/* Code sinking for trees
- Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2002, 2003, 2004, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>
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)
+the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
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, 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 "coretypes.h"
#include "tm.h"
-#include "ggc.h"
#include "tree.h"
#include "basic-block.h"
#include "diagnostic.h"
+#include "gimple-pretty-print.h"
#include "tree-inline.h"
#include "tree-flow.h"
-#include "tree-gimple.h"
+#include "gimple.h"
#include "tree-dump.h"
#include "timevar.h"
#include "fibheap.h"
#include "hashtab.h"
#include "tree-iterator.h"
-#include "real.h"
#include "alloc-pool.h"
#include "tree-pass.h"
#include "flags.h"
else
y = *q;
-
+
should become
sinktemp = p;
p = p + 1;
y = *q
}
Store copy propagation will take care of the store elimination above.
-
+
2. Sinking using Partial Dead Code Elimination. */
static struct
-{
+{
/* The number of statements sunk down the flowgraph by code sinking. */
int sunk;
-
+
} sink_stats;
we return NULL. */
static basic_block
-find_bb_for_arg (tree phi, tree def)
+find_bb_for_arg (gimple phi, tree def)
{
- int i;
+ size_t i;
bool foundone = false;
basic_block result = NULL;
- for (i = 0; i < PHI_NUM_ARGS (phi); i++)
+ for (i = 0; i < gimple_phi_num_args (phi); i++)
if (PHI_ARG_DEF (phi, i) == def)
{
if (foundone)
return NULL;
foundone = true;
- result = PHI_ARG_EDGE (phi, i)->src;
+ result = gimple_phi_arg_edge (phi, i)->src;
}
return result;
}
used in, so that you only have one place you can sink it to. */
static bool
-all_immediate_uses_same_place (tree stmt)
+all_immediate_uses_same_place (gimple stmt)
{
- tree firstuse = NULL_TREE;
+ gimple firstuse = NULL;
ssa_op_iter op_iter;
imm_use_iterator imm_iter;
use_operand_p use_p;
{
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
- if (firstuse == NULL_TREE)
+ if (is_gimple_debug (USE_STMT (use_p)))
+ continue;
+ if (firstuse == NULL)
firstuse = USE_STMT (use_p);
else
if (firstuse != USE_STMT (use_p))
return true;
}
-/* Some global stores don't necessarily have V_MAY_DEF's of global variables,
+/* Some global stores don't necessarily have VDEF's of global variables,
but we still must avoid moving them around. */
bool
-is_hidden_global_store (tree stmt)
+is_hidden_global_store (gimple stmt)
{
/* Check virtual definitions. If we get here, the only virtual
- definitions we should see are those generated by assignment
+ definitions we should see are those generated by assignment or call
statements. */
- if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
+ if (gimple_vdef (stmt))
{
tree lhs;
- gcc_assert (TREE_CODE (stmt) == MODIFY_EXPR);
+ gcc_assert (is_gimple_assign (stmt) || is_gimple_call (stmt));
/* Note that we must not check the individual virtual operands
here. In particular, if this is an aliased store, we could
int x;
p_1 = (i_2 > 3) ? &x : p;
- # x_4 = V_MAY_DEF <x_3>
+ # x_4 = VDEF <x_3>
*p_1 = 5;
return 2;
variable.
