/*
 * 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:
 *    Jason Ekstrand (jason@jlekstrand.net)
 *
 */


#ifndef _NIR_WORKLIST_
#define _NIR_WORKLIST_

#include "nir.h"
#include "util/set.h"
#include "util/u_vector.h"
#include "util/u_worklist.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef u_worklist nir_block_worklist;

#define nir_block_worklist_init(w, num_blocks, mem_ctx) \
        u_worklist_init(w, num_blocks, mem_ctx)

#define nir_block_worklist_fini(w) u_worklist_fini(w)

#define nir_block_worklist_is_empty(w) u_worklist_is_empty(w)

#define nir_block_worklist_push_head(w, block) \
        u_worklist_push_head(w, block, index)

#define nir_block_worklist_peek_head(w) \
        u_worklist_peek_head(w, nir_block, index)

#define nir_block_worklist_pop_head(w) \
        u_worklist_pop_head(w, nir_block, index)

#define nir_block_worklist_push_tail(w, block) \
        u_worklist_push_tail(w, block, index)

#define nir_block_worklist_peek_tail(w) \
        u_worklist_peek_tail(w, nir_block, index)

#define nir_block_worklist_pop_tail(w) \
        u_worklist_pop_tail(w, nir_block, index)

void nir_block_worklist_add_all(nir_block_worklist *w, nir_function_impl *impl);

/*
 * This worklist implementation, in contrast to the block worklist, does not
 * have unique entries, meaning a nir_instr can be inserted more than once
 * into the worklist. It uses u_vector to keep the overhead and memory
 * footprint at a minimum.
 *
 * Making it unique by using a set was tested, but for the single usecase
 * (nir_opt_dce) it did not improve speed. There we check the pass_flag bit
 * and abort immediately if there's nothing to do, so the added overhead of
 * the set was higher than just processing the few extra entries.
 */

typedef struct {
   struct u_vector instr_vec;
} nir_instr_worklist;

static inline nir_instr_worklist *
nir_instr_worklist_create() {
   nir_instr_worklist *wl = malloc(sizeof(nir_instr_worklist));
   if (!wl)
      return NULL;

   if (!u_vector_init_pow2(&wl->instr_vec, 8, sizeof(struct nir_instr *))) {
      free(wl);
      return NULL;
   }

   return wl;
}

static inline uint32_t
nir_instr_worklist_length(nir_instr_worklist *wl)
{
   return u_vector_length(&wl->instr_vec);
}

static inline bool
nir_instr_worklist_is_empty(nir_instr_worklist *wl)
{
   return nir_instr_worklist_length(wl) == 0;
}

static inline void
nir_instr_worklist_destroy(nir_instr_worklist *wl)
{
   u_vector_finish(&wl->instr_vec);
   free(wl);
}

static inline void
nir_instr_worklist_push_tail(nir_instr_worklist *wl, nir_instr *instr)
{
   struct nir_instr **vec_instr = u_vector_add(&wl->instr_vec);
   *vec_instr = instr;
}

static inline nir_instr *
nir_instr_worklist_pop_head(nir_instr_worklist *wl)
{
   struct nir_instr **vec_instr = u_vector_remove(&wl->instr_vec);

   if (vec_instr == NULL)
      return NULL;

   return *vec_instr;
}

void
nir_instr_worklist_add_ssa_srcs(nir_instr_worklist *wl, nir_instr *instr);

#define nir_foreach_instr_in_worklist(instr, wl) \
   for (nir_instr *instr; (instr = nir_instr_worklist_pop_head(wl));)

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /* _NIR_WORKLIST_ */