i965: Factor out virtual GRF allocation to a separate object.

Right now virtual GRF book-keeping and allocation is performed in each
visitor class separately (among other hundred different things),
leading to duplicated logic in each visitor and preventing layering as
it forces any code that manipulates i965 IR and needs to allocate
virtual registers to depend on the specific visitor that happens to be
used to translate from GLSL IR.

v2: Use realloc()/free() to allocate VGRF book-keeping arrays (Connor).

Reviewed-by: Matt Turner <mattst88@gmail.com>

1 files changed, 87 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_ir_allocator.h b/src/mesa/drivers/dri/i965/brw_ir_allocator.h
new file mode 100644
index 0000000..b1237ed
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_ir_allocator.h
@@ -0,0 +1,87 @@
+/* -*- c++ -*- */
+/*
+ * Copyright © 2010-2014 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.
+ */
+
+#ifndef BRW_IR_ALLOCATOR_H
+#define BRW_IR_ALLOCATOR_H
+
+#include "main/macros.h"
+
+namespace brw {
+   /**
+    * Simple allocator used to keep track of virtual GRFs.
+    */
+   class simple_allocator {
+   public:
+      simple_allocator() :
+         sizes(NULL), offsets(NULL), count(0), total_size(0), capacity(0)
+      {
+      }
+
+      ~simple_allocator()
+      {
+         free(offsets);
+         free(sizes);
+      }
+
+      unsigned
+      allocate(unsigned size)
+      {
+         if (capacity <= count) {
+            capacity = MAX2(16, capacity * 2);
+            sizes = (unsigned *)realloc(sizes, capacity * sizeof(unsigned));
+            offsets = (unsigned *)realloc(offsets, capacity * sizeof(unsigned));
+         }
+
+         sizes[count] = size;
+         offsets[count] = total_size;
+         total_size += size;
+
+         return count++;
+      }
+
+      /**
+       * Array of sizes for each allocation.  The allocation unit is up to the
+       * back-end, but it's expected to be one scalar value in the FS back-end
+       * and one vec4 in the VEC4 back-end.
+       */
+      unsigned *sizes;
+
+      /**
+       * Array of offsets from the start of the VGRF space in allocation
+       * units.
+       */
+      unsigned *offsets;
+
+      /** Total number of VGRFs allocated. */
+      unsigned count;
+
+      /** Cumulative size in allocation units. */
+      unsigned total_size;
+
+   private:
+      unsigned capacity;
+   };
+}
+
+#endif