nir/spirv: Rework function argument setup

Now that we have proper pointer types, we can be more sensible about the
way we set up function arguments and deal with the two cases of pointer
vs. SSA parameters distinctly.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

3 files changed, 34 insertions, 28 deletions

diff --git a/src/compiler/spirv/spirv_to_nir.c b/src/compiler/spirv/spirv_to_nir.c
index 462b0494f9..1743d8915a 100644
--- a/src/compiler/spirv/spirv_to_nir.c
+++ b/src/compiler/spirv/spirv_to_nir.c
@@ -185,10 +185,6 @@ vtn_ssa_value(struct vtn_builder *b, uint32_t value_id)
    case vtn_value_type_ssa:
       return val->ssa;
 
-   case vtn_value_type_pointer:
-      /* This is needed for function parameters */
-      return vtn_variable_load(b, val->pointer);
-
    default:
       unreachable("Invalid type for an SSA value");
    }
diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c
index c1677b49aa..df54b3c485 100644
--- a/src/compiler/spirv/vtn_cfg.c
+++ b/src/compiler/spirv/vtn_cfg.c
@@ -65,6 +65,7 @@ vtn_cfg_handle_prepass_instruction(struct vtn_builder *b, SpvOp opcode,
       func->return_type = func_type->return_type->type;
 
       b->func->impl = nir_function_impl_create(func);
+      b->nb.cursor = nir_before_cf_list(&b->func->impl->body);
 
       b->func_param_idx = 0;
       break;
@@ -77,40 +78,47 @@ vtn_cfg_handle_prepass_instruction(struct vtn_builder *b, SpvOp opcode,
 
    case SpvOpFunctionParameter: {
       struct vtn_type *type = vtn_value(b, w[1], vtn_value_type_type)->type;
-      if (type->base_type == vtn_base_type_pointer) {
-         type = type->deref;
-         assert(type->base_type != vtn_base_type_pointer);
-      }
 
       assert(b->func_param_idx < b->func->impl->num_params);
       nir_variable *param = b->func->impl->params[b->func_param_idx++];
 
-      assert(type->type == param->type);
+      if (type->base_type == vtn_base_type_pointer) {
+         struct vtn_variable *vtn_var = rzalloc(b, struct vtn_variable);
+         vtn_var->type = type->deref;
+         vtn_var->var = param;
+
+         assert(vtn_var->type->type == param->type);
+
+         struct vtn_type *without_array = vtn_var->type;
+         while(glsl_type_is_array(without_array->type))
+            without_array = without_array->array_element;
+
+         if (glsl_type_is_image(without_array->type)) {
+            vtn_var->mode = vtn_variable_mode_image;
+            param->interface_type = without_array->type;
+         } else if (glsl_type_is_sampler(without_array->type)) {
+            vtn_var->mode = vtn_variable_mode_sampler;
+            param->interface_type = without_array->type;
+         } else {
+            vtn_var->mode = vtn_variable_mode_param;
+         }
 
-      struct vtn_variable *vtn_var = rzalloc(b, struct vtn_variable);
-      vtn_var->type = type;
-      vtn_var->var = param;
+         struct vtn_value *val =
+            vtn_push_value(b, w[2], vtn_value_type_pointer);
 
-      struct vtn_type *without_array = type;
-      while(glsl_type_is_array(without_array->type))
-         without_array = without_array->array_element;
+         /* Name the parameter so it shows up nicely in NIR */
+         param->name = ralloc_strdup(param, val->name);
 
-      if (glsl_type_is_image(without_array->type)) {
-         vtn_var->mode = vtn_variable_mode_image;
-         param->interface_type = without_array->type;
-      } else if (glsl_type_is_sampler(without_array->type)) {
-         vtn_var->mode = vtn_variable_mode_sampler;
-         param->interface_type = without_array->type;
+         val->pointer = vtn_pointer_for_variable(b, vtn_var, type);
       } else {
-         vtn_var->mode = vtn_variable_mode_param;
-      }
+         /* We're a regular SSA value. */
+         struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa);
 
-      struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_pointer);
+         /* Name the parameter so it shows up nicely in NIR */
+         param->name = ralloc_strdup(param, val->name);
 
-      /* Name the parameter so it shows up nicely in NIR */
-      param->name = ralloc_strdup(param, val->name);
-
-      val->pointer = vtn_pointer_for_variable(b, vtn_var, NULL);
+         val->ssa = vtn_local_load(b, nir_deref_var_create(b, param));
+      }
       break;
    }
 
diff --git a/src/compiler/spirv/vtn_variables.c b/src/compiler/spirv/vtn_variables.c
index 1ff7427ffb..5af27bfdb1 100644
--- a/src/compiler/spirv/vtn_variables.c
+++ b/src/compiler/spirv/vtn_variables.c
@@ -233,6 +233,8 @@ vtn_pointer_for_variable(struct vtn_builder *b,
 
    pointer->mode = var->mode;
    pointer->type = var->type;
+   assert(ptr_type->base_type == vtn_base_type_pointer);
+   assert(ptr_type->deref->type == var->type->type);
    pointer->ptr_type = ptr_type;
    pointer->var = var;