/* High-level loop manipulation functions.
- Copyright (C) 2004 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
-Free Software Foundation; either version 2, or (at your option) any
+Free Software Foundation; either version 3, or (at your option) any
later version.
GCC is distributed in the hope that it will be useful, but WITHOUT
for more details.
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. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "tree-pass.h"
#include "cfglayout.h"
#include "tree-scalar-evolution.h"
+#include "params.h"
+#include "tree-inline.h"
/* Creates an induction variable with value BASE + STEP * iteration in LOOP.
It is expected that neither BASE nor STEP are shared with other expressions
(unless the sharing rules allow this). Use VAR as a base var_decl for it
(if NULL, a new temporary will be created). The increment will occur at
- INCR_POS (after it if AFTER is true, before it otherwise). The ssa versions
+ INCR_POS (after it if AFTER is true, before it otherwise). INCR_POS and
+ AFTER can be computed using standard_iv_increment_position. The ssa versions
of the variable before and after increment will be stored in VAR_BEFORE and
VAR_AFTER (unless they are NULL). */
void
create_iv (tree base, tree step, tree var, struct loop *loop,
- block_stmt_iterator *incr_pos, bool after,
+ gimple_stmt_iterator *incr_pos, bool after,
tree *var_before, tree *var_after)
{
- tree stmt, initial, step1, stmts;
+ gimple stmt;
+ tree initial, step1;
+ gimple_seq stmts;
tree vb, va;
enum tree_code incr_op = PLUS_EXPR;
+ edge pe = loop_preheader_edge (loop);
if (!var)
{
var = create_tmp_var (TREE_TYPE (base), "ivtmp");
- add_referenced_tmp_var (var);
+ add_referenced_var (var);
}
- vb = make_ssa_name (var, NULL_TREE);
+ vb = make_ssa_name (var, NULL);
if (var_before)
*var_before = vb;
- va = make_ssa_name (var, NULL_TREE);
+ va = make_ssa_name (var, NULL);
if (var_after)
*var_after = va;
{
if (TYPE_UNSIGNED (TREE_TYPE (step)))
{
- step1 = fold (build1 (NEGATE_EXPR, TREE_TYPE (step), step));
+ step1 = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
if (tree_int_cst_lt (step1, step))
{
incr_op = MINUS_EXPR;
}
else
{
- if (!tree_expr_nonnegative_p (step)
+ bool ovf;
+
+ if (!tree_expr_nonnegative_warnv_p (step, &ovf)
&& may_negate_without_overflow_p (step))
{
incr_op = MINUS_EXPR;
- step = fold (build1 (NEGATE_EXPR, TREE_TYPE (step), step));
+ step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
}
}
}
+ if (POINTER_TYPE_P (TREE_TYPE (base)))
+ {
+ step = fold_convert (sizetype, step);
+ if (incr_op == MINUS_EXPR)
+ step = fold_build1 (NEGATE_EXPR, sizetype, step);
+ incr_op = POINTER_PLUS_EXPR;
+ }
+ /* 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, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (pe, stmts);
- stmt = build2 (MODIFY_EXPR, void_type_node, va,
- build2 (incr_op, TREE_TYPE (base),
- vb, step));
- SSA_NAME_DEF_STMT (va) = stmt;
+ stmt = gimple_build_assign_with_ops (incr_op, va, vb, step);
if (after)
- bsi_insert_after (incr_pos, stmt, BSI_NEW_STMT);
+ gsi_insert_after (incr_pos, stmt, GSI_NEW_STMT);
else
- bsi_insert_before (incr_pos, stmt, BSI_NEW_STMT);
+ gsi_insert_before (incr_pos, stmt, GSI_NEW_STMT);
initial = force_gimple_operand (base, &stmts, true, var);
if (stmts)
- {
- edge pe = loop_preheader_edge (loop);
-
- bsi_insert_on_edge_immediate_loop (pe, stmts);
- }
+ gsi_insert_seq_on_edge_immediate (pe, stmts);
stmt = create_phi_node (vb, loop->header);
SSA_NAME_DEF_STMT (vb) = stmt;
- add_phi_arg (&stmt, initial, loop_preheader_edge (loop));
- add_phi_arg (&stmt, va, loop_latch_edge (loop));
+ add_phi_arg (stmt, initial, loop_preheader_edge (loop));
+ add_phi_arg (stmt, va, loop_latch_edge (loop));
}
/* Add exit phis for the USE on EXIT. */
static void
add_exit_phis_edge (basic_block exit, tree use)
{
- tree phi, def_stmt = SSA_NAME_DEF_STMT (use);
- basic_block def_bb = bb_for_stmt (def_stmt);
+ gimple phi, def_stmt = SSA_NAME_DEF_STMT (use);
+ basic_block def_bb = gimple_bb (def_stmt);
struct loop *def_loop;
edge e;
edge_iterator ei;
return;
phi = create_phi_node (use, exit);
-
+ create_new_def_for (gimple_phi_result (phi), phi,
+ gimple_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_phi_arg (phi, use, e);
}
/* Add exit phis for VAR that is used in LIVEIN.
