i965: check-point commit of new constant buffer support

Currently, shader constants are stored in the GRF (loaded from the CURBE
prior to shader execution).  This severly limits the number of constants
and temps that we can support.

This new code will support (practically) unlimited size constant buffers
and free up registers in the GRF.  We allocate a new buffer object for the
constants and read them with "Read" messages/instructions.  When only a
small number of constants are used, we can still use the old method.

The code works for fragment shaders only (and is actually disabled) for now.
Need to do the same thing for vertex shaders and need to add the necessary
code-gen to fetch the constants which are referenced by the shader
instructions.

1 files changed, 14 insertions, 3 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index a020b621d6..01e07c967f 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -167,6 +167,9 @@ struct brw_fragment_program {
    struct gl_fragment_program program;
    GLuint id;  /**< serial no. to identify frag progs, never re-used */
    GLboolean isGLSL;  /**< really, any IF/LOOP/CONT/BREAK instructions */
+
+   /** Program constant buffer/surface */
+   dri_bo *const_buffer;
 };
 
 
@@ -238,8 +241,16 @@ struct brw_vs_ouput_sizes {
 };
 
 
+/** Number of texture sampler units */
 #define BRW_MAX_TEX_UNIT 16
-#define BRW_WM_MAX_SURF BRW_MAX_TEX_UNIT + MAX_DRAW_BUFFERS
+
+/**
+ * Size of our surface binding table.
+ * This contains pointers to the drawing surfaces and current texture
+ * objects and shader constant buffer (+1).
+ */
+#define BRW_WM_MAX_SURF (MAX_DRAW_BUFFERS + BRW_MAX_TEX_UNIT + 1)
+
 
 enum brw_cache_id {
    BRW_CC_VP,
@@ -513,8 +524,8 @@ struct brw_context
    /* BRW_NEW_CURBE_OFFSETS: 
     */
    struct {
-      GLuint wm_start;
-      GLuint wm_size;
+      GLuint wm_start;  /**< pos of first wm const in CURBE buffer */
+      GLuint wm_size;   /**< number of float[4] consts, multiple of 16 */
       GLuint clip_start;
       GLuint clip_size;
       GLuint vs_start;