[gcc(refs/users/guojiufu/heads/personal-branch)] v3 split reg which is used before define

[gcc(refs/users/guojiufu/heads/personal-branch)] v3 split reg which is used before define

[Jiu Fu Guo]

https://gcc.gnu.org/g:da2d6740d4be6f19a7013b8fd32a55deca4f123c

commit da2d6740d4be6f19a7013b8fd32a55deca4f123c
Author: Jiufu Guo <guojiufu@linux.ibm.com