Fix PR rtl-optimization/113140

Message ID 5902287.MhkbZ0Pkbq@fomalhaut
State Accepted
Headers
Series Fix PR rtl-optimization/113140 |

Checks

Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Eric Botcazou Jan. 9, 2024, 9:27 a.m. UTC
  This is a small regression present on the mainline and 13 branch, although the 
underlying problem has probably been there for ages, in the form of a segfault 
during the delay slot scheduling pass, for a function that falls through to 
exit without any RTL instruction generated for the end of function.

Tested on SPARC64/Linux, applied on the mainline and 13 branch.


2024-01-09  Eric Botcazou  <ebotcazou@adacore.com>

	PR rtl-optimization/113140
	* reorg.cc (fill_slots_from_thread): If we are to branch after the
	last instruction of the function, create an end label.


2024-01-09  Eric Botcazou  <ebotcazou@adacore.com>

	* g++.dg/opt/delay-slot-2.C: New test.
  

Patch

diff --git a/gcc/reorg.cc b/gcc/reorg.cc
index e85af7134f4..99228a22c69 100644
--- a/gcc/reorg.cc
+++ b/gcc/reorg.cc
@@ -2641,7 +2641,8 @@  fill_slots_from_thread (rtx_jump_insn *insn, rtx condition,
      arithmetic insn after the jump insn and put the arithmetic insn in the
      delay slot.  If we can't do this, return.  */
   if (delay_list->is_empty () && likely
-      && new_thread && !ANY_RETURN_P (new_thread)
+      && new_thread
+      && !ANY_RETURN_P (new_thread)
       && NONJUMP_INSN_P (new_thread)
       && !RTX_FRAME_RELATED_P (new_thread)
       && GET_CODE (PATTERN (new_thread)) != ASM_INPUT
@@ -2729,14 +2730,16 @@  fill_slots_from_thread (rtx_jump_insn *insn, rtx condition,
 
       gcc_assert (thread_if_true);
 
-      if (new_thread && simplejump_or_return_p (new_thread)
+      if (new_thread
+	  && simplejump_or_return_p (new_thread)
 	  && redirect_with_delay_list_safe_p (insn,
 					      JUMP_LABEL (new_thread),
 					      *delay_list))
-	new_thread = follow_jumps (JUMP_LABEL (new_thread), insn,
-				   &crossing);
+	new_thread = follow_jumps (JUMP_LABEL (new_thread), insn, &crossing);
 
-      if (ANY_RETURN_P (new_thread))
+      if (!new_thread)
+	label = find_end_label (simple_return_rtx);
+      else if (ANY_RETURN_P (new_thread))
 	label = find_end_label (new_thread);
       else if (LABEL_P (new_thread))
 	label = new_thread;