/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Connor Abbott (cwabbott0@gmail.com)
 *
 */

#include "nir.h"

#pragma once

#ifdef __cplusplus
extern "C" {
#endif

/** NIR Control Flow Modification
 *
 * This file contains various API's that make modifying control flow in NIR,
 * while maintaining the invariants checked by the validator, much easier.
 */

/* Helper struct for representing a point to extract/insert. Helps reduce the
 * combinatorial explosion of possible points to extract.
 */

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);
}

/** Control flow insertion. */

/** puts a control flow node where the cursor is */
void nir_cf_node_insert(nir_cursor cursor, nir_cf_node *node);

/** puts a control flow node immediately after another control flow node */
static inline void
nir_cf_node_insert_after(nir_cf_node *node, nir_cf_node *after)
{
   nir_cf_node_insert(nir_after_cf_node(node), after);
}

/** puts a control flow node immediately before another control flow node */
static inline void
nir_cf_node_insert_before(nir_cf_node *node, nir_cf_node *before)
{
   nir_cf_node_insert(nir_before_cf_node(node), before);
}

/** puts a control flow node at the beginning of a list from an if, loop, or function */
static inline void
nir_cf_node_insert_begin(struct exec_list *list, nir_cf_node *node)
{
   nir_cf_node_insert(nir_before_cf_list(list), node);
}

/** puts a control flow node at the end of a list from an if, loop, or function */
static inline void
nir_cf_node_insert_end(struct exec_list *list, nir_cf_node *node)
{
   nir_cf_node_insert(nir_after_cf_list(list), node);
}

/** removes a control flow node, doing any cleanup necessary */
void nir_cf_node_remove(nir_cf_node *node);

#ifdef __cplusplus
}
#endif