radv: add a new function for exporting VS outputs

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 fc598222fcfd35e165d0e260ccf65212b4787b57..ba0fb557266529ad885bf8da1ae69461bc871870 100644 (file)
--- a/src/amd/vulkan/radv_nir_to_llvm.c
+++ b/src/amd/vulkan/radv_nir_to_llvm.c
@@ -2750,6 +2750,134 @@ radv_build_param_exports(struct radv_shader_context *ctx,
        outinfo->param_exports = param_count;
 }
 
+/* Generate export instructions for hardware VS shader stage or NGG GS stage
+ * (position and parameter data only).
+ */
+static void
+radv_llvm_export_vs(struct radv_shader_context *ctx,
+                    struct radv_shader_output_values *outputs,
+                    unsigned noutput,
+                    struct radv_vs_output_info *outinfo,
+                   bool export_clip_dists)
+{
+       LLVMValueRef psize_value = NULL, layer_value = NULL, viewport_value = NULL;
+       struct ac_export_args pos_args[4] = {};
+       unsigned pos_idx, index;
+       int i;
+
+       /* Build position exports */
+       for (i = 0; i < noutput; i++) {
+               switch (outputs[i].slot_name) {
+               case VARYING_SLOT_POS:
+                       si_llvm_init_export_args(ctx, outputs[i].values, 0xf,
+                                                V_008DFC_SQ_EXP_POS, &pos_args[0]);
+                       break;
+               case VARYING_SLOT_PSIZ:
+                       psize_value = outputs[i].values[0];
+                       break;
+               case VARYING_SLOT_LAYER:
+                       layer_value = outputs[i].values[0];
+                       break;
+               case VARYING_SLOT_VIEWPORT:
+                       viewport_value = outputs[i].values[0];
+                       break;
+               case VARYING_SLOT_CLIP_DIST0:
+               case VARYING_SLOT_CLIP_DIST1:
+                       index = 2 + outputs[i].slot_index;
+                       si_llvm_init_export_args(ctx, outputs[i].values, 0xf,
+                                                V_008DFC_SQ_EXP_POS + index,
+                                                &pos_args[index]);
+                       break;
+               default:
+                       break;
+               }
+       }
+
+       /* We need to add the position output manually if it's missing. */
+       if (!pos_args[0].out[0]) {
+               pos_args[0].enabled_channels = 0xf; /* writemask */
+               pos_args[0].valid_mask = 0; /* EXEC mask */
+               pos_args[0].done = 0; /* last export? */
+               pos_args[0].target = V_008DFC_SQ_EXP_POS;
+               pos_args[0].compr = 0; /* COMPR flag */
+               pos_args[0].out[0] = ctx->ac.f32_0; /* X */
+               pos_args[0].out[1] = ctx->ac.f32_0; /* Y */
+               pos_args[0].out[2] = ctx->ac.f32_0; /* Z */
+               pos_args[0].out[3] = ctx->ac.f32_1;  /* W */
+       }
+
+       if (outinfo->writes_pointsize ||
+           outinfo->writes_layer ||
+           outinfo->writes_viewport_index) {
+               pos_args[1].enabled_channels = ((outinfo->writes_pointsize == true ? 1 : 0) |
+                                               (outinfo->writes_layer == true ? 4 : 0));
+               pos_args[1].valid_mask = 0;
+               pos_args[1].done = 0;
+               pos_args[1].target = V_008DFC_SQ_EXP_POS + 1;
+               pos_args[1].compr = 0;
+               pos_args[1].out[0] = ctx->ac.f32_0; /* X */
+               pos_args[1].out[1] = ctx->ac.f32_0; /* Y */
+               pos_args[1].out[2] = ctx->ac.f32_0; /* Z */
+               pos_args[1].out[3] = ctx->ac.f32_0;  /* W */
+
+               if (outinfo->writes_pointsize == true)
+                       pos_args[1].out[0] = psize_value;
+               if (outinfo->writes_layer == true)
+                       pos_args[1].out[2] = layer_value;
+               if (outinfo->writes_viewport_index == true) {
+                       if (ctx->options->chip_class >= GFX9) {
+                               /* GFX9 has the layer in out.z[10:0] and the viewport
+                                * index in out.z[19:16].
+                                */
+                               LLVMValueRef v = viewport_value;
+                               v = ac_to_integer(&ctx->ac, v);
+                               v = LLVMBuildShl(ctx->ac.builder, v,
+                                                LLVMConstInt(ctx->ac.i32, 16, false),
+                                                "");
+                               v = LLVMBuildOr(ctx->ac.builder, v,
+                                               ac_to_integer(&ctx->ac, pos_args[1].out[2]), "");
+
+                               pos_args[1].out[2] = ac_to_float(&ctx->ac, v);
+                               pos_args[1].enabled_channels |= 1 << 2;
+                       } else {
+                               pos_args[1].out[3] = viewport_value;
+                               pos_args[1].enabled_channels |= 1 << 3;
+                       }
+               }
+       }
+
+       for (i = 0; i < 4; i++) {
+               if (pos_args[i].out[0])
+                       outinfo->pos_exports++;
+       }
+
+       /* Navi10-14 skip POS0 exports if EXEC=0 and DONE=0, causing a hang.
+        * Setting valid_mask=1 prevents it and has no other effect.
+        */
+       if (ctx->ac.family == CHIP_NAVI10 ||
+           ctx->ac.family == CHIP_NAVI12 ||
+           ctx->ac.family == CHIP_NAVI14)
+               pos_args[0].valid_mask = 1;
+
+       pos_idx = 0;
+       for (i = 0; i < 4; i++) {
+               if (!pos_args[i].out[0])
+                       continue;
+
+               /* Specify the target we are exporting */
+               pos_args[i].target = V_008DFC_SQ_EXP_POS + pos_idx++;
+
+               if (pos_idx == outinfo->pos_exports)
+                       /* Specify that this is the last export */
+                       pos_args[i].done = 1;
+
+               ac_build_export(&ctx->ac, &pos_args[i]);
+       }
+
+       /* Build parameter exports */
+       radv_build_param_exports(ctx, outputs, noutput, outinfo, export_clip_dists);
+}
+
 static void
 handle_vs_outputs_post(struct radv_shader_context *ctx,
                       bool export_prim_id,