1 files changed, 214 insertions, 187 deletions
diff --git a/mesalib/src/glsl/loop_unroll.cpp b/mesalib/src/glsl/loop_unroll.cpp
index 90797bde3..c54f2ca3d 100644
--- a/mesalib/src/glsl/loop_unroll.cpp
+++ b/mesalib/src/glsl/loop_unroll.cpp
@@ -1,187 +1,214 @@
-/*
- * Copyright © 2010 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- */
-
-#include "glsl_types.h"
-#include "loop_analysis.h"
-#include "ir_hierarchical_visitor.h"
-
-class loop_unroll_visitor : public ir_hierarchical_visitor {
-public:
-   loop_unroll_visitor(loop_state *state, unsigned max_iterations)
-   {
-      this->state = state;
-      this->progress = false;
-      this->max_iterations = max_iterations;
-   }
-
-   virtual ir_visitor_status visit_leave(ir_loop *ir);
-
-   loop_state *state;
-
-   bool progress;
-   unsigned max_iterations;
-};
-
-
-ir_visitor_status
-loop_unroll_visitor::visit_leave(ir_loop *ir)
-{
-   loop_variable_state *const ls = this->state->get(ir);
-   int iterations;
-
-   /* If we've entered a loop that hasn't been analyzed, something really,
-    * really bad has happened.
-    */
-   if (ls == NULL) {
-      assert(ls != NULL);
-      return visit_continue;
-   }
-
-   iterations = ls->max_iterations;
-
-   /* Don't try to unroll loops where the number of iterations is not known
-    * at compile-time.
-    */
-   if (iterations < 0)
-      return visit_continue;
-
-   /* Don't try to unroll loops that have zillions of iterations either.
-    */
-   if (iterations > max_iterations)
-      return visit_continue;
-
-   if (ls->num_loop_jumps > 1)
-      return visit_continue;
-   else if (ls->num_loop_jumps) {
-      /* recognize loops in the form produced by ir_lower_jumps */
-      ir_instruction *last_ir =
-	 ((ir_instruction*)ir->body_instructions.get_tail());
-
-      assert(last_ir != NULL);
-
-      ir_if *last_if = last_ir->as_if();
-      if (last_if) {
-	 bool continue_from_then_branch;
-
-	 /* Determine which if-statement branch, if any, ends with a break.
-	  * The branch that did *not* have the break will get a temporary
-	  * continue inserted in each iteration of the loop unroll.
-	  *
-	  * Note that since ls->num_loop_jumps is <= 1, it is impossible for
-	  * both branches to end with a break.
-	  */
-	 ir_instruction *last =
-	    (ir_instruction *) last_if->then_instructions.get_tail();
-
-	 if (last && last->ir_type == ir_type_loop_jump
-	     && ((ir_loop_jump*) last)->is_break()) {
-	    continue_from_then_branch = false;
-	 } else {
-	    last = (ir_instruction *) last_if->then_instructions.get_tail();
-
-	    if (last && last->ir_type == ir_type_loop_jump
-		&& ((ir_loop_jump*) last)->is_break())
-	       continue_from_then_branch = true;
-	    else
-	       /* Bail out if neither if-statement branch ends with a break.
-		*/
-	       return visit_continue;
-	 }
-
-	 /* Remove the break from the if-statement.
-	  */
-	 last->remove();
-
-         void *const mem_ctx = talloc_parent(ir);
-         ir_instruction *ir_to_replace = ir;
-
-         for (int i = 0; i < iterations; i++) {
-            exec_list copy_list;
-
-            copy_list.make_empty();
-            clone_ir_list(mem_ctx, &copy_list, &ir->body_instructions);
-
-            last_if = ((ir_instruction*)copy_list.get_tail())->as_if();
-            assert(last_if);
-
-            ir_to_replace->insert_before(&copy_list);
-            ir_to_replace->remove();
-
-            /* placeholder that will be removed in the next iteration */
-            ir_to_replace =
-	       new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
-
-            exec_list *const list = (continue_from_then_branch)
-	       ? &last_if->then_instructions : &last_if->else_instructions;
-
-            list->push_tail(ir_to_replace);
-         }
-
-         ir_to_replace->remove();
-
-         this->progress = true;
-         return visit_continue;
-      } else if (last_ir->ir_type == ir_type_loop_jump
-		 && ((ir_loop_jump *)last_ir)->is_break()) {
-	 /* If the only loop-jump is a break at the end of the loop, the loop
-	  * will execute exactly once.  Remove the break, set the iteration
-	  * count, and fall through to the normal unroller.
-	  */
-         last_ir->remove();
-	 iterations = 1;
-
-	 this->progress = true;
-      } else
-         return visit_continue;
-   }
-
-   void *const mem_ctx = talloc_parent(ir);
-
-   for (int i = 0; i < iterations; i++) {
-      exec_list copy_list;
-
-      copy_list.make_empty();
-      clone_ir_list(mem_ctx, &copy_list, &ir->body_instructions);
-
-      ir->insert_before(&copy_list);
-   }
-
-   /* The loop has been replaced by the unrolled copies.  Remove the original
-    * loop from the IR sequence.
