i965/vs: Improve live interval calculation.

This is derived from the FS visitor code for the same, but tracks each channel
separately (otherwise, some typical fill-a-channel-at-a-time patterns would
produce excessive live intervals across loops and cause spilling).

Reviewed-by: Kenneth Graunke <[email protected]>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=48375
          (crash -> failure, can turn into pass by forcing unrolling still)

1 files changed, 81 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_live_variables.h b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.h
new file mode 100644
index 00000000000..438a03e45d9
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_vec4_live_variables.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright © 2012 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.
+ *
+ * Authors:
+ *    Eric Anholt <[email protected]>
+ *
+ */
+
+#include "brw_vec4.h"
+
+namespace brw {
+
+struct block_data {
+   /**
+    * Which variables are defined before being used in the block.
+    *
+    * Note that for our purposes, "defined" means unconditionally, completely
+    * defined.
+    */
+   bool *def;
+
+   /**
+    * Which variables are used before being defined in the block.
+    */
+   bool *use;
+
+   /** Which defs reach the entry point of the block. */
+   bool *livein;
+
+   /** Which defs reach the exit point of the block. */
+   bool *liveout;
+};
+
+class vec4_live_variables {
+public:
+   static void* operator new(size_t size, void *ctx)
+   {
+      void *node;
+
+      node = rzalloc_size(ctx, size);
+      assert(node != NULL);
+
+      return node;
+   }
+
+   vec4_live_variables(vec4_visitor *v, cfg_t *cfg);
+   ~vec4_live_variables();
+
+   void setup_def_use();
+   void compute_live_variables();
+
+   vec4_visitor *v;
+   cfg_t *cfg;
+   void *mem_ctx;
+
+   int num_vars;
+
+   /** Per-basic-block information on live variables */
+   struct block_data *bd;
+};
+
+} /* namespace brw */