lima/ppir: rework tex lowering

Move steps from lowering to emit, since they can be done earlier in a
single place, rather than in two-steps.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4975>

src/gallium/drivers/lima/ir/pp/lower.c

@@ -160,42 +160,7 @@ static bool ppir_lower_ddxy(ppir_block *block, ppir_node *node)
 
 static bool ppir_lower_texture(ppir_block *block, ppir_node *node)
 {
-   ppir_load_texture_node *load_tex = ppir_node_to_load_texture(node);
    ppir_dest *dest = ppir_node_get_dest(node);
-   ppir_node *src_coords = ppir_node_get_src(node, 0)->node;
-   ppir_load_node *load = NULL;
-
-   if (src_coords && ppir_node_has_single_src_succ(src_coords) &&
-       (src_coords->op == ppir_op_load_coords))
-      load = ppir_node_to_load(src_coords);
-   else {
-      /* Create load_coords node */
-      load = ppir_node_create(block, ppir_op_load_coords_reg, -1, 0);
-      if (!load)
-         return false;
-      list_addtail(&load->node.list, &node->list);
-
-      load->src = load_tex->src[0];
-      load->num_src = 1;
-      if (load_tex->sampler_dim == GLSL_SAMPLER_DIM_CUBE)
-         load->num_components = 3;
-      else
-         load->num_components = 2;
-
-      ppir_debug("%s create load_coords node %d for %d\n",
-                 __FUNCTION__, load->node.index, node->index);
-
-      ppir_node_foreach_pred_safe(node, dep) {
-         ppir_node *pred = dep->pred;
-         ppir_node_remove_dep(dep);
-         ppir_node_add_dep(&load->node, pred, ppir_dep_src);
-      }
-      ppir_node_add_dep(node, &load->node, ppir_dep_src);
-   }
-
-   assert(load);
-   load_tex->src[0].type = load->dest.type = ppir_target_pipeline;
-   load_tex->src[0].pipeline = load->dest.pipeline = ppir_pipeline_reg_discard;
 
    /* Always create move node since there can be successors in other blocks */
    ppir_node *move = ppir_node_insert_mov(node);

src/gallium/drivers/lima/ir/pp/nir.c

@@ -99,20 +99,6 @@ static void ppir_node_add_src(ppir_compiler *comp, ppir_node *node,
 
    if (ns->is_ssa) {
       child = comp->var_nodes[ns->ssa->index];
-      switch (child->op) {
-      case ppir_op_load_varying:
-         /* If at least one successor is load_texture, promote it to
-          * load_coords to ensure that is has exactly one successor */
-         if (node->op == ppir_op_load_texture) {
-            nir_tex_src *nts = (nir_tex_src *)ns;
-            if (nts->src_type == nir_tex_src_coord)
-               child->op = ppir_op_load_coords;
-         }
-         break;
-      default:
-         break;
-      }
-
       if (child->op != ppir_op_undef)
          ppir_node_add_dep(node, child, ppir_dep_src);
    }
@@ -459,6 +445,19 @@ static bool ppir_emit_tex(ppir_block *block, nir_instr *ni)
       return false;
    }
 
+   switch (instr->sampler_dim) {
+   case GLSL_SAMPLER_DIM_2D:
+   case GLSL_SAMPLER_DIM_CUBE:
+   case GLSL_SAMPLER_DIM_RECT:
+   case GLSL_SAMPLER_DIM_EXTERNAL:
+      break;
+   default:
+      ppir_error("unsupported sampler dim: %d\n", instr->sampler_dim);
+      return false;
+   }
+
+   /* emit ld_tex node */
+
    unsigned mask = 0;
    if (!instr->dest.is_ssa)
       mask = u_bit_consecutive(0, nir_tex_instr_dest_size(instr));
@@ -468,18 +467,6 @@ static bool ppir_emit_tex(ppir_block *block, nir_instr *ni)
       return false;
 
