/* A pass for lowering trees to RTL.
- Copyright (C) 2004 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+Boston, MA 02110-1301, USA. */
#include "config.h"
#include "system.h"
#include "flags.h"
#include "diagnostic.h"
#include "toplev.h"
+#include "debug.h"
+#include "params.h"
+
+/* Verify that there is exactly single jump instruction since last and attach
+ REG_BR_PROB note specifying probability.
+ ??? We really ought to pass the probability down to RTL expanders and let it
+ re-distribute it when the conditional expands into multiple conditionals.
+ This is however difficult to do. */
+static void
+add_reg_br_prob_note (rtx last, int probability)
+{
+ if (profile_status == PROFILE_ABSENT)
+ return;
+ for (last = NEXT_INSN (last); last && NEXT_INSN (last); last = NEXT_INSN (last))
+ if (JUMP_P (last))
+ {
+ /* It is common to emit condjump-around-jump sequence when we don't know
+ how to reverse the conditional. Special case this. */
+ if (!any_condjump_p (last)
+ || !JUMP_P (NEXT_INSN (last))
+ || !simplejump_p (NEXT_INSN (last))
+ || !BARRIER_P (NEXT_INSN (NEXT_INSN (last)))
+ || !LABEL_P (NEXT_INSN (NEXT_INSN (NEXT_INSN (last))))
+ || NEXT_INSN (NEXT_INSN (NEXT_INSN (NEXT_INSN (last)))))
+ goto failed;
+ gcc_assert (!find_reg_note (last, REG_BR_PROB, 0));
+ REG_NOTES (last)
+ = gen_rtx_EXPR_LIST (REG_BR_PROB,
+ GEN_INT (REG_BR_PROB_BASE - probability),
+ REG_NOTES (last));
+ return;
+ }
+ if (!last || !JUMP_P (last) || !any_condjump_p (last))
+ goto failed;
+ gcc_assert (!find_reg_note (last, REG_BR_PROB, 0));
+ REG_NOTES (last)
+ = gen_rtx_EXPR_LIST (REG_BR_PROB,
+ GEN_INT (probability), REG_NOTES (last));
+ return;
+failed:
+ if (dump_file)
+ fprintf (dump_file, "Failed to add probability note\n");
+}
#ifndef LOCAL_ALIGNMENT
#define STACK_ALIGNMENT_NEEDED 1
#endif
-#ifdef FRAME_GROWS_DOWNWARD
-# undef FRAME_GROWS_DOWNWARD
-# define FRAME_GROWS_DOWNWARD 1
-#else
-# define FRAME_GROWS_DOWNWARD 0
-#endif
-
/* This structure holds data relevant to one variable that will be
placed in a stack slot. */
(frame_offset+frame_phase) % PREFERRED_STACK_BOUNDARY == 0. */
static int frame_phase;
+/* Used during expand_used_vars to remember if we saw any decls for
+ which we'd like to enable stack smashing protection. */
+static bool has_protected_decls;
+
+/* Used during expand_used_vars. Remember if we say a character buffer
+ smaller than our cutoff threshold. Used for -Wstack-protector. */
+static bool has_short_buffer;
/* Discover the byte alignment to use for DECL. Ignore alignment
we can't do with expected alignment of the stack boundary. */
gcc_assert (index < stack_vars_conflict_alloc);
return stack_vars_conflict[index];
}
-
+
+/* Returns true if TYPE is or contains a union type. */
+
+static bool
+aggregate_contains_union_type (tree type)
+{
+ tree field;
+
+ if (TREE_CODE (type) == UNION_TYPE
+ || TREE_CODE (type) == QUAL_UNION_TYPE)
+ return true;
+ if (TREE_CODE (type) == ARRAY_TYPE)
+ return aggregate_contains_union_type (TREE_TYPE (type));
+ if (TREE_CODE (type) != RECORD_TYPE)
+ return false;
+
+ for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
+ if (TREE_CODE (field) == FIELD_DECL)
+ if (aggregate_contains_union_type (TREE_TYPE (field)))
+ return true;
+
+ return false;
+}
+
/* A subroutine of expand_used_vars. If two variables X and Y have alias
sets that do not conflict, then do add a conflict for these variables
- in the interference graph. We also have to mind MEM_IN_STRUCT_P and
- MEM_SCALAR_P. */
+ in the interference graph. We also need to make sure to add conflicts
+ for union containing structures. Else RTL alias analysis comes along
+ and due to type based aliasing rules decides that for two overlapping
+ union temporaries { short s; int i; } accesses to the same mem through
+ different types may not alias and happily reorders stores across
+ life-time boundaries of the temporaries (See PR25654).
