/* High-level loop manipulation functions.
- Copyright (C) 2004, 2005 Free Software Foundation, Inc.
-
+ Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010
+ 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
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "rtl.h"
#include "tm_p.h"
-#include "hard-reg-set.h"
#include "basic-block.h"
#include "output.h"
#include "diagnostic.h"
#include "cfglayout.h"
#include "tree-scalar-evolution.h"
#include "params.h"
+#include "tree-inline.h"
+#include "langhooks.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). INCR_POS and
+ 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);
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;
}
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;
}
}
}
-
+ if (POINTER_TYPE_P (TREE_TYPE (base)))
+ {
+ if (TREE_CODE (base) == ADDR_EXPR)
+ mark_addressable (TREE_OPERAND (base, 0));
+ 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, var);
+ step = force_gimple_operand (step, &stmts, true, NULL_TREE);
if (stmts)
- bsi_insert_on_edge_immediate_loop (pe, 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)
- 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), UNKNOWN_LOCATION);
+ add_phi_arg (stmt, va, loop_latch_edge (loop), UNKNOWN_LOCATION);
}
/* 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 (PHI_RESULT (phi), phi, PHI_RESULT_PTR (phi));
+ 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);
+ add_phi_arg (phi, use, e, UNKNOWN_LOCATION);
}
/* 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;
if (is_gimple_reg (var))
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])
NEED_PHIS. */
static void
-find_uses_to_rename_stmt (tree stmt, bitmap *use_blocks, bitmap need_phis)
+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);
- FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)
+ if (is_gimple_debug (stmt))
+ return;
+
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
find_uses_to_rename_use (bb, var, use_blocks, need_phis);
}
static void
find_uses_to_rename_bb (basic_block bb, bitmap *use_blocks, bitmap need_phis)
{
- block_stmt_iterator bsi;
+ gimple_stmt_iterator bsi;
edge e;
edge_iterator ei;
- tree phi;
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),
+ 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 = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- find_uses_to_rename_stmt (bsi_stmt (bsi), 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. If CHANGED_BBS is not NULL,
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.
-
+
If CHANGED_BBS is not NULL, we look for uses outside loops only in
the basic blocks in this set.
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, old_num_ssa_names;
- bitmap names_to_rename = BITMAP_ALLOC (NULL);
+ bitmap names_to_rename;
+
+ loops_state_set (LOOP_CLOSED_SSA);
+ if (number_of_loops () <= 1)
+ return;
+
+ loop_exits = get_loops_exits ();
+ names_to_rename = BITMAP_ALLOC (NULL);
/* If the pass has caused the SSA form to be out-of-date, update it
now. */
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 || !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;
- FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES | SSA_OP_ALL_KILLS)
+ if (is_gimple_debug (stmt))
+ return;
+
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_USES)
check_loop_closed_ssa_use (bb, var);
}
-/* Checks that invariants of the loop closed ssa form are preserved. */
+/* Checks that invariants of the loop closed ssa form are preserved.
+ Call verify_ssa when VERIFY_SSA_P is true. */
void
-verify_loop_closed_ssa (void)
+verify_loop_closed_ssa (bool verify_ssa_p)
{
basic_block bb;
- block_stmt_iterator bsi;
- tree phi;
- unsigned i;
+ gimple_stmt_iterator bsi;
+ gimple phi;
+ edge e;
+ edge_iterator ei;
- if (current_loops == NULL)
+ if (number_of_loops () <= 1)
return;
- verify_ssa (false);
+ if (verify_ssa_p)
+ verify_ssa (false);
FOR_EACH_BB (bb)
{
- for (phi = phi_nodes (bb); phi; phi = PHI_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;
+ source_location locus;
- for (phi = phi_nodes (dest); phi; phi = PHI_CHAIN (phi))
+ for (psi = gsi_start_phis (dest); !gsi_end_p (psi); gsi_next (&psi))
{
+ phi = gsi_stmt (psi);
op_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, single_succ_edge (bb));
+ locus = gimple_phi_arg_location_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, locus);
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;
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;
}
}
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;
- 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 (true);
#endif
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. */
return true;
}
-/* Build if (COND) goto THEN_LABEL; else goto ELSE_LABEL; */
-
-static tree
-build_if_stmt (tree cond, tree then_label, tree else_label)
-{
- return build3 (COND_EXPR, void_type_node,
- cond,
- build1 (GOTO_EXPR, void_type_node, then_label),
- build1 (GOTO_EXPR, void_type_node, else_label));
-}
-
/* Returns true if we can unroll LOOP FACTOR times. Number
of iterations of the loop is returned in NITER. */
return false;
if (!number_of_iterations_exit (loop, exit, niter, false)
- || niter->cmp == ERROR_MARK)
+ || 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. */
return false;
/* The final loop should be small enough. */
- if (tree_num_loop_insns (loop) * factor
+ if (tree_num_loop_insns (loop, &eni_size_weights) * factor
> (unsigned) PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS))
return false;
tree *exit_base, tree *exit_step,
enum tree_code *exit_cmp, tree *exit_bound)
{
- tree stmts;
+ gimple_seq stmts;
tree base = desc->control.base;
tree step = desc->control.step;
tree bound = desc->bound;
- tree type = TREE_TYPE (base);
+ 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;
of the loop, i.e., BOUND - step * FACTOR does not overflow.
