tree stmt, initial, step1, stmts;
tree vb, va;
enum tree_code incr_op = PLUS_EXPR;
+ edge pe = loop_preheader_edge (loop);
if (!var)
{
}
}
+ /* Gimplify the step if necessary. We put the computations in front of the
+ loop (i.e. the step should be loop invariant). */
+ step = force_gimple_operand (step, &stmts, true, var);
+ if (stmts)
+ bsi_insert_on_edge_immediate_loop (pe, stmts);
+
stmt = build2 (MODIFY_EXPR, void_type_node, va,
build2 (incr_op, TREE_TYPE (base),
vb, step));
initial = force_gimple_operand (base, &stmts, true, var);
if (stmts)
- {
- edge pe = loop_preheader_edge (loop);
-
- bsi_insert_on_edge_immediate_loop (pe, stmts);
- }
+ bsi_insert_on_edge_immediate_loop (pe, stmts);
stmt = create_phi_node (vb, loop->header);
SSA_NAME_DEF_STMT (vb) = stmt;
return;
phi = create_phi_node (use, exit);
-
+ create_new_def_for (PHI_RESULT (phi), phi, PHI_RESULT_PTR (phi));
FOR_EACH_EDGE (e, ei, exit->preds)
add_phi_arg (phi, use, e);
-
- SSA_NAME_DEF_STMT (use) = def_stmt;
}
/* Add exit phis for VAR that is used in LIVEIN.
basic_block def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var));
bitmap_iterator bi;
- bitmap_clear_bit (livein, def_bb->index);
+ if (is_gimple_reg (var))
+ bitmap_clear_bit (livein, def_bb->index);
+ else
+ bitmap_set_bit (livein, def_bb->index);
def = BITMAP_ALLOC (NULL);
bitmap_set_bit (def, def_bb->index);
/* For USE in BB, if it is used outside of the loop it is defined in,
mark it for rewrite. Record basic block BB where it is used
- to USE_BLOCKS. */
+ to USE_BLOCKS. Record the ssa name index to NEED_PHIS bitmap. */
static void
-find_uses_to_rename_use (basic_block bb, tree use, bitmap *use_blocks)
+find_uses_to_rename_use (basic_block bb, tree use, bitmap *use_blocks,
+ bitmap need_phis)
{
unsigned ver;
basic_block def_bb;
if (TREE_CODE (use) != SSA_NAME)
return;
+ /* We don't need to keep virtual operands in loop-closed form. */
+ if (!is_gimple_reg (use))
+ return;
+
ver = SSA_NAME_VERSION (use);
def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (use));
if (!def_bb)
use_blocks[ver] = BITMAP_ALLOC (NULL);
bitmap_set_bit (use_blocks[ver], bb->index);
- if (!flow_bb_inside_loop_p (def_loop, bb))
- mark_for_rewrite (use);
+ bitmap_set_bit (need_phis, ver);
}
/* For uses in STMT, mark names that are used outside of the loop they are
defined to rewrite. Record the set of blocks in that the ssa
- names are defined to USE_BLOCKS. */
+ names are defined to USE_BLOCKS and the ssa names themselves to
+ NEED_PHIS. */
static void
-find_uses_to_rename_stmt (tree stmt, bitmap *use_blocks)
+find_uses_to_rename_stmt (tree stmt, bitmap *use_blocks, bitmap need_phis)
{
ssa_op_iter iter;
tree var;
basic_block bb = bb_for_stmt (stmt);
- get_stmt_operands (stmt);
-
FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)
- find_uses_to_rename_use (bb, var, use_blocks);
+ find_uses_to_rename_use (bb, var, use_blocks, need_phis);
}
/* Marks names that are used in BB and outside of the loop they are
defined in for rewrite. Records the set of blocks in that the ssa
- names are defined to USE_BLOCKS. */
+ names are defined to USE_BLOCKS. Record the SSA names that will
+ need exit PHIs in NEED_PHIS. */
static void
-find_uses_to_rename_bb (basic_block bb, bitmap *use_blocks)
+find_uses_to_rename_bb (basic_block bb, bitmap *use_blocks, bitmap need_phis)
{
block_stmt_iterator bsi;
edge e;
