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Remove dead loop-based LC SSA rewrite

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The following removes the now unused per-loop path in LC SSA rewrite.

	* tree-ssa-loop-manip.cc (find_uses_to_rename_def): Remove.
	(find_uses_to_rename_in_loop): Likewise.
	(rewrite_into_loop_closed_ssa_1): Remove loop parameter and
	uses.
	(rewrite_into_loop_closed_ssa): Adjust.
This commit is contained in:
Richard Biener
2022-07-05 14:09:36 +02:00
parent c3d2600cfb
commit 1cc08ceb5b
1 changed files with 4 additions and 105 deletions
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gcc/tree-ssa-loop-manip.cc
+4 -105
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@@ -498,94 +498,6 @@ find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis,
find_uses_to_rename_bb (bb, use_blocks, need_phis, use_flags);
}
/* Mark uses of DEF that are used outside of the loop they are defined in for
rewrite. Record the set of blocks in which the ssa names are used to
USE_BLOCKS. Record the SSA names that will need exit PHIs in NEED_PHIS. */
static void
find_uses_to_rename_def (tree def, bitmap *use_blocks, bitmap need_phis)
{
gimple *use_stmt;
imm_use_iterator imm_iter;
FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, def)
{
if (is_gimple_debug (use_stmt))
continue;
basic_block use_bb = gimple_bb (use_stmt);
use_operand_p use_p;
FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
{
if (gimple_code (use_stmt) == GIMPLE_PHI)
{
edge e = gimple_phi_arg_edge (as_a <gphi *> (use_stmt),
PHI_ARG_INDEX_FROM_USE (use_p));
use_bb = e->src;
}
find_uses_to_rename_use (use_bb, USE_FROM_PTR (use_p), use_blocks,
need_phis);
}
}
}
/* Marks names matching USE_FLAGS that are defined in LOOP and used outside of
it for rewrite. Records the set of blocks in which the ssa names are used to
USE_BLOCKS. Record the SSA names that will need exit PHIs in NEED_PHIS. */
static void
find_uses_to_rename_in_loop (class loop *loop, bitmap *use_blocks,
bitmap need_phis, int use_flags)
{
bool do_virtuals = (use_flags & SSA_OP_VIRTUAL_USES) != 0;
bool do_nonvirtuals = (use_flags & SSA_OP_USE) != 0;
int def_flags = ((do_virtuals ? SSA_OP_VIRTUAL_DEFS : 0)
| (do_nonvirtuals ? SSA_OP_DEF : 0));
basic_block *bbs = get_loop_body (loop);
for (unsigned int i = 0; i < loop->num_nodes; i++)
{
basic_block bb = bbs[i];
for (gphi_iterator bsi = gsi_start_phis (bb); !gsi_end_p (bsi);
gsi_next (&bsi))
{
gphi *phi = bsi.phi ();
tree res = gimple_phi_result (phi);
bool virtual_p = virtual_operand_p (res);
if ((virtual_p && do_virtuals)
|| (!virtual_p && do_nonvirtuals))
find_uses_to_rename_def (res, use_blocks, need_phis);
}
for (gimple_stmt_iterator bsi = gsi_start_bb (bb); !gsi_end_p (bsi);
gsi_next (&bsi))
{
gimple *stmt = gsi_stmt (bsi);
/* FOR_EACH_SSA_TREE_OPERAND iterator does not allows
SSA_OP_VIRTUAL_DEFS only. */
if (def_flags == SSA_OP_VIRTUAL_DEFS)
{
tree vdef = gimple_vdef (stmt);
if (vdef != NULL)
find_uses_to_rename_def (vdef, use_blocks, need_phis);
}
else
{
tree var;
ssa_op_iter iter;
FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, def_flags)
find_uses_to_rename_def (var, use_blocks, need_phis);
}
}
}
XDELETEVEC (bbs);
}
/* Rewrites the program into a loop closed ssa form -- i.e. inserts extra
phi nodes to ensure that no variable is used outside the loop it is
defined in.
@@ -615,8 +527,7 @@ find_uses_to_rename_in_loop (class loop *loop, bitmap *use_blocks,
is not well-behaved, while the second one is an induction variable with
base 99 and step 1.
If LOOP is non-null, only rewrite uses that have defs in LOOP. Otherwise,
if CHANGED_BBS is not NULL, we look for uses outside loops only in the
If CHANGED_BBS is not NULL, we look for uses outside loops only in the
basic blocks in this set.
USE_FLAGS allows us to specify whether we want virtual, non-virtual or
@@ -627,7 +538,7 @@ find_uses_to_rename_in_loop (class loop *loop, bitmap *use_blocks,
static void
rewrite_into_loop_closed_ssa_1 (bitmap changed_bbs, unsigned update_flag,
int use_flags, class loop *loop)
int use_flags)
{
bitmap *use_blocks;
bitmap names_to_rename;
@@ -651,18 +562,7 @@ rewrite_into_loop_closed_ssa_1 (bitmap changed_bbs, unsigned update_flag,
because we know that we will only have entries for the SSA names
in NAMES_TO_RENAME. */
use_blocks = XNEWVEC (bitmap, num_ssa_names);
if (loop != NULL)
{
gcc_assert (changed_bbs == NULL);
find_uses_to_rename_in_loop (loop, use_blocks, names_to_rename,
use_flags);
}
else
{
gcc_assert (loop == NULL);
find_uses_to_rename (changed_bbs, use_blocks, names_to_rename, use_flags);
}
find_uses_to_rename (changed_bbs, use_blocks, names_to_rename, use_flags);
if (!bitmap_empty_p (names_to_rename))
{
@@ -694,8 +594,7 @@ rewrite_into_loop_closed_ssa_1 (bitmap changed_bbs, unsigned update_flag,
void
rewrite_into_loop_closed_ssa (bitmap changed_bbs, unsigned update_flag)
{
rewrite_into_loop_closed_ssa_1 (changed_bbs, update_flag,
SSA_OP_ALL_USES, NULL);
rewrite_into_loop_closed_ssa_1 (changed_bbs, update_flag, SSA_OP_ALL_USES);
}
/* Check invariants of the loop closed ssa form for the def in DEF_BB. */