[Mesa-dev] [PATCH 04/78] i965/nir/vec4: Add setup of input variables in NIR->vec4 pass

[Eduardo Lima Mitev]

This implementation sets up a map of input variable offsets to source registers
that are already initialized with the corresponding register offset.

This map will then be queried when processing load_input intrinsic operations,
to obtain the correct register source from which the input data will be loaded.

This pattern of initializing an array map at setup time and then consuming it
during instruction emission is common in fs_nir, while the actual offset
calculations are taken from vec4_visitor.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89580
---
 src/mesa/drivers/dri/i965/brw_vec4.h       |  2 ++
 src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 13 ++++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index 7f78e7f..be47c82 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -411,6 +411,8 @@ public:
    virtual void nir_emit_jump(nir_jump_instr *instr);
    virtual void nir_emit_texture(nir_tex_instr *instr);
 
+   src_reg *nir_inputs;
+
 protected:
    void emit_vertex();
    void lower_attributes_to_hw_regs(const int *attribute_map,
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
index ae3b962..c2342b6 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
@@ -71,7 +71,18 @@ vec4_visitor::nir_setup_system_values(nir_shader *shader)
 void
 vec4_visitor::nir_setup_inputs(nir_shader *shader)
 {
-   /* @TODO: Not yet implemented */
+   nir_inputs = ralloc_array(mem_ctx, src_reg, shader->num_inputs);
+
+   foreach_list_typed(nir_variable, var, node, &shader->inputs) {
+      int offset = var->data.driver_location;
+      unsigned size = type_size(var->type);
+      for (unsigned i = 0; i < size; i++) {
+         src_reg src = src_reg(ATTR, var->data.location + i, var->type);
+         src = retype(src, brw_type_for_base_type(var->type));
+         nir_inputs[offset] = src;
+         offset++;
+      }
+   }
 }
 
 void
-- 
2.1.4