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| author | Richard Biener <rguenther@suse.de> | 2022-04-05 15:23:54 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-05-04 09:51:19 +0200 |
| commit | 1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d (patch) | |
| tree | 4e1fb053f4fddbc9bcf465f41088e9d6d898613f | |
| parent | c4ae175881f773383f392ee39bad4ac1c0fa53ca (diff) | |
| download | gcc-1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d.zip gcc-1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d.tar.gz gcc-1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d.tar.bz2 | |
debug/105158 - improve debug stmt retaining for forwarder removal
Currently when we cannot move debug stmt from a forwarder to the
destination block we drop/reset them. But in some cases as for
the testcase we can move them to the predecessor when that has
a single successor and we can insert after the last stmt of the
block. That allows us to preserve debug info here.
2022-04-05 Richard Biener <rguenther@suse.de>
PR debug/105158
* tree-cfgcleanup.cc (move_debug_stmts_from_forwarder):
Move debug stmts to the predecessor if moving to the
destination is not possible.
(remove_forwarder_block): Adjust.
(remove_forwarder_block_with_phi): Likewise.
| -rw-r--r-- | gcc/tree-cfgcleanup.cc | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/gcc/tree-cfgcleanup.cc b/gcc/tree-cfgcleanup.cc index 6c05ef2..893619e 100644 --- a/gcc/tree-cfgcleanup.cc +++ b/gcc/tree-cfgcleanup.cc @@ -468,15 +468,34 @@ phi_alternatives_equal (basic_block dest, edge e1, edge e2) return true; } -/* Move debug stmts from the forwarder block SRC to DEST. */ +/* Move debug stmts from the forwarder block SRC to DEST or PRED. */ static void -move_debug_stmts_from_forwarder (basic_block src, basic_block dest, - bool dest_single_pred_p) +move_debug_stmts_from_forwarder (basic_block src, + basic_block dest, bool dest_single_pred_p, + basic_block pred, bool pred_single_succ_p) { if (!MAY_HAVE_DEBUG_STMTS) return; + /* If we cannot move to the destination but to the predecessor do that. */ + if (!dest_single_pred_p && pred_single_succ_p) + { + gimple_stmt_iterator gsi_to = gsi_last_bb (pred); + if (gsi_end_p (gsi_to) || !stmt_ends_bb_p (gsi_stmt (gsi_to))) + { + for (gimple_stmt_iterator gsi = gsi_after_labels (src); + !gsi_end_p (gsi);) + { + gimple *debug = gsi_stmt (gsi); + gcc_assert (is_gimple_debug (debug)); + gsi_move_after (&gsi, &gsi_to); + } + return; + } + } + + /* Else move to DEST or drop/reset them. */ gimple_stmt_iterator gsi_to = gsi_after_labels (dest); for (gimple_stmt_iterator gsi = gsi_after_labels (src); !gsi_end_p (gsi);) { @@ -627,7 +646,8 @@ remove_forwarder_block (basic_block bb) /* Move debug statements. Reset them if the destination does not have a single predecessor. */ - move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p); + move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p, + pred, pred && single_succ_p (pred)); bitmap_set_bit (cfgcleanup_altered_bbs, dest->index); @@ -1309,7 +1329,8 @@ remove_forwarder_block_with_phi (basic_block bb) /* Move debug statements. Reset them if the destination does not have a single predecessor. */ - move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p); + move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p, + pred, pred && single_succ_p (pred)); /* Update the dominators. */ dombb = get_immediate_dominator (CDI_DOMINATORS, bb); |