nir/lower_vars_to_ssa: Pass around the nir_shader instead of a void mem_ctx
[mesa.git] / src / glsl / nir / nir_opt_peephole_select.c
index 247fe050a70d165b419db9f2c54a4d1e908b175d..f400cfd66da3ecf4e6656a593f2056922f78b95b 100644 (file)
@@ -52,36 +52,68 @@ struct peephole_select_state {
 };
 
 static bool
-are_all_move_to_phi(nir_block *block)
+block_check_for_allowed_instrs(nir_block *block)
 {
    nir_foreach_instr(block, instr) {
-      if (instr->type != nir_instr_type_alu)
-         return false;
+      switch (instr->type) {
+      case nir_instr_type_intrinsic: {
+         nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
+
+         switch (intrin->intrinsic) {
+         case nir_intrinsic_load_var:
+            switch (intrin->variables[0]->var->data.mode) {
+            case nir_var_shader_in:
+            case nir_var_uniform:
+               break;
+
+            default:
+               return false;
+            }
+            break;
+
+         default:
+            return false;
+         }
 
-      /* It must be a move operation */
-      nir_alu_instr *mov = nir_instr_as_alu(instr);
-      if (mov->op != nir_op_fmov && mov->op != nir_op_imov)
-         return false;
+         break;
+      }
 
-      /* Can't handle saturate */
-      if (mov->dest.saturate)
-         return false;
+      case nir_instr_type_load_const:
+         break;
 
-      /* It must be SSA */
-      if (!mov->dest.dest.is_ssa)
-         return false;
+      case nir_instr_type_alu: {
+         /* It must be a move operation */
+         nir_alu_instr *mov = nir_instr_as_alu(instr);
+         if (mov->op != nir_op_fmov && mov->op != nir_op_imov &&
+             mov->op != nir_op_fneg && mov->op != nir_op_ineg &&
+             mov->op != nir_op_fabs && mov->op != nir_op_iabs)
+            return false;
 
-      /* It cannot have any if-uses */
-      if (mov->dest.dest.ssa.if_uses->entries != 0)
-         return false;
+         /* Can't handle saturate */
+         if (mov->dest.saturate)
+            return false;
+
+         /* It must be SSA */
+         if (!mov->dest.dest.is_ssa)
+            return false;
 
-      /* The only uses of this definition must be phi's in the successor */
-      struct set_entry *entry;
-      set_foreach(mov->dest.dest.ssa.uses, entry) {
-         const nir_instr *dest_instr = entry->key;
-         if (dest_instr->type != nir_instr_type_phi ||
-             dest_instr->block != block->successors[0])
+         /* It cannot have any if-uses */
+         if (mov->dest.dest.ssa.if_uses->entries != 0)
             return false;
+
+         /* The only uses of this definition must be phi's in the successor */
+         struct set_entry *entry;
+         set_foreach(mov->dest.dest.ssa.uses, entry) {
+            const nir_instr *dest_instr = entry->key;
+            if (dest_instr->type != nir_instr_type_phi ||
+                dest_instr->block != block->successors[0])
+               return false;
+         }
+         break;
+      }
+
+      default:
+         return false;
       }
    }
 
@@ -119,8 +151,9 @@ nir_opt_peephole_select_block(nir_block *block, void *void_state)
    nir_block *then_block = nir_cf_node_as_block(then_node);
    nir_block *else_block = nir_cf_node_as_block(else_node);
 
-   /* ... and those blocks must only contain move-to-phi. */
-   if (!are_all_move_to_phi(then_block) || !are_all_move_to_phi(else_block))
+   /* ... and those blocks must only contain "allowed" instructions. */
+   if (!block_check_for_allowed_instrs(then_block) ||
+       !block_check_for_allowed_instrs(else_block))
       return true;
 
