radeonsi: disable the patch ID workaround on SI when the patch ID isn't used (v2)

The workaround causes a massive performance decrease on 1-SE parts.
(Cape Verde, Hainan, Oland)

The performance regression is already part of 17.0 and 17.1.

v2: check tess_uses_prim_id

Cc: 17.0 17.1 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index 108929c..5559946 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -371,6 +371,7 @@ struct si_context {
        struct si_shader_selector *last_tcs;
        int                     last_num_tcs_input_cp;
        int                     last_tes_sh_base;
+       bool                    last_tess_uses_primid;
        unsigned                last_num_patches;
 
        /* Debug state. */

diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index cd069e3..8508259 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -102,6 +102,9 @@ static void si_emit_derived_tess_state(struct si_context *sctx,
         * It would be wrong to think that TCS = TES. */
        struct si_shader_selector *tcs =
                sctx->tcs_shader.cso ? sctx->tcs_shader.cso : sctx->tes_shader.cso;
+       unsigned tess_uses_primid = sctx->ia_multi_vgt_param_key.u.tess_uses_prim_id;
+       bool has_primid_instancing_bug = sctx->b.chip_class == SI &&
+                                        sctx->b.screen->info.max_se == 1;
        unsigned tes_sh_base = sctx->shader_userdata.sh_base[PIPE_SHADER_TESS_EVAL];
        unsigned num_tcs_input_cp = info->vertices_per_patch;
        unsigned num_tcs_output_cp, num_tcs_inputs, num_tcs_outputs;
@@ -128,7 +131,9 @@ static void si_emit_derived_tess_state(struct si_context *sctx,
        if (sctx->last_ls == ls_current &&
            sctx->last_tcs == tcs &&
            sctx->last_tes_sh_base == tes_sh_base &&
-           sctx->last_num_tcs_input_cp == num_tcs_input_cp) {
+           sctx->last_num_tcs_input_cp == num_tcs_input_cp &&
+           (!has_primid_instancing_bug ||
+            (sctx->last_tess_uses_primid == tess_uses_primid))) {
                *num_patches = sctx->last_num_patches;
                return;
        }
@@ -137,6 +142,7 @@ static void si_emit_derived_tess_state(struct si_context *sctx,
        sctx->last_tcs = tcs;
        sctx->last_tes_sh_base = tes_sh_base;
        sctx->last_num_tcs_input_cp = num_tcs_input_cp;
+       sctx->last_tess_uses_primid = tess_uses_primid;
 
        /* This calculates how shader inputs and outputs among VS, TCS, and TES
         * are laid out in LDS. */
@@ -194,22 +200,21 @@ static void si_emit_derived_tess_state(struct si_context *sctx,
                 */
                unsigned one_wave = 64 / MAX2(num_tcs_input_cp, num_tcs_output_cp);
                *num_patches = MIN2(*num_patches, one_wave);
-
-               if (sctx->screen->b.info.max_se == 1) {
-                       /* The VGT HS block increments the patch ID unconditionally
-                        * within a single threadgroup. This results in incorrect
-                        * patch IDs when instanced draws are used.
-                        *
-                        * The intended solution is to restrict threadgroups to
-                        * a single instance by setting SWITCH_ON_EOI, which
-                        * should cause IA to split instances up. However, this
-                        * doesn't work correctly on SI when there is no other
-                        * SE to switch to.
-                        */
-                       *num_patches = 1;
-               }
        }
 
+       /* The VGT HS block increments the patch ID unconditionally
+        * within a single threadgroup. This results in incorrect
+        * patch IDs when instanced draws are used.
+        *
+        * The intended solution is to restrict threadgroups to
+        * a single instance by setting SWITCH_ON_EOI, which
+        * should cause IA to split instances up. However, this
+        * doesn't work correctly on SI when there is no other
+        * SE to switch to.
+        */
+       if (has_primid_instancing_bug)
+               *num_patches = 1;
+
        sctx->last_num_patches = *num_patches;
 
        output_patch0_offset = input_patch_size * *num_patches;