[Mesa-dev] [PATCH 2/4] nir/lower_tex_proj: add support projector lowering per sampler type

[Rob Clark]

From: Rob Clark <robclark at freedesktop.org>

Some hardware, such as adreno a3xx, supports txp on some but not all
sampler types.  In this case we want more fine grained control over
which texture projectors get lowered.

Signed-off-by: Rob Clark <robclark at freedesktop.org>
---
 src/glsl/nir/nir.h                     |  2 +-
 src/glsl/nir/nir_lower_tex_projector.c | 31 +++++++++++++++++++++++--------
 src/mesa/drivers/dri/i965/brw_nir.c    |  2 +-
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 284fccd..9d47001 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1830,7 +1830,7 @@ void nir_lower_samplers(nir_shader *shader,
                         const struct gl_shader_program *shader_program);
 
 void nir_lower_system_values(nir_shader *shader);
-void nir_lower_tex_projector(nir_shader *shader);
+void nir_lower_tex_projector(nir_shader *shader, unsigned lower_txp);
 void nir_lower_idiv(nir_shader *shader);
 
 void nir_lower_clip_vs(nir_shader *shader, unsigned ucp_enables);
diff --git a/src/glsl/nir/nir_lower_tex_projector.c b/src/glsl/nir/nir_lower_tex_projector.c
index 11fcd61..ce20956 100644
--- a/src/glsl/nir/nir_lower_tex_projector.c
+++ b/src/glsl/nir/nir_lower_tex_projector.c
@@ -30,6 +30,11 @@
 #include "nir.h"
 #include "nir_builder.h"
 
+typedef struct {
+   nir_builder b;
+   unsigned lower_txp;
+} lower_tex_state;
+
 static void
 project_src(nir_builder *b, nir_tex_instr *tex)
 {
@@ -109,37 +114,47 @@ project_src(nir_builder *b, nir_tex_instr *tex)
 static bool
 nir_lower_tex_projector_block(nir_block *block, void *void_state)
 {
-   nir_builder *b = void_state;
+   lower_tex_state *state = void_state;
+   nir_builder *b = &state->b;
 
    nir_foreach_instr_safe(block, instr) {
       if (instr->type != nir_instr_type_tex)
          continue;
 
       nir_tex_instr *tex = nir_instr_as_tex(instr);
+      bool lower_txp = !!(state->lower_txp & (1 << tex->sampler_dim));
+
+      if (lower_txp)
+         project_src(b, tex);
 
-      project_src(b, tex);
    }
 
    return true;
 }
 
 static void
-nir_lower_tex_projector_impl(nir_function_impl *impl)
+nir_lower_tex_projector_impl(nir_function_impl *impl, lower_tex_state *state)
 {
-   nir_builder b;
-   nir_builder_init(&b, impl);
+   nir_builder_init(&state->b, impl);
 
-   nir_foreach_block(impl, nir_lower_tex_projector_block, &b);
+   nir_foreach_block(impl, nir_lower_tex_projector_block, state);
 
    nir_metadata_preserve(impl, nir_metadata_block_index |
                                nir_metadata_dominance);
 }
 
+/**
+ * lower_txp:
+ *    bitmask of (1 << GLSL_SAMPLER_DIM_x) to control for which
+ *    sampler types a texture projector is lowered.
+ */
 void
-nir_lower_tex_projector(nir_shader *shader)
+nir_lower_tex_projector(nir_shader *shader, unsigned lower_txp)
 {
+   lower_tex_state state;
+   state.lower_txp = lower_txp;
    nir_foreach_overload(shader, overload) {
       if (overload->impl)
-         nir_lower_tex_projector_impl(overload->impl);
+         nir_lower_tex_projector_impl(overload->impl, &state);
    }
 }
diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index f326b23..2a924bb 100644
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -96,7 +96,7 @@ brw_create_nir(struct brw_context *brw,
    nir_lower_global_vars_to_local(nir);
    nir_validate_shader(nir);
 
-   nir_lower_tex_projector(nir);
+   nir_lower_tex_projector(nir, ~0);
    nir_validate_shader(nir);
 
    nir_normalize_cubemap_coords(nir);
-- 
2.4.3