3) # of iterations is at least FACTOR */
- if (!zero_p (desc->may_be_zero))
+ if (!integer_zerop (desc->may_be_zero))
cond = fold_build2 (TRUTH_AND_EXPR, boolean_type_node,
invert_truthvalue (desc->may_be_zero),
cond);
cond = force_gimple_operand (unshare_expr (cond), &stmts, false, NULL_TREE);
if (stmts)
- bsi_insert_on_edge_immediate_loop (loop_preheader_edge (loop), 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. */
{
cond = force_gimple_operand (cond, &stmts, true, NULL_TREE);
if (stmts)
- bsi_insert_on_edge_immediate_loop (loop_preheader_edge (loop), 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)
- bsi_insert_on_edge_immediate_loop (loop_preheader_edge (loop), 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)
- bsi_insert_on_edge_immediate_loop (loop_preheader_edge (loop), stmts);
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
*exit_base = base;
*exit_step = bigstep;
*exit_bound = bound;
}
-/* Unroll LOOP FACTOR times. LOOPS is the loops tree. DESC describes
- number of iterations of LOOP. EXIT is the exit of the loop to that
- DESC corresponds.
-
+/* Scales the frequencies of all basic blocks in LOOP that are strictly
+ dominated by BB by NUM/DEN. */
+
+static void
+scale_dominated_blocks_in_loop (struct loop *loop, basic_block bb,
+ int num, int den)
+{
+ basic_block son;
+
+ if (den == 0)
+ return;
+
+ 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);
+ }
+}
+
+/* Unroll LOOP FACTOR times. DESC describes number of iterations of LOOP.
+ EXIT is the exit of the loop to that DESC corresponds.
+
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);
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;
pre;
post;
N -= FACTOR;
-
+
} while (N >= FACTOR);
rest:
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. */
+
+/* Probability in % that the unrolled loop is entered. Just a guess. */
+#define PROB_UNROLLED_LOOP_ENTERED 90
void
-tree_unroll_loop (struct loops *loops, struct loop *loop, unsigned factor,
- edge exit, struct tree_niter_desc *desc)
+tree_transform_and_unroll_loop (struct loop *loop, unsigned factor,
+ edge exit, struct tree_niter_desc *desc,
+ transform_callback transform,
+ void *data)
{
- tree dont_exit, exit_if, ctr_before, ctr_after;
+ gimple exit_if;
+ tree ctr_before, ctr_after;
tree enter_main_cond, exit_base, exit_step, exit_bound;
enum tree_code exit_cmp;
- tree phi_old_loop, phi_new_loop, phi_rest, init, next, new_init, var;
+ 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 nonexit, new_nonexit;
- block_stmt_iterator bsi;
+ edge new_nonexit, e;
+ gimple_stmt_iterator bsi;
use_operand_p op;
bool ok;
- unsigned est_niter;
+ 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);
- new_loop = loop_version (loops, loop, enter_main_cond, NULL, true);
+ /* 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);
- /* Unroll the loop and remove the old exits. */
- dont_exit = ((exit->flags & EDGE_TRUE_VALUE)
- ? boolean_false_node
- : boolean_true_node);
- if (exit == EDGE_SUCC (exit->src, 0))
- nonexit = EDGE_SUCC (exit->src, 1);
- else
- nonexit = EDGE_SUCC (exit->src, 0);
- nonexit->probability = REG_BR_PROB_BASE;
- exit->probability = 0;
- nonexit->count += exit->count;
- exit->count = 0;
- exit_if = last_stmt (exit->src);
- COND_EXPR_COND (exit_if) = dont_exit;
- update_stmt (exit_if);
-
- wont_exit = sbitmap_alloc (factor);
- sbitmap_ones (wont_exit);
- ok = tree_duplicate_loop_to_header_edge
