Avoid unused sbitmap in update_ssa
Commit Message
The following avoids copying and using blocks_to_update to
the interesting_blocks sbitmap when doing update_ssa as it is
unused besides the redundant query in the domwalk.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
* tree-into-ssa.cc (rewrite_update_dom_walker::before_dom_children):
Do not look at interesting_blocks which is a copy of
blocks_to_update.
(update_ssa): Do not initialize it.
(pass_build_ssa::execute): Set interesting_blocks to NULL
after releasing it.
---
gcc/tree-into-ssa.cc | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
@@ -2214,15 +2214,11 @@ rewrite_update_dom_walker::before_dom_children (basic_block bb)
}
/* Step 2. Rewrite every variable used in each statement in the block. */
- if (bitmap_bit_p (interesting_blocks, bb->index))
- {
- gcc_checking_assert (bitmap_bit_p (blocks_to_update, bb->index));
- for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
- if (rewrite_update_stmt (gsi_stmt (gsi), gsi))
- gsi_remove (&gsi, true);
- else
- gsi_next (&gsi);
- }
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
+ if (rewrite_update_stmt (gsi_stmt (gsi), gsi))
+ gsi_remove (&gsi, true);
+ else
+ gsi_next (&gsi);
/* Step 3. Update PHI nodes. */
rewrite_update_phi_arguments (bb);
@@ -2460,6 +2456,7 @@ pass_build_ssa::execute (function *fun)
free (dfs);
sbitmap_free (interesting_blocks);
+ interesting_blocks = NULL;
fini_ssa_renamer ();
@@ -3503,15 +3500,8 @@ update_ssa (unsigned update_flags)
get_var_info (sym)->info.current_def = NULL_TREE;
/* Now start the renaming process at START_BB. */
- interesting_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun));
- bitmap_clear (interesting_blocks);
- EXECUTE_IF_SET_IN_BITMAP (blocks_to_update, 0, i, bi)
- bitmap_set_bit (interesting_blocks, i);
-
rewrite_blocks (start_bb, REWRITE_UPDATE);
- sbitmap_free (interesting_blocks);
-
/* Debugging dumps. */
if (dump_file)
{