The following removes a special case to not merge a block with
only a non-local label. We have a restriction of non-local labels
to be the first statement (and label) in a block, but otherwise nothing,
if the last stmt of A is a non-local label then it will be still
the first statement of the combined A + B. In particular we'd
happily merge when there's a stmt after that label.
The check originates from the tree-ssa merge.
Bootstrapped and tested on x86_64-unknown-linux-gnu with all
languages.
Will push later.
* tree-cfg.cc (gimple_can_merge_blocks_p): Remove condition
rejecting the merge when A contains only a non-local label.
---
gcc/tree-cfg.cc | 6 ------
1 file changed, 6 deletions(-)
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index a9fcc7fd050..ae53e15158a 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -1960,12 +1960,6 @@ gimple_can_merge_blocks_p (basic_block a, basic_block b)
if (stmt && stmt_ends_bb_p (stmt))
return false;
- /* Do not allow a block with only a non-local label to be merged. */
- if (stmt)
- if (glabel *label_stmt = dyn_cast <glabel *> (stmt))
- if (DECL_NONLOCAL (gimple_label_label (label_stmt)))
- return false;
-
/* Examine the labels at the beginning of B. */
for (gimple_stmt_iterator gsi = gsi_start_bb (b); !gsi_end_p (gsi);
gsi_next (&gsi))
--
2.35.3
