radeonsi: Store inputs to memory when not using a TCS.

We need to copy the VS outputs to memory. I decided to do this
using a shader key, as the value depends on other shaders.

I also switch the fixed function TCS over to monolithic, as
otherwisze many of the user SGPR's need to be passed to the
epilog, which increases register pressure, or complexity to
avoid that. The main body of the fixed function TCS is not
that interesting to precompile anyway, since we do it on
demand and it is very small.

v2: Use u_bit_scan64.

Signed-off-by: Bas Nieuwenhuizen <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>

1 files changed, 45 insertions, 0 deletions

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 83bcf5eac18..b04d0f7375a 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -2444,6 +2444,48 @@ handle_semantic:
 	}
 }
 
+static void si_copy_tcs_inputs(struct lp_build_tgsi_context *bld_base)
+{
+	struct si_shader_context *ctx = si_shader_context(bld_base);
+	struct gallivm_state *gallivm = bld_base->base.gallivm;
+	LLVMValueRef invocation_id, rw_buffers, buffer, buffer_offset;
+	LLVMValueRef lds_vertex_stride, lds_vertex_offset, lds_base;
+	uint64_t inputs;
+
+	invocation_id = unpack_param(ctx, SI_PARAM_REL_IDS, 8, 5);
+
+	rw_buffers = LLVMGetParam(ctx->radeon_bld.main_fn, SI_PARAM_RW_BUFFERS);
+	buffer = build_indexed_load_const(ctx, rw_buffers,
+	                lp_build_const_int32(gallivm, SI_HS_RING_TESS_OFFCHIP));
+
+	buffer_offset = LLVMGetParam(ctx->radeon_bld.main_fn, ctx->param_oc_lds);
+
+	lds_vertex_stride = unpack_param(ctx, SI_PARAM_TCS_IN_LAYOUT, 13, 8);
+	lds_vertex_offset = LLVMBuildMul(gallivm->builder, invocation_id,
+	                                 lds_vertex_stride, "");
+	lds_base = get_tcs_in_current_patch_offset(ctx);
+	lds_base = LLVMBuildAdd(gallivm->builder, lds_base, lds_vertex_offset, "");
+
+	inputs = ctx->shader->key.tcs.epilog.inputs_to_copy;
+	while (inputs) {
+		unsigned i = u_bit_scan64(&inputs);
+
+		LLVMValueRef lds_ptr = LLVMBuildAdd(gallivm->builder, lds_base,
+		                            lp_build_const_int32(gallivm, 4 * i),
+		                             "");
+
+		LLVMValueRef buffer_addr = get_tcs_tes_buffer_address(ctx,
+		                              invocation_id,
+		                              lp_build_const_int32(gallivm, i));
+
+		LLVMValueRef value = lds_load(bld_base, TGSI_TYPE_SIGNED, ~0,
+		                              lds_ptr);
+
+		build_tbuffer_store_dwords(ctx, buffer, value, 4, buffer_addr,
+		                           buffer_offset, 0);
+	}
+}
+
 static void si_write_tess_factors(struct lp_build_tgsi_context *bld_base,
 				  LLVMValueRef rel_patch_id,
 				  LLVMValueRef invocation_id,
@@ -2585,6 +2627,7 @@ static void si_llvm_emit_tcs_epilogue(struct lp_build_tgsi_context *bld_base)
 		return;
 	}
 
+	si_copy_tcs_inputs(bld_base);
 	si_write_tess_factors(bld_base, rel_patch_id, invocation_id, tf_lds_offset);
 }
 
@@ -7426,6 +7469,8 @@ int si_shader_create(struct si_screen *sscreen, LLVMTargetMachineRef tm,
 	      shader->key.vs.as_ls != mainp->key.vs.as_ls)) ||
 	    (shader->selector->type == PIPE_SHADER_TESS_EVAL &&
 	     shader->key.tes.as_es != mainp->key.tes.as_es) ||
+	    (shader->selector->type == PIPE_SHADER_TESS_CTRL &&
+	     shader->key.tcs.epilog.inputs_to_copy) ||
 	    shader->selector->type == PIPE_SHADER_COMPUTE) {
 		/* Monolithic shader (compiled as a whole, has many variants,
 		 * may take a long time to compile).