libxtrans fontconfig glproto libX11 libxcb xcbproto mesa xserver pixman xkeyboard-config git update 22 Dec 2013

xserver          commit a68df147421da21528b5be2d34678383922fa352
libxcb           commit f653464554469b5767f1c99abced25a76bace047
libxcb/xcb-proto commit 4087fc682c5ceb849b74442e17a6b73176e5eecb
xkeyboard-config commit a224a636139d22e1dc7ca7d23782cd656e87bcf5
libX11           commit 3d69b0a83e62f8f6fbdd952fc49cdbdf8825e1e6
libXdmcp         commit 089081dca4ba3598c6f9bf401c029378943b5854
libXext          commit bb24f2970f2e425f4df90c9b73d078ad15a73fbb
libfontenc       commit 3acba630d8b57084f7e92c15732408711ed5137a
libXinerama      commit edd95182b26eb5d576d4878c559e0f17dddaa909
libXau           commit 304a11be4727c5a7feeb2501e8e001466f8ce84e
xkbcomp          commit e3e6e938535532bfad175c1635256ab7fb3ac943
pixman           commit 945ab7a6f3eb6241f07e8f094dc0e647d1f10d9d
xextproto        commit 3f355f138d6df57e067458a20f47307883048adb
randrproto       commit e7526e6b5fe0966929cda10b2ded0258413744db
glproto          commit f84853d97d5749308992412a215fa518b6536eb3
mkfontscale      commit 880a0c4733e62e54e6a0f1238c7430727d23657b
xwininfo         commit ba0d1b0da21d2dbdd81098ed5778f3792b472e13
libXft           commit 4acfdaf95adb0a05c2a25550bdde036c865902f4
libXmu           commit 22d9c590901e121936f50dee97dc60c4f7defb63
libxtrans        commit 2c0a7840a28ae696e80e73157856d7a049fdf6c7
fontconfig       commit 5c725f2f5829238d16116f782d00d8bb0defaf08
mesa             commit 2efe7927d38983029784825fc4897e9b77aa237e

1 files changed, 205 insertions, 113 deletions

diff --git a/mesalib/src/glsl/loop_unroll.cpp b/mesalib/src/glsl/loop_unroll.cpp
index ff97766f1..6eced1736 100644
--- a/mesalib/src/glsl/loop_unroll.cpp
+++ b/mesalib/src/glsl/loop_unroll.cpp
@@ -37,6 +37,10 @@ public:
    }
 
    virtual ir_visitor_status visit_leave(ir_loop *ir);
+   void simple_unroll(ir_loop *ir, int iterations);
+   void complex_unroll(ir_loop *ir, int iterations,
+                       bool continue_from_then_branch);
+   void splice_post_if_instructions(ir_if *ir_if, exec_list *splice_dest);
 
    loop_state *state;
 
@@ -86,6 +90,138 @@ public:
 };
 
 
+/**
+ * Unroll a loop which does not contain any jumps.  For example, if the input
+ * is:
+ *
+ *     (loop (...) ...instrs...)
+ *
+ * And the iteration count is 3, the output will be:
+ *
+ *     ...instrs... ...instrs... ...instrs...
+ */
+void
+loop_unroll_visitor::simple_unroll(ir_loop *ir, int iterations)
+{
+   void *const mem_ctx = ralloc_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;
+}
+
+
+/**
+ * Unroll a loop whose last statement is an ir_if.  If \c
+ * continue_from_then_branch is true, the loop is repeated only when the
+ * "then" branch of the if is taken; otherwise it is repeated only when the
+ * "else" branch of the if is taken.
+ *
+ * For example, if the input is:
+ *
+ *     (loop (...)
+ *      ...body...
+ *      (if (cond)
+ *          (...then_instrs...)
+ *        (...else_instrs...)))
+ *
+ * And the iteration count is 3, and \c continue_from_then_branch is true,
+ * then the output will be:
+ *
+ *     ...body...
+ *     (if (cond)
+ *         (...then_instrs...
+ *          ...body...
+ *          (if (cond)
+ *              (...then_instrs...
+ *               ...body...
+ *               (if (cond)
+ *                   (...then_instrs...)
+ *                 (...else_instrs...)))
+ *            (...else_instrs...)))
+ *       (...else_instrs))
+ */
+void
+loop_unroll_visitor::complex_unroll(ir_loop *ir, int iterations,
+                                    bool continue_from_then_branch)
+{
+   void *const mem_ctx = ralloc_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_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;
+}
+
+
+/**
+ * Move all of the instructions which follow \c ir_if to the end of
+ * \c splice_dest.
+ *
+ * For example, in the code snippet:
+ *
+ *     (if (cond)
+ *         (...then_instructions...
+ *          break)
+ *       (...else_instructions...))
+ *     ...post_if_instructions...
+ *
+ * If \c ir_if points to the "if" instruction, and \c splice_dest points to
+ * (...else_instructions...), the code snippet is transformed into:
+ *
+ *     (if (cond)
+ *         (...then_instructions...
+ *          break)
+ *       (...else_instructions...
+ *        ...post_if_instructions...))
+ */
+void
+loop_unroll_visitor::splice_post_if_instructions(ir_if *ir_if,
+                                                 exec_list *splice_dest)
+{
+   while (!ir_if->get_next()->is_tail_sentinel()) {
+      ir_instruction *move_ir = (ir_instruction *) ir_if->get_next();
+
+      move_ir->remove();
+      splice_dest->push_tail(move_ir);
+   }
+}
+
+
 ir_visitor_status
 loop_unroll_visitor::visit_leave(ir_loop *ir)
 {
@@ -100,14 +236,14 @@ loop_unroll_visitor::visit_leave(ir_loop *ir)
       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)
+   if (ls->limiting_terminator == NULL)
       return visit_continue;
 