    /* At this point, we know that the previous CFG node is an if-then
@@ -129,48 +162,51 @@ nir_opt_peephole_select_block(nir_block *block, void *void_state)
     * selects.
     */
 
+   nir_block *prev_block = nir_cf_node_as_block(nir_cf_node_prev(prev_node));
+   assert(prev_block->cf_node.type == nir_cf_node_block);
+
+   /* First, we move the remaining instructions from the blocks to the
+    * block before.  We have already guaranteed that this is safe by
+    * calling block_check_for_allowed_instrs()
+    */
+   nir_foreach_instr_safe(then_block, instr) {
+      exec_node_remove(&instr->node);
+      instr->block = prev_block;
+      exec_list_push_tail(&prev_block->instr_list, &instr->node);
+   }
+
+   nir_foreach_instr_safe(else_block, instr) {
+      exec_node_remove(&instr->node);
+      instr->block = prev_block;
+      exec_list_push_tail(&prev_block->instr_list, &instr->node);
+   }
+
    nir_foreach_instr_safe(block, instr) {
       if (instr->type != nir_instr_type_phi)
          break;
 
       nir_phi_instr *phi = nir_instr_as_phi(instr);
       nir_alu_instr *sel = nir_alu_instr_create(state->mem_ctx, nir_op_bcsel);
-      sel->src[0].src = nir_src_copy(if_stmt->condition, state->mem_ctx);
+      nir_src_copy(&sel->src[0].src, &if_stmt->condition, state->mem_ctx);
+      /* Splat the condition to all channels */
+      memset(sel->src[0].swizzle, 0, sizeof sel->src[0].swizzle);
 
       assert(exec_list_length(&phi->srcs) == 2);
-      foreach_list_typed(nir_phi_src, src, node, &phi->srcs) {
+      nir_foreach_phi_src(phi, src) {
          assert(src->pred == then_block || src->pred == else_block);
          assert(src->src.is_ssa);
 
          unsigned idx = src->pred == then_block ? 1 : 2;
-
-         if (src->src.ssa->parent_instr->block == src->pred) {
-            /* We already know that this instruction must be a move with
-             * this phi's in this block as its only users.
-             */
-            nir_alu_instr *mov = nir_instr_as_alu(src->src.ssa->parent_instr);
-            assert(mov->instr.type == nir_instr_type_alu);
-            assert(mov->op == nir_op_fmov || mov->op == nir_op_imov);
-
-            sel->src[idx].src = nir_src_copy(mov->src[0].src, state->mem_ctx);
-            sel->src[idx].negate = mov->src[0].negate;
-            sel->src[idx].abs = mov->src[0].abs;
-            memcpy(sel->src[idx].swizzle, mov->src[0].swizzle, 4);
-         } else {
-            sel->src[idx].src = nir_src_copy(src->src, state->mem_ctx);
-         }
+         nir_src_copy(&sel->src[idx].src, &src->src, state->mem_ctx);
       }
 
-      sel->dest.dest.is_ssa = true;
-      nir_ssa_def_init(&sel->instr, &sel->dest.dest.ssa,
-                       phi->dest.ssa.num_components, phi->dest.ssa.name);
+      nir_ssa_dest_init(&sel->instr, &sel->dest.dest,
+                        phi->dest.ssa.num_components, phi->dest.ssa.name);
       sel->dest.write_mask = (1 << phi->dest.ssa.num_components) - 1;
 
-      nir_src sel_dest_src = {
-         .is_ssa = true,
-         .ssa = &sel->dest.dest.ssa,
-      };
-      nir_ssa_def_rewrite_uses(&phi->dest.ssa, sel_dest_src, state->mem_ctx);
+      nir_ssa_def_rewrite_uses(&phi->dest.ssa,
+                               nir_src_for_ssa(&sel->dest.dest.ssa),
+                               state->mem_ctx);
 
       nir_instr_insert_before(&phi->instr, &sel->instr);
       nir_instr_remove(&phi->instr);