re PR rtl-optimization/88018 (ICE in insert_insn_on_edge at cfgrtl.c:1952 since r255066)

	PR rtl-optimization/88018
	* cfgrtl.c (fixup_abnormal_edges): Guard moving insns to fallthru edge
	on the presence of fallthru edge, rather than if it is a USE or not.

	* g++.dg/tsan/pr88018.C: New test.

From-SVN: r266174

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 174ee43..4bf4307 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-11-15  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/88018
+       * cfgrtl.c (fixup_abnormal_edges): Guard moving insns to fallthru edge
+       on the presence of fallthru edge, rather than if it is a USE or not.
+
 2018-11-15  Richard Biener  <rguenther@suse.de>
 
        PR middle-end/87917

diff --git a/gcc/cfgrtl.c b/gcc/cfgrtl.c
index 741a312..3d4a114 100644 (file)
--- a/gcc/cfgrtl.c
+++ b/gcc/cfgrtl.c
@@ -3332,8 +3332,15 @@ fixup_abnormal_edges (void)
                         If it's placed after a trapping call (i.e. that
                         call is the last insn anyway), we have no fallthru
                         edge.  Simply delete this use and don't try to insert
-                        on the non-existent edge.  */
-                     if (GET_CODE (PATTERN (insn)) != USE)
+                        on the non-existent edge.
+                        Similarly, sometimes a call that can throw is
+                        followed in the source with __builtin_unreachable (),
+                        meaning that there is UB if the call returns rather
+                        than throws.  If there weren't any instructions
+                        following such calls before, supposedly even the ones
+                        we've deleted aren't significant and can be
+                        removed.  */
+                     if (e)
                        {
                          /* We're not deleting it, we're moving it.  */
                          insn->set_undeleted ();

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0bcd8e0..3c6c47f 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-15  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/88018
+       * g++.dg/tsan/pr88018.C: New test.
+
 2018-11-15  Richard Biener  <rguenther@suse.de>
 
        PR middle-end/87917