When one of the first two stages of DSE removes a throwing stmt
we have to purge dead EH edges before the DF re-analyze fires off
a fast DCE since that cannot cope with the situation.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
I'll add a testcase when it has finished reducing in time.
Richard.
2022-05-12 Richard Biener <rguent...@suse.de>
PR rtl-optimization/105577
* dse.cc (rest_of_handle_dse): Make sure to purge dead EH
edges before running fast DCE via df_analyze.
---
gcc/dse.cc | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/gcc/dse.cc b/gcc/dse.cc
index a58c17e0ccb..30c11cee034 100644
--- a/gcc/dse.cc
+++ b/gcc/dse.cc
@@ -3682,6 +3682,16 @@ rest_of_handle_dse (void)
dse_step0 ();
dse_step1 ();
+ /* DSE can eliminate potentially-trapping MEMs.
+ Remove any EH edges associated with them, since otherwise
+ DF_LR_RUN_DCE will complain later. */
+ if ((locally_deleted || globally_deleted)
+ && cfun->can_throw_non_call_exceptions
+ && purge_all_dead_edges ())
+ {
+ free_dominance_info (CDI_DOMINATORS);
+ delete_unreachable_blocks ();
+ }
dse_step2_init ();
if (dse_step2 ())
{
--
2.35.3