    node->sampler = instr->texture_index;
-
-   switch (instr->sampler_dim) {
-   case GLSL_SAMPLER_DIM_2D:
-   case GLSL_SAMPLER_DIM_CUBE:
-   case GLSL_SAMPLER_DIM_RECT:
-   case GLSL_SAMPLER_DIM_EXTERNAL:
-      break;
-   default:
-      ppir_error("unsupported sampler dim: %d\n", instr->sampler_dim);
-      return NULL;
-   }
-
    node->sampler_dim = instr->sampler_dim;
 
    for (int i = 0; i < instr->coord_components; i++)
@@ -487,11 +474,25 @@ static bool ppir_emit_tex(ppir_block *block, nir_instr *ni)
 
    for (int i = 0; i < instr->num_srcs; i++) {
       switch (instr->src[i].src_type) {
-      case nir_tex_src_coord:
+      case nir_tex_src_coord: {
+         nir_src *ns = &instr->src[i].src;
+         if (ns->is_ssa) {
+            ppir_node *child = block->comp->var_nodes[ns->ssa->index];
+            if (child->op == ppir_op_load_varying) {
+               /* If the successor is load_texture, promote it to load_coords */
+               nir_tex_src *nts = (nir_tex_src *)ns;
+               if (nts->src_type == nir_tex_src_coord)
+                  child->op = ppir_op_load_coords;
+            }
+         }
+
+         /* src[0] is not used by the ld_tex instruction but ensures
+          * correct scheduling due to the pipeline dependency */
          ppir_node_add_src(block->comp, &node->node, &node->src[0], &instr->src[i].src,
                            u_bit_consecutive(0, instr->coord_components));
          node->num_src++;
          break;
+      }
       case nir_tex_src_bias:
       case nir_tex_src_lod:
          node->lod_bias_en = true;
@@ -506,6 +507,44 @@ static bool ppir_emit_tex(ppir_block *block, nir_instr *ni)
    }
 
    list_addtail(&node->node.list, &block->node_list);
+
+   /* validate load coords node */
+
+   ppir_node *src_coords = ppir_node_get_src(&node->node, 0)->node;
+   ppir_load_node *load = NULL;
+
+   if (src_coords && ppir_node_has_single_src_succ(src_coords) &&
+       (src_coords->op == ppir_op_load_coords))
+      load = ppir_node_to_load(src_coords);
+   else {
+      /* Create load_coords node */
+      load = ppir_node_create(block, ppir_op_load_coords_reg, -1, 0);
+      if (!load)
+         return false;
+      list_addtail(&load->node.list, &block->node_list);
+
+      load->src = node->src[0];
+      load->num_src = 1;
+      if (node->sampler_dim == GLSL_SAMPLER_DIM_CUBE)
+         load->num_components = 3;
+      else
+         load->num_components = 2;
+
+      ppir_debug("%s create load_coords node %d for %d\n",
+                 __FUNCTION__, load->index, node->node.index);
+
+      ppir_node_foreach_pred_safe((&node->node), dep) {
+         ppir_node *pred = dep->pred;
+         ppir_node_remove_dep(dep);
+         ppir_node_add_dep(&load->node, pred, ppir_dep_src);
+      }
+      ppir_node_add_dep(&node->node, &load->node, ppir_dep_src);
+   }
+
+   assert(load);
+   node->src[0].type = load->dest.type = ppir_target_pipeline;
+   node->src[0].pipeline = load->dest.pipeline = ppir_pipeline_reg_discard;
+
    return true;
 }
 

src/gallium/drivers/lima/ir/pp/ppir.h

@@ -270,8 +270,7 @@ typedef struct {
 typedef struct {
    ppir_node node;
    ppir_dest dest;
-   ppir_src src[2]; /* src[0] temporarily stores src_coords,
-                       not to be used after lowering */
+   ppir_src src[2];
    int num_src;
    int sampler;
    int sampler_dim;