Remove never looping loop in label_rtx_for_bb
Commit Message
This refactors the IL "walk" in a way to avoid the loop which will
never iterate.
Bootstrapped and tested on x86_64-unknown-linux-gnu, will push later
unless there are comments explaining the function is wrong in other
ways.
Richard.
2021-11-25 Richard Biener <rguenther@suse.de>
* cfgexpand.c (label_rtx_for_bb): Remove dead loop construct.
---
gcc/cfgexpand.c | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
@@ -2461,9 +2461,6 @@ static hash_map<basic_block, rtx_code_label *> *lab_rtx_for_bb;
static rtx_code_label *
label_rtx_for_bb (basic_block bb ATTRIBUTE_UNUSED)
{
- gimple_stmt_iterator gsi;
- tree lab;
-
if (bb->flags & BB_RTL)
return block_label (bb);
@@ -2472,21 +2469,12 @@ label_rtx_for_bb (basic_block bb ATTRIBUTE_UNUSED)
return *elt;
/* Find the tree label if it is present. */
-
- for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
- {
- glabel *lab_stmt;
-
- lab_stmt = dyn_cast <glabel *> (gsi_stmt (gsi));
- if (!lab_stmt)
- break;
-
- lab = gimple_label_label (lab_stmt);
- if (DECL_NONLOCAL (lab))
- break;
-
- return jump_target_rtx (lab);
- }
+ gimple_stmt_iterator gsi = gsi_start_bb (bb);
+ glabel *lab_stmt;
+ if (!gsi_end_p (gsi)
+ && (lab_stmt = dyn_cast <glabel *> (gsi_stmt (gsi)))
+ && !DECL_NONLOCAL (gimple_label_label (lab_stmt)))
+ return jump_target_rtx (gimple_label_label (lab_stmt));
rtx_code_label *l = gen_label_rtx ();
lab_rtx_for_bb->put (bb, l);