From e838acf37d055ba3734d720804b72eb1ecf02577 Mon Sep 17 00:00:00 2001 From: Erik Faye-Lund Date: Thu, 4 Jun 2020 12:38:08 +0200 Subject: [PATCH] nir: do not try to merge xfb-outputs It's tricky to merge XFB-outputs correctly, because we need there to not be any overlaps when we get to `nir_gather_xfb_info_with_varyings` later on. We currently trigger an assert there if we end up merging here. So let's not even try. This is an optimization, and we can optimize this in safe cases later if needed. For now, let's play it safe. Reviewed-by: Jason Ekstrand Part-of: --- src/compiler/nir/nir_lower_io_to_vector.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/compiler/nir/nir_lower_io_to_vector.c b/src/compiler/nir/nir_lower_io_to_vector.c index f85e53ac758..b1ea871a402 100644 --- a/src/compiler/nir/nir_lower_io_to_vector.c +++ b/src/compiler/nir/nir_lower_io_to_vector.c @@ -135,6 +135,18 @@ variables_can_merge(const nir_shader *shader, a->data.index != b->data.index) return false; + /* It's tricky to merge XFB-outputs correctly, because we need there + * to not be any overlaps when we get to + * nir_gather_xfb_info_with_varyings later on. We'll end up + * triggering an assert there if we merge here. + */ + if ((shader->info.stage == MESA_SHADER_VERTEX || + shader->info.stage == MESA_SHADER_TESS_EVAL || + shader->info.stage == MESA_SHADER_GEOMETRY) && + a->data.mode == nir_var_shader_out && + (a->data.explicit_xfb_buffer || b->data.explicit_xfb_buffer)) + return false; + return true; } -- 2.30.2