+ We also have to mind MEM_IN_STRUCT_P and MEM_SCALAR_P. */
static void
add_alias_set_conflicts (void)
for (i = 0; i < n; ++i)
{
- bool aggr_i = AGGREGATE_TYPE_P (TREE_TYPE (stack_vars[i].decl));
- HOST_WIDE_INT set_i = get_alias_set (stack_vars[i].decl);
+ tree type_i = TREE_TYPE (stack_vars[i].decl);
+ bool aggr_i = AGGREGATE_TYPE_P (type_i);
+ bool contains_union;
+ contains_union = aggregate_contains_union_type (type_i);
for (j = 0; j < i; ++j)
{
- bool aggr_j = AGGREGATE_TYPE_P (TREE_TYPE (stack_vars[j].decl));
- HOST_WIDE_INT set_j = get_alias_set (stack_vars[j].decl);
- if (aggr_i != aggr_j || !alias_sets_conflict_p (set_i, set_j))
+ tree type_j = TREE_TYPE (stack_vars[j].decl);
+ bool aggr_j = AGGREGATE_TYPE_P (type_j);
+ if (aggr_i != aggr_j
+ /* Either the objects conflict by means of type based
+ aliasing rules, or we need to add a conflict. */
+ || !objects_must_conflict_p (type_i, type_j)
+ /* In case the types do not conflict ensure that access
+ to elements will conflict. In case of unions we have
+ to be careful as type based aliasing rules may say
+ access to the same memory does not conflict. So play
+ safe and add a conflict in this case. */
+ || contains_union)
add_stack_var_conflict (i, j);
}
}
with that location. */
static void
-expand_stack_vars (void)
+expand_stack_vars (bool (*pred) (tree))
{
size_t si, i, j, n = stack_vars_num;
if (stack_vars[i].representative != i)
continue;
+ /* Skip variables that have already had rtl assigned. See also
+ add_stack_var where we perpetrate this pc_rtx hack. */
+ if (DECL_RTL (stack_vars[i].decl) != pc_rtx)
+ continue;
+
+ /* Check the predicate to see whether this variable should be
+ allocated in this pass. */
+ if (pred && !pred (stack_vars[i].decl))
+ continue;
+
offset = alloc_stack_frame_space (stack_vars[i].size,
stack_vars[i].alignb);
static void
expand_one_static_var (tree var)
{
+ /* In unit-at-a-time all the static variables are expanded at the end
+ of compilation process. */
+ if (flag_unit_at_a_time)
+ return;
/* If this is an inlined copy of a static local variable,
look up the original. */
var = DECL_ORIGIN (var);
}
/* A subroutine of expand_one_var. Called to assign rtl to a VAR_DECL that
- has some associated error, e.g. it's type is error-mark. We just need
+ has some associated error, e.g. its type is error-mark. We just need
to pick something that won't crash the rest of the compiler. */
static void
static bool
defer_stack_allocation (tree var, bool toplevel)
{
+ /* If stack protection is enabled, *all* stack variables must be deferred,
+ so that we can re-order the strings to the top of the frame. */
+ if (flag_stack_protect)
+ return true;
+
/* Variables in the outermost scope automatically conflict with
every other variable. The only reason to want to defer them
at all is that, after sorting, we can more efficiently pack
lang_hooks.expand_decl (var);
else if (DECL_EXTERNAL (var))
;
- else if (DECL_VALUE_EXPR (var))
+ else if (DECL_HAS_VALUE_EXPR_P (var))
;
else if (TREE_STATIC (var))
expand_one_static_var (var);
clear_tree_used (t);
}
+/* Examine TYPE and determine a bit mask of the following features. */
+
+#define SPCT_HAS_LARGE_CHAR_ARRAY 1
+#define SPCT_HAS_SMALL_CHAR_ARRAY 2
+#define SPCT_HAS_ARRAY 4
+#define SPCT_HAS_AGGREGATE 8
+
+static unsigned int
+stack_protect_classify_type (tree type)
+{
+ unsigned int ret = 0;
+ tree t;
+
