1 files changed, 204 insertions, 190 deletions
diff --git a/mesalib/src/glsl/opt_discard_simplification.cpp b/mesalib/src/glsl/opt_discard_simplification.cpp
index 37622eb02..a19947ddd 100644
--- a/mesalib/src/glsl/opt_discard_simplification.cpp
+++ b/mesalib/src/glsl/opt_discard_simplification.cpp
@@ -1,190 +1,204 @@
-/*
- * 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.
- */
-
-/**
- * \file opt_discard_simplification.cpp
- *
- * This pass simplifies if-statements and loops containing unconditional
- * discards.
- *
- * Case 1: Both branches contain unconditional discards:
- * -----------------------------------------------------
- *
- *    if (cond) {
- *	 s1;
- *	 discard;
- *	 s2;
- *    } else {
- *	 s3;
- *	 discard;
- *	 s4;
- *    }
- *
- * becomes:
- *
- *    discard
- *
- * Case 2: The "then" clause contains an unconditional discard:
- * ------------------------------------------------------------
- *
- *    if (cond) {
- *       s1;
- *       discard;
- *       s2;
- *    } else {
- *	 s3;
- *    }
- *
- * becomes:
- *
- *    if (cond) {
- *	 discard;
- *    } else {
- *	 s3;
- *    }
- *
- * Case 3: The "else" clause contains an unconditional discard:
- * ------------------------------------------------------------
- *
- *    if (cond) {
- *       s1;
- *    } else {
- *       s2;
- *       discard;
- *	 s3;
- *    }
- *
- * becomes:
- *
- *    if (cond) {
- *	 s1;
- *    } else {
- *	 discard;
- *    }
- */
-
-#include "glsl_types.h"
-#include "ir.h"
-
-class discard_simplifier : public ir_hierarchical_visitor {
-public:
-   discard_simplifier()
-   {
-      this->progress = false;
-   }
-
-   ir_visitor_status visit_enter(ir_if *);
-   ir_visitor_status visit_enter(ir_loop *);
-   ir_visitor_status visit_enter(ir_assignment *);
-
-   bool progress;
-};
-
-static ir_discard *
-find_unconditional_discard(exec_list &instructions)
-{
-   foreach_list(n, &instructions) {
-      ir_discard *ir = ((ir_instruction *) n)->as_discard();
-      if (ir != NULL && ir->condition == NULL)
-	 return ir;
-   }
-   return NULL;
-}
-
-static bool
-is_only_instruction(ir_discard *discard)
-{
-   return (discard->prev->is_head_sentinel() &&
-	   discard->next->is_tail_sentinel());
-}
-
-/* We only care about the top level instructions, so don't descend
- * into expressions.
- */
-ir_visitor_status
-discard_simplifier::visit_enter(ir_assignment *ir)
-{
-   return visit_continue_with_parent;
-}
-
-ir_visitor_status
-discard_simplifier::visit_enter(ir_if *ir)
-{
-   ir_discard *then_discard = find_unconditional_discard(ir->then_instructions);
-   ir_discard *else_discard = find_unconditional_discard(ir->else_instructions);
-
-   if (then_discard == NULL && else_discard == NULL)
-      return visit_continue;
-
-   /* If both branches result in discard, replace whole if with discard. */
-   if (then_discard != NULL && else_discard != NULL) {
-      this->progress = true;
-      ir->replace_with(then_discard);
-      return visit_continue_with_parent;
-   }
-
-   /* Otherwise, one branch has a discard. */
-   if (then_discard != NULL && !is_only_instruction(then_discard)) {
-      this->progress = true;
-      ir->then_instructions.make_empty();
-      ir->then_instructions.push_tail(then_discard);
-   } else if (else_discard != NULL && !is_only_instruction(else_discard)) {
-      this->progress = true;
-      ir->else_instructions.make_empty();
-      ir->else_instructions.push_tail(else_discard);
-   }
-
-   visit_list_elements(this, &ir->then_instructions);
-   return visit_continue_with_parent;
-}
-
-ir_visitor_status
-discard_simplifier::visit_enter(ir_loop *ir)
-{
-   ir_discard *discard = find_unconditional_discard(ir->body_instructions);
-
-   if (discard) {
-      ir->replace_with(discard);
-      return visit_continue_with_parent;
-   }
-
-   return visit_continue;
-}
-
-bool
-do_discard_simplification(exec_list *instructions)
-{
-   /* Look for a top-level unconditional discard */
-   ir_discard *discard = find_unconditional_discard(*instructions);
-   if (discard != NULL) {
-      instructions->make_empty();
-      instructions->push_tail(discard);
-      return true;
-   }
-
-   discard_simplifier v;
-
-   visit_list_elements(&v, 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.
+ */
+
+/**
+ * \file opt_discard_simplification.cpp
+ *
+ * This pass simplifies if-statements and loops containing unconditional
+ * discards.
