/* The next stack variable in the partition, or EOC. */
size_t next;
+
+ /* The numbers of conflicting stack variables. */
+ bitmap conflicts;
};
#define EOC ((size_t)-1)
is non-decreasing. */
static size_t *stack_vars_sorted;
-/* We have an interference graph between such objects. This graph
- is lower triangular. */
-static bool *stack_vars_conflict;
-static size_t stack_vars_conflict_alloc;
-static size_t n_stack_vars_conflict;
-
/* The phase of the stack frame. This is the known misalignment of
virtual_stack_vars_rtx from PREFERRED_STACK_BOUNDARY. That is,
(frame_offset+frame_phase) % PREFERRED_STACK_BOUNDARY == 0. */
stack_vars[stack_vars_num].representative = stack_vars_num;
stack_vars[stack_vars_num].next = EOC;
+ /* All variables initially conflict with no other. */
+ stack_vars[stack_vars_num].conflicts = NULL;
+
/* Ensure that this decl doesn't get put onto the list twice. */
set_rtl (decl, pc_rtx);
stack_vars_num++;
}
-/* Compute the linear index of a lower-triangular coordinate (I, J). */
-
-static size_t
-triangular_index (size_t i, size_t j)
-{
- if (i < j)
- {
- size_t t;
- t = i, i = j, j = t;
- }
-
- if (i & 1)
- return ((i + 1) / 2) * i + j;
- else
- return (i / 2) * (i + 1) + j;
-}
-
-/* Ensure that STACK_VARS_CONFLICT is large enough for N objects. */
-
-static void
-resize_stack_vars_conflict (size_t n)
-{
- size_t size = triangular_index (n-1, n-1) + 1;
-
- if (size <= stack_vars_conflict_alloc)
- {
- if (n > n_stack_vars_conflict)
- fatal_error ("program is too large to be compiled on this machine");
- return;
- }
-
- stack_vars_conflict = XRESIZEVEC (bool, stack_vars_conflict, size);
- memset (stack_vars_conflict + stack_vars_conflict_alloc, 0,
- (size - stack_vars_conflict_alloc) * sizeof (bool));
- stack_vars_conflict_alloc = size;
- n_stack_vars_conflict = n;
-}
-
/* Make the decls associated with luid's X and Y conflict. */
static void
add_stack_var_conflict (size_t x, size_t y)
{
- size_t index = triangular_index (x, y);
- gcc_assert (index < stack_vars_conflict_alloc);
- stack_vars_conflict[index] = true;
+ struct stack_var *a = &stack_vars[x];
+ struct stack_var *b = &stack_vars[y];
+ if (!a->conflicts)
+ a->conflicts = BITMAP_ALLOC (NULL);
+ if (!b->conflicts)
+ b->conflicts = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (a->conflicts, y);
+ bitmap_set_bit (b->conflicts, x);
}
/* Check whether the decls associated with luid's X and Y conflict. */
static bool
stack_var_conflict_p (size_t x, size_t y)
{
- size_t index = triangular_index (x, y);
- gcc_assert (index < stack_vars_conflict_alloc);
- return stack_vars_conflict[index];
+ struct stack_var *a = &stack_vars[x];
+ struct stack_var *b = &stack_vars[y];
+ if (!a->conflicts || !b->conflicts)
+ return false;
+ return bitmap_bit_p (a->conflicts, y);
}
/* Returns true if TYPE is or contains a union type. */
union_stack_vars (size_t a, size_t b, HOST_WIDE_INT offset)
{
size_t i, last;
+ struct stack_var *vb = &stack_vars[b];
+ bitmap_iterator bi;
+ unsigned u;
/* Update each element of partition B with the given offset,
and merge them into partition A. */
stack_vars[a].alignb = stack_vars[b].alignb;
/* Update the interference graph and merge the conflicts. */
- for (last = stack_vars_num, i = 0; i < last; ++i)
- if (stack_var_conflict_p (b, i))
- add_stack_var_conflict (a, i);
+ if (vb->conflicts)
+ {
+ EXECUTE_IF_SET_IN_BITMAP (vb->conflicts, 0, u, bi)
+ add_stack_var_conflict (a, stack_vars[u].representative);
+ BITMAP_FREE (vb->conflicts);
+ }
}
/* A subroutine of expand_used_vars. Binpack the variables into
qsort (stack_vars_sorted, n, sizeof (size_t), stack_var_size_cmp);
- /* Special case: detect when all variables conflict, and thus we can't
- do anything during the partitioning loop. It isn't uncommon (with
- C code at least) to declare all variables at the top of the function,
- and if we're not inlining, then all variables will be in the same scope.