+ switch (TREE_CODE (type))
+ {
+ case ARRAY_TYPE:
+ t = TYPE_MAIN_VARIANT (TREE_TYPE (type));
+ if (t == char_type_node
+ || t == signed_char_type_node
+ || t == unsigned_char_type_node)
+ {
+ unsigned HOST_WIDE_INT max = PARAM_VALUE (PARAM_SSP_BUFFER_SIZE);
+ unsigned HOST_WIDE_INT len;
+
+ if (!TYPE_SIZE_UNIT (type)
+ || !host_integerp (TYPE_SIZE_UNIT (type), 1))
+ len = max;
+ else
+ len = tree_low_cst (TYPE_SIZE_UNIT (type), 1);
+
+ if (len < max)
+ ret = SPCT_HAS_SMALL_CHAR_ARRAY | SPCT_HAS_ARRAY;
+ else
+ ret = SPCT_HAS_LARGE_CHAR_ARRAY | SPCT_HAS_ARRAY;
+ }
+ else
+ ret = SPCT_HAS_ARRAY;
+ break;
+
+ case UNION_TYPE:
+ case QUAL_UNION_TYPE:
+ case RECORD_TYPE:
+ ret = SPCT_HAS_AGGREGATE;
+ for (t = TYPE_FIELDS (type); t ; t = TREE_CHAIN (t))
+ if (TREE_CODE (t) == FIELD_DECL)
+ ret |= stack_protect_classify_type (TREE_TYPE (t));
+ break;
+
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+/* Return nonzero if DECL should be segregated into the "vulnerable" upper
+ part of the local stack frame. Remember if we ever return nonzero for
+ any variable in this function. The return value is the phase number in
+ which the variable should be allocated. */
+
+static int
+stack_protect_decl_phase (tree decl)
+{
+ unsigned int bits = stack_protect_classify_type (TREE_TYPE (decl));
+ int ret = 0;
+
+ if (bits & SPCT_HAS_SMALL_CHAR_ARRAY)
+ has_short_buffer = true;
+
+ if (flag_stack_protect == 2)
+ {
+ if ((bits & (SPCT_HAS_SMALL_CHAR_ARRAY | SPCT_HAS_LARGE_CHAR_ARRAY))
+ && !(bits & SPCT_HAS_AGGREGATE))
+ ret = 1;
+ else if (bits & SPCT_HAS_ARRAY)
+ ret = 2;
+ }
+ else
+ ret = (bits & SPCT_HAS_LARGE_CHAR_ARRAY) != 0;
+
+ if (ret)
+ has_protected_decls = true;
+
+ return ret;
+}
+
+/* Two helper routines that check for phase 1 and phase 2. These are used
+ as callbacks for expand_stack_vars. */
+
+static bool
+stack_protect_decl_phase_1 (tree decl)
+{
+ return stack_protect_decl_phase (decl) == 1;
+}
+
+static bool
+stack_protect_decl_phase_2 (tree decl)
+{
+ return stack_protect_decl_phase (decl) == 2;
+}
+
+/* Ensure that variables in different stack protection phases conflict
+ so that they are not merged and share the same stack slot. */
+
+static void
+add_stack_protection_conflicts (void)
+{
+ size_t i, j, n = stack_vars_num;
+ unsigned char *phase;
+
+ phase = XNEWVEC (unsigned char, n);
+ for (i = 0; i < n; ++i)
+ phase[i] = stack_protect_decl_phase (stack_vars[i].decl);
+
+ for (i = 0; i < n; ++i)
+ {
+ unsigned char ph_i = phase[i];
+ for (j = 0; j < i; ++j)
+ if (ph_i != phase[j])
+ add_stack_var_conflict (i, j);
+ }
+
+ XDELETEVEC (phase);
+}
+
+/* Create a decl for the guard at the top of the stack frame. */
+
+static void
+create_stack_guard (void)
+{
+ tree guard = build_decl (VAR_DECL, NULL, ptr_type_node);
+ TREE_THIS_VOLATILE (guard) = 1;
+ TREE_USED (guard) = 1;
+ expand_one_stack_var (guard);
+ cfun->stack_protect_guard = guard;
+}
+
/* Expand all variables used in the function. */
static void
/* 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;
+
/* 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))
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 ();
+ }
+
+ /* There are several conditions under which we should create a
+ stack guard: protect-all, alloca used, protected decls present. */
+ if (flag_stack_protect == 2
+ || (flag_stack_protect
+ && (current_function_calls_alloca || has_protected_decls)))