{
bitmap def;
unsigned index;
- basic_block def_bb = bb_for_stmt (SSA_NAME_DEF_STMT (var));
+ basic_block def_bb = gimple_bb (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_XMALLOC ();
+ def = BITMAP_ALLOC (NULL);
bitmap_set_bit (def, def_bb->index);
compute_global_livein (livein, def);
- BITMAP_XFREE (def);
+ BITMAP_FREE (def);
EXECUTE_IF_AND_IN_BITMAP (exits, livein, 0, index, bi)
{
static bitmap
get_loops_exits (void)
{
- bitmap exits = BITMAP_XMALLOC ();
+ bitmap exits = BITMAP_ALLOC (NULL);
basic_block bb;
edge e;
edge_iterator ei;
/* 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));
+ def_bb = gimple_bb (SSA_NAME_DEF_STMT (use));
if (!def_bb)
return;
def_loop = def_bb->loop_father;
- /* If the definition is not inside loop, it is not interesting. */
- if (!def_loop->outer)
+ /* If the definition is not inside a loop, it is not interesting. */
+ if (!loop_outer (def_loop))
+ return;
+
+ /* If the use is not outside of the loop it is defined in, it is not
+ interesting. */
+ if (flow_bb_inside_loop_p (def_loop, bb))
return;
if (!use_blocks[ver])
- use_blocks[ver] = BITMAP_XMALLOC ();
+ 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 (gimple stmt, bitmap *use_blocks, bitmap need_phis)
{
ssa_op_iter iter;
tree var;
- basic_block bb = bb_for_stmt (stmt);
+ basic_block bb = gimple_bb (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);
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
+ 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. 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, bitmap need_phis)
+{
+ gimple_stmt_iterator bsi;
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ for (bsi = gsi_start_phis (e->dest); !gsi_end_p (bsi); gsi_next (&bsi))
+ find_uses_to_rename_use (bb, PHI_ARG_DEF_FROM_EDGE (gsi_stmt (bsi), e),
+ use_blocks, need_phis);
+
+ for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+ find_uses_to_rename_stmt (gsi_stmt (bsi), use_blocks, need_phis);
+}
+
/* Marks names that are used 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. If CHANGED_BBS is not NULL,
+ scan only blocks in this set. */
static void
-find_uses_to_rename (bitmap *use_blocks)
+find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis)
{
basic_block bb;
- block_stmt_iterator bsi;
- tree phi;
- unsigned i;
+ unsigned index;
+ bitmap_iterator bi;
- FOR_EACH_BB (bb)
+ if (changed_bbs && !bitmap_empty_p (changed_bbs))
{
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
- for (i = 0; i < (unsigned) PHI_NUM_ARGS (phi); i++)
- find_uses_to_rename_use (PHI_ARG_EDGE (phi, i)->src,
- PHI_ARG_DEF (phi, i), use_blocks);
-
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- find_uses_to_rename_stmt (bsi_stmt (bsi), use_blocks);
+ EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi)
+ {
+ 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, need_phis);
+ }
}
}
Looking from the outer loop with the normal SSA form, the first use of k
is not well-behaved, while the second one is an induction variable with
- base 99 and step 1. */
+ 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.
+
+ UPDATE_FLAG is used in the call to update_ssa. See
+ TODO_update_ssa* for documentation. */
void
-rewrite_into_loop_closed_ssa (void)
+rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag)
{
- bitmap loop_exits = get_loops_exits ();
+ bitmap loop_exits;
bitmap *use_blocks;
- unsigned i;
+ unsigned i, old_num_ssa_names;
bitmap names_to_rename;
- gcc_assert (!any_marked_for_rewrite_p ());
+ loops_state_set (LOOP_CLOSED_SSA);
+ if (number_of_loops () <= 1)
+ return;
+
+ loop_exits = get_loops_exits ();
+ names_to_rename = BITMAP_ALLOC (NULL);
- use_blocks = xcalloc (num_ssa_names, sizeof (bitmap));
+ /* If the pass has caused the SSA form to be out-of-date, update it
+ now. */
+ update_ssa (update_flag);
+
+ old_num_ssa_names = num_ssa_names;
+ use_blocks = XCNEWVEC (bitmap, old_num_ssa_names);
/* Find the uses outside loops. */
- find_uses_to_rename (use_blocks);
+ 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++)
- BITMAP_XFREE (use_blocks[i]);
+ for (i = 0; i < old_num_ssa_names; i++)
+ BITMAP_FREE (use_blocks[i]);
free (use_blocks);
- BITMAP_XFREE (loop_exits);
- BITMAP_XFREE (names_to_rename);
+ 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. */
static void
check_loop_closed_ssa_use (basic_block bb, tree use)
{
- tree def;
+ gimple 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);
- def_bb = bb_for_stmt (def);
+ def_bb = gimple_bb (def);
gcc_assert (!def_bb
|| flow_bb_inside_loop_p (def_bb->loop_father, bb));
}
/* Checks invariants of loop closed ssa form in statement STMT in BB. */
static void
-check_loop_closed_ssa_stmt (basic_block bb, tree stmt)
+check_loop_closed_ssa_stmt (basic_block bb, gimple stmt)
{
ssa_op_iter iter;
tree var;
- get_stmt_operands (stmt);
-
FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
