glsl: Accept nonconstant array references in lower_ubo_reference

Instead of falling back to just the block name (which we won't find),
look for the first element of the block array. We'll deal with the rest
in the backend by arranging for the blocks to be laid out contiguously.

V2: Squashed together patches 3, 5 of V1, plus a naming tweak.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 32 insertions, 11 deletions

diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
index 9729ea071b3..67b752d3d22 100644
--- a/src/glsl/lower_ubo_reference.cpp
+++ b/src/glsl/lower_ubo_reference.cpp
@@ -69,9 +69,11 @@ public:
  * \c UniformBlocks array.
  */
 static const char *
-interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
+interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d,
+                     ir_rvalue **nonconst_block_index)
 {
-   ir_constant *previous_index = NULL;
+   ir_rvalue *previous_index = NULL;
+   *nonconst_block_index = NULL;
 
    while (d != NULL) {
       switch (d->ir_type) {
@@ -79,13 +81,21 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
          ir_dereference_variable *v = (ir_dereference_variable *) d;
          if (previous_index
              && v->var->is_interface_instance()
-             && v->var->type->is_array())
-            return ralloc_asprintf(mem_ctx,
-                                   "%s[%d]",
-                                   base_name,
-                                   previous_index->get_uint_component(0));
-         else
+             && v->var->type->is_array()) {
+
+            ir_constant *const_index = previous_index->as_constant();
+            if (!const_index) {
+               *nonconst_block_index = previous_index;
+               return ralloc_asprintf(mem_ctx, "%s[0]", base_name);
+            } else {
+               return ralloc_asprintf(mem_ctx,
+                                      "%s[%d]",
+                                      base_name,
+                                      const_index->get_uint_component(0));
+            }
+         } else {
             return base_name;
+         }
 
          break;
       }
@@ -101,7 +111,8 @@ interface_field_name(void *mem_ctx, char *base_name, ir_dereference *d)
          ir_dereference_array *a = (ir_dereference_array *) d;
 
          d = a->array->as_dereference();
-         previous_index = a->array_index->as_constant();
+         previous_index = a->array_index;
+
          break;
       }
 
@@ -131,14 +142,24 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
 
    mem_ctx = ralloc_parent(*rvalue);
 
+   ir_rvalue *nonconst_block_index;
    const char *const field_name =
       interface_field_name(mem_ctx, (char *) var->get_interface_type()->name,
-                           deref);
+                           deref, &nonconst_block_index);
 
    this->uniform_block = NULL;
    for (unsigned i = 0; i < shader->NumUniformBlocks; i++) {
       if (strcmp(field_name, shader->UniformBlocks[i].Name) == 0) {
-         this->uniform_block = new(mem_ctx) ir_constant(i);
+
+         ir_constant *index = new(mem_ctx) ir_constant(i);
+
+         if (nonconst_block_index) {
+            if (nonconst_block_index->type != glsl_type::uint_type)
+               nonconst_block_index = i2u(nonconst_block_index);
+            this->uniform_block = add(nonconst_block_index, index);
+         } else {
+            this->uniform_block = index;
+         }
 
          struct gl_uniform_block *block = &shader->UniformBlocks[i];