = FALSE;
> +      }
> +
>         bld->gs_args->gs_epilogue(&bld->bld_base,
>                                   bld->total_emitted_vertices_vec,
>                                   bld->emitted_prims_vec,
> @@ -2572,6 +2608,7 @@ lp_build_tgsi_soa(struct gallivm_state *gallivm,
>      bld.bld_base.op_actions[TGSI_OPCODE_BGNLOOP].emit = bgnloop_emit;
>      bld.bld_base.op_actions[TGSI_OPCODE_BGNSUB].emit = bgnsub_emit;
>      bld.bld_base.op_actions[TGSI_OPCODE_BRK].emit = brk_emit;
> +   bld.bld_base.op_actions[TGSI_OPCODE_BREAKC].emit = breakc_emit;
>      bld.bld_base.op_actions[TGSI_OPCODE_CAL].emit = cal_emit;
>      bld.bld_base.op_actions[TGSI_OPCODE_CONT].emit = cont_emit;
>      bld.bld_base.op_actions[TGSI_OPCODE_DDX].emit = ddx_emit;
> @@ -2607,6 +2644,7 @@ lp_build_tgsi_soa(struct gallivm_state *gallivm,
>         /* inputs are always indirect with gs */
>         bld.indirect_files |= (1<<  TGSI_FILE_INPUT);
>         bld.gs_args = gs_args;
> +      bld.pending_end_primitive = FALSE;
>         bld.bld_base.emit_fetch_funcs[TGSI_FILE_INPUT] = emit_fetch_gs_input;
>         bld.bld_base.op_actions[TGSI_OPCODE_EMIT].emit = emit_vertex;
>         bld.bld_base.op_actions[TGSI_OPCODE_ENDPRIM].emit = end_primitive;