[Mesa-dev] [PATCH 11/21] i965/fs: Rework uniform handling

[Jason Ekstrand]

Previously, we treated the entire UNIFORM file as if it had two elements:
One for direct things and one for indirect.  This is substantially
different from how the old visitor code handled it where each element was
effectively its own uniform.  This commit makes the NIR path more like the
old ir_visitor path where each uniform is separate.  This should allow us
to more easily make decisions about what to push.
---
 src/mesa/drivers/dri/i965/brw_fs.h       |  3 ---
 src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 30 ++++++++----------------------
 src/mesa/drivers/dri/i965/brw_nir.c      |  7 +++----
 3 files changed, 11 insertions(+), 29 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 6d18929..6bca762 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -318,9 +318,6 @@ public:
    /** Number of uniform variable components visited. */
    unsigned uniforms;
 
-   /** Total number of direct uniforms we can get from NIR */
-   unsigned num_direct_uniforms;
-
    /** Byte-offset for the next available spot in the scratch space buffer. */
    unsigned last_scratch;
 
diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 32a05dc..81de4ab 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -175,19 +175,9 @@ fs_visitor::nir_setup_outputs(nir_shader *shader)
 void
 fs_visitor::nir_setup_uniforms(nir_shader *shader)
 {
-   num_direct_uniforms = shader->num_direct_uniforms;
-
    if (dispatch_width != 8)
       return;
 
-   /* We split the uniform register file in half.  The first half is
-    * entirely direct uniforms.  The second half is indirect.
-    */
-   if (num_direct_uniforms > 0)
-      param_size[0] = num_direct_uniforms;
-   if (shader->num_uniforms > num_direct_uniforms)
-      param_size[num_direct_uniforms] = shader->num_uniforms - num_direct_uniforms;
-
    uniforms = shader->num_uniforms;
 
    if (shader_prog) {
@@ -200,15 +190,19 @@ fs_visitor::nir_setup_uniforms(nir_shader *shader)
             nir_setup_builtin_uniform(var);
          else
             nir_setup_uniform(var);
+
+         param_size[var->data.driver_location] = type_size_scalar(var->type);
       }
    } else {
-      /* prog_to_nir doesn't create uniform variables; set param up directly. */
+      /* prog_to_nir only creates a single giant uniform variable so we can
+       * just set param up directly. */
       for (unsigned p = 0; p < prog->Parameters->NumParameters; p++) {
          for (unsigned int i = 0; i < 4; i++) {
             stage_prog_data->param[4 * p + i] =
                &prog->Parameters->ParameterValues[p][i];
          }
       }
+      param_size[0] = prog->Parameters->NumParameters * 4;
    }
 }
 
@@ -1459,21 +1453,13 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       has_indirect = true;
       /* fallthrough */
    case nir_intrinsic_load_uniform: {
-      unsigned index = instr->const_index[0] + instr->const_index[1];
-
-      fs_reg uniform_reg;
-      if (index < num_direct_uniforms) {
-         uniform_reg = fs_reg(UNIFORM, 0);
-      } else {
-         uniform_reg = fs_reg(UNIFORM, num_direct_uniforms);
-         index -= num_direct_uniforms;
-      }
+      fs_reg uniform_reg(UNIFORM, instr->const_index[0]);
+      uniform_reg.reg_offset = instr->const_index[1];
 
       for (unsigned j = 0; j < instr->num_components; j++) {
-         fs_reg src = offset(retype(uniform_reg, dest.type), bld, index);
+         fs_reg src = offset(retype(uniform_reg, dest.type), bld, j);
          if (has_indirect)
             src.reladdr = new(mem_ctx) fs_reg(get_nir_src(instr->src[0]));
-         index++;
 
          bld.MOV(dest, src);
          dest = offset(dest, bld, 1);
diff --git a/src/mesa/drivers/dri/i965/brw_nir.c b/src/mesa/drivers/dri/i965/brw_nir.c
index 3d04363..dfac44f 100644
--- a/src/mesa/drivers/dri/i965/brw_nir.c
+++ b/src/mesa/drivers/dri/i965/brw_nir.c
@@ -111,10 +111,9 @@ brw_create_nir(struct brw_context *brw,
    nir_optimize(nir, is_scalar);
 
    if (is_scalar) {
-      nir_assign_var_locations_direct_first(nir, &nir->uniforms,
-                                            &nir->num_direct_uniforms,
-                                            &nir->num_uniforms,
-                                            type_size_scalar);
+      nir_assign_var_locations(&nir->uniforms,
+                               &nir->num_uniforms,
+                               type_size_scalar);
       nir_assign_var_locations(&nir->inputs, &nir->num_inputs, type_size_scalar);
       nir_assign_var_locations(&nir->outputs, &nir->num_outputs, type_size_scalar);
       nir_lower_io(nir, type_size_scalar);
-- 
2.4.3