[Mesa-dev] [PATCH 2/3] radv/gfx10: declare an external symbol for the ESGS ring

[Samuel Pitoiset]

It will be used for stream output but for now only declares it
if VS and if the PrimitiveID needs to be exported.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/vulkan/radv_nir_to_llvm.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/amd/vulkan/radv_nir_to_llvm.c b/src/amd/vulkan/radv_nir_to_llvm.c
index 176e95537c1..d40635c6510 100644
--- a/src/amd/vulkan/radv_nir_to_llvm.c
+++ b/src/amd/vulkan/radv_nir_to_llvm.c
@@ -3716,6 +3716,25 @@ static void prepare_gs_input_vgprs(struct radv_shader_context *ctx)
 	ctx->gs_wave_id = ac_unpack_param(&ctx->ac, ctx->merged_wave_info, 16, 8);
 }
 
+/* Ensure that the esgs ring is declared.
+ *
+ * We declare it with 64KB alignment as a hint that the
+ * pointer value will always be 0.
+ */
+static void declare_esgs_ring(struct radv_shader_context *ctx)
+{
+	if (ctx->esgs_ring)
+		return;
+
+	assert(!LLVMGetNamedGlobal(ctx->ac.module, "esgs_ring"));
+
+	ctx->esgs_ring = LLVMAddGlobalInAddressSpace(
+		ctx->ac.module, LLVMArrayType(ctx->ac.i32, 0),
+		"esgs_ring",
+		AC_ADDR_SPACE_LDS);
+	LLVMSetLinkage(ctx->esgs_ring, LLVMExternalLinkage);
+	LLVMSetAlignment(ctx->esgs_ring, 64 * 1024);
+}
 
 static
 LLVMModuleRef ac_translate_nir_to_llvm(struct ac_llvm_compiler *ac_llvm,
@@ -3832,6 +3851,12 @@ LLVMModuleRef ac_translate_nir_to_llvm(struct ac_llvm_compiler *ac_llvm,
 			ctx.abi.emit_kill = radv_emit_kill;
 		}
 
+		if (shaders[i]->info.stage == MESA_SHADER_VERTEX &&
+		    ctx.options->key.vs_common_out.as_ngg &&
+		    ctx.options->key.vs_common_out.export_prim_id) {
+			declare_esgs_ring(&ctx);
+		}
+
 		if (i)
 			ac_emit_barrier(&ctx.ac, ctx.stage);
 
-- 
2.22.0