check_loop_closed_ssa_use (bb, var);
}
verify_loop_closed_ssa (void)
{
basic_block bb;
- block_stmt_iterator bsi;
- tree phi;
- unsigned i;
+ gimple_stmt_iterator bsi;
+ gimple phi;
+ edge e;
+ edge_iterator ei;
+
+ if (number_of_loops () <= 1)
+ return;
- verify_ssa ();
+ verify_ssa (false);
FOR_EACH_BB (bb)
{
- for (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
- for (i = 0; i < (unsigned) PHI_NUM_ARGS (phi); i++)
- check_loop_closed_ssa_use (PHI_ARG_EDGE (phi, i)->src,
- PHI_ARG_DEF (phi, i));
+ for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+ {
+ phi = gsi_stmt (bsi);
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ check_loop_closed_ssa_use (e->src,
+ PHI_ARG_DEF_FROM_EDGE (phi, e));
+ }
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- check_loop_closed_ssa_stmt (bb, bsi_stmt (bsi));
+ for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
+ check_loop_closed_ssa_stmt (bb, gsi_stmt (bsi));
}
}
/* Split loop exit edge EXIT. The things are a bit complicated by a need to
- preserve the loop closed ssa form. */
+ preserve the loop closed ssa form. The newly created block is returned. */
-void
+basic_block
split_loop_exit_edge (edge exit)
{
basic_block dest = exit->dest;
- basic_block bb = loop_split_edge_with (exit, NULL);
- tree phi, new_phi, new_name, name;
+ basic_block bb = split_edge (exit);
+ gimple phi, new_phi;
+ tree new_name, name;
use_operand_p op_p;
+ gimple_stmt_iterator psi;
- for (phi = phi_nodes (dest); phi; phi = TREE_CHAIN (phi))
+ for (psi = gsi_start_phis (dest); !gsi_end_p (psi); gsi_next (&psi))
{
- op_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, EDGE_SUCC (bb, 0));
+ phi = gsi_stmt (psi);
+ op_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, single_succ_edge (bb));
name = USE_FROM_PTR (op_p);
- /* If the argument of the phi node is a constant, we do not need
+ /* If the argument of the PHI node is a constant, we do not need
to keep it inside loop. */
if (TREE_CODE (name) != SSA_NAME)
continue;
/* Otherwise create an auxiliary phi node that will copy the value
- of the ssa name out of the loop. */
+ of the SSA name out of the loop. */
new_name = duplicate_ssa_name (name, NULL);
new_phi = create_phi_node (new_name, bb);
SSA_NAME_DEF_STMT (new_name) = new_phi;
- add_phi_arg (&new_phi, name, exit);
+ add_phi_arg (new_phi, name, exit);
SET_USE (op_p, new_name);
}
-}
-
-/* Insert statement STMT to the edge E and update the loop structures.
- Returns the newly created block (if any). */
-
-basic_block
-bsi_insert_on_edge_immediate_loop (edge e, tree stmt)
-{
- basic_block src, dest, new_bb;
- struct loop *loop_c;
-
- src = e->src;
- dest = e->dest;
-
- loop_c = find_common_loop (src->loop_father, dest->loop_father);
-
- new_bb = bsi_insert_on_edge_immediate (e, stmt);
-
- if (!new_bb)
- return NULL;
-
- add_bb_to_loop (new_bb, loop_c);
- if (dest->loop_father->latch == src)
- dest->loop_father->latch = new_bb;
- return new_bb;
+ return bb;
}
/* Returns the basic block in that statements should be emitted for induction
basic_block
ip_normal_pos (struct loop *loop)
{
- tree last;
+ gimple last;
basic_block bb;
edge exit;
- if (EDGE_COUNT (loop->latch->preds) > 1)
+ if (!single_pred_p (loop->latch))
return NULL;
- bb = EDGE_PRED (loop->latch, 0)->src;
+ bb = single_pred (loop->latch);
last = last_stmt (bb);
- if (TREE_CODE (last) != COND_EXPR)
+ if (!last
+ || gimple_code (last) != GIMPLE_COND)
return NULL;
exit = EDGE_SUCC (bb, 0);
the increment should be inserted after *BSI. */
void
-standard_iv_increment_position (struct loop *loop, block_stmt_iterator *bsi,
+standard_iv_increment_position (struct loop *loop, gimple_stmt_iterator *bsi,
bool *insert_after)
{
basic_block bb = ip_normal_pos (loop), latch = ip_end_pos (loop);
- tree last = last_stmt (latch);
+ gimple last = last_stmt (latch);
if (!bb
- || (last && TREE_CODE (last) != LABEL_EXPR))
+ || (last && gimple_code (last) != GIMPLE_LABEL))
{
- *bsi = bsi_last (latch);
+ *bsi = gsi_last_bb (latch);
*insert_after = true;
}
else
{
- *bsi = bsi_last (bb);
+ *bsi = gsi_last_bb (bb);
*insert_after = false;
}
}
unsigned i;
for (i = first_new_block; i < (unsigned) last_basic_block; i++)
- BASIC_BLOCK (i)->rbi->duplicated = 1;
+ BASIC_BLOCK (i)->flags |= BB_DUPLICATED;
for (i = first_new_block; i < (unsigned) last_basic_block; i++)
add_phi_args_after_copy_bb (BASIC_BLOCK (i));
for (i = first_new_block; i < (unsigned) last_basic_block; i++)
- 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;
-
- 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);
+ BASIC_BLOCK (i)->flags &= ~BB_DUPLICATED;
}
-/* Sets SSA_NAME_DEF_STMT for results of all phi nodes in BB. */
-static void
-set_phi_def_stmts (basic_block bb)
-{
- tree phi;
+/* 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 (phi = phi_nodes (bb); phi; phi = TREE_CHAIN (phi))
- SSA_NAME_DEF_STMT (PHI_RESULT (phi)) = phi;