+ create_stack_guard ();
+
+ /* Assign rtl to each variable based on these partitions. */
+ if (stack_vars_num > 0)
+ {
+ /* Reorder decls to be protected by iterating over the variables
+ array multiple times, and allocating out of each phase in turn. */
+ /* ??? We could probably integrate this into the qsort we did
+ earlier, such that we naturally see these variables first,
+ and thus naturally allocate things in the right order. */
+ if (has_protected_decls)
+ {
+ /* Phase 1 contains only character arrays. */
+ expand_stack_vars (stack_protect_decl_phase_1);
+
+ /* Phase 2 contains other kinds of arrays. */
+ if (flag_stack_protect == 2)
+ expand_stack_vars (stack_protect_decl_phase_2);
+ }
- /* Assign rtl to each variable based on these partitions. */
- expand_stack_vars ();
+ expand_stack_vars (NULL);
/* Free up stack variable graph data. */
XDELETEVEC (stack_vars);
}
+/* If we need to produce a detailed dump, print the tree representation
+ for STMT to the dump file. SINCE is the last RTX after which the RTL
+ generated for STMT should have been appended. */
+
+static void
+maybe_dump_rtl_for_tree_stmt (tree stmt, rtx since)
+{
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "\n;; ");
+ print_generic_expr (dump_file, stmt, TDF_SLIM);
+ fprintf (dump_file, "\n");
+
+ print_rtl (dump_file, since ? NEXT_INSN (since) : since);
+ }
+}
+
/* A subroutine of expand_gimple_basic_block. Expand one COND_EXPR.
Returns a new basic block if we've terminated the current basic
block and created a new one. */
tree pred = COND_EXPR_COND (stmt);
tree then_exp = COND_EXPR_THEN (stmt);
tree else_exp = COND_EXPR_ELSE (stmt);
- rtx last;
+ rtx last2, last;
+
+ last2 = last = get_last_insn ();
extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
if (EXPR_LOCUS (stmt))
if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp))
{
jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
+ add_reg_br_prob_note (last, true_edge->probability);
+ maybe_dump_rtl_for_tree_stmt (stmt, last);
+ if (EXPR_LOCUS (then_exp))
+ emit_line_note (*(EXPR_LOCUS (then_exp)));
return NULL;
}
if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp))
{
jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp)));
+ add_reg_br_prob_note (last, false_edge->probability);
+ maybe_dump_rtl_for_tree_stmt (stmt, last);
+ if (EXPR_LOCUS (else_exp))
+ emit_line_note (*(EXPR_LOCUS (else_exp)));
return NULL;
}
gcc_assert (TREE_CODE (then_exp) == GOTO_EXPR
&& TREE_CODE (else_exp) == GOTO_EXPR);
jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
+ add_reg_br_prob_note (last, true_edge->probability);
last = get_last_insn ();
expand_expr (else_exp, const0_rtx, VOIDmode, 0);
BB_END (new_bb) = PREV_INSN (BB_END (new_bb));
update_bb_for_insn (new_bb);
- if (dump_file)
- {
- dump_bb (bb, dump_file, 0);
- dump_bb (new_bb, dump_file, 0);
- }
+ maybe_dump_rtl_for_tree_stmt (stmt, last2);
+
+ if (EXPR_LOCUS (else_exp))
+ emit_line_note (*(EXPR_LOCUS (else_exp)));
return new_bb;
}
static basic_block
expand_gimple_tailcall (basic_block bb, tree stmt, bool *can_fallthru)
{
- rtx last = get_last_insn ();
+ rtx last2, last;
edge e;
+ edge_iterator ei;
int probability;
gcov_type count;
+ last2 = last = get_last_insn ();
+
expand_expr_stmt (stmt);
for (last = NEXT_INSN (last); last; last = NEXT_INSN (last))
if (CALL_P (last) && SIBLING_CALL_P (last))
goto found;
