nir/types: Make glsl_get_length smarter

Previously, this function returned the number of elements for structures
and arrays and 0 for everything else.  In NIR, this is almost never what
you want because we also treat matricies as arrays so you have to
special-case constantly.  This commit  glsl_get_length treat matrices
as an array of columns by returning the number of columns instead of 0

This also fixes a bug in locals_to_regs caused by not checking for the
matrix case in one place.

v2: Only special-case for matrices and return a length of 0 for vectors as
    we did before.  This was needed to not break the TGSI-based drivers and
    doesn't really affect NIR at the moment.

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Tested-by: Rob Clark <robclark@freedesktop.org>

src/glsl/nir/nir_lower_locals_to_regs.c

@@ -100,15 +100,8 @@ get_reg_for_deref(nir_deref_var *deref, struct locals_to_regs_state *state)
    unsigned array_size = 1;
    nir_deref *tail = &deref->deref;
    while (tail->child) {
-      if (tail->child->deref_type == nir_deref_type_array) {
-         /* Multiply by the parent's type. */
-         if (glsl_type_is_matrix(tail->type)) {
-            array_size *= glsl_get_matrix_columns(tail->type);
-         } else {
-            assert(glsl_get_length(tail->type) > 0);
-            array_size *= glsl_get_length(tail->type);
-         }
-      }
+      if (tail->child->deref_type == nir_deref_type_array)
+         array_size *= glsl_get_length(tail->type);
       tail = tail->child;
    }
 

src/glsl/nir/nir_lower_var_copies.c

@@ -64,26 +64,6 @@ get_deref_tail(nir_deref *deref)
    return deref;
 }
 
-static int
-type_get_length(const struct glsl_type *type)
-{
-   switch (glsl_get_base_type(type)) {
-   case GLSL_TYPE_STRUCT:
-   case GLSL_TYPE_ARRAY:
-      return glsl_get_length(type);
-   case GLSL_TYPE_FLOAT:
-   case GLSL_TYPE_INT:
-   case GLSL_TYPE_UINT:
-   case GLSL_TYPE_BOOL:
-      if (glsl_type_is_matrix(type))
-         return glsl_get_matrix_columns(type);
-      else
-         return glsl_get_vector_elements(type);
-   default:
-      unreachable("Invalid deref base type");
-   }
-}
-
 /* This function recursively walks the given deref chain and replaces the
  * given copy instruction with an equivalent sequence load/store
  * operations.
@@ -121,9 +101,9 @@ emit_copy_load_store(nir_intrinsic_instr *copy_instr,
       nir_deref_array *src_arr = nir_deref_as_array(src_arr_parent->child);
       nir_deref_array *dest_arr = nir_deref_as_array(dest_arr_parent->child);
 
-      unsigned length = type_get_length(src_arr_parent->type);
+      unsigned length = glsl_get_length(src_arr_parent->type);
       /* The wildcards should represent the same number of elements */
-      assert(length == type_get_length(dest_arr_parent->type));
+      assert(length == glsl_get_length(dest_arr_parent->type));
       assert(length > 0);
 
       /* Walk over all of the elements that this wildcard refers to and

src/glsl/nir/nir_lower_vars_to_ssa.c

@@ -90,32 +90,12 @@ struct lower_variables_state {
    struct hash_table *phi_table;
 };
 
-static int
-type_get_length(const struct glsl_type *type)
-{
-   switch (glsl_get_base_type(type)) {
-   case GLSL_TYPE_STRUCT:
-   case GLSL_TYPE_ARRAY:
-      return glsl_get_length(type);
-   case GLSL_TYPE_FLOAT:
-   case GLSL_TYPE_INT:
-   case GLSL_TYPE_UINT:
-   case GLSL_TYPE_BOOL:
-      if (glsl_type_is_matrix(type))
-         return glsl_get_matrix_columns(type);
-      else
-         return glsl_get_vector_elements(type);
-   default:
-      unreachable("Invalid deref base type");
-   }
-}
-
 static struct deref_node *
 deref_node_create(struct deref_node *parent,
                   const struct glsl_type *type, nir_shader *shader)
 {
    size_t size = sizeof(struct deref_node) +
-                 type_get_length(type) * sizeof(struct deref_node *);
+                 glsl_get_length(type) * sizeof(struct deref_node *);
 
    struct deref_node *node = rzalloc_size(shader, size);
    node->type = type;
@@ -165,7 +145,7 @@ get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
       case nir_deref_type_struct: {
          nir_deref_struct *deref_struct = nir_deref_as_struct(tail);
 
-         assert(deref_struct->index < type_get_length(node->type));
+         assert(deref_struct->index < glsl_get_length(node->type));
 
          if (node->children[deref_struct->index] == NULL)
             node->children[deref_struct->index] =
@@ -184,7 +164,7 @@ get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
              * out-of-bounds offset.  We need to handle this at least
              * somewhat gracefully.
              */
-            if (arr->base_offset >= type_get_length(node->type))
+            if (arr->base_offset >= glsl_get_length(node->type))
                return NULL;
 
             if (node->children[arr->base_offset] == NULL)

src/glsl/nir/nir_types.cpp

@@ -103,7 +103,7 @@ glsl_get_matrix_columns(const struct glsl_type *type)
 unsigned
 glsl_get_length(const struct glsl_type *type)
 {
-   return type->length;
+   return type->is_matrix() ? type->matrix_columns : type->length;
 }
 
 const char *