-}
-
-/* The same ad 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,
- struct loops *loops,
+gimple_duplicate_loop_to_header_edge (struct loop *loop, edge e,
unsigned int ndupl, sbitmap wont_exit,
- edge orig, edge *to_remove,
- unsigned int *n_to_remove, int flags)
+ edge orig, VEC (edge, heap) **to_remove,
+ int flags)
{
unsigned first_new_block;
- basic_block bb;
- unsigned i;
- bitmap definitions;
- if (!(loops->state & LOOPS_HAVE_SIMPLE_LATCHES))
+ if (!loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES))
return false;
- if (!(loops->state & LOOPS_HAVE_PREHEADERS))
+ if (!loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS))
return false;
#ifdef ENABLE_CHECKING
- verify_loop_closed_ssa ();
+ if (loops_state_satisfies_p (LOOP_CLOSED_SSA))
+ 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))
+ if (!duplicate_loop_to_header_edge (loop, e, ndupl, wont_exit,
+ orig, to_remove, flags))
return false;
/* Readd the removed phi args for e. */
/* 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_XFREE (definitions);
+ scev_reset ();
- /* 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. */
+ return true;
+}
- 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);
- }
+/* Returns true if we can unroll LOOP FACTOR times. Number
+ of iterations of the loop is returned in NITER. */
- scev_reset ();
-#ifdef ENABLE_CHECKING
- verify_loop_closed_ssa ();
-#endif
+bool
+can_unroll_loop_p (struct loop *loop, unsigned factor,
+ struct tree_niter_desc *niter)
+{
+ edge exit;
+
+ /* Check whether unrolling is possible. We only want to unroll loops
+ for that we are able to determine number of iterations. We also
+ want to split the extra iterations of the loop from its end,
+ therefore we require that the loop has precisely one
+ exit. */
+
+ exit = single_dom_exit (loop);
+ if (!exit)
+ return false;
+
+ if (!number_of_iterations_exit (loop, exit, niter, false)
+ || niter->cmp == ERROR_MARK
+ /* Scalar evolutions analysis might have copy propagated
+ the abnormal ssa names into these expressions, hence
+ emitting the computations based on them during loop
+ unrolling might create overlapping life ranges for
+ them, and failures in out-of-ssa. */
+ || contains_abnormal_ssa_name_p (niter->may_be_zero)
+ || contains_abnormal_ssa_name_p (niter->control.base)
+ || contains_abnormal_ssa_name_p (niter->control.step)
+ || contains_abnormal_ssa_name_p (niter->bound))
+ return false;
+
+ /* And of course, we must be able to duplicate the loop. */
+ if (!can_duplicate_loop_p (loop))
+ return false;
+
+ /* The final loop should be small enough. */
+ if (tree_num_loop_insns (loop, &eni_size_weights) * factor
+ > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS))
+ return false;
return true;
}
-/*---------------------------------------------------------------------------
- Loop versioning
- ---------------------------------------------------------------------------*/
-
-/* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy
- of 'first'. Both of them are dominated by 'new_head' basic block. When
- 'new_head' was created by 'second's incoming edge it received phi arguments
- on the edge by split_edge(). Later, additional edge 'e' was created to
- connect 'new_head' and 'first'. Now this routine adds phi args on this
- additional edge 'e' that new_head to second edge received as part of edge
- splitting.
-*/
+/* Determines the conditions that control execution of LOOP unrolled FACTOR
+ times. DESC is number of iterations of LOOP. ENTER_COND is set to
+ condition that must be true if the main loop can be entered.
+ EXIT_BASE, EXIT_STEP, EXIT_CMP and EXIT_BOUND are set to values describing
+ how the exit from the unrolled loop should be controlled. */
static void
-lv_adjust_loop_header_phi (basic_block first, basic_block second,
- basic_block new_head, edge e)
+determine_exit_conditions (struct loop *loop, struct tree_niter_desc *desc,
+ unsigned factor, tree *enter_cond,
+ tree *exit_base, tree *exit_step,
+ enum tree_code *exit_cmp, tree *exit_bound)
{
- tree phi1, phi2;
+ gimple_seq stmts;
+ tree base = desc->control.base;
+ tree step = desc->control.step;
+ tree bound = desc->bound;
+ tree type = TREE_TYPE (step);
+ tree bigstep, delta;
+ tree min = lower_bound_in_type (type, type);
+ tree max = upper_bound_in_type (type, type);
+ enum tree_code cmp = desc->cmp;
+ tree cond = boolean_true_node, assum;
+
+ /* For pointers, do the arithmetics in the type of step (sizetype). */
+ base = fold_convert (type, base);
+ bound = fold_convert (type, bound);
+
+ *enter_cond = boolean_false_node;
+ *exit_base = NULL_TREE;
+ *exit_step = NULL_TREE;
+ *exit_cmp = ERROR_MARK;
+ *exit_bound = NULL_TREE;
+ gcc_assert (cmp != ERROR_MARK);
+
+ /* We only need to be correct when we answer question
+ "Do at least FACTOR more iterations remain?" in the unrolled loop.
