ir_to_mesa: Handle loops with loop controls set

The downside of our talloc usage is that we can't really make static
(i.e., not created with new) instances of our IR types.  This leads to
a lot of unnecessary dynamic allocation in this patch.

diff --git a/src/mesa/program/ir_to_mesa.cpp b/src/mesa/program/ir_to_mesa.cpp
index f0e14b8..839d6f0 100644 (file)
--- a/src/mesa/program/ir_to_mesa.cpp
+++ b/src/mesa/program/ir_to_mesa.cpp
@@ -882,13 +882,53 @@ ir_to_mesa_visitor::visit(ir_variable *ir)
 void
 ir_to_mesa_visitor::visit(ir_loop *ir)
 {
-   assert(!ir->from);
-   assert(!ir->to);
-   assert(!ir->increment);
-   assert(!ir->counter);
+   ir_dereference_variable *counter = NULL;
+
+   if (ir->counter != NULL)
+      counter = new(ir) ir_dereference_variable(ir->counter);
+
+   if (ir->from != NULL) {
+      assert(ir->counter != NULL);
+
+      ir_assignment *a = new(ir) ir_assignment(counter, ir->from, NULL);
+
+      a->accept(this);
+      delete a;
+   }
 
    ir_to_mesa_emit_op0(NULL, OPCODE_BGNLOOP);
+
+   if (ir->to) {
+      ir_expression *e =
+        new(ir) ir_expression(ir->cmp, glsl_type::bool_type,
+                              counter, ir->to);
+      ir_if *if_stmt =  new(ir) ir_if(e);
+
+      ir_loop_jump *brk = new(ir) ir_loop_jump(ir_loop_jump::jump_break);
+
+      if_stmt->then_instructions.push_tail(brk);
+
+      if_stmt->accept(this);
+
+      delete if_stmt;
+      delete e;
+      delete brk;
+   }
+
    visit_exec_list(&ir->body_instructions, this);
+
+   if (ir->increment) {
+      ir_expression *e =
+        new(ir) ir_expression(ir_binop_add, counter->type,
+                              counter, ir->increment);
+
+      ir_assignment *a = new(ir) ir_assignment(counter, e, NULL);
+
+      a->accept(this);
+      delete a;
+      delete e;
+   }
+
    ir_to_mesa_emit_op0(NULL, OPCODE_ENDLOOP);
 }