sched: Do not mix prologue and epilogue insns

diff --git a/gcc/function.c b/gcc/function.c
index ea40ad1..0b1d168 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -5752,6 +5752,18 @@  contains (const_rtx insn, hash_table<insn_cache_hasher> *hash)
 }
 
 int
+prologue_contains (const_rtx insn)
+{
+  return contains (insn, prologue_insn_hash);
+}
+
+int
+epilogue_contains (const_rtx insn)
+{
+  return contains (insn, epilogue_insn_hash);
+}
+
+int
 prologue_epilogue_contains (const_rtx insn)
 {
   if (contains (insn, prologue_insn_hash))
@@ -5761,6 +5773,17 @@  prologue_epilogue_contains (const_rtx insn)
   return 0;
 }
 
+void
+record_prologue_seq (rtx_insn *seq)
+{
+  record_insns (seq, NULL, &prologue_insn_hash);
+}
+
+void
+record_epilogue_seq (rtx_insn *seq)
+{
+  record_insns (seq, NULL, &epilogue_insn_hash);
+}
 
 /* Set JUMP_LABEL for a return insn.  */
 
diff --git a/gcc/function.h b/gcc/function.h
index 590a490..e854c7f 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -628,7 +628,11 @@  extern void clobber_return_register (void);
 extern void expand_function_end (void);
 extern rtx get_arg_pointer_save_area (void);
 extern void maybe_copy_prologue_epilogue_insn (rtx, rtx);
+extern int prologue_contains (const_rtx);
+extern int epilogue_contains (const_rtx);
 extern int prologue_epilogue_contains (const_rtx);
+extern void record_prologue_seq (rtx_insn *);
+extern void record_epilogue_seq (rtx_insn *);
 extern void emit_return_into_block (bool simple_p, basic_block bb);
 extern void set_return_jump_label (rtx_insn *);
 extern bool active_insn_between (rtx_insn *head, rtx_insn *tail);
diff --git a/gcc/sched-deps.c b/gcc/sched-deps.c
index 6cd8332..1ebd776 100644
--- a/gcc/sched-deps.c
+++ b/gcc/sched-deps.c
@@ -3502,6 +3502,31 @@  sched_analyze_insn (struct deps_desc *deps, rtx x, rtx_insn *insn)
       if (!deps->readonly)
 	deps->last_args_size = insn;
     }
+
+  /* We must not mix prologue and epilogue insns.  See PR78029.  */
+  if (prologue_contains (insn))
+    {
+      add_dependence_list (insn, deps->last_epilogue, true, REG_DEP_ANTI, true);
+      if (!deps->readonly)
+	{
+	  if (deps->last_logue_was_epilogue)
+	    free_INSN_LIST_list (&deps->last_prologue);
+	  deps->last_prologue = alloc_INSN_LIST (insn, deps->last_prologue);
+	  deps->last_logue_was_epilogue = false;
+	}
+    }
+
+  if (epilogue_contains (insn))
+    {
+      add_dependence_list (insn, deps->last_prologue, true, REG_DEP_ANTI, true);
+      if (!deps->readonly)
+	{
+	  if (!deps->last_logue_was_epilogue)
+	    free_INSN_LIST_list (&deps->last_epilogue);
+	  deps->last_epilogue = alloc_INSN_LIST (insn, deps->last_epilogue);
+	  deps->last_logue_was_epilogue = true;
+	}
+    }
 }
 
 /* Return TRUE if INSN might not always return normally (e.g. call exit,
@@ -3907,6 +3932,9 @@  init_deps (struct deps_desc *deps, bool lazy_reg_last)
   deps->in_post_call_group_p = not_post_call;
   deps->last_debug_insn = 0;
   deps->last_args_size = 0;
+  deps->last_prologue = 0;
+  deps->last_epilogue = 0;
+  deps->last_logue_was_epilogue = false;
   deps->last_reg_pending_barrier = NOT_A_BARRIER;
   deps->readonly = 0;
 }
diff --git a/gcc/sched-int.h b/gcc/sched-int.h
index b4a7f92..d067b43 100644
--- a/gcc/sched-int.h
+++ b/gcc/sched-int.h
@@ -537,6 +537,17 @@  struct deps_desc
   /* The last insn bearing REG_ARGS_SIZE that we've seen.  */
   rtx_insn *last_args_size;
 
+  /* A list of all prologue insns we have seen without intervening epilogue
+     insns, and one of all epilogue insns we have seen without intervening
+     prologue insns.  This is used to prevent mixing prologue and epilogue
+     insns.  See PR78029.  */
+  rtx_insn_list *last_prologue;
+  rtx_insn_list *last_epilogue;
+
+  /* Whether the last *logue insn was an epilogue insn or a prologue insn
+     instead.  */
+  bool last_logue_was_epilogue;
+
   /* The maximum register number for the following arrays.  Before reload
      this is max_reg_num; after reload it is FIRST_PSEUDO_REGISTER.  */
   int max_reg;
diff --git a/gcc/shrink-wrap.c b/gcc/shrink-wrap.c
index 7345d25..4395d8a 100644
--- a/gcc/shrink-wrap.c
+++ b/gcc/shrink-wrap.c
@@ -1434,6 +1434,7 @@  emit_common_heads_for_components (sbitmap components)
 	  targetm.shrink_wrap.emit_prologue_components (pro);
 	  rtx_insn *seq = get_insns ();
 	  end_sequence ();
+	  record_prologue_seq (seq);
 
 	  emit_insn_after (seq, bb_note (bb));
 
@@ -1446,6 +1447,7 @@  emit_common_heads_for_components (sbitmap components)
 	  targetm.shrink_wrap.emit_epilogue_components (epi);
 	  rtx_insn *seq = get_insns ();
 	  end_sequence ();
+	  record_epilogue_seq (seq);
 
 	  emit_insn_after (seq, bb_note (bb));
 
@@ -1533,6 +1535,7 @@  emit_common_tails_for_components (sbitmap components)
 	  targetm.shrink_wrap.emit_epilogue_components (epi);
 	  rtx_insn *seq = get_insns ();
 	  end_sequence ();
+	  record_epilogue_seq (seq);
 
 	  if (control_flow_insn_p (last_insn))
 	    emit_insn_before (seq, last_insn);
@@ -1548,6 +1551,7 @@  emit_common_tails_for_components (sbitmap components)
 	  targetm.shrink_wrap.emit_prologue_components (pro);
 	  rtx_insn *seq = get_insns ();
 	  end_sequence ();
+	  record_prologue_seq (seq);
 
 	  if (control_flow_insn_p (last_insn))
 	    emit_insn_before (seq, last_insn);
@@ -1612,6 +1616,7 @@  insert_prologue_epilogue_for_components (sbitmap components)
 	      targetm.shrink_wrap.emit_epilogue_components (epi);
 	      rtx_insn *seq = get_insns ();
 	      end_sequence ();
+	      record_epilogue_seq (seq);
 
 	      if (e->flags & EDGE_SIBCALL)
 		{
@@ -1635,6 +1640,7 @@  insert_prologue_epilogue_for_components (sbitmap components)
 	      targetm.shrink_wrap.emit_prologue_components (pro);
 	      seq = get_insns ();
 	      end_sequence ();
+	      record_prologue_seq (seq);
 
 	      insert_insn_on_edge (seq, e);
 	    }