nv50: allow using inline vertex data submit when gl_VertexID is used

The hardware can actually generates vertexid when vertices come from
a client-side buffer like when glDrawElements is used.

This doesn't fix (or break) any piglit tests but it improves the
previous attempt of Ilia (c830d19 "nv50: avoid using inline vertex
data submit when gl_VertexID is used")

The only disadvantage is that only works on G84+, but we don't really
care of that weird and old NV50 chipset.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>

5 files changed, 46 insertions, 15 deletions

diff --git a/src/gallium/drivers/nouveau/nv50/nv50_program.c b/src/gallium/drivers/nouveau/nv50/nv50_program.c
index 48057d20f4e..a4b8ddfda95 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_program.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_program.c
@@ -66,7 +66,6 @@ nv50_vertprog_assign_slots(struct nv50_ir_prog_info *info)
       case TGSI_SEMANTIC_VERTEXID:
          prog->vp.attrs[2] |= NV50_3D_VP_GP_BUILTIN_ATTR_EN_VERTEX_ID;
          prog->vp.attrs[2] |= NV50_3D_VP_GP_BUILTIN_ATTR_EN_VERTEX_ID_DRAW_ARRAYS_ADD_START;
-         prog->vp.vertexid = 1;
          continue;
       default:
          break;
@@ -383,6 +382,8 @@ nv50_program_translate(struct nv50_program *prog, uint16_t chipset,
    prog->max_gpr = MAX2(4, (info->bin.maxGPR >> 1) + 1);
    prog->tls_space = info->bin.tlsSpace;
 
+   prog->vp.need_vertex_id = info->io.vertexId < PIPE_MAX_SHADER_INPUTS;
+
    if (prog->type == PIPE_SHADER_FRAGMENT) {
       if (info->prop.fp.writesDepth) {
          prog->fp.flags[0] |= NV50_3D_FP_CONTROL_EXPORTS_Z;
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_program.h b/src/gallium/drivers/nouveau/nv50/nv50_program.h
index f0016707163..1de5122a56e 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_program.h
+++ b/src/gallium/drivers/nouveau/nv50/nv50_program.h
@@ -76,9 +76,9 @@ struct nv50_program {
       ubyte psiz;        /* output slot of point size */
       ubyte bfc[2];      /* indices into varying for FFC (FP) or BFC (VP) */
       ubyte edgeflag;
-      ubyte vertexid;
       ubyte clpd[2];     /* output slot of clip distance[i]'s 1st component */
       ubyte clpd_nr;
+      bool need_vertex_id;
    } vp;
 
    struct {
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_push.c b/src/gallium/drivers/nouveau/nv50/nv50_push.c
index f31eaa0e314..cbef95d07f6 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_push.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_push.c
@@ -24,6 +24,10 @@ struct push_context {
    struct translate *translate;
 
    bool primitive_restart;
+
+   bool need_vertex_id;
+   int32_t index_bias;
+
    uint32_t prim;
    uint32_t restart_index;
    uint32_t instance_id;
@@ -74,6 +78,11 @@ emit_vertices_i08(struct push_context *ctx, unsigned start, unsigned count)
 
       size = ctx->vertex_words * nr;
 
+      if (unlikely(ctx->need_vertex_id)) {
+         BEGIN_NV04(ctx->push, NV84_3D(VERTEX_ID_BASE), 1);
+         PUSH_DATA (ctx->push, *elts + ctx->index_bias);
+      }
+
       BEGIN_NI04(ctx->push, NV50_3D(VERTEX_DATA), size);
 
       ctx->translate->run_elts8(ctx->translate, elts, nr, 0, ctx->instance_id,
@@ -107,6 +116,11 @@ emit_vertices_i16(struct push_context *ctx, unsigned start, unsigned count)
 
       size = ctx->vertex_words * nr;
 
+      if (unlikely(ctx->need_vertex_id)) {
+         BEGIN_NV04(ctx->push, NV84_3D(VERTEX_ID_BASE), 1);
+         PUSH_DATA (ctx->push, *elts + ctx->index_bias);
+      }
+
       BEGIN_NI04(ctx->push, NV50_3D(VERTEX_DATA), size);
 
       ctx->translate->run_elts16(ctx->translate, elts, nr, 0, ctx->instance_id,
@@ -140,6 +154,11 @@ emit_vertices_i32(struct push_context *ctx, unsigned start, unsigned count)
 
       size = ctx->vertex_words * nr;
 
+      if (unlikely(ctx->need_vertex_id)) {
+         BEGIN_NV04(ctx->push, NV84_3D(VERTEX_ID_BASE), 1);
+         PUSH_DATA (ctx->push, *elts + ctx->index_bias);
+      }
+
       BEGIN_NI04(ctx->push, NV50_3D(VERTEX_DATA), size);
 
       ctx->translate->run_elts(ctx->translate, elts, nr, 0, ctx->instance_id,
@@ -161,10 +180,18 @@ emit_vertices_i32(struct push_context *ctx, unsigned start, unsigned count)
 static void
 emit_vertices_seq(struct push_context *ctx, unsigned start, unsigned count)
 {
+   uint32_t elts = 0;
+
    while (count) {
       unsigned push = MIN2(count, ctx->packet_vertex_limit);
       unsigned size = ctx->vertex_words * push;
 
