radeonsi: don't use the real barrier instruction in tess ctrl shaders

Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index bf3f00867e94fc70e415a89c7b97675349ffec70..08da3e37550e4e583d936069cd08dfc1b43bc0ce 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -4282,6 +4282,14 @@ static void si_llvm_emit_barrier(const struct lp_build_tgsi_action *action,
        struct si_shader_context *ctx = si_shader_context(bld_base);
        struct gallivm_state *gallivm = bld_base->base.gallivm;
 
+       /* The real barrier instruction isn’t needed, because an entire patch
+        * always fits into a single wave.
+        */
+       if (ctx->type == TGSI_PROCESSOR_TESS_CTRL) {
+               emit_optimization_barrier(ctx);
+               return;
+       }
+
        lp_build_intrinsic(gallivm->builder,
                           HAVE_LLVM >= 0x0309 ? "llvm.amdgcn.s.barrier"
                                               : "llvm.AMDGPU.barrier.local",