+ maybe_dump_rtl_for_tree_stmt (stmt, last2);
+
*can_fallthru = true;
return NULL;
all edges here, or redirecting the existing fallthru edge to
the exit block. */
- e = bb->succ;
probability = 0;
count = 0;
- while (e)
- {
- edge next = e->succ_next;
+ for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
+ {
if (!(e->flags & (EDGE_ABNORMAL | EDGE_EH)))
{
if (e->dest != EXIT_BLOCK_PTR)
probability += e->probability;
remove_edge (e);
}
-
- e = next;
+ else
+ ei_next (&ei);
}
/* This is somewhat ugly: the call_expr expander often emits instructions
after the sibcall (to perform the function return). These confuse the
- find_sub_basic_blocks code, so we need to get rid of these. */
+ find_many_sub_basic_blocks code, so we need to get rid of these. */
last = NEXT_INSN (last);
gcc_assert (BARRIER_P (last));
BB_END (bb) = PREV_INSN (last);
}
+ maybe_dump_rtl_for_tree_stmt (stmt, last2);
+
return bb;
}
/* Expand basic block BB from GIMPLE trees to RTL. */
static basic_block
-expand_gimple_basic_block (basic_block bb, FILE * dump_file)
+expand_gimple_basic_block (basic_block bb)
{
block_stmt_iterator bsi = bsi_start (bb);
tree stmt = NULL;
rtx note, last;
edge e;
+ edge_iterator ei;
if (dump_file)
{
- tree_register_cfg_hooks ();
- dump_bb (bb, dump_file, 0);
- rtl_register_cfg_hooks ();
+ fprintf (dump_file,
+ "\n;; Generating RTL for tree basic block %d\n",
+ bb->index);
}
+ init_rtl_bb_info (bb);
+ bb->flags |= BB_RTL;
+
if (!bsi_end_p (bsi))
stmt = bsi_stmt (bsi);
BB_HEAD (bb) = NEXT_INSN (BB_HEAD (bb));
bsi_next (&bsi);
note = emit_note_after (NOTE_INSN_BASIC_BLOCK, BB_HEAD (bb));
+
+ maybe_dump_rtl_for_tree_stmt (stmt, last);
}
else
note = BB_HEAD (bb) = emit_note (NOTE_INSN_BASIC_BLOCK);
NOTE_BASIC_BLOCK (note) = bb;
- e = bb->succ;
- while (e)
+ for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
{
- edge next = e->succ_next;
-
/* Clear EDGE_EXECUTABLE. This flag is never used in the backend. */
e->flags &= ~EDGE_EXECUTABLE;
/* At the moment not all abnormal edges match the RTL representation.
- It is safe to remove them here as find_sub_basic_blocks will
+ It is safe to remove them here as find_many_sub_basic_blocks will
rediscover them. In the future we should get this fixed properly. */
if (e->flags & EDGE_ABNORMAL)
remove_edge (e);
-
- e = next;
+ else
+ ei_next (&ei);
}
for (; !bsi_end_p (bsi); bsi_next (&bsi))
}
}
else
- expand_expr_stmt (stmt);
+ {
+ last = get_last_insn ();
+ expand_expr_stmt (stmt);
+ maybe_dump_rtl_for_tree_stmt (stmt, last);
+ }
}
}
do_pending_stack_adjust ();
- /* Find the the block tail. The last insn is the block is the insn
+ /* Find the block tail. The last insn in the block is the insn
before a barrier and/or table jump insn. */
last = get_last_insn ();
if (BARRIER_P (last))
last = PREV_INSN (PREV_INSN (last));
BB_END (bb) = last;
- if (dump_file)
- dump_bb (bb, dump_file, 0);
update_bb_for_insn (bb);
return bb;
construct_init_block (void)
{
basic_block init_block, first_block;
- edge e;
+ edge e = NULL;
+ int flags;
- for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next)
- if (e->dest == ENTRY_BLOCK_PTR->next_bb)
- break;
+ /* Multiple entry points not supported yet. */
+ gcc_assert (EDGE_COUNT (ENTRY_BLOCK_PTR->succs) == 1);
+ init_rtl_bb_info (ENTRY_BLOCK_PTR);
+ init_rtl_bb_info (EXIT_BLOCK_PTR);
+ ENTRY_BLOCK_PTR->flags |= BB_RTL;
+ EXIT_BLOCK_PTR->flags |= BB_RTL;
+