Therefore, we check the base address of the LHS. If the
- address is a pointer, we check if its name tag or type tag is
+ address is a pointer, we check if its name tag or symbol tag is
a global variable. Otherwise, we check if the base variable
is a global. */
- lhs = TREE_OPERAND (stmt, 0);
+ lhs = gimple_get_lhs (stmt);
+
if (REFERENCE_CLASS_P (lhs))
lhs = get_base_address (lhs);
}
else if (INDIRECT_REF_P (lhs))
- {
- tree ptr = TREE_OPERAND (lhs, 0);
- struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
- tree nmt = (pi) ? pi->name_mem_tag : NULL_TREE;
- tree tmt = var_ann (SSA_NAME_VAR (ptr))->type_mem_tag;
-
- /* If either the name tag or the type tag for PTR is a
- global variable, then the store is necessary. */
- if ((nmt && is_global_var (nmt))
- || (tmt && is_global_var (tmt)))
- {
- return true;
- }
- }
+ return ptr_deref_may_alias_global_p (TREE_OPERAND (lhs, 0));
else
gcc_unreachable ();
}
+
return false;
}
/* Find the nearest common dominator of all of the immediate uses in IMM. */
static basic_block
-nearest_common_dominator_of_uses (tree stmt)
-{
+nearest_common_dominator_of_uses (gimple stmt, bool *debug_stmts)
+{
bitmap blocks = BITMAP_ALLOC (NULL);
basic_block commondom;
unsigned int j;
{
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, var)
{
- tree usestmt = USE_STMT (use_p);
+ gimple usestmt = USE_STMT (use_p);
basic_block useblock;
- if (TREE_CODE (usestmt) == PHI_NODE)
+ if (gimple_code (usestmt) == GIMPLE_PHI)
{
int idx = PHI_ARG_INDEX_FROM_USE (use_p);
- useblock = PHI_ARG_EDGE (usestmt, idx)->src;
+ useblock = gimple_phi_arg_edge (usestmt, idx)->src;
+ }
+ else if (is_gimple_debug (usestmt))
+ {
+ *debug_stmts = true;
+ continue;
}
else
{
- useblock = bb_for_stmt (usestmt);
+ useblock = gimple_bb (usestmt);
}
/* Short circuit. Nothing dominates the entry block. */
}
commondom = BASIC_BLOCK (bitmap_first_set_bit (blocks));
EXECUTE_IF_SET_IN_BITMAP (blocks, 0, j, bi)
- commondom = nearest_common_dominator (CDI_DOMINATORS, commondom,
+ commondom = nearest_common_dominator (CDI_DOMINATORS, commondom,
BASIC_BLOCK (j));
BITMAP_FREE (blocks);
return commondom;
}
-/* Given a statement (STMT) and the basic block it is currently in (FROMBB),
+/* Given a statement (STMT) and the basic block it is currently in (FROMBB),
determine the location to sink the statement to, if any.
- Return the basic block to sink it to, or NULL if we should not sink
- it. */
+ Returns true if there is such location; in that case, TOGSI points to the
+ statement before that STMT should be moved. */
-static tree
-statement_sink_location (tree stmt, basic_block frombb)
+static bool
+statement_sink_location (gimple stmt, basic_block frombb,
+ gimple_stmt_iterator *togsi)
{
- tree use, def;
+ gimple use;
+ tree def;
use_operand_p one_use = NULL_USE_OPERAND_P;
basic_block sinkbb;
use_operand_p use_p;
def_operand_p def_p;
ssa_op_iter iter;
- stmt_ann_t ann;
- tree rhs;
imm_use_iterator imm_iter;
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
{
FOR_EACH_IMM_USE_FAST (one_use, imm_iter, def)
{
+ if (is_gimple_debug (USE_STMT (one_use)))
+ continue;
+
break;
}
if (one_use != NULL_USE_OPERAND_P)
/* Return if there are no immediate uses of this stmt. */
if (one_use == NULL_USE_OPERAND_P)
- return NULL;
+ return false;
- if (TREE_CODE (stmt) != MODIFY_EXPR)
- return NULL;
- rhs = TREE_OPERAND (stmt, 1);
+ if (gimple_code (stmt) != GIMPLE_ASSIGN)
+ return false;
/* There are a few classes of things we can't or don't move, some because we
don't have code to handle it, some because it's not profitable and some
- because it's not legal.
-
+ because it's not legal.
+
We can't sink things that may be global stores, at least not without
calculating a lot more information, because we may cause it to no longer
be seen by an external routine that needs it depending on where it gets
- moved to.
-
+ moved to.
+
We don't want to sink loads from memory.
We can't sink statements that end basic blocks without splitting the
incoming edge for the sink location to place it there.
- We can't sink statements that have volatile operands.
+ We can't sink statements that have volatile operands.
We don't want to sink dead code, so anything with 0 immediate uses is not
- sunk.
+ sunk.
+
+ Don't sink BLKmode assignments if current function has any local explicit
+ register variables, as BLKmode assignments may involve memcpy or memset
+ calls or, on some targets, inline expansion thereof that sometimes need
+ to use specific hard registers.