+      if (unlikely(ctx->need_vertex_id)) {
+         /* For non-indexed draws, gl_VertexID goes up after each vertex. */
+         BEGIN_NV04(ctx->push, NV84_3D(VERTEX_ID_BASE), 1);
+         PUSH_DATA (ctx->push, elts++);
+      }
+
       BEGIN_NI04(ctx->push, NV50_3D(VERTEX_DATA), size);
 
       ctx->translate->run(ctx->translate, start, push, 0, ctx->instance_id,
@@ -216,7 +243,14 @@ nv50_push_vbo(struct nv50_context *nv50, const struct pipe_draw_info *info)
 
    ctx.push = nv50->base.pushbuf;
    ctx.translate = nv50->vertex->translate;
-   ctx.packet_vertex_limit = nv50->vertex->packet_vertex_limit;
+
+   ctx.need_vertex_id = nv50->screen->base.class_3d >= NV84_3D_CLASS &&
+      nv50->vertprog->vp.need_vertex_id && (nv50->vertex->num_elements < 32);
+   ctx.index_bias = info->index_bias;
+
+   /* For indexed draws, gl_VertexID must be emitted for every vertex. */
+   ctx.packet_vertex_limit =
+      ctx.need_vertex_id ? 1 : nv50->vertex->packet_vertex_limit;
    ctx.vertex_words = nv50->vertex->vertex_size;
 
    assert(nv50->num_vtxbufs <= PIPE_MAX_ATTRIBS);
@@ -307,4 +341,10 @@ nv50_push_vbo(struct nv50_context *nv50, const struct pipe_draw_info *info)
       ctx.instance_id++;
       ctx.prim |= NV50_3D_VERTEX_BEGIN_GL_INSTANCE_NEXT;
    }
+
+   if (unlikely(ctx.need_vertex_id)) {
+      /* Reset gl_VertexID to prevent future indexed draws to be confused. */
+      BEGIN_NV04(ctx.push, NV84_3D(VERTEX_ID_BASE), 1);
+      PUSH_DATA (ctx.push, nv50->state.index_bias);
+   }
 }
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_state_validate.c b/src/gallium/drivers/nouveau/nv50/nv50_state_validate.c
index b6181edf24f..02a759c23ad 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_state_validate.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_state_validate.c
@@ -503,8 +503,7 @@ static struct state_validate {
     { nv50_validate_samplers,      NV50_NEW_SAMPLERS },
     { nv50_stream_output_validate, NV50_NEW_STRMOUT |
                                    NV50_NEW_VERTPROG | NV50_NEW_GMTYPROG },
-    { nv50_vertex_arrays_validate, NV50_NEW_VERTEX | NV50_NEW_ARRAYS |
-                                   NV50_NEW_VERTPROG },
+    { nv50_vertex_arrays_validate, NV50_NEW_VERTEX | NV50_NEW_ARRAYS },
     { nv50_validate_min_samples,   NV50_NEW_MIN_SAMPLES },
 };
 #define validate_list_len (sizeof(validate_list) / sizeof(validate_list[0]))
diff --git a/src/gallium/drivers/nouveau/nv50/nv50_vbo.c b/src/gallium/drivers/nouveau/nv50/nv50_vbo.c
index ac0c4d99dbb..85878d5fcc7 100644
--- a/src/gallium/drivers/nouveau/nv50/nv50_vbo.c
+++ b/src/gallium/drivers/nouveau/nv50/nv50_vbo.c
@@ -294,8 +294,7 @@ nv50_vertex_arrays_validate(struct nv50_context *nv50)
    uint64_t addrs[PIPE_MAX_ATTRIBS];
    uint32_t limits[PIPE_MAX_ATTRIBS];
    struct nouveau_pushbuf *push = nv50->base.pushbuf;
-   struct nv50_vertex_stateobj dummy = {};
-   struct nv50_vertex_stateobj *vertex = nv50->vertex ? nv50->vertex : &dummy;
+   struct nv50_vertex_stateobj *vertex = nv50->vertex;
    struct pipe_vertex_buffer *vb;
    struct nv50_vertex_element *ve;
    uint32_t mask;
@@ -303,14 +302,6 @@ nv50_vertex_arrays_validate(struct nv50_context *nv50)
    unsigned i;
    const unsigned n = MAX2(vertex->num_elements, nv50->state.num_vtxelts);
 
-   /* A vertexid is not generated for inline data uploads. Have to use a
-    * VBO. This check must come after the vertprog has been validated,
-    * otherwise vertexid may be unset.
-    */
-   assert(nv50->vertprog->translated);
-   if (nv50->vertprog->vp.vertexid)
-      nv50->vbo_push_hint = 0;
-
    if (unlikely(vertex->need_conversion))
       nv50->vbo_fifo = ~0;
    else