+ Thus, transforming BASE + STEP * i <> BOUND to
+ BASE + STEP * i < BOUND is ok. */
+ if (cmp == NE_EXPR)
+ {
+ if (tree_int_cst_sign_bit (step))
+ cmp = GT_EXPR;
+ else
+ cmp = LT_EXPR;
+ }
+ else if (cmp == LT_EXPR)
+ {
+ gcc_assert (!tree_int_cst_sign_bit (step));
+ }
+ else if (cmp == GT_EXPR)
+ {
+ gcc_assert (tree_int_cst_sign_bit (step));
+ }
+ else
+ gcc_unreachable ();
+
+ /* The main body of the loop may be entered iff:
+
+ 1) desc->may_be_zero is false.
+ 2) it is possible to check that there are at least FACTOR iterations
+ of the loop, i.e., BOUND - step * FACTOR does not overflow.
+ 3) # of iterations is at least FACTOR */
+
+ if (!integer_zerop (desc->may_be_zero))
+ cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
+ invert_truthvalue (desc->may_be_zero),
+ cond);
+
+ bigstep = fold_build2 (MULT_EXPR, type, step,
+ build_int_cst_type (type, factor));
+ delta = fold_build2 (MINUS_EXPR, type, bigstep, step);
+ if (cmp == LT_EXPR)
+ assum = fold_build2 (GE_EXPR, boolean_type_node,
+ bound,
+ fold_build2 (PLUS_EXPR, type, min, delta));
+ else
+ assum = fold_build2 (LE_EXPR, boolean_type_node,
+ bound,
+ fold_build2 (PLUS_EXPR, type, max, delta));
+ cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond);
- /* Browse all 'second' basic block phi nodes and add phi args to
- edge 'e' for 'first' head. PHI args are always in correct order. */
+ bound = fold_build2 (MINUS_EXPR, type, bound, delta);
+ assum = fold_build2 (cmp, boolean_type_node, base, bound);
+ cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node, assum, cond);
- for (phi2 = phi_nodes (second), phi1 = phi_nodes (first);
- phi2 && phi1;
- phi2 = TREE_CHAIN (phi2), phi1 = TREE_CHAIN (phi1))
+ cond = force_gimple_operand (unshare_expr (cond), &stmts, false, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+ /* cond now may be a gimple comparison, which would be OK, but also any
+ other gimple rhs (say a && b). In this case we need to force it to
+ operand. */
+ if (!is_gimple_condexpr (cond))
{
- int i;
- for (i = 0; i < PHI_NUM_ARGS (phi2); i++)
- {
- if (PHI_ARG_EDGE (phi2, i)->src == new_head)
- {
- tree def = PHI_ARG_DEF (phi2, i);
- add_phi_arg (&phi1, def, e);
- }
- }
+ cond = force_gimple_operand (cond, &stmts, true, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
}
+ *enter_cond = cond;
+
+ base = force_gimple_operand (unshare_expr (base), &stmts, true, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+ bound = force_gimple_operand (unshare_expr (bound), &stmts, true, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+
+ *exit_base = base;
+ *exit_step = bigstep;
+ *exit_cmp = cmp;
+ *exit_bound = bound;
}
-/* Adjust entry edge for lv.
-
- e is a incoming edge.
+/* Scales the frequencies of all basic blocks in LOOP that are strictly
+ dominated by BB by NUM/DEN. */
- --- edge e ---- > [second_head]
+static void
+scale_dominated_blocks_in_loop (struct loop *loop, basic_block bb,
+ int num, int den)
+{
+ basic_block son;
- Split it and insert new conditional expression and adjust edges.