-    */
-   ir->remove();
-
-   this->progress = true;
-   return visit_continue;
-}
-
-
-bool
-unroll_loops(exec_list *instructions, loop_state *ls, unsigned max_iterations)
-{
-   loop_unroll_visitor v(ls, max_iterations);
-
-   v.run(instructions);
-
-   return v.progress;
-}
+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "glsl_types.h"
+#include "loop_analysis.h"
+#include "ir_hierarchical_visitor.h"
+
+class loop_unroll_visitor : public ir_hierarchical_visitor {
+public:
+   loop_unroll_visitor(loop_state *state, unsigned max_iterations)
+   {
+      this->state = state;
+      this->progress = false;
+      this->max_iterations = max_iterations;
+   }
+
+   virtual ir_visitor_status visit_leave(ir_loop *ir);
+
+   loop_state *state;
+
+   bool progress;
+   unsigned max_iterations;
+};
+
+
+static bool
+is_break(ir_instruction *ir)
+{
+   return ir != NULL && ir->ir_type == ir_type_loop_jump
+		     && ((ir_loop_jump *) ir)->is_break();
+}
+
+
+ir_visitor_status
+loop_unroll_visitor::visit_leave(ir_loop *ir)
+{
+   loop_variable_state *const ls = this->state->get(ir);
+   int iterations;
+
+   /* If we've entered a loop that hasn't been analyzed, something really,
+    * really bad has happened.
+    */
+   if (ls == NULL) {
+      assert(ls != NULL);
+      return visit_continue;
+   }
+
+   iterations = ls->max_iterations;
+
+   /* Don't try to unroll loops where the number of iterations is not known
+    * at compile-time.
+    */
+   if (iterations < 0)
+      return visit_continue;
+
+   /* Don't try to unroll loops that have zillions of iterations either.
+    */
+   if (iterations > (int) max_iterations)
+      return visit_continue;
+
+   if (ls->num_loop_jumps > 1)
+      return visit_continue;
+   else if (ls->num_loop_jumps) {
+      ir_instruction *last_ir = (ir_instruction *) ir->body_instructions.get_tail();
+      assert(last_ir != NULL);
+
+      if (is_break(last_ir)) {
+         /* If the only loop-jump is a break at the end of the loop, the loop
+          * will execute exactly once.  Remove the break, set the iteration
+          * count, and fall through to the normal unroller.
+          */
+         last_ir->remove();
+         iterations = 1;
+
+         this->progress = true;
+      } else {
+         ir_if *ir_if = NULL;
+         ir_instruction *break_ir = NULL;
+         bool continue_from_then_branch = false;
+
+         foreach_list(node, &ir->body_instructions) {
+            /* recognize loops in the form produced by ir_lower_jumps */
+            ir_instruction *cur_ir = (ir_instruction *) node;
+
+            ir_if = cur_ir->as_if();
+            if (ir_if != NULL) {
+	       /* Determine which if-statement branch, if any, ends with a
+		* break.  The branch that did *not* have the break will get a
+		* temporary continue inserted in each iteration of the loop
+		* unroll.
+		*
+		* Note that since ls->num_loop_jumps is <= 1, it is impossible
+		* for both branches to end with a break.
+		*/
+               ir_instruction *ir_if_last =
+                  (ir_instruction *) ir_if->then_instructions.get_tail();
+
+               if (is_break(ir_if_last)) {
+                  continue_from_then_branch = false;
+                  break_ir = ir_if_last;
+                  break;
+               } else {
+                  ir_if_last =
+		     (ir_instruction *) ir_if->else_instructions.get_tail();
+
+                  if (is_break(ir_if_last)) {
+                     break_ir = ir_if_last;
+                     continue_from_then_branch = true;
+                     break;
+                  }
+               }
+            }
+         }
+
+         if (break_ir == NULL)
+            return visit_continue;
+
+         /* move instructions after then if in the continue branch */
+         while (!ir_if->get_next()->is_tail_sentinel()) {
+            ir_instruction *move_ir = (ir_instruction *) ir_if->get_next();
+
+            move_ir->remove();
+            if (continue_from_then_branch)
+               ir_if->then_instructions.push_tail(move_ir);
+            else
+               ir_if->else_instructions.push_tail(move_ir);
+         }
+
+         /* Remove the break from the if-statement.
+          */
+         break_ir->remove();
+
+         void *const mem_ctx = talloc_parent(ir);
+         ir_instruction *ir_to_replace = ir;
+
+         for (int i = 0; i < iterations; i++) {
+            exec_list copy_list;
+
+            copy_list.make_empty();
+            clone_ir_list(mem_ctx, &copy_list, &ir->body_instructions);
+
+            ir_if = ((ir_instruction *) copy_list.get_tail())->as_if();
+            assert(ir_if != NULL);
+
+            ir_to_replace->insert_before(&copy_list);
+            ir_to_replace->remove();
+
+            /* placeholder that will be removed in the next iteration */
+            ir_to_replace =
+	       new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
+
+            exec_list *const list = (continue_from_then_branch)
+               ? &ir_if->then_instructions : &ir_if->else_instructions;
+
+            list->push_tail(ir_to_replace);
+         }
+
+         ir_to_replace->remove();
+
+         this->progress = true;
+         return visit_continue;
+      }
+   }
+
+   void *const mem_ctx = talloc_parent(ir);
+
+   for (int i = 0; i < iterations; i++) {
+      exec_list copy_list;
+
+      copy_list.make_empty();
+      clone_ir_list(mem_ctx, &copy_list, &ir->body_instructions);
+
+      ir->insert_before(&copy_list);
+   }
+
+   /* The loop has been replaced by the unrolled copies.  Remove the original
+    * loop from the IR sequence.
+    */
+   ir->remove();
+
+   this->progress = true;
+   return visit_continue;
+}
+
+
+bool
+unroll_loops(exec_list *instructions, loop_state *ls, unsigned max_iterations)
+{
+   loop_unroll_visitor v(ls, max_iterations);
+
+   v.run(instructions);
+
+   return v.progress;
+}