+ e = EDGE_SUCC (ENTRY_BLOCK_PTR, 0);
+
+ /* When entry edge points to first basic block, we don't need jump,
+ otherwise we have to jump into proper target. */
+ if (e && e->dest != ENTRY_BLOCK_PTR->next_bb)
+ {
+ tree label = tree_block_label (e->dest);
+
+ emit_jump (label_rtx (label));
+ flags = 0;
+ }
+ else
+ flags = EDGE_FALLTHRU;
init_block = create_basic_block (NEXT_INSN (get_insns ()),
get_last_insn (),
{
first_block = e->dest;
redirect_edge_succ (e, init_block);
- e = make_edge (init_block, first_block, EDGE_FALLTHRU);
+ e = make_edge (init_block, first_block, flags);
}
else
e = make_edge (init_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
rtx head = get_last_insn ();
rtx end;
basic_block exit_block;
- edge e, e2, next;
+ edge e, e2;
+ unsigned ix;
+ edge_iterator ei;
/* Make sure the locus is set to the end of the function, so that
epilogue line numbers and warnings are set properly. */
EXIT_BLOCK_PTR->prev_bb);
exit_block->frequency = EXIT_BLOCK_PTR->frequency;
exit_block->count = EXIT_BLOCK_PTR->count;
- for (e = EXIT_BLOCK_PTR->pred; e; e = next)
+
+ ix = 0;
+ while (ix < EDGE_COUNT (EXIT_BLOCK_PTR->preds))
{
- next = e->pred_next;
+ e = EDGE_PRED (EXIT_BLOCK_PTR, ix);
if (!(e->flags & EDGE_ABNORMAL))
- redirect_edge_succ (e, exit_block);
+ redirect_edge_succ (e, exit_block);
+ else
+ ix++;
}
+
e = make_edge (exit_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
e->probability = REG_BR_PROB_BASE;
e->count = EXIT_BLOCK_PTR->count;
- for (e2 = EXIT_BLOCK_PTR->pred; e2; e2 = e2->pred_next)
+ FOR_EACH_EDGE (e2, ei, EXIT_BLOCK_PTR->preds)
if (e2 != e)
{
e->count -= e2->count;
update_bb_for_insn (exit_block);
}
+/* Helper function for discover_nonconstant_array_refs.
+ Look for ARRAY_REF nodes with non-constant indexes and mark them
+ addressable. */
+
+static tree
+discover_nonconstant_array_refs_r (tree * tp, int *walk_subtrees,
+ void *data ATTRIBUTE_UNUSED)
+{
+ tree t = *tp;
+
+ if (IS_TYPE_OR_DECL_P (t))
+ *walk_subtrees = 0;
+ else if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
+ {
+ while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
+ && is_gimple_min_invariant (TREE_OPERAND (t, 1))
+ && (!TREE_OPERAND (t, 2)
+ || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
+ || (TREE_CODE (t) == COMPONENT_REF
+ && (!TREE_OPERAND (t,2)
+ || is_gimple_min_invariant (TREE_OPERAND (t, 2))))
+ || TREE_CODE (t) == BIT_FIELD_REF
+ || TREE_CODE (t) == REALPART_EXPR
+ || TREE_CODE (t) == IMAGPART_EXPR
+ || TREE_CODE (t) == VIEW_CONVERT_EXPR
+ || TREE_CODE (t) == NOP_EXPR
+ || TREE_CODE (t) == CONVERT_EXPR)
+ t = TREE_OPERAND (t, 0);
+
+ if (TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
+ {
+ t = get_base_address (t);
+ if (t && DECL_P (t))
+ TREE_ADDRESSABLE (t) = 1;
+ }
+
+ *walk_subtrees = 0;
+ }
+
+ return NULL_TREE;
+}
+
+/* RTL expansion is not able to compile array references with variable
+ offsets for arrays stored in single register. Discover such
+ expressions and mark variables as addressable to avoid this
+ scenario. */
+
+static void
+discover_nonconstant_array_refs (void)
+{
+ basic_block bb;
+ block_stmt_iterator bsi;
+
+ FOR_EACH_BB (bb)
+ {
+ for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
+ walk_tree (bsi_stmt_ptr (bsi), discover_nonconstant_array_refs_r,
+ NULL , NULL);
+ }
+}
+
/* Translate the intermediate representation contained in the CFG
from GIMPLE trees to RTL.
