[Mesa-dev] [PATCH] Revert "intel/nir: Call nir_lower_io_to_scalar_early"

[Jason Ekstrand]

Commit 4434591bf56a6b0 caused substantially more URB messages in
geometry and tessellation shaders.  Before we can really enable this
sort of optimization,  We either need some way of combining them back
together into vectors or we need to do cross-stage vector element
elimination without splitting everything into scalars.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107510
---
 src/intel/compiler/brw_nir.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index 31ffbe613ec..29ad68fdb2a 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -713,18 +713,6 @@ brw_nir_link_shaders(const struct brw_compiler *compiler,
    nir_validate_shader(*producer);
    nir_validate_shader(*consumer);
 
-   const bool p_is_scalar =
-      compiler->scalar_stage[(*producer)->info.stage];
-   const bool c_is_scalar =
-      compiler->scalar_stage[(*consumer)->info.stage];
-
-   if (p_is_scalar && c_is_scalar) {
-      NIR_PASS_V(*producer, nir_lower_io_to_scalar_early, nir_var_shader_out);
-      NIR_PASS_V(*consumer, nir_lower_io_to_scalar_early, nir_var_shader_in);
-      *producer = brw_nir_optimize(*producer, compiler, p_is_scalar);
-      *consumer = brw_nir_optimize(*consumer, compiler, c_is_scalar);
-   }
-
    NIR_PASS_V(*producer, nir_remove_dead_variables, nir_var_shader_out);
    NIR_PASS_V(*consumer, nir_remove_dead_variables, nir_var_shader_in);
 
@@ -741,7 +729,12 @@ brw_nir_link_shaders(const struct brw_compiler *compiler,
       NIR_PASS_V(*consumer, nir_lower_indirect_derefs,
                  brw_nir_no_indirect_mask(compiler, (*consumer)->info.stage));
 
+      const bool p_is_scalar =
+         compiler->scalar_stage[(*producer)->info.stage];
       *producer = brw_nir_optimize(*producer, compiler, p_is_scalar);
+
+      const bool c_is_scalar =
+         compiler->scalar_stage[(*consumer)->info.stage];
       *consumer = brw_nir_optimize(*consumer, compiler, c_is_scalar);
    }
 }
-- 
2.17.1