- (loop, loop_latch_edge (loop), loops, factor - 1,
- wont_exit, NULL, NULL, NULL, DLTHE_FLAG_UPDATE_FREQ);
- free (wont_exit);
- gcc_assert (ok);
- update_ssa (TODO_update_ssa);
+ /* Determine the probability of the exit edge of the unrolled loop. */
+ new_est_niter = est_niter / factor;
- /* Prepare the cfg and update the phi nodes. */
+ /* 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;
+ }
+
+ /* 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);
- loop_split_edge_with (loop_latch_edge (loop), NULL);
+ 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);
- new_exit->count = loop_preheader_edge (loop)->count;
- est_niter = est_niter / factor + 1;
- new_exit->probability = REG_BR_PROB_BASE / est_niter;
+ 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->probability = REG_BR_PROB_BASE - new_exit->probability;
+ 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 (phi_old_loop = phi_nodes (loop->header),
- phi_new_loop = phi_nodes (new_loop->header);
- phi_old_loop;
- phi_old_loop = PHI_CHAIN (phi_old_loop),
- phi_new_loop = PHI_CHAIN (phi_new_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))
{
+ 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)));
/* 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)
+ if (TREE_CODE (next) == SSA_NAME
+ && useless_type_conversion_p (TREE_TYPE (next),
+ TREE_TYPE (init)))
var = SSA_NAME_VAR (next);
- else if (TREE_CODE (init) == SSA_NAME)
+ else if (TREE_CODE (init) == SSA_NAME
+ && useless_type_conversion_p (TREE_TYPE (init),
+ TREE_TYPE (next)))
var = SSA_NAME_VAR (init);
+ else if (useless_type_conversion_p (TREE_TYPE (next), TREE_TYPE (init)))
+ {
+ var = create_tmp_var (TREE_TYPE (next), "unrinittmp");
+ add_referenced_var (var);
+ }
else
{
var = create_tmp_var (TREE_TYPE (init), "unrinittmp");
add_referenced_var (var);
}
- new_init = make_ssa_name (var, NULL_TREE);
+ 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);
+ add_phi_arg (phi_rest, init, precond_edge, UNKNOWN_LOCATION);
+ add_phi_arg (phi_rest, next, new_exit, UNKNOWN_LOCATION);
SET_USE (op, new_init);
}
+ remove_path (exit);
+
+ /* Transform the loop. */
+ if (transform)
+ (*transform) (loop, data);
+
+ /* 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++)
+ {
+ 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 = bsi_last (exit_bb);
+ bsi = gsi_last_bb (exit_bb);
+ exit_if = gsi_stmt (bsi);
create_iv (exit_base, exit_step, NULL_TREE, loop,
- &bsi, true, &ctr_before, &ctr_after);
- exit_if = build_if_stmt (build2 (exit_cmp, boolean_type_node, ctr_after,
- exit_bound),
- tree_block_label (loop->latch),
- tree_block_label (rest));
- bsi_insert_after (&bsi, exit_if, BSI_NEW_STMT);
+ &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 (loops);
- verify_loop_closed_ssa ();
+ verify_loop_structure ();
+ verify_loop_closed_ssa (true);
#endif
}
+
+/* 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. */
+
+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);
+}
+
+/* Rewrite the phi node at position PSI in function of the main
+ induction variable MAIN_IV and insert the generated code at GSI. */
+
+static void
+rewrite_phi_with_iv (loop_p loop,
+ gimple_stmt_iterator *psi,
+ gimple_stmt_iterator *gsi,
+ tree main_iv)
+{
+ affine_iv iv;
+ gimple stmt, phi = gsi_stmt (*psi);
+ tree atype, mtype, val, res = PHI_RESULT (phi);
+
+ if (!is_gimple_reg (res) || res == main_iv)
+ {
