nir: Move nir_cursor to nir.h.

We want to use this for normal instruction insertion too, not just
control flow.  Generally these functions are going to be extremely
useful when working with NIR, so I want them to be widely available
without having to include a separate file.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>
Acked-by: Connor Abbott <[email protected]>

1 files changed, 97 insertions, 0 deletions

diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 40871f73e96..49430cdce68 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -1546,6 +1546,101 @@ nir_deref *nir_copy_deref(void *mem_ctx, nir_deref *deref);
 nir_load_const_instr *
 nir_deref_get_const_initializer_load(nir_shader *shader, nir_deref_var *deref);
 
+/**
+ * NIR Cursors and Instruction Insertion API
+ * @{
+ *
+ * A tiny struct representing a point to insert/extract instructions or
+ * control flow nodes.  Helps reduce the combinatorial explosion of possible
+ * points to insert/extract.
+ *
+ * \sa nir_control_flow.h
+ */
+typedef enum {
+   nir_cursor_before_block,
+   nir_cursor_after_block,
+   nir_cursor_before_instr,
+   nir_cursor_after_instr,
+} nir_cursor_option;
+
+typedef struct {
+   nir_cursor_option option;
+   union {
+      nir_block *block;
+      nir_instr *instr;
+   };
+} nir_cursor;
+
+static inline nir_cursor
+nir_before_block(nir_block *block)
+{
+   nir_cursor cursor;
+   cursor.option = nir_cursor_before_block;
+   cursor.block = block;
+   return cursor;
+}
+
+static inline nir_cursor
+nir_after_block(nir_block *block)
+{
+   nir_cursor cursor;
+   cursor.option = nir_cursor_after_block;
+   cursor.block = block;
+   return cursor;
+}
+
+static inline nir_cursor
+nir_before_instr(nir_instr *instr)
+{
+   nir_cursor cursor;
+   cursor.option = nir_cursor_before_instr;
+   cursor.instr = instr;
+   return cursor;
+}
+
+static inline nir_cursor
+nir_after_instr(nir_instr *instr)
+{
+   nir_cursor cursor;
+   cursor.option = nir_cursor_after_instr;
+   cursor.instr = instr;
+   return cursor;
+}
+
+static inline nir_cursor
+nir_before_cf_node(nir_cf_node *node)
+{
+   if (node->type == nir_cf_node_block)
+      return nir_before_block(nir_cf_node_as_block(node));
+
+   return nir_after_block(nir_cf_node_as_block(nir_cf_node_prev(node)));
+}
+
+static inline nir_cursor
+nir_after_cf_node(nir_cf_node *node)
+{
+   if (node->type == nir_cf_node_block)
+      return nir_after_block(nir_cf_node_as_block(node));
+
+   return nir_before_block(nir_cf_node_as_block(nir_cf_node_next(node)));
+}
+
+static inline nir_cursor
+nir_before_cf_list(struct exec_list *cf_list)
+{
+   nir_cf_node *first_node = exec_node_data(nir_cf_node,
+                                            exec_list_get_head(cf_list), node);
+   return nir_before_cf_node(first_node);
+}
+
+static inline nir_cursor
+nir_after_cf_list(struct exec_list *cf_list)
+{
+   nir_cf_node *last_node = exec_node_data(nir_cf_node,
+                                           exec_list_get_tail(cf_list), node);
+   return nir_after_cf_node(last_node);
+}
+
 void nir_instr_insert_before(nir_instr *instr, nir_instr *before);
 void nir_instr_insert_after(nir_instr *instr, nir_instr *after);
 
@@ -1560,6 +1655,8 @@ void nir_instr_insert_after_cf_list(struct exec_list *list, nir_instr *after);
 
 void nir_instr_remove(nir_instr *instr);
 
+/** @} */
+
 typedef bool (*nir_foreach_ssa_def_cb)(nir_ssa_def *def, void *state);
 typedef bool (*nir_foreach_dest_cb)(nir_dest *dest, void *state);
 typedef bool (*nir_foreach_src_cb)(nir_src *src, void *state);