Mesa (glsl2): glsl2: Fix inlining with sampler array or struct dereferences as arguments.

[Eric Anholt]

Module: Mesa
Branch: glsl2
Commit: 199c441239762eec86b3cb4b558aef486907a8b6
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=199c441239762eec86b3cb4b558aef486907a8b6

Author: Eric Anholt <eric at anholt.net>
Date:   Fri Aug  6 00:21:12 2010 -0700

glsl2: Fix inlining with sampler array or struct dereferences as arguments.

Previously, we'd replace an argument of mysampler[2] with a plain
reference to mysampler by using the cloning hash table.  Instead, use
a visitor to clone whatever complicated sampler dereference into the
sampler parameter derefs in the inlined function body.

---

 src/glsl/ir_function_inlining.cpp |  143 +++++++++++++++++++++++++++++++++++--
 1 files changed, 138 insertions(+), 5 deletions(-)

diff --git a/src/glsl/ir_function_inlining.cpp b/src/glsl/ir_function_inlining.cpp
index 9738137..35eb2b3 100644
--- a/src/glsl/ir_function_inlining.cpp
+++ b/src/glsl/ir_function_inlining.cpp
@@ -35,6 +35,11 @@
 #include "glsl_types.h"
 #include "program/hash_table.h"
 
+static void
+do_sampler_replacement(exec_list *instructions,
+		       ir_variable *sampler,
+		       ir_dereference *deref);
+
 class ir_function_inlining_visitor : public ir_hierarchical_visitor {
 public:
    ir_function_inlining_visitor()
@@ -96,7 +101,7 @@ replace_return_with_assignment(ir_instruction *ir, void *data)
 	 /* un-valued return has to be the last return, or we shouldn't
 	  * have reached here. (see can_inline()).
 	  */
-	 assert(!ret->next->is_tail_sentinel());
+	 assert(ret->next->is_tail_sentinel());
 	 ret->remove();
       }
    }
@@ -142,10 +147,9 @@ ir_call::generate_inline(ir_instruction *next_ir)
 	 /* For samplers, we want the inlined sampler references
 	  * referencing the passed in sampler variable, since that
 	  * will have the location information, which an assignment of
-	  * a sampler wouldn't.
+	  * a sampler wouldn't.  Fix it up below.
 	  */
 	 parameters[i] = NULL;
-	 hash_table_insert(ht, param->variable_referenced(), sig_param);
       } else {
 	 parameters[i] = sig_param->clone(ctx, ht);
 	 parameters[i]->mode = ir_var_auto;
@@ -166,15 +170,40 @@ ir_call::generate_inline(ir_instruction *next_ir)
       param_iter.next();
    }
 
-   /* Generate the inlined body of the function. */
+   exec_list new_instructions;
+
+   /* Generate the inlined body of the function to a new list */
    foreach_iter(exec_list_iterator, iter, callee->body) {
       ir_instruction *ir = (ir_instruction *)iter.get();
       ir_instruction *new_ir = ir->clone(ctx, ht);
 
-      next_ir->insert_before(new_ir);
+      new_instructions.push_tail(new_ir);
       visit_tree(new_ir, replace_return_with_assignment, retval);
    }
 
+   /* If any samplers were passed in, replace any deref of the sampler
+    * with a deref of the sampler argument.
+    */
+   param_iter = this->actual_parameters.iterator();
+   sig_param_iter = this->callee->parameters.iterator();
+   for (i = 0; i < num_parameters; i++) {
+      ir_instruction *const param = (ir_instruction *) param_iter.get();
+      ir_variable *sig_param = (ir_variable *) sig_param_iter.get();
+
+      if (sig_param->type->base_type == GLSL_TYPE_SAMPLER) {
+	 ir_dereference *deref = param->as_dereference();
+
+	 assert(deref);
+	 do_sampler_replacement(&new_instructions, sig_param, deref);
+      }
+   }
+
+   /* Now push those new instructions in. */
+   foreach_iter(exec_list_iterator, iter, new_instructions) {
+      ir_instruction *ir = (ir_instruction *)iter.get();
+      next_ir->insert_before(ir);
+   }
+
    /* Copy back the value of any 'out' parameters from the function body
     * variables to our own.
     */
@@ -280,3 +309,107 @@ ir_function_inlining_visitor::visit_enter(ir_assignment *ir)
 
    return visit_continue;
 }
+
+/**
+ * Replaces references to the "sampler" variable with a clone of "deref."
+ *
+ * From the spec, samplers can appear in the tree as function
+ * (non-out) parameters and as the result of array indexing and
+ * structure field selection.  In our builtin implementation, they
+ * also appear in the sampler field of an ir_tex instruction.
+ */
+
+class ir_sampler_replacement_visitor : public ir_hierarchical_visitor {
+public:
+   ir_sampler_replacement_visitor(ir_variable *sampler, ir_dereference *deref)
+   {
+      this->sampler = sampler;
+      this->deref = deref;
+   }
+
+   virtual ~ir_sampler_replacement_visitor()
+   {
+   }
+
+   virtual ir_visitor_status visit_leave(ir_call *);
+   virtual ir_visitor_status visit_leave(ir_dereference_array *);
+   virtual ir_visitor_status visit_leave(ir_dereference_record *);
+   virtual ir_visitor_status visit_leave(ir_texture *);
+
+   void replace_deref(ir_dereference **deref);
+   void replace_rvalue(ir_rvalue **rvalue);
+
+   ir_variable *sampler;
+   ir_dereference *deref;
+};
+
+void
+ir_sampler_replacement_visitor::replace_deref(ir_dereference **deref)
+{
+   ir_dereference_variable *deref_var = (*deref)->as_dereference_variable();
+   if (deref_var && deref_var->var == this->sampler) {
+      *deref = this->deref->clone(talloc_parent(*deref), NULL);
+   }
+}
+
+void
+ir_sampler_replacement_visitor::replace_rvalue(ir_rvalue **rvalue)
+{
+   if (!*rvalue)
+      return;
+
+   ir_dereference *deref = (*rvalue)->as_dereference();
+
+   if (!deref)
+      return;
+
+   replace_deref(&deref);
+   *rvalue = deref;
+}
+
+ir_visitor_status
+ir_sampler_replacement_visitor::visit_leave(ir_texture *ir)
+{
+   replace_deref(&ir->sampler);
+
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_sampler_replacement_visitor::visit_leave(ir_dereference_array *ir)
+{
+   replace_rvalue(&ir->array);
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_sampler_replacement_visitor::visit_leave(ir_dereference_record *ir)
+{
+   replace_rvalue(&ir->record);
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_sampler_replacement_visitor::visit_leave(ir_call *ir)
+{
+   foreach_iter(exec_list_iterator, iter, *ir) {
+      ir_rvalue *param = (ir_rvalue *)iter.get();
+      ir_rvalue *new_param = param;
+      replace_rvalue(&new_param);
+
+      if (new_param != param) {
+	 param->replace_with(new_param);
+      }
+   }
+   return visit_continue;
+}
+
+static void
+do_sampler_replacement(exec_list *instructions,
+		       ir_variable *sampler,
+		       ir_dereference *deref)
+{
+   ir_sampler_replacement_visitor v(sampler, deref);
+
+   visit_list_elements(&v, instructions);
+}