+ gsi_next (psi);
+ return;
+ }
+
+ if (!simple_iv (loop, loop, res, &iv, true))
+ {
+ gsi_next (psi);
+ return;
+ }
+
+ remove_phi_node (psi, false);
+
+ atype = TREE_TYPE (res);
+ mtype = POINTER_TYPE_P (atype) ? sizetype : atype;
+ val = fold_build2 (MULT_EXPR, mtype, unshare_expr (iv.step),
+ fold_convert (mtype, main_iv));
+ val = fold_build2 (POINTER_TYPE_P (atype)
+ ? POINTER_PLUS_EXPR : PLUS_EXPR,
+ atype, unshare_expr (iv.base), val);
+ val = force_gimple_operand_gsi (gsi, val, false, NULL_TREE, true,
+ GSI_SAME_STMT);
+ stmt = gimple_build_assign (res, val);
+ gsi_insert_before (gsi, stmt, GSI_SAME_STMT);
+ SSA_NAME_DEF_STMT (res) = stmt;
+}
+
+/* Rewrite all the phi nodes of LOOP in function of the main induction
+ variable MAIN_IV. */
+
+static void
+rewrite_all_phi_nodes_with_iv (loop_p loop, tree main_iv)
+{
+ unsigned i;
+ basic_block *bbs = get_loop_body_in_dom_order (loop);
+ gimple_stmt_iterator psi;
+
+ for (i = 0; i < loop->num_nodes; i++)
+ {
+ basic_block bb = bbs[i];
+ gimple_stmt_iterator gsi = gsi_after_labels (bb);
+
+ if (bb->loop_father != loop)
+ continue;
+
+ for (psi = gsi_start_phis (bb); !gsi_end_p (psi); )
+ rewrite_phi_with_iv (loop, &psi, &gsi, main_iv);
+ }
+
+ free (bbs);
+}
+
+/* Bases all the induction variables in LOOP on a single induction
+ variable (unsigned with base 0 and step 1), whose final value is
+ compared with *NIT. When the IV type precision has to be larger
+ than *NIT type precision, *NIT is converted to the larger type, the
+ conversion code is inserted before the loop, and *NIT is updated to
+ the new definition. When BUMP_IN_LATCH is true, the induction
+ variable is incremented in the loop latch, otherwise it is
+ incremented in the loop header. Return the induction variable that
+ was created. */
+
+tree
+canonicalize_loop_ivs (struct loop *loop, tree *nit, bool bump_in_latch)
+{
+ unsigned precision = TYPE_PRECISION (TREE_TYPE (*nit));
+ unsigned original_precision = precision;
+ tree type, var_before;
+ gimple_stmt_iterator gsi, psi;
+ gimple stmt;
+ edge exit = single_dom_exit (loop);
+ gimple_seq stmts;
+
+ for (psi = gsi_start_phis (loop->header);
+ !gsi_end_p (psi); gsi_next (&psi))
+ {
+ gimple phi = gsi_stmt (psi);
+ tree res = PHI_RESULT (phi);
+
+ if (is_gimple_reg (res) && TYPE_PRECISION (TREE_TYPE (res)) > precision)
+ precision = TYPE_PRECISION (TREE_TYPE (res));
+ }
+
+ type = lang_hooks.types.type_for_size (precision, 1);
+
+ if (original_precision != precision)
+ {
+ *nit = fold_convert (type, *nit);
+ *nit = force_gimple_operand (*nit, &stmts, true, NULL_TREE);
+ if (stmts)
+ gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+ }
+
+ gsi = gsi_last_bb (bump_in_latch ? loop->latch : loop->header);
+ create_iv (build_int_cst_type (type, 0), build_int_cst (type, 1), NULL_TREE,
+ loop, &gsi, bump_in_latch, &var_before, NULL);
+
+ rewrite_all_phi_nodes_with_iv (loop, var_before);
+
+ stmt = last_stmt (exit->src);
+ /* Make the loop exit if the control condition is not satisfied. */
+ if (exit->flags & EDGE_TRUE_VALUE)
+ {
+ edge te, fe;
+
+ extract_true_false_edges_from_block (exit->src, &te, &fe);
+ te->flags = EDGE_FALSE_VALUE;
+ fe->flags = EDGE_TRUE_VALUE;
+ }
+ gimple_cond_set_code (stmt, LT_EXPR);
+ gimple_cond_set_lhs (stmt, var_before);
+ gimple_cond_set_rhs (stmt, *nit);
+ update_stmt (stmt);
+
+ return var_before;
+}
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