- Take advantage of very fast libc routines for this scan. */
- gcc_assert (sizeof(bool) == sizeof(char));
- if (memchr (stack_vars_conflict, false, stack_vars_conflict_alloc) == NULL)
- return;
-
for (si = 0; si < n; ++si)
{
size_t i = stack_vars_sorted[si];
/* Since we do not track exact variable lifetimes (which is not even
possible for variables whose address escapes), we mirror the block
tree in the interference graph. Here we cause all variables at this
- level, and all sublevels, to conflict. Do make certain that a
- variable conflicts with itself. */
+ level, and all sublevels, to conflict. */
if (old_sv_num < this_sv_num)
{
new_sv_num = stack_vars_num;
- resize_stack_vars_conflict (new_sv_num);
for (i = old_sv_num; i < new_sv_num; ++i)
- for (j = i < this_sv_num ? i+1 : this_sv_num; j-- > old_sv_num ;)
+ for (j = i < this_sv_num ? i : this_sv_num; j-- > old_sv_num ;)
add_stack_var_conflict (i, j);
}
}
static HOST_WIDE_INT
account_used_vars_for_block (tree block, bool toplevel)
{
- size_t i, j, old_sv_num, this_sv_num, new_sv_num;
tree t;
HOST_WIDE_INT size = 0;
- old_sv_num = toplevel ? 0 : stack_vars_num;
-
/* Expand all variables at this level. */
for (t = BLOCK_VARS (block); t ; t = TREE_CHAIN (t))
if (TREE_USED (t))
size += expand_one_var (t, toplevel, false);
- this_sv_num = stack_vars_num;
-
/* Expand all variables at containing levels. */
for (t = BLOCK_SUBBLOCKS (block); t ; t = BLOCK_CHAIN (t))
size += account_used_vars_for_block (t, false);
- /* Since we do not track exact variable lifetimes (which is not even
- possible for variables whose address escapes), we mirror the block
- tree in the interference graph. Here we cause all variables at this
- level, and all sublevels, to conflict. Do make certain that a
- variable conflicts with itself. */
- if (old_sv_num < this_sv_num)
- {
- new_sv_num = stack_vars_num;
- resize_stack_vars_conflict (new_sv_num);
-
- for (i = old_sv_num; i < new_sv_num; ++i)
- for (j = i < this_sv_num ? i+1 : this_sv_num; j-- > old_sv_num ;)
- add_stack_var_conflict (i, j);
- }
return size;
}
static void
fini_vars_expansion (void)
{
+ size_t i, n = stack_vars_num;
+ for (i = 0; i < n; i++)
+ BITMAP_FREE (stack_vars[i].conflicts);
XDELETEVEC (stack_vars);
XDELETEVEC (stack_vars_sorted);
- XDELETEVEC (stack_vars_conflict);
stack_vars = NULL;
stack_vars_alloc = stack_vars_num = 0;
- stack_vars_conflict = NULL;
- stack_vars_conflict_alloc = 0;
}
/* Make a fair guess for the size of the stack frame of the current
/* A subroutine of expand_gimple_cond. Given E, a fallthrough edge
of a basic block where we just expanded the conditional at the end,
- possibly clean up the CFG and instruction sequence. */
+ possibly clean up the CFG and instruction sequence. LAST is the
+ last instruction before the just emitted jump sequence. */
static void
-maybe_cleanup_end_of_block (edge e)
+maybe_cleanup_end_of_block (edge e, rtx last)
{
/* Special case: when jumpif decides that the condition is
trivial it emits an unconditional jump (and the necessary
normally isn't there in a cleaned CFG), fix it here. */
if (BARRIER_P (get_last_insn ()))
{
- basic_block bb = e->src;
rtx insn;
remove_edge (e);
/* Now, we have a single successor block, if we have insns to
/* Make sure we have an unconditional jump. Otherwise we're
confused. */
gcc_assert (JUMP_P (insn) && !any_condjump_p (insn));
- for (insn = PREV_INSN (insn); insn != BB_HEAD (bb);)
+ for (insn = PREV_INSN (insn); insn != last;)
{
insn = PREV_INSN (insn);
if (JUMP_P (NEXT_INSN (insn)))
}
true_edge->goto_block = NULL;
false_edge->flags |= EDGE_FALLTHRU;
- maybe_cleanup_end_of_block (false_edge);
+ maybe_cleanup_end_of_block (false_edge, last);
return NULL;
}
if (true_edge->dest == bb->next_bb)
}
false_edge->goto_block = NULL;
true_edge->flags |= EDGE_FALLTHRU;
- maybe_cleanup_end_of_block (true_edge);
+ maybe_cleanup_end_of_block (true_edge, last);
return NULL;
}
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