basic_block bb, init_block;
sbitmap blocks;
- profile_status = PROFILE_ABSENT;
-
/* Some backends want to know that we are expanding to RTL. */
currently_expanding_to_rtl = 1;
/* Prepare the rtl middle end to start recording block changes. */
reset_block_changes ();
+ /* Mark arrays indexed with non-constant indices with TREE_ADDRESSABLE. */
+ discover_nonconstant_array_refs ();
+
/* Expand the variables recorded during gimple lowering. */
expand_used_vars ();
+ /* Honor stack protection warnings. */
+ if (warn_stack_protect)
+ {
+ if (current_function_calls_alloca)
+ warning (0, "not protecting local variables: variable length buffer");
+ if (has_short_buffer && !cfun->stack_protect_guard)
+ warning (0, "not protecting function: no buffer at least %d bytes long",
+ (int) PARAM_VALUE (PARAM_SSP_BUFFER_SIZE));
+ }
+
/* Set up parameters and prepare for return, for the function. */
expand_function_start (current_function_decl);
&& DECL_FILE_SCOPE_P (current_function_decl))
expand_main_function ();
+ /* Initialize the stack_protect_guard field. This must happen after the
+ call to __main (if any) so that the external decl is initialized. */
+ if (cfun->stack_protect_guard)
+ stack_protect_prologue ();
+
/* Register rtl specific functions for cfg. */
rtl_register_cfg_hooks ();
init_block = construct_init_block ();
FOR_BB_BETWEEN (bb, init_block->next_bb, EXIT_BLOCK_PTR, next_bb)
- bb = expand_gimple_basic_block (bb, dump_file);
+ bb = expand_gimple_basic_block (bb);
construct_exit_block ();
/* We're done expanding trees to RTL. */
currently_expanding_to_rtl = 0;
- /* Convert from NOTE_INSN_EH_REGION style notes, and do other
- sorts of eh initialization. */
+ /* Convert tree EH labels to RTL EH labels, and clean out any unreachable
+ EH regions. */
convert_from_eh_region_ranges ();
rebuild_jump_labels (get_insns ());
blocks = sbitmap_alloc (last_basic_block);
sbitmap_ones (blocks);
find_many_sub_basic_blocks (blocks);
- purge_all_dead_edges (0);
+ purge_all_dead_edges ();
sbitmap_free (blocks);
compact_blocks ();
generating_concat_p = 0;
finalize_block_changes ();
+
+ if (dump_file)
+ {
+ fprintf (dump_file,
+ "\n\n;;\n;; Full RTL generated for this function:\n;;\n");
+ /* And the pass manager will dump RTL for us. */
+ }
+
+ /* If we're emitting a nested function, make sure its parent gets
+ emitted as well. Doing otherwise confuses debug info. */
+ {
+ tree parent;
+ for (parent = DECL_CONTEXT (current_function_decl);
+ parent != NULL_TREE;
+ parent = get_containing_scope (parent))
+ if (TREE_CODE (parent) == FUNCTION_DECL)
+ TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (parent)) = 1;
+ }
+
+ /* We are now committed to emitting code for this function. Do any
+ preparation, such as emitting abstract debug info for the inline
+ before it gets mangled by optimization. */
+ if (cgraph_function_possibly_inlined_p (current_function_decl))
+ (*debug_hooks->outlining_inline_function) (current_function_decl);
+
+ TREE_ASM_WRITTEN (current_function_decl) = 1;
+
+ /* After expanding, the return labels are no longer needed. */
+ return_label = NULL;
+ naked_return_label = NULL;
}
struct tree_opt_pass pass_expand =
/* ??? If TER is enabled, we actually receive GENERIC. */
PROP_gimple_leh | PROP_cfg, /* properties_required */
PROP_rtl, /* properties_provided */
- PROP_gimple_leh, /* properties_destroyed */
+ PROP_trees, /* properties_destroyed */
0, /* todo_flags_start */
- 0, /* todo_flags_finish */
+ TODO_dump_func, /* todo_flags_finish */
'r' /* letter */
};