iris: Stop setting up fake params

In d1c4e64a69e, we added a parameter to tell the back-end compiler to
ignore the param array and just push however many constants you ask it
to push.  Iris doesn't want to push anything so it gives a bogus number
of parameters and trusts the back-end compiler to dead-code all of them.
Now that we can tell the back-end compiler to stop re-arranging things,
delete the hack and enable the new simpler code path.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

2 files changed, 6 insertions, 13 deletions

diff --git a/src/gallium/drivers/iris/iris_program.c b/src/gallium/drivers/iris/iris_program.c
index f2269a4a147..21b07cde299 100644
--- a/src/gallium/drivers/iris/iris_program.c
+++ b/src/gallium/drivers/iris/iris_program.c
@@ -308,13 +308,6 @@ iris_setup_uniforms(const struct brw_compiler *compiler,
 {
    UNUSED const struct gen_device_info *devinfo = compiler->devinfo;
 
-   /* The intel compiler assumes that num_uniforms is in bytes. For
-    * scalar that means 4 bytes per uniform slot.
-    *
-    * Ref: brw_nir_lower_uniforms, type_size_scalar_bytes.
-    */
-   nir->num_uniforms *= 4;
-
    const unsigned IRIS_MAX_SYSTEM_VALUES =
       PIPE_MAX_SHADER_IMAGES * BRW_IMAGE_PARAM_SIZE;
    enum brw_param_builtin *system_values =
@@ -513,12 +506,12 @@ iris_setup_uniforms(const struct brw_compiler *compiler,
    assert(num_cbufs < PIPE_MAX_CONSTANT_BUFFERS);
    nir_validate_shader(nir, "after remap");
 
-   /* We don't use params[], but fs_visitor::nir_setup_uniforms() asserts
-    * about it for compute shaders, so go ahead and make some fake ones
-    * which the backend will dead code eliminate.
+   /* We don't use params[] but gallium leaves num_uniforms set.  We use this
+    * to detect when cbuf0 exists but we don't need it anymore when we get
+    * here.  Instead, zero it out so that the back-end doesn't get confused
+    * when nr_params * 4 != num_uniforms != nr_params * 4.
     */
-   prog_data->nr_params = nir->num_uniforms / 4;
-   prog_data->param = rzalloc_array(mem_ctx, uint32_t, prog_data->nr_params);
+   nir->num_uniforms = 0;
 
    /* Constant loads (if any) need to go at the end of the constant buffers so
     * we need to know num_cbufs before we can lower to them.
diff --git a/src/gallium/drivers/iris/iris_screen.c b/src/gallium/drivers/iris/iris_screen.c
index 7516e457b28..cbefa9dfb13 100644
--- a/src/gallium/drivers/iris/iris_screen.c
+++ b/src/gallium/drivers/iris/iris_screen.c
@@ -673,7 +673,7 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
    screen->compiler->shader_perf_log = iris_shader_perf_log;
    screen->compiler->supports_pull_constants = false;
    screen->compiler->supports_shader_constants = true;
-   screen->compiler->compact_params = true;
+   screen->compiler->compact_params = false;
 
    iris_disk_cache_init(screen);