-
- --- edge e ---> [cond expr] ---> [first_head]
- |
- +---------> [second_head]
+ if (den == 0)
+ return;
-*/
-
-static basic_block
-lv_adjust_loop_entry_edge (basic_block first_head,
- basic_block second_head,
- edge e,
- tree cond_expr)
-{
- block_stmt_iterator bsi;
- basic_block new_head = NULL;
- tree goto1 = NULL_TREE;
- tree goto2 = NULL_TREE;
- tree new_cond_expr = NULL_TREE;
- edge e0, e1;
-
- gcc_assert (e->dest == second_head);
-
- /* Split edge 'e'. This will create a new basic block, where we can
- insert conditional expr. */
- new_head = split_edge (e);
-
- /* Build new conditional expr */
- goto1 = build1 (GOTO_EXPR, void_type_node, tree_block_label (first_head));
- goto2 = build1 (GOTO_EXPR, void_type_node, tree_block_label (second_head));
- new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr, goto1, goto2);
-
- /* Add new cond. in new head. */
- bsi = bsi_start (new_head);
- bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT);
-
- /* Adjust edges appropriately to connect new head with first head
- as well as second head. */
- e0 = EDGE_SUCC (new_head, 0);
- e0->flags &= ~EDGE_FALLTHRU;
- e0->flags |= EDGE_FALSE_VALUE;
- e1 = make_edge (new_head, first_head, EDGE_TRUE_VALUE);
- set_immediate_dominator (CDI_DOMINATORS, first_head, new_head);
- set_immediate_dominator (CDI_DOMINATORS, second_head, new_head);
-
- /* Adjust loop header phi nodes. */
- lv_adjust_loop_header_phi (first_head, second_head, new_head, e1);
-
- return new_head;
+ for (son = first_dom_son (CDI_DOMINATORS, bb);
+ son;
+ son = next_dom_son (CDI_DOMINATORS, son))
+ {
+ if (!flow_bb_inside_loop_p (loop, son))
+ continue;
+ scale_bbs_frequencies_int (&son, 1, num, den);
+ scale_dominated_blocks_in_loop (loop, son, num, den);
+ }
}
-/* Main entry point for Loop Versioning transformation.
-
-This transformation given a condition and a loop, creates
--if (condition) { loop_copy1 } else { loop_copy2 },
-where loop_copy1 is the loop transformed in one way, and loop_copy2
-is the loop transformed in another way (or unchanged). 'condition'
-may be a run time test for things that were not resolved by static
-analysis (overlapping ranges (anti-aliasing), alignment, etc.). */
-
-struct loop *
-tree_ssa_loop_version (struct loops *loops, struct loop * loop,
- tree cond_expr, basic_block *condition_bb)
-{
- edge entry, latch_edge, exit, true_edge, false_edge;
- basic_block first_head, second_head;
- int irred_flag;
- struct loop *nloop;
+/* Unroll LOOP FACTOR times. DESC describes number of iterations of LOOP.
+ EXIT is the exit of the loop to that DESC corresponds.
- /* CHECKME: Loop versioning does not handle nested loop at this point. */
- if (loop->inner)
- return NULL;
+ If N is number of iterations of the loop and MAY_BE_ZERO is the condition
+ under that loop exits in the first iteration even if N != 0,
+
+ while (1)
+ {
+ x = phi (init, next);
+
+ pre;
+ if (st)
+ break;
+ post;
+ }
+
+ becomes (with possibly the exit conditions formulated a bit differently,
+ avoiding the need to create a new iv):
+
+ if (MAY_BE_ZERO || N < FACTOR)
+ goto rest;
+
+ do
+ {
+ x = phi (init, next);
+
+ pre;
+ post;
+ pre;
+ post;
+ ...
+ pre;
+ post;
+ N -= FACTOR;
+
+ } while (N >= FACTOR);
+
+ rest:
+ init' = phi (init, x);
+
+ while (1)
+ {
+ x = phi (init', next);
+
+ pre;
+ if (st)
+ break;
+ post;
+ }
+
+ Before the loop is unrolled, TRANSFORM is called for it (only for the
+ unrolled loop, but not for its versioned copy). DATA is passed to
+ TRANSFORM. */
- /* Record entry and latch edges for the loop */
- entry = loop_preheader_edge (loop);
+/* Probability in % that the unrolled loop is entered. Just a guess. */
+#define PROB_UNROLLED_LOOP_ENTERED 90
- /* Note down head of loop as first_head. */
- first_head = entry->dest;
+void
+tree_transform_and_unroll_loop (struct loop *loop, unsigned factor,
+ edge exit, struct tree_niter_desc *desc,
+ transform_callback transform,
+ void *data)
+{
+ gimple exit_if;
+ tree ctr_before, ctr_after;
+ tree enter_main_cond, exit_base, exit_step, exit_bound;
+ enum tree_code exit_cmp;
+ gimple phi_old_loop, phi_new_loop, phi_rest;
+ gimple_stmt_iterator psi_old_loop, psi_new_loop;
+ tree init, next, new_init, var;
+ struct loop *new_loop;
+ basic_block rest, exit_bb;
+ edge old_entry, new_entry, old_latch, precond_edge, new_exit;
+ edge new_nonexit, e;
+ gimple_stmt_iterator bsi;
+ use_operand_p op;
+ bool ok;
+ unsigned est_niter, prob_entry, scale_unrolled, scale_rest, freq_e, freq_h;
+ unsigned new_est_niter, i, prob;
+ unsigned irr = loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP;
+ sbitmap wont_exit;
+ VEC (edge, heap) *to_remove = NULL;
+
+ est_niter = expected_loop_iterations (loop);
+ determine_exit_conditions (loop, desc, factor,
+ &enter_main_cond, &exit_base, &exit_step,
+ &exit_cmp, &exit_bound);
+
+ /* Let us assume that the unrolled loop is quite likely to be entered. */
+ if (integer_nonzerop (enter_main_cond))
+ prob_entry = REG_BR_PROB_BASE;
+ else
+ prob_entry = PROB_UNROLLED_LOOP_ENTERED * REG_BR_PROB_BASE / 100;
+
+ /* The values for scales should keep profile consistent, and somewhat close
+ to correct.