FOR_EACH_EDGE (e, ei, bb->succs)
for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
find_uses_to_rename_use (bb, PHI_ARG_DEF_FROM_EDGE (phi, e),
- use_blocks);
+ use_blocks, need_phis);
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- find_uses_to_rename_stmt (bsi_stmt (bsi), use_blocks);
+ find_uses_to_rename_stmt (bsi_stmt (bsi), use_blocks, need_phis);
}
/* Marks names that are used outside of the loop they are defined in
scan only blocks in this set. */
static void
-find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks)
+find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis)
{
basic_block bb;
unsigned index;
bitmap_iterator bi;
- if (changed_bbs)
+ if (changed_bbs && !bitmap_empty_p (changed_bbs))
{
EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi)
{
- find_uses_to_rename_bb (BASIC_BLOCK (index), use_blocks);
+ find_uses_to_rename_bb (BASIC_BLOCK (index), use_blocks, need_phis);
}
}
else
{
FOR_EACH_BB (bb)
{
- find_uses_to_rename_bb (bb, use_blocks);
+ find_uses_to_rename_bb (bb, use_blocks, need_phis);
}
}
}
base 99 and step 1.
If CHANGED_BBS is not NULL, we look for uses outside loops only in
- the basic blocks in this set. */
+ the basic blocks in this set.
+
+ UPDATE_FLAG is used in the call to update_ssa. See
+ TODO_update_ssa* for documentation. */
void
-rewrite_into_loop_closed_ssa (bitmap changed_bbs)
+rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag)
{
bitmap loop_exits = get_loops_exits ();
bitmap *use_blocks;
- unsigned i;
- bitmap names_to_rename;
+ unsigned i, old_num_ssa_names;
+ bitmap names_to_rename = BITMAP_ALLOC (NULL);
- gcc_assert (!any_marked_for_rewrite_p ());
+ /* If the pass has caused the SSA form to be out-of-date, update it
+ now. */
+ update_ssa (update_flag);
- use_blocks = xcalloc (num_ssa_names, sizeof (bitmap));
+ old_num_ssa_names = num_ssa_names;
+ use_blocks = xcalloc (old_num_ssa_names, sizeof (bitmap));
/* Find the uses outside loops. */
- find_uses_to_rename (changed_bbs, use_blocks);
-
- if (!any_marked_for_rewrite_p ())
- {
- free (use_blocks);
- BITMAP_FREE (loop_exits);
- return;
- }
+ find_uses_to_rename (changed_bbs, use_blocks, names_to_rename);
- /* Add the phi nodes on exits of the loops for the names we need to
+ /* Add the PHI nodes on exits of the loops for the names we need to
rewrite. */
- names_to_rename = marked_ssa_names ();
add_exit_phis (names_to_rename, use_blocks, loop_exits);
- for (i = 0; i < num_ssa_names; i++)
+ for (i = 0; i < old_num_ssa_names; i++)
BITMAP_FREE (use_blocks[i]);
free (use_blocks);
BITMAP_FREE (loop_exits);
BITMAP_FREE (names_to_rename);
- /* Do the rewriting. */
- rewrite_ssa_into_ssa ();
+ /* Fix up all the names found to be used outside their original
+ loops. */
+ update_ssa (TODO_update_ssa);
}
/* Check invariants of the loop closed ssa form for the USE in BB. */
tree def;
basic_block def_bb;
- if (TREE_CODE (use) != SSA_NAME)
+ if (TREE_CODE (use) != SSA_NAME || !is_gimple_reg (use))
return;
def = SSA_NAME_DEF_STMT (use);
ssa_op_iter iter;
tree var;
- get_stmt_operands (stmt);
-
- FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)
check_loop_closed_ssa_use (bb, var);
}
tree phi;
unsigned i;
+ if (current_loops == NULL)
+ return;
+
verify_ssa (false);
FOR_EACH_BB (bb)
BASIC_BLOCK (i)->rbi->duplicated = 0;
}
-/* Renames variables in the area copied by tree_duplicate_loop_to_header_edge.