*/
- ann = stmt_ann (stmt);
if (stmt_ends_bb_p (stmt)
- || TREE_SIDE_EFFECTS (rhs)
- || TREE_CODE (rhs) == EXC_PTR_EXPR
- || TREE_CODE (rhs) == FILTER_EXPR
+ || gimple_has_side_effects (stmt)
|| is_hidden_global_store (stmt)
- || ann->has_volatile_ops
- || !ZERO_SSA_OPERANDS (stmt, SSA_OP_VUSE))
- return NULL;
-
+ || gimple_has_volatile_ops (stmt)
+ || gimple_vuse (stmt)
+ || (cfun->has_local_explicit_reg_vars
+ && TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt))) == BLKmode))
+ return false;
+
FOR_EACH_SSA_DEF_OPERAND (def_p, stmt, iter, SSA_OP_ALL_DEFS)
{
tree def = DEF_FROM_PTR (def_p);
if (is_global_var (SSA_NAME_VAR (def))
|| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def))
- return NULL;
+ return false;
}
-
+
FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_ALL_USES)
{
tree use = USE_FROM_PTR (use_p);
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (use))
- return NULL;
+ return false;
}
-
+
/* If all the immediate uses are not in the same place, find the nearest
common dominator of all the immediate uses. For PHI nodes, we have to
find the nearest common dominator of all of the predecessor blocks, since
that is where insertion would have to take place. */
if (!all_immediate_uses_same_place (stmt))
{
- basic_block commondom = nearest_common_dominator_of_uses (stmt);
-
+ bool debug_stmts = false;
+ basic_block commondom = nearest_common_dominator_of_uses (stmt,
+ &debug_stmts);
+
if (commondom == frombb)
- return NULL;
+ return false;
/* Our common dominator has to be dominated by frombb in order to be a
trivially safe place to put this statement, since it has multiple
- uses. */
+ uses. */
if (!dominated_by_p (CDI_DOMINATORS, commondom, frombb))
- return NULL;
-
+ return false;
+
/* It doesn't make sense to move to a dominator that post-dominates
frombb, because it means we've just moved it into a path that always
executes if frombb executes, instead of reducing the number of
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Not moving store, common dominator post-dominates from block.\n");
- return NULL;
+ return false;
}
if (commondom == frombb || commondom->loop_depth > frombb->loop_depth)
- return NULL;
+ return false;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Common dominator of all uses is %d\n",
commondom->index);
}
- return first_stmt (commondom);
+
+ *togsi = gsi_after_labels (commondom);
+
+ return true;
}
use = USE_STMT (one_use);
- if (TREE_CODE (use) != PHI_NODE)
+ if (gimple_code (use) != GIMPLE_PHI)
{
- sinkbb = bb_for_stmt (use);
+ sinkbb = gimple_bb (use);
if (sinkbb == frombb || sinkbb->loop_depth > frombb->loop_depth
|| sinkbb->loop_father != frombb->loop_father)
- return NULL;
- return use;
+ return false;
+
+ /* Move the expression to a post dominator can't reduce the number of
+ executions. */
+ if (dominated_by_p (CDI_POST_DOMINATORS, frombb, sinkbb))
+ return false;
+
+ *togsi = gsi_for_stmt (use);
+
+ return true;
}
/* Note that at this point, all uses must be in the same statement, so it
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
break;
-
sinkbb = find_bb_for_arg (use, def);
if (!sinkbb)
- return NULL;
+ return false;
/* This will happen when you have
a_3 = PHI <a_13, a_26>
-
- a_26 = V_MAY_DEF <a_3>
- If the use is a phi, and is in the same bb as the def,
+ a_26 = VDEF <a_3>
+
+ If the use is a phi, and is in the same bb as the def,
we can't sink it. */
- if (bb_for_stmt (use) == frombb)
- return NULL;
+ if (gimple_bb (use) == frombb)
+ return false;
if (sinkbb == frombb || sinkbb->loop_depth > frombb->loop_depth
|| sinkbb->loop_father != frombb->loop_father)
- return NULL;
+ return false;
- return first_stmt (sinkbb);
+ /* Move the expression to a post dominator can't reduce the number of
+ executions. */
+ if (dominated_by_p (CDI_POST_DOMINATORS, frombb, sinkbb))
+ return false;
+
+ *togsi = gsi_after_labels (sinkbb);
+
+ return true;
}
/* Perform code sinking on BB */
