#include "toplev.h"
#include "debug.h"
#include "params.h"
+#include "tree-inline.h"
/* Verify that there is exactly single jump instruction since last and attach
REG_BR_PROB note specifying probability.
}
}
+/* Take into account all sizes of partitions and reset DECL_RTLs. */
+static HOST_WIDE_INT
+account_stack_vars (void)
+{
+ size_t si, j, i, n = stack_vars_num;
+ HOST_WIDE_INT size = 0;
+
+ for (si = 0; si < n; ++si)
+ {
+ i = stack_vars_sorted[si];
+
+ /* Skip variables that aren't partition representatives, for now. */
+ if (stack_vars[i].representative != i)
+ continue;
+
+ size += stack_vars[i].size;
+ for (j = i; j != EOC; j = stack_vars[j].next)
+ SET_DECL_RTL (stack_vars[j].decl, NULL);
+ }
+ return size;
+}
+
/* A subroutine of expand_one_var. Called to immediately assign rtl
to a variable to be allocated in the stack frame. */
/* A subroutine of expand_used_vars. Expand one variable according to
its flavor. Variables to be placed on the stack are not actually
- expanded yet, merely recorded. */
+ expanded yet, merely recorded.
+ When REALLY_EXPAND is false, only add stack values to be allocated.
+ Return stack usage this variable is supposed to take.
+*/
-static void
-expand_one_var (tree var, bool toplevel)
+static HOST_WIDE_INT
+expand_one_var (tree var, bool toplevel, bool really_expand)
{
if (TREE_CODE (var) != VAR_DECL)
- lang_hooks.expand_decl (var);
+ {
+ if (really_expand)
+ lang_hooks.expand_decl (var);
+ }
else if (DECL_EXTERNAL (var))
;
else if (DECL_HAS_VALUE_EXPR_P (var))
;
else if (TREE_STATIC (var))
- expand_one_static_var (var);
+ {
+ if (really_expand)
+ expand_one_static_var (var);
+ }
else if (DECL_RTL_SET_P (var))
;
else if (TREE_TYPE (var) == error_mark_node)
- expand_one_error_var (var);
+ {
+ if (really_expand)
+ expand_one_error_var (var);
+ }
else if (DECL_HARD_REGISTER (var))
- expand_one_hard_reg_var (var);
+ {
+ if (really_expand)
+ expand_one_hard_reg_var (var);
+ }
else if (use_register_for_decl (var))
- expand_one_register_var (var);
+ {
+ if (really_expand)
+ expand_one_register_var (var);
+ }
else if (defer_stack_allocation (var, toplevel))
add_stack_var (var);
else
- expand_one_stack_var (var);
+ {
+ if (really_expand)
+ expand_one_stack_var (var);
+ return tree_low_cst (DECL_SIZE_UNIT (var), 1);
+ }
+ return 0;
}
/* A subroutine of expand_used_vars. Walk down through the BLOCK tree
care of this. */
|| (!flag_unit_at_a_time && TREE_STATIC (t)
&& DECL_PRESERVE_P (t)))
- expand_one_var (t, toplevel);
+ expand_one_var (t, toplevel, true);
this_sv_num = stack_vars_num;
cfun->stack_protect_guard = guard;
}
+/* A subroutine of expand_used_vars. Walk down through the BLOCK tree
+ expanding variables. Those variables that can be put into registers
+ are allocated pseudos; those that can't are put on the stack.
+
+ TOPLEVEL is true if this is the outermost BLOCK. */
+
+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;
+}
+
+/* Prepare for expanding variables. */
+static void
+init_vars_expansion (void)
+{
+ tree t;
+ /* Set TREE_USED on all variables in the unexpanded_var_list. */
+ for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t))
+ TREE_USED (TREE_VALUE (t)) = 1;
+
+ /* Clear TREE_USED on all variables associated with a block scope. */
+ clear_tree_used (DECL_INITIAL (current_function_decl));
+
+ /* Initialize local stack smashing state. */
+ has_protected_decls = false;
+ has_short_buffer = false;
+}
+
+/* Free up stack variable graph data. */
+static void
+fini_vars_expansion (void)
+{
+ 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;
+}
+
+HOST_WIDE_INT
+estimated_stack_frame_size (void)
+{
+ HOST_WIDE_INT size = 0;
+ tree t, outer_block = DECL_INITIAL (current_function_decl);
+
+ init_vars_expansion ();
+
+ /* At this point all variables on the unexpanded_var_list with TREE_USED
+ set are not associated with any block scope. Lay them out. */
+ for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t))
+ {
+ tree var = TREE_VALUE (t);
+
+ if (TREE_USED (var))
+ size += expand_one_var (var, true, false);
+ TREE_USED (var) = 1;
+ }
+ size += account_used_vars_for_block (outer_block, true);
+ if (stack_vars_num > 0)
+ {
+ /* Due to the way alias sets work, no variables with non-conflicting
+ alias sets may be assigned the same address. Add conflicts to
+ reflect this. */
+ add_alias_set_conflicts ();
+
+ /* If stack protection is enabled, we don't share space between
+ vulnerable data and non-vulnerable data. */
+ if (flag_stack_protect)
+ add_stack_protection_conflicts ();
+
+ /* Now that we have collected all stack variables, and have computed a
+ minimal interference graph, attempt to save some stack space. */
+ partition_stack_vars ();
+ if (dump_file)
+ dump_stack_var_partition ();
+
+ size += account_stack_vars ();
+ fini_vars_expansion ();
+ }
+ return size;
+}
+
/* Expand all variables used in the function. */
static void
frame_phase = off ? align - off : 0;
}
- /* Set TREE_USED on all variables in the unexpanded_var_list. */
- for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t))
- TREE_USED (TREE_VALUE (t)) = 1;
-
- /* Clear TREE_USED on all variables associated with a block scope. */
- clear_tree_used (outer_block);
-
- /* Initialize local stack smashing state. */
- has_protected_decls = false;
- has_short_buffer = false;
+ init_vars_expansion ();
/* At this point all variables on the unexpanded_var_list with TREE_USED
set are not associated with any block scope. Lay them out. */
TREE_USED (var) = 1;
if (expand_now)
- expand_one_var (var, true);
+ expand_one_var (var, true, true);
}
cfun->unexpanded_var_list = NULL_TREE;
expand_stack_vars (NULL);
- /* Free up stack variable graph data. */
- 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;
+ fini_vars_expansion ();
}
/* If the target requires that FRAME_OFFSET be aligned, do it. */
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