+
+ TODO: The current value of SCALE_REST makes it appear that the loop that
+ is created by splitting the remaining iterations of the unrolled loop is
+ executed the same number of times as the original loop, and with the same
+ frequencies, which is obviously wrong. This does not appear to cause
+ problems, so we do not bother with fixing it for now. To make the profile
+ correct, we would need to change the probability of the exit edge of the
+ loop, and recompute the distribution of frequencies in its body because
+ of this change (scale the frequencies of blocks before and after the exit
+ by appropriate factors). */
+ scale_unrolled = prob_entry;
+ scale_rest = REG_BR_PROB_BASE;
+
+ new_loop = loop_version (loop, enter_main_cond, NULL,
+ prob_entry, scale_unrolled, scale_rest, true);
+ gcc_assert (new_loop != NULL);
+ update_ssa (TODO_update_ssa);
+
+ /* Determine the probability of the exit edge of the unrolled loop. */
+ new_est_niter = est_niter / factor;
+
+ /* Without profile feedback, loops for that we do not know a better estimate
+ are assumed to roll 10 times. When we unroll such loop, it appears to
+ roll too little, and it may even seem to be cold. To avoid this, we
+ ensure that the created loop appears to roll at least 5 times (but at
+ most as many times as before unrolling). */
+ if (new_est_niter < 5)
+ {
+ if (est_niter < 5)
+ new_est_niter = est_niter;
+ else
+ new_est_niter = 5;
+ }
- /* Duplicate loop. */
- irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP;
- entry->flags &= ~EDGE_IRREDUCIBLE_LOOP;
- if (!tree_duplicate_loop_to_header_edge (loop, entry, loops, 1,
- NULL, NULL, NULL, NULL, 0))
+ /* Prepare the cfg and update the phi nodes. Move the loop exit to the
+ loop latch (and make its condition dummy, for the moment). */
+ rest = loop_preheader_edge (new_loop)->src;
+ precond_edge = single_pred_edge (rest);
+ split_edge (loop_latch_edge (loop));
+ exit_bb = single_pred (loop->latch);
+
+ /* Since the exit edge will be removed, the frequency of all the blocks
+ in the loop that are dominated by it must be scaled by
+ 1 / (1 - exit->probability). */
+ scale_dominated_blocks_in_loop (loop, exit->src,
+ REG_BR_PROB_BASE,
+ REG_BR_PROB_BASE - exit->probability);
+
+ bsi = gsi_last_bb (exit_bb);
+ exit_if = gimple_build_cond (EQ_EXPR, integer_zero_node,
+ integer_zero_node,
+ NULL_TREE, NULL_TREE);
+
+ gsi_insert_after (&bsi, exit_if, GSI_NEW_STMT);
+ new_exit = make_edge (exit_bb, rest, EDGE_FALSE_VALUE | irr);
+ rescan_loop_exit (new_exit, true, false);
+
+ /* Set the probability of new exit to the same of the old one. Fix
+ the frequency of the latch block, by scaling it back by
+ 1 - exit->probability. */
+ new_exit->count = exit->count;
+ new_exit->probability = exit->probability;
+ new_nonexit = single_pred_edge (loop->latch);
+ new_nonexit->probability = REG_BR_PROB_BASE - exit->probability;
+ new_nonexit->flags = EDGE_TRUE_VALUE;
+ new_nonexit->count -= exit->count;
+ if (new_nonexit->count < 0)
+ new_nonexit->count = 0;
+ scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability,
+ REG_BR_PROB_BASE);
+
+ old_entry = loop_preheader_edge (loop);
+ new_entry = loop_preheader_edge (new_loop);
+ old_latch = loop_latch_edge (loop);
+ for (psi_old_loop = gsi_start_phis (loop->header),
+ psi_new_loop = gsi_start_phis (new_loop->header);
+ !gsi_end_p (psi_old_loop);
+ gsi_next (&psi_old_loop), gsi_next (&psi_new_loop))
{
- entry->flags |= irred_flag;
- return NULL;
+ phi_old_loop = gsi_stmt (psi_old_loop);
+ phi_new_loop = gsi_stmt (psi_new_loop);
+
+ init = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_entry);
+ op = PHI_ARG_DEF_PTR_FROM_EDGE (phi_new_loop, new_entry);
+ gcc_assert (operand_equal_for_phi_arg_p (init, USE_FROM_PTR (op)));
+ next = PHI_ARG_DEF_FROM_EDGE (phi_old_loop, old_latch);
+
+ /* Prefer using original variable as a base for the new ssa name.
+ This is necessary for virtual ops, and useful in order to avoid
+ losing debug info for real ops. */
+ if (TREE_CODE (next) == SSA_NAME)
+ var = SSA_NAME_VAR (next);
+ else if (TREE_CODE (init) == SSA_NAME)
+ var = SSA_NAME_VAR (init);
+ else
+ {
+ var = create_tmp_var (TREE_TYPE (init), "unrinittmp");
+ add_referenced_var (var);
+ }
+
+ new_init = make_ssa_name (var, NULL);
+ phi_rest = create_phi_node (new_init, rest);
+ SSA_NAME_DEF_STMT (new_init) = phi_rest;
+
+ add_phi_arg (phi_rest, init, precond_edge);
+ add_phi_arg (phi_rest, next, new_exit);
+ SET_USE (op, new_init);
}
- /* After duplication entry edge now points to new loop head block.