+ *
+ * Case 1: Both branches contain unconditional discards:
+ * -----------------------------------------------------
+ *
+ *    if (cond) {
+ *	 s1;
+ *	 discard;
+ *	 s2;
+ *    } else {
+ *	 s3;
+ *	 discard;
+ *	 s4;
+ *    }
+ *
+ * becomes:
+ *
+ *    discard
+ *
+ * Case 2: The "then" clause contains an unconditional discard:
+ * ------------------------------------------------------------
+ *
+ *    if (cond) {
+ *       s1;
+ *       discard;
+ *       s2;
+ *    } else {
+ *	 s3;
+ *    }
+ *
+ * becomes:
+ *
+ *    if (cond) {
+ *	 discard;
+ *    } else {
+ *	 s3;
+ *    }
+ *
+ * Case 3: The "else" clause contains an unconditional discard:
+ * ------------------------------------------------------------
+ *
+ *    if (cond) {
+ *       s1;
+ *    } else {
+ *       s2;
+ *       discard;
+ *	 s3;
+ *    }
+ *
+ * becomes:
+ *
+ *    if (cond) {
+ *	 s1;
+ *    } else {
+ *	 discard;
+ *    }
+ */
+
+#include "glsl_types.h"
+#include "ir.h"
+
+class discard_simplifier : public ir_hierarchical_visitor {
+public:
+   discard_simplifier()
+   {
+      this->progress = false;
+   }
+
+   ir_visitor_status visit_enter(ir_if *);
+   ir_visitor_status visit_enter(ir_loop *);
+   ir_visitor_status visit_enter(ir_assignment *);
+
+   bool progress;
+};
+
+static ir_discard *
+find_unconditional_discard(exec_list &instructions)
+{
+   foreach_list(n, &instructions) {
+      ir_instruction *ir = (ir_instruction *)n;
+
+      if (ir->ir_type == ir_type_return ||
+	  ir->ir_type == ir_type_loop_jump)
+	 return NULL;
+
+      /* So far, this code doesn't know how to look inside of flow
+       * control to see if a discard later on at this level is
+       * unconditional.
+       */
+      if (ir->ir_type == ir_type_if ||
+	  ir->ir_type == ir_type_loop)
+	 return NULL;
+
+      ir_discard *discard = ir->as_discard();
+      if (discard != NULL && discard->condition == NULL)
+	 return discard;
+   }
+   return NULL;
+}
+
+static bool
+is_only_instruction(ir_discard *discard)
+{
+   return (discard->prev->is_head_sentinel() &&
+	   discard->next->is_tail_sentinel());
+}
+
+/* We only care about the top level instructions, so don't descend
+ * into expressions.
+ */
+ir_visitor_status
+discard_simplifier::visit_enter(ir_assignment *ir)
+{
+   return visit_continue_with_parent;
+}
+
+ir_visitor_status
+discard_simplifier::visit_enter(ir_if *ir)
+{
+   ir_discard *then_discard = find_unconditional_discard(ir->then_instructions);
+   ir_discard *else_discard = find_unconditional_discard(ir->else_instructions);
+
+   if (then_discard == NULL && else_discard == NULL)
+      return visit_continue;
+
+   /* If both branches result in discard, replace whole if with discard. */
+   if (then_discard != NULL && else_discard != NULL) {
+      this->progress = true;
+      ir->replace_with(then_discard);
+      return visit_continue_with_parent;
+   }
+
+   /* Otherwise, one branch has a discard. */
+   if (then_discard != NULL && !is_only_instruction(then_discard)) {
+      this->progress = true;
+      ir->then_instructions.make_empty();
+      ir->then_instructions.push_tail(then_discard);
+   } else if (else_discard != NULL && !is_only_instruction(else_discard)) {
+      this->progress = true;
+      ir->else_instructions.make_empty();
+      ir->else_instructions.push_tail(else_discard);
+   }
+
+   visit_list_elements(this, &ir->then_instructions);
+   return visit_continue_with_parent;
+}
+
+ir_visitor_status
+discard_simplifier::visit_enter(ir_loop *ir)
+{
+   ir_discard *discard = find_unconditional_discard(ir->body_instructions);
+
+   if (discard) {
+      ir->replace_with(discard);
+      return visit_continue_with_parent;
+   }
+
+   return visit_continue;
+}
+
+bool
+do_discard_simplification(exec_list *instructions)
+{
+   /* Look for a top-level unconditional discard */
+   ir_discard *discard = find_unconditional_discard(*instructions);
+   if (discard != NULL) {
+      instructions->make_empty();
+      instructions->push_tail(discard);
+      return true;
+   }
+
+   discard_simplifier v;
+
+   visit_list_elements(&v, instructions);
+
+   return v.progress;
+}