radv/gfx10: export the PrimitiveID for ES stages (VS or TES)

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/vulkan/radv_nir_to_llvm.c b/src/amd/vulkan/radv_nir_to_llvm.c
index a5551203d290fd9da47abf3e123ec127da1b236c..339c9d93423932ed72375868d62e8319b6b60990 100644 (file)
--- a/src/amd/vulkan/radv_nir_to_llvm.c
+++ b/src/amd/vulkan/radv_nir_to_llvm.c
@@ -3321,9 +3321,27 @@ handle_ngg_outputs_post(struct radv_shader_context *ctx)
 
        /* TODO: streamout */
 
-       /* TODO: VS primitive ID */
-       if (ctx->options->key.vs_common_out.export_prim_id)
-               assert(0);
+       /* Copy Primitive IDs from GS threads to the LDS address corresponding
+        * to the ES thread of the provoking vertex.
+        */
+       if (ctx->stage == MESA_SHADER_VERTEX &&
+           ctx->options->key.vs_common_out.export_prim_id) {
+               /* TODO: streamout */
+
+               ac_build_ifcc(&ctx->ac, is_gs_thread, 5400);
+               /* Extract the PROVOKING_VTX_INDEX field. */
+               LLVMValueRef provoking_vtx_in_prim =
+                       LLVMConstInt(ctx->ac.i32, 0, false);
+
+               /* provoking_vtx_index = vtxindex[provoking_vtx_in_prim]; */
+               LLVMValueRef indices = ac_build_gather_values(&ctx->ac, vtxindex, 3);
+               LLVMValueRef provoking_vtx_index =
+                       LLVMBuildExtractElement(builder, indices, provoking_vtx_in_prim, "");
+
+               LLVMBuildStore(builder, ctx->abi.gs_prim_id,
+                              ac_build_gep0(&ctx->ac, ctx->esgs_ring, provoking_vtx_index));
+               ac_build_endif(&ctx->ac, 5400);
+       }
 
        /* TODO: primitive culling */
 
@@ -3367,9 +3385,41 @@ handle_ngg_outputs_post(struct radv_shader_context *ctx)
        /* Export per-vertex data (positions and parameters). */
        ac_nir_build_if(&if_state, ctx, is_es_thread);
        {
-               handle_vs_outputs_post(ctx, ctx->options->key.vs_common_out.export_prim_id,
+               struct radv_vs_output_info *outinfo =
+                       ctx->stage == MESA_SHADER_TESS_EVAL ? &ctx->shader_info->tes.outinfo : &ctx->shader_info->vs.outinfo;
+
+               /* Exporting the primitive ID is handled below. */
+               /* TODO: use the new VS export path */
+               handle_vs_outputs_post(ctx, false,
                                       ctx->options->key.vs_common_out.export_clip_dists,
-                                      ctx->stage == MESA_SHADER_TESS_EVAL ? &ctx->shader_info->tes.outinfo : &ctx->shader_info->vs.outinfo);
+                                      outinfo);
+
+               if (ctx->options->key.vs_common_out.export_prim_id) {
+                       unsigned param_count = outinfo->param_exports;
+                       LLVMValueRef values[4];
+
+                       if (ctx->stage == MESA_SHADER_VERTEX) {
+                               /* Wait for GS stores to finish. */
+                               ac_build_s_barrier(&ctx->ac);
+
+                               tmp = ac_build_gep0(&ctx->ac, ctx->esgs_ring,
+                                                   get_thread_id_in_tg(ctx));
+                               values[0] = LLVMBuildLoad(builder, tmp, "");
+                       } else {
+                               assert(ctx->stage == MESA_SHADER_TESS_EVAL);
+                               values[0] = ctx->abi.tes_patch_id;
+                       }
+
+                       values[0] = ac_to_float(&ctx->ac, values[0]);
+                       for (unsigned j = 1; j < 4; j++)
+                               values[j] = ctx->ac.f32_0;
+
+                       radv_export_param(ctx, param_count, values, 0x1);
+
+                       outinfo->vs_output_param_offset[VARYING_SLOT_PRIMITIVE_ID] = param_count++;
+                       outinfo->export_prim_id = true;
+                       outinfo->param_exports = param_count;
+               }
        }
        ac_nir_build_endif(&if_state);
 }