nir: Add an initialization function for SSA definitions

Reviewed-by: Connor Abbott <cwabbott0@gmail.com>

src/glsl/nir/nir.c

@@ -1597,6 +1597,20 @@ nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state)
    return nir_foreach_dest(instr, visit_dest_indirect, &dest_state);
 }
 
+void
+nir_ssa_def_init(nir_function_impl *impl, nir_instr *instr, nir_ssa_def *def,
+                 unsigned num_components, const char *name)
+{
+   void *mem_ctx = ralloc_parent(instr);
+
+   def->name = name;
+   def->index = impl->ssa_alloc++;
+   def->parent_instr = instr;
+   def->uses = _mesa_set_create(mem_ctx, _mesa_key_pointer_equal);
+   def->if_uses = _mesa_set_create(mem_ctx, _mesa_key_pointer_equal);
+   def->num_components = num_components;
+}
+
 
 static bool foreach_cf_node(nir_cf_node *node, nir_foreach_block_cb cb,
                             bool reverse, void *state);

src/glsl/nir/nir.h

@@ -1278,6 +1278,10 @@ typedef bool (*nir_foreach_src_cb)(nir_src *src, void *state);
 bool nir_foreach_dest(nir_instr *instr, nir_foreach_dest_cb cb, void *state);
 bool nir_foreach_src(nir_instr *instr, nir_foreach_src_cb cb, void *state);
 
+void nir_ssa_def_init(nir_function_impl *impl, nir_instr *instr,
+                      nir_ssa_def *def, unsigned num_components,
+                      const char *name);
+
 /* visits basic blocks in source-code order */
 typedef bool (*nir_foreach_block_cb)(nir_block *block, void *state);
 bool nir_foreach_block(nir_function_impl *impl, nir_foreach_block_cb cb,

src/glsl/nir/nir_to_ssa.c

@@ -163,12 +163,9 @@ static nir_ssa_def *get_ssa_src(nir_register *reg, rewrite_state *state)
        * to preserve the information that this source is undefined
        */
       nir_ssa_undef_instr *instr = nir_ssa_undef_instr_create(state->mem_ctx);
-      instr->def.index = state->impl->ssa_alloc++;
+      nir_ssa_def_init(state->impl, &instr->instr, &instr->def,
-      instr->def.num_components = reg->num_components;
+                       reg->num_components, NULL);
-      instr->def.uses = _mesa_set_create(state->mem_ctx,
+
-                                         _mesa_key_pointer_equal);
-      instr->def.if_uses = _mesa_set_create(state->mem_ctx,
-                                            _mesa_key_pointer_equal);
       /*
        * We could just insert the undefined instruction before the instruction
        * we're rewriting, but we could be rewriting a phi source in which case
@@ -254,13 +251,8 @@ rewrite_def_forwards(nir_dest *dest, void *_state)
       name = ralloc_asprintf(state->mem_ctx, "%s_%u", dest->reg.reg->name,
                              state->states[index].num_defs);
 
-   dest->ssa.index = state->impl->ssa_alloc++;
+   nir_ssa_def_init(state->impl, state->parent_instr, &dest->ssa,
-   dest->ssa.num_components = reg->num_components;
+                    reg->num_components, name);
-   dest->ssa.parent_instr = state->parent_instr;
-   dest->ssa.uses = _mesa_set_create(state->mem_ctx, _mesa_key_pointer_equal);
-   dest->ssa.if_uses = _mesa_set_create(state->mem_ctx,
-                                        _mesa_key_pointer_equal);
-   dest->ssa.name = name;
 
    /* push our SSA destination on the stack */
    state->states[index].index++;
@@ -327,14 +319,8 @@ rewrite_alu_instr_forward(nir_alu_instr *instr, rewrite_state *state)
 
       instr->dest.write_mask = (1 << num_components) - 1;
       instr->dest.dest.is_ssa = true;
-      instr->dest.dest.ssa.index = state->impl->ssa_alloc++;
+      nir_ssa_def_init(state->impl, &instr->instr, &instr->dest.dest.ssa,
-      instr->dest.dest.ssa.num_components = num_components;
+                       num_components, name);
-      instr->dest.dest.ssa.name = name;
-      instr->dest.dest.ssa.parent_instr = &instr->instr;
-      instr->dest.dest.ssa.uses = _mesa_set_create(state->mem_ctx,
-                                                   _mesa_key_pointer_equal);
-      instr->dest.dest.ssa.if_uses = _mesa_set_create(state->mem_ctx,
-                                                      _mesa_key_pointer_equal);
 
       if (nir_op_infos[instr->op].output_size == 0) {
          /*