i965: Pull stage_prog_data.nr_params out of the NIR shader

Previously, we had a bunch of code in each stage to figure out how many
slots we needed in stage_prog_data.param.  This code was mostly identical
across the stages and had been copied and pasted around.  Unfortunately,
this meant that any time you did something special, you had to add code for
it to each of these places.  In particular, none of the stages took
subroutines into account; they were working entirely by accident.  By
taking this data from the NIR shader, we know the exact number of entries
we need and everything goes a bit smoother.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>

src/mesa/drivers/dri/i965/brw_cs.c

@@ -30,6 +30,7 @@
 #include "intel_mipmap_tree.h"
 #include "brw_state.h"
 #include "intel_batchbuffer.h"
+#include "glsl/nir/nir.h"
 
 static bool
 brw_codegen_cs_prog(struct brw_context *brw,
@@ -55,8 +56,7 @@ brw_codegen_cs_prog(struct brw_context *brw,
     * prog_data associated with the compiled program, and which will be freed
     * by the state cache.
     */
-   int param_count = cs->base.num_uniform_components +
-                     cs->base.NumImages * BRW_IMAGE_PARAM_SIZE;
+   int param_count = cp->program.Base.nir->num_uniforms;
 
    /* The backend also sometimes adds params for texture size. */
    param_count += 2 * ctx->Const.Program[MESA_SHADER_COMPUTE].MaxTextureImageUnits;

src/mesa/drivers/dri/i965/brw_gs.c

@@ -32,6 +32,7 @@
 #include "brw_vec4_gs_visitor.h"
 #include "brw_state.h"
 #include "brw_ff_gs.h"
+#include "glsl/nir/nir.h"
 
 
 bool
@@ -60,9 +61,7 @@ brw_codegen_gs_prog(struct brw_context *brw,
     * every uniform is a float which gets padded to the size of a vec4.
     */
    struct gl_shader *gs = prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
-   int param_count = gs->num_uniform_components * 4;
-
-   param_count += gs->NumImages * BRW_IMAGE_PARAM_SIZE;
+   int param_count = gp->program.Base.nir->num_uniforms * 4;
 
    c.prog_data.base.base.param =
       rzalloc_array(NULL, const gl_constant_value *, param_count);

src/mesa/drivers/dri/i965/brw_vs.c

@@ -109,18 +109,13 @@ brw_codegen_vs_prog(struct brw_context *brw,
     * prog_data associated with the compiled program, and which will be freed
     * by the state cache.
     */
-   int param_count;
-   if (vs) {
-      /* We add padding around uniform values below vec4 size, with the worst
-       * case being a float value that gets blown up to a vec4, so be
-       * conservative here.
-       */
-      param_count = vs->base.num_uniform_components * 4 +
-                    vs->base.NumImages * BRW_IMAGE_PARAM_SIZE;
-      stage_prog_data->nr_image_params = vs->base.NumImages;
-   } else {
-      param_count = vp->program.Base.Parameters->NumParameters * 4;
-   }
+   int param_count = vp->program.Base.nir->num_uniforms;
+   if (!brw->intelScreen->compiler->scalar_vs)
+      param_count *= 4;
+
+   if (vs)
+      prog_data.base.base.nr_image_params = vs->base.NumImages;
+
    /* vec4_visitor::setup_uniform_clipplane_values() also uploads user clip
     * planes as uniforms.
     */

src/mesa/drivers/dri/i965/brw_wm.c

@@ -35,6 +35,7 @@
 #include "program/prog_parameter.h"
 #include "program/program.h"
 #include "intel_mipmap_tree.h"
+#include "glsl/nir/nir.h"
 
 #include "util/ralloc.h"
 
@@ -173,14 +174,9 @@ brw_codegen_wm_prog(struct brw_context *brw,
     * prog_data associated with the compiled program, and which will be freed
     * by the state cache.
     */
-   int param_count;
-   if (fs) {
-      param_count = fs->base.num_uniform_components +
-                    fs->base.NumImages * BRW_IMAGE_PARAM_SIZE;
+   int param_count = fp->program.Base.nir->num_uniforms;
+   if (fs)
       prog_data.base.nr_image_params = fs->base.NumImages;
-   } else {
-      param_count = fp->program.Base.Parameters->NumParameters * 4;
-   }
    /* The backend also sometimes adds params for texture size. */
    param_count += 2 * ctx->Const.Program[MESA_SHADER_FRAGMENT].MaxTextureImageUnits;
    prog_data.base.param =