gallium/i915: overhaul of fragment shader compilation, constant/immediate allocation

Before, fragment shaders were translated to i915 hw code at bind time, rather
than create time.  Now there's an i915_fragment_shader struct with the expected
contents that's created by i915_create_fs_state().  Translation to i915 code
takes place there too.

Immediates are handled correctly now.  During program translation we keep
track of which constant buffer slots are free (i.e. not referenced by the
shader).  Then the TGSI immediates and ancillary immediates (introduced for
SIN/COS/etc) are put into those free slots.

When it's time to upload the constant buffer, use the fp->constant_flags[]
array to determine if we should grab an immediate from the shader, or a
user-defined parameter from the gallium constant buffer.

1 files changed, 36 insertions, 6 deletions

diff --git a/src/gallium/drivers/i915simple/i915_context.h b/src/gallium/drivers/i915simple/i915_context.h
index 2d876925b2..5cc38cdc85 100644
--- a/src/gallium/drivers/i915simple/i915_context.h
+++ b/src/gallium/drivers/i915simple/i915_context.h
@@ -79,6 +79,40 @@
 #define I915_MAX_CONSTANT  32
 
 
+/** See constant_flags[] below */
+#define I915_CONSTFLAG_USER 0x1f
+
+
+/**
+ * Subclass of pipe_shader_state
+ */
+struct i915_fragment_shader
+{
+   struct pipe_shader_state state;
+   uint *program;
+   uint program_len;
+
+   /**
+    * constants introduced during translation.
+    * These are placed at the end of the constant buffer and grow toward
+    * the beginning (eg: slot 31, 30 29, ...)
+    * User-provided constants start at 0.
+    * This allows both types of constants to co-exist (until there's too many)
+    * and doesn't require regenerating/changing the fragment program to
+    * shuffle constants around.
+    */
+   uint num_constants;
+   float constants[I915_MAX_CONSTANT][4];
+
+   /**
+    * Status of each constant
+    * if I915_CONSTFLAG_PARAM, the value must be taken from the corresponding
+    * slot of the user's constant buffer. (set by pipe->set_constant_buffer())
+    * Else, the bitmask indicates which components are occupied by immediates.
+    */
+   ubyte constant_flags[I915_MAX_CONSTANT];
+};
+
 
 struct i915_cache_context;
 
@@ -93,11 +127,6 @@ struct i915_state
    float constants[PIPE_SHADER_TYPES][I915_MAX_CONSTANT][4];
    /** number of constants passed in through a constant buffer */
    uint num_user_constants[PIPE_SHADER_TYPES];
-   /** user constants, plus extra constants from shader translation */
-   uint num_constants[PIPE_SHADER_TYPES];
-
-   uint *program;
-   uint program_len;
 
    /* texture sampler state */
    unsigned sampler[I915_TEX_UNITS][3];
@@ -187,7 +216,8 @@ struct i915_context
    const struct i915_sampler_state         *sampler[PIPE_MAX_SAMPLERS];
    const struct i915_depth_stencil_state   *depth_stencil;
    const struct i915_rasterizer_state      *rasterizer;
-   const struct pipe_shader_state *fs;
+
+   struct i915_fragment_shader *fs;
 
    struct pipe_blend_color blend_color;
    struct pipe_clip_state clip;