intel: Use a system value for gl_FragCoord

It's kind-of an anomaly that the Intel drivers are still treating
gl_FragCoord as an input.  It also makes zero sense because we have to
special-case it in the back-end.

Because ANV is the only user of nir_lower_wpos_center, we go ahead and
just update it to look for nir_intrinsic_load_frag_coord as part of this
patch.

Reviewed-by: Kenneth Graunke <[email protected]>

3 files changed, 3 insertions, 27 deletions

diff --git a/src/intel/blorp/blorp_blit.c b/src/intel/blorp/blorp_blit.c
index 78a47c9cbe5..323e94e3d28 100644
--- a/src/intel/blorp/blorp_blit.c
+++ b/src/intel/blorp/blorp_blit.c
@@ -60,9 +60,6 @@ struct brw_blorp_blit_vars {
    nir_variable *v_dst_offset;
    nir_variable *v_src_inv_size;
 
-   /* gl_FragCoord */
-   nir_variable *frag_coord;
-
    /* gl_FragColor */
    nir_variable *color_out;
 };
@@ -84,10 +81,6 @@ brw_blorp_blit_vars_init(nir_builder *b, struct brw_blorp_blit_vars *v,
 
 #undef LOAD_INPUT
 
-   v->frag_coord = nir_variable_create(b->shader, nir_var_shader_in,
-                                       glsl_vec4_type(), "gl_FragCoord");
-   v->frag_coord->data.location = VARYING_SLOT_POS;
-
    v->color_out = nir_variable_create(b->shader, nir_var_shader_out,
                                       glsl_vec4_type(), "gl_FragColor");
    v->color_out->data.location = FRAG_RESULT_COLOR;
@@ -98,7 +91,7 @@ blorp_blit_get_frag_coords(nir_builder *b,
                            const struct brw_blorp_blit_prog_key *key,
                            struct brw_blorp_blit_vars *v)
 {
-   nir_ssa_def *coord = nir_f2i32(b, nir_load_var(b, v->frag_coord));
+   nir_ssa_def *coord = nir_f2i32(b, nir_load_frag_coord(b));
 
    /* Account for destination surface intratile offset
     *
diff --git a/src/intel/blorp/blorp_clear.c b/src/intel/blorp/blorp_clear.c
index 7e77e80565f..af7c0d506f3 100644
--- a/src/intel/blorp/blorp_clear.c
+++ b/src/intel/blorp/blorp_clear.c
@@ -70,12 +70,7 @@ blorp_params_get_clear_kernel(struct blorp_batch *batch,
    nir_ssa_def *color = nir_load_var(&b, v_color);
 
    if (clear_rgb_as_red) {
-      nir_variable *frag_coord =
-         nir_variable_create(b.shader, nir_var_shader_in,
-                             glsl_vec4_type(), "gl_FragCoord");
-      frag_coord->data.location = VARYING_SLOT_POS;
-
-      nir_ssa_def *pos = nir_f2i32(&b, nir_load_var(&b, frag_coord));
+      nir_ssa_def *pos = nir_f2i32(&b, nir_load_frag_coord(&b));
       nir_ssa_def *comp = nir_umod(&b, nir_channel(&b, pos, 0),
                                        nir_imm_int(&b, 3));
       nir_ssa_def *color_component =
@@ -976,7 +971,7 @@ blorp_params_get_mcs_partial_resolve_kernel(struct blorp_batch *batch,
 
    /* Do an MCS fetch and check if it is equal to the magic clear value */
    nir_ssa_def *mcs =
-      blorp_nir_txf_ms_mcs(&b, nir_f2i32(&b, blorp_nir_frag_coord(&b)),
+      blorp_nir_txf_ms_mcs(&b, nir_f2i32(&b, nir_load_frag_coord(&b)),
                                nir_load_layer_id(&b));
    nir_ssa_def *is_clear =
       blorp_nir_mcs_is_clear_color(&b, mcs, blorp_key.num_samples);
diff --git a/src/intel/blorp/blorp_nir_builder.h b/src/intel/blorp/blorp_nir_builder.h
index 9664bdbcd27..0ba855fcd66 100644
--- a/src/intel/blorp/blorp_nir_builder.h
+++ b/src/intel/blorp/blorp_nir_builder.h
@@ -37,18 +37,6 @@ blorp_nir_init_shader(nir_builder *b,
 }
 
 static inline nir_ssa_def *
-blorp_nir_frag_coord(nir_builder *b)
-{
-   nir_variable *frag_coord =
-      nir_variable_create(b->shader, nir_var_shader_in,
-                          glsl_vec4_type(), "gl_FragCoord");
-
-   frag_coord->data.location = VARYING_SLOT_POS;
-
-   return nir_load_var(b, frag_coord);
-}
-
-static inline nir_ssa_def *
 blorp_nir_txf_ms_mcs(nir_builder *b, nir_ssa_def *xy_pos, nir_ssa_def *layer)
 {
    nir_tex_instr *tex = nir_tex_instr_create(b->shader, 1);