- FIRST_NEW_BLOCK is the first block in the copied area. DEFINITIONS is
- a bitmap of all ssa names defined inside the loop. */
-static void
-rename_variables (unsigned first_new_block, bitmap definitions)
-{
- unsigned i, copy_number = 0;
- basic_block bb;
- htab_t ssa_name_map = NULL;
+/* The same as cfgloopmanip.c:duplicate_loop_to_header_edge, but also
+ updates the PHI nodes at start of the copied region. In order to
+ achieve this, only loops whose exits all lead to the same location
+ are handled.
- for (i = first_new_block; i < (unsigned) last_basic_block; i++)
- {
- bb = BASIC_BLOCK (i);
-
- /* We assume that first come all blocks from the first copy, then all
- blocks from the second copy, etc. */
- if (copy_number != (unsigned) bb->rbi->copy_number)
- {
- allocate_ssa_names (definitions, &ssa_name_map);
- copy_number = bb->rbi->copy_number;
- }
-
- rewrite_to_new_ssa_names_bb (bb, ssa_name_map);
- }
-
- htab_delete (ssa_name_map);
-}
-
-/* Sets SSA_NAME_DEF_STMT for results of all phi nodes in BB. */
-
-static void
-set_phi_def_stmts (basic_block bb)
-{
- tree phi;
-
- for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
- SSA_NAME_DEF_STMT (PHI_RESULT (phi)) = phi;
-}
-
-/* The same as cfgloopmanip.c:duplicate_loop_to_header_edge, but also updates
- ssa. In order to achieve this, only loops whose exits all lead to the same
- location are handled.
-
- FIXME: we create some degenerate phi nodes that could be avoided by copy
- propagating them instead. Unfortunately this is not completely
- straightforward due to problems with constant folding. */
+ Notice that we do not completely update the SSA web after
+ duplication. The caller is responsible for calling update_ssa
+ after the loop has been duplicated. */
bool
tree_duplicate_loop_to_header_edge (struct loop *loop, edge e,
unsigned int *n_to_remove, int flags)
{
unsigned first_new_block;
- basic_block bb;
- unsigned i;
- bitmap definitions;
if (!(loops->state & LOOPS_HAVE_SIMPLE_LATCHES))
return false;
verify_loop_closed_ssa ();
#endif
- gcc_assert (!any_marked_for_rewrite_p ());
-
first_new_block = last_basic_block;
if (!duplicate_loop_to_header_edge (loop, e, loops, ndupl, wont_exit,
orig, to_remove, n_to_remove, flags))
/* Copy the phi node arguments. */
copy_phi_node_args (first_new_block);
- /* Rename the variables. */
- definitions = marked_ssa_names ();
- rename_variables (first_new_block, definitions);
- unmark_all_for_rewrite ();
- BITMAP_FREE (definitions);
-
- /* For some time we have the identical ssa names as results in multiple phi
- nodes. When phi node is resized, it sets SSA_NAME_DEF_STMT of its result
- to the new copy. This means that we cannot easily ensure that the ssa
- names defined in those phis are pointing to the right one -- so just
- recompute SSA_NAME_DEF_STMT for them. */
-
- for (i = first_new_block; i < (unsigned) last_basic_block; i++)
- {
- bb = BASIC_BLOCK (i);
- set_phi_def_stmts (bb);
- if (bb->rbi->copy_number == 1)
- set_phi_def_stmts (bb->rbi->original);
- }
-
scev_reset ();
-#ifdef ENABLE_CHECKING
- verify_loop_closed_ssa ();
-#endif
return true;
}
-
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