- Note down new head as second_head. */
- second_head = entry->dest;
+ remove_path (exit);
- /* Split loop entry edge and insert new block with cond expr. */
- *condition_bb = lv_adjust_loop_entry_edge (first_head, second_head, entry,
- cond_expr);
+ /* Transform the loop. */
+ if (transform)
+ (*transform) (loop, data);
- latch_edge = EDGE_SUCC (loop->latch->rbi->copy, 0);
-
- extract_true_false_edges_from_block (*condition_bb, &true_edge, &false_edge);
- nloop = loopify (loops,
- latch_edge,
- EDGE_PRED (loop->header->rbi->copy, 0),
- *condition_bb, true_edge, false_edge,
- false /* Do not redirect all edges. */);
-
- exit = loop->single_exit;
- if (exit)
- nloop->single_exit = find_edge (exit->src->rbi->copy, exit->dest);
-
- /* loopify redirected latch_edge. Update its PENDING_STMTS. */
- flush_pending_stmts (latch_edge);
-
- /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */
- extract_true_false_edges_from_block (*condition_bb, &true_edge, &false_edge);
- flush_pending_stmts (false_edge);
-
- /* Adjust irreducible flag. */
- if (irred_flag)
+ /* Unroll the loop and remove the exits in all iterations except for the
+ last one. */
+ wont_exit = sbitmap_alloc (factor);
+ sbitmap_ones (wont_exit);
+ RESET_BIT (wont_exit, factor - 1);
+
+ ok = gimple_duplicate_loop_to_header_edge
+ (loop, loop_latch_edge (loop), factor - 1,
+ wont_exit, new_exit, &to_remove, DLTHE_FLAG_UPDATE_FREQ);
+ free (wont_exit);
+ gcc_assert (ok);
+
+ for (i = 0; VEC_iterate (edge, to_remove, i, e); i++)
{
- (*condition_bb)->flags |= BB_IRREDUCIBLE_LOOP;
- loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP;
- loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP;
- EDGE_PRED ((*condition_bb), 0)->flags |= EDGE_IRREDUCIBLE_LOOP;
+ ok = remove_path (e);
+ gcc_assert (ok);
}
+ VEC_free (edge, heap, to_remove);
+ update_ssa (TODO_update_ssa);
+
+ /* Ensure that the frequencies in the loop match the new estimated
+ number of iterations, and change the probability of the new
+ exit edge. */
+ freq_h = loop->header->frequency;
+ freq_e = EDGE_FREQUENCY (loop_preheader_edge (loop));
+ if (freq_h != 0)
+ scale_loop_frequencies (loop, freq_e * (new_est_niter + 1), freq_h);
+
+ exit_bb = single_pred (loop->latch);
+ new_exit = find_edge (exit_bb, rest);
+ new_exit->count = loop_preheader_edge (loop)->count;
+ new_exit->probability = REG_BR_PROB_BASE / (new_est_niter + 1);
+
+ rest->count += new_exit->count;
+ rest->frequency += EDGE_FREQUENCY (new_exit);
+
+ new_nonexit = single_pred_edge (loop->latch);
+ prob = new_nonexit->probability;
+ new_nonexit->probability = REG_BR_PROB_BASE - new_exit->probability;
+ new_nonexit->count = exit_bb->count - new_exit->count;
+ if (new_nonexit->count < 0)
+ new_nonexit->count = 0;
+ if (prob > 0)
+ scale_bbs_frequencies_int (&loop->latch, 1, new_nonexit->probability,
+ prob);
+
+ /* Finally create the new counter for number of iterations and add the new
+ exit instruction. */
+ bsi = gsi_last_bb (exit_bb);
+ exit_if = gsi_stmt (bsi);
+ create_iv (exit_base, exit_step, NULL_TREE, loop,
+ &bsi, false, &ctr_before, &ctr_after);
+ gimple_cond_set_code (exit_if, exit_cmp);
+ gimple_cond_set_lhs (exit_if, ctr_after);
+ gimple_cond_set_rhs (exit_if, exit_bound);
+ update_stmt (exit_if);
+
+#ifdef ENABLE_CHECKING
+ verify_flow_info ();
+ verify_dominators (CDI_DOMINATORS);
+ verify_loop_structure ();
+ verify_loop_closed_ssa ();
+#endif
+}
- /* At this point condition_bb is loop predheader with two successors,
- first_head and second_head. Make sure that loop predheader has only
- one successor. */
- loop_split_edge_with (loop_preheader_edge (loop), NULL);
- loop_split_edge_with (loop_preheader_edge (nloop), NULL);
+/* Wrapper over tree_transform_and_unroll_loop for case we do not
+ want to transform the loop before unrolling. The meaning
+ of the arguments is the same as for tree_transform_and_unroll_loop. */
- return nloop;
+void
+tree_unroll_loop (struct loop *loop, unsigned factor,
+ edge exit, struct tree_niter_desc *desc)
+{
+ tree_transform_and_unroll_loop (loop, factor, exit, desc,
+ NULL, NULL);
}