+   iterations = ls->limiting_terminator->iterations;
+
    /* Don't try to unroll loops that have zillions of iterations either.
     */
    if (iterations > (int) max_iterations)
@@ -120,127 +256,83 @@ loop_unroll_visitor::visit_leave(ir_loop *ir)
    if (count.fail || count.nodes * iterations > (int)max_iterations * 5)
       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 = ralloc_parent(ir);
-         ir_instruction *ir_to_replace = ir;
-
-         for (int i = 0; i < iterations; i++) {
-            exec_list copy_list;
+   /* Note: the limiting terminator contributes 1 to ls->num_loop_jumps.
+    * We'll be removing the limiting terminator before we unroll.
+    */
+   assert(ls->num_loop_jumps > 0);
+   unsigned predicted_num_loop_jumps = ls->num_loop_jumps - 1;
 
-            copy_list.make_empty();
-            clone_ir_list(mem_ctx, &copy_list, &ir->body_instructions);
+   if (predicted_num_loop_jumps > 1)
+      return visit_continue;
 
-            ir_if = ((ir_instruction *) copy_list.get_tail())->as_if();
-            assert(ir_if != NULL);
+   if (predicted_num_loop_jumps == 0) {
+      ls->limiting_terminator->ir->remove();
+      simple_unroll(ir, iterations);
+      return visit_continue;
+   }
 
-            ir_to_replace->insert_before(&copy_list);
-            ir_to_replace->remove();
+   ir_instruction *last_ir = (ir_instruction *) ir->body_instructions.get_tail();
+   assert(last_ir != NULL);
 
-            /* placeholder that will be removed in the next iteration */
-            ir_to_replace =
-	       new(mem_ctx) ir_loop_jump(ir_loop_jump::jump_continue);
+   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 and use the simple
+       * unroller with an iteration count of 1.
+       */
+      last_ir->remove();
 
-            exec_list *const list = (continue_from_then_branch)
-               ? &ir_if->then_instructions : &ir_if->else_instructions;
+      ls->limiting_terminator->ir->remove();
+      simple_unroll(ir, 1);
+      return visit_continue;
+   }
 
-            list->push_tail(ir_to_replace);
+   foreach_list(node, &ir->body_instructions) {
+      /* recognize loops in the form produced by ir_lower_jumps */
+      ir_instruction *cur_ir = (ir_instruction *) node;
+
+      /* Skip the limiting terminator, since it will go away when we
+       * unroll.
+       */
+      if (cur_ir == ls->limiting_terminator->ir)
+         continue;
+
+      ir_if *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)) {
+            ls->limiting_terminator->ir->remove();
+            splice_post_if_instructions(ir_if, &ir_if->else_instructions);
+            ir_if_last->remove();
+            complex_unroll(ir, iterations, false);
+            return visit_continue;
+         } else {
+            ir_if_last =
+               (ir_instruction *) ir_if->else_instructions.get_tail();
+
+            if (is_break(ir_if_last)) {
+               ls->limiting_terminator->ir->remove();
+               splice_post_if_instructions(ir_if, &ir_if->then_instructions);
+               ir_if_last->remove();
+               complex_unroll(ir, iterations, true);
+               return visit_continue;
+            }
          }
-
-         ir_to_replace->remove();
-
-         this->progress = true;
-         return visit_continue;
       }
    }
 
-   void *const mem_ctx = ralloc_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.
+   /* Did not find the break statement.  It must be in a complex if-nesting,
+    * so don't try to unroll.
     */
-   ir->remove();
-
-   this->progress = true;
    return visit_continue;
 }