sink_code_in_bb (basic_block bb)
{
basic_block son;
- block_stmt_iterator bsi;
+ gimple_stmt_iterator gsi;
edge_iterator ei;
edge e;
-
+ bool last = true;
+
/* If this block doesn't dominate anything, there can't be any place to sink
the statements to. */
if (first_dom_son (CDI_DOMINATORS, bb) == NULL)
if (e->flags & EDGE_ABNORMAL)
goto earlyout;
- for (bsi = bsi_last (bb); !bsi_end_p (bsi);)
+ for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi);)
{
- tree stmt = bsi_stmt (bsi);
- block_stmt_iterator tobsi;
- tree sinkstmt;
-
- sinkstmt = statement_sink_location (stmt, bb);
- if (!sinkstmt)
+ gimple stmt = gsi_stmt (gsi);
+ gimple_stmt_iterator togsi;
+
+ if (!statement_sink_location (stmt, bb, &togsi))
{
- if (!bsi_end_p (bsi))
- bsi_prev (&bsi);
+ if (!gsi_end_p (gsi))
+ gsi_prev (&gsi);
+ last = false;
continue;
- }
+ }
if (dump_file)
{
fprintf (dump_file, "Sinking ");
- print_generic_expr (dump_file, stmt, TDF_VOPS);
+ print_gimple_stmt (dump_file, stmt, 0, TDF_VOPS);
fprintf (dump_file, " from bb %d to bb %d\n",
- bb->index, bb_for_stmt (sinkstmt)->index);
+ bb->index, (gsi_bb (togsi))->index);
}
- tobsi = bsi_for_stmt (sinkstmt);
- /* Find the first non-label. */
- while (!bsi_end_p (tobsi)
- && TREE_CODE (bsi_stmt (tobsi)) == LABEL_EXPR)
- bsi_next (&tobsi);
-
+
/* If this is the end of the basic block, we need to insert at the end
of the basic block. */
- if (bsi_end_p (tobsi))
- bsi_move_to_bb_end (&bsi, bb_for_stmt (sinkstmt));
+ if (gsi_end_p (togsi))
+ gsi_move_to_bb_end (&gsi, gsi_bb (togsi));
else
- bsi_move_before (&bsi, &tobsi);
+ gsi_move_before (&gsi, &togsi);
sink_stats.sunk++;
- if (!bsi_end_p (bsi))
- bsi_prev (&bsi);
-
+
+ /* If we've just removed the last statement of the BB, the
+ gsi_end_p() test below would fail, but gsi_prev() would have
+ succeeded, and we want it to succeed. So we keep track of
+ whether we're at the last statement and pick up the new last
+ statement. */
+ if (last)
+ {
+ gsi = gsi_last_bb (bb);
+ continue;
+ }
+
+ last = false;
+ if (!gsi_end_p (gsi))
+ gsi_prev (&gsi);
+
}
earlyout:
for (son = first_dom_son (CDI_POST_DOMINATORS, bb);
{
sink_code_in_bb (son);
}
-}
+}
/* Perform code sinking.
This moves code down the flowgraph when we know it would be
executions of the statement.
IE given
-
+
a_1 = b + c;
if (<something>)
{
static void
execute_sink_code (void)
{
- struct loops *loops = loop_optimizer_init (dump_file);
+ loop_optimizer_init (LOOPS_NORMAL);
+
connect_infinite_loops_to_exit ();
memset (&sink_stats, 0, sizeof (sink_stats));
- calculate_dominance_info (CDI_DOMINATORS | CDI_POST_DOMINATORS);
- sink_code_in_bb (EXIT_BLOCK_PTR);
- if (dump_file && (dump_flags & TDF_STATS))
- fprintf (dump_file, "Sunk statements:%d\n", sink_stats.sunk);
+ calculate_dominance_info (CDI_DOMINATORS);
+ calculate_dominance_info (CDI_POST_DOMINATORS);
+ sink_code_in_bb (EXIT_BLOCK_PTR);
+ statistics_counter_event (cfun, "Sunk statements", sink_stats.sunk);
free_dominance_info (CDI_POST_DOMINATORS);
remove_fake_exit_edges ();
- loop_optimizer_finalize (loops, dump_file);
+ loop_optimizer_finalize ();
}
/* Gate and execute functions for PRE. */
-static void
+static unsigned int
do_sink (void)
{
execute_sink_code ();
+ return 0;
}
static bool
return flag_tree_sink != 0;
}
-struct tree_opt_pass pass_sink_code =
+struct gimple_opt_pass pass_sink_code =
{
+ {
+ GIMPLE_PASS,
"sink", /* name */
gate_sink, /* gate */
do_sink, /* execute */
0, /* static_pass_number */
TV_TREE_SINK, /* tv_id */
PROP_no_crit_edges | PROP_cfg
- | PROP_ssa | PROP_alias, /* properties_required */
+ | PROP_ssa, /* properties_required */
0, /* properties_provided */
0, /* properties_destroyed */
0, /* todo_flags_start */
- TODO_update_ssa
+ TODO_update_ssa
| TODO_dump_func
| TODO_ggc_collect
- | TODO_verify_ssa, /* todo_flags_finish */
- 0 /* letter */
+ | TODO_verify_ssa /* todo_flags_finish */
+ }
};
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