Mesa (main): intel/compiler: add flag to indicate edge flags vertex input is last

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 8da92b5c0a358e30be557cae3303a4027b24db1c
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=8da92b5c0a358e30be557cae3303a4027b24db1c

Author: Dave Airlie <airlied at redhat.com>
Date:   Tue Jun  8 15:04:42 2021 +1000

intel/compiler: add flag to indicate edge flags vertex input is last

965 and the mesa st disagree on how vertex elements are ordered when
edgeflags are involved. 965 wants them in gl_vert_attrib order,
but gallium supplies the edgeflag as the last vertex element regardless.

This adds a flag which is enabled for gen4/5 to denote that the
edgeflag is at the end. When we reap 965 later we can resolve this
better.

Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11146>

---

 src/intel/compiler/brw_compiler.h |  1 +
 src/intel/compiler/brw_nir.c      | 13 +++++++++++--
 src/intel/compiler/brw_nir.h      |  1 +
 src/intel/compiler/brw_vec4.cpp   |  2 +-
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/intel/compiler/brw_compiler.h b/src/intel/compiler/brw_compiler.h
index 3009161fc3f..3152dc3005a 100644
--- a/src/intel/compiler/brw_compiler.h
+++ b/src/intel/compiler/brw_compiler.h
@@ -1472,6 +1472,7 @@ struct brw_compile_vs_params {
    const struct brw_vs_prog_key *key;
    struct brw_vs_prog_data *prog_data;
 
+   bool edgeflag_is_last; /* true for gallium */
    bool shader_time;
    int shader_time_index;
 
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index ee5f3cf40bd..6169fe99fbf 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -160,6 +160,7 @@ remap_patch_urb_offsets(nir_block *block, nir_builder *b,
 
 void
 brw_nir_lower_vs_inputs(nir_shader *nir,
+                        bool edgeflag_is_last,
                         const uint8_t *vs_attrib_wa_flags)
 {
    /* Start with the location of the variable's base. */
@@ -270,8 +271,16 @@ brw_nir_lower_vs_inputs(nir_shader *nir,
                 * before it and counting the bits.
                 */
                int attr = nir_intrinsic_base(intrin);
-               int slot = util_bitcount64(nir->info.inputs_read &
-                                            BITFIELD64_MASK(attr));
+               uint64_t inputs_read = nir->info.inputs_read;
+               int slot = -1;
+               if (edgeflag_is_last) {
+                  inputs_read &= ~BITFIELD64_BIT(VERT_ATTRIB_EDGEFLAG);
+                  if (attr == VERT_ATTRIB_EDGEFLAG)
+                     slot = num_inputs - 1;
+               }
+               if (slot == -1)
+                  slot = util_bitcount64(inputs_read &
+                                         BITFIELD64_MASK(attr));
                nir_intrinsic_set_base(intrin, slot);
                break;
             }
diff --git a/src/intel/compiler/brw_nir.h b/src/intel/compiler/brw_nir.h
index 0e46e80f421..7a8b3051090 100644
--- a/src/intel/compiler/brw_nir.h
+++ b/src/intel/compiler/brw_nir.h
@@ -105,6 +105,7 @@ void brw_nir_lower_legacy_clipping(nir_shader *nir,
                                    int nr_userclip_plane_consts,
                                    struct brw_stage_prog_data *prog_data);
 void brw_nir_lower_vs_inputs(nir_shader *nir,
+                             bool edgeflag_is_last,
                              const uint8_t *vs_attrib_wa_flags);
 void brw_nir_lower_vue_inputs(nir_shader *nir,
                               const struct brw_vue_map *vue_map);
diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp
index 8fefecd6429..a6ce2efcfd8 100644
--- a/src/intel/compiler/brw_vec4.cpp
+++ b/src/intel/compiler/brw_vec4.cpp
@@ -2905,7 +2905,7 @@ brw_compile_vs(const struct brw_compiler *compiler,
    prog_data->inputs_read = nir->info.inputs_read;
    prog_data->double_inputs_read = nir->info.vs.double_inputs;
 
-   brw_nir_lower_vs_inputs(nir, key->gl_attrib_wa_flags);
+   brw_nir_lower_vs_inputs(nir, params->edgeflag_is_last, key->gl_attrib_wa_flags);
    brw_nir_lower_vue_outputs(nir);
    brw_postprocess_nir(nir, compiler, is_scalar, debug_enabled,
                        key->base.robust_buffer_access);