Skip to content

Commit

Permalink
Optimize by removing indirection/ptrs.
Browse files Browse the repository at this point in the history 
See
http://www.shlomifish.org/humour/fortunes/show.cgi?id=linus-torvalds-about-indirections
:

<<<
Trust me: every problem in computer science may be solved by an
indirection, but those indirections are expensive. Pointer chasing is
just about the most expensive thing you can do on modern CPUs.
>>>

-- Linus Torvalds.
  • Loading branch information
@shlomif
shlomif committed Jun 1, 2017
1 parent 7c51f87 commit ea01d89
Showing 1 changed file with 18 additions and 17 deletions.
35 changes: 18 additions & 17 deletions fc-solve/source/scans_impl.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -758,8 +758,8 @@ static inline int fc_solve_soft_dfs_do_solve(

DECLARE_STATE();
ASSIGN_ptr_state(the_soft_dfs_info->state);
fcs_derived_states_list_t *derived_states_list =
&(the_soft_dfs_info->derived_states_list);
fcs_derived_states_list_t derived_list =
the_soft_dfs_info->derived_states_list;
fcs_rand_t *const rand_gen = &(DFS_VAR(soft_thread, rand_gen));
calculate_real_depth(calc_real_depth, PTR_STATE);
const_AUTO(by_depth_units,
Expand Down Expand Up @@ -818,13 +818,12 @@ static inline int fc_solve_soft_dfs_do_solve(
the_soft_dfs_info = &(DFS_VAR(soft_thread, soft_dfs_info)[DEPTH()]);
dfs_max_depth = DFS_VAR(soft_thread, dfs_max_depth);
/* This too has to be re-synced */
derived_states_list = &(the_soft_dfs_info->derived_states_list);
derived_list = the_soft_dfs_info->derived_states_list;
}

TRACE0("Before current_state_index check");
/* All the resultant states in the last test conducted were covered */
if (the_soft_dfs_info->current_state_index ==
derived_states_list->num_states)
if (the_soft_dfs_info->current_state_index == derived_list.num_states)
{
/* Check if we already tried all the tests here. */
if (the_soft_dfs_info->move_func_list_idx ==
Expand All @@ -844,9 +843,9 @@ static inline int fc_solve_soft_dfs_do_solve(
}
else
{
the_soft_dfs_info->derived_states_list = derived_list;
--the_soft_dfs_info;
derived_states_list =
&(the_soft_dfs_info->derived_states_list);
derived_list = the_soft_dfs_info->derived_states_list;
ASSIGN_ptr_state(the_soft_dfs_info->state);
VERIFY_PTR_STATE_TRACE0("Verify Foo");
soft_thread->num_vacant_freecells =
Expand All @@ -864,7 +863,7 @@ static inline int fc_solve_soft_dfs_do_solve(
continue; /* Just to make sure depth is not -1 now */
}

derived_states_list->num_states = 0;
derived_list.num_states = 0;

TRACE0("Before iter_handler");
/* If this is the first test, then count the number of unoccupied
Expand Down Expand Up @@ -938,7 +937,7 @@ static inline int fc_solve_soft_dfs_do_solve(
the_soft_dfs_info->move_func_list_idx =
THE_MOVE_FUNCS_LIST.num_lists;
fc_solve_derived_states_list_add_state(
derived_states_list, derived, 0);
&derived_list, derived, 0);
if (the_soft_dfs_info
->derived_states_random_indexes_max_size < 1)
{
Expand Down Expand Up @@ -979,7 +978,7 @@ static inline int fc_solve_soft_dfs_do_solve(
THE_MOVE_FUNCS_LIST
.lists[the_soft_dfs_info->move_func_list_idx]
.move_funcs[the_soft_dfs_info->move_func_idx](
soft_thread, &pass, derived_states_list);
soft_thread, &pass, &derived_list);

VERIFY_PTR_STATE_TRACE0("Verify Glanko");

Expand All @@ -994,10 +993,10 @@ static inline int fc_solve_soft_dfs_do_solve(
break;
}
} while ((local_shuffling_type != FCS_NO_SHUFFLING) ||
(derived_states_list->num_states == 0));
(derived_list.num_states == 0));
}

const_SLOT(num_states, derived_states_list);
const_AUTO(num_states, derived_list.num_states);
if (num_states >
the_soft_dfs_info->derived_states_random_indexes_max_size)
{
Expand Down Expand Up @@ -1049,7 +1048,7 @@ static inline int fc_solve_soft_dfs_do_solve(
if (orig_idx < THE_MOVE_FUNCS_LIST.num_lists)
{
fcs_derived_states_list_item_t *const derived_states =
derived_states_list->states;
derived_list.states;
for (size_t i = 0; i < num_states; i++)
{
rand_array[i].rating = befs_rate_state(soft_thread,
Expand Down Expand Up @@ -1084,9 +1083,9 @@ static inline int fc_solve_soft_dfs_do_solve(
the_soft_dfs_info->current_state_index = 0;
}

const_SLOT(num_states, derived_states_list);
const_AUTO(num_states, derived_list.num_states);
fcs_derived_states_list_item_t *const derived_states =
derived_states_list->states;
derived_list.states;
var_AUTO(state_idx, the_soft_dfs_info->current_state_index - 1);
const fcs_rating_with_index_t *rand_int_ptr =
the_soft_dfs_info->derived_states_random_indexes + state_idx;
Expand Down Expand Up @@ -1118,6 +1117,7 @@ static inline int fc_solve_soft_dfs_do_solve(
RECALC_BY_DEPTH_LIMITS();
}
the_soft_dfs_info->current_state_index = state_idx;
the_soft_dfs_info->derived_states_list = derived_list;
++the_soft_dfs_info;
ASSIGN_ptr_state(single_derived_state);
the_soft_dfs_info->state = PTR_STATE;
Expand All @@ -1126,8 +1126,8 @@ static inline int fc_solve_soft_dfs_do_solve(
the_soft_dfs_info->move_func_list_idx = 0;
the_soft_dfs_info->move_func_idx = 0;
the_soft_dfs_info->current_state_index = 0;
derived_states_list = &(the_soft_dfs_info->derived_states_list);
derived_states_list->num_states = 0;
derived_list = the_soft_dfs_info->derived_states_list;
derived_list.num_states = 0;

calculate_real_depth(calc_real_depth, PTR_STATE);

Expand All @@ -1141,6 +1141,7 @@ static inline int fc_solve_soft_dfs_do_solve(
#endif
if (check_if_limits_exceeded())
{
the_soft_dfs_info->derived_states_list = derived_list;
TRACE0("Returning FCS_STATE_SUSPEND_PROCESS (inside "
"current_state_index)");
return FCS_STATE_SUSPEND_PROCESS;
Expand Down

0 comments on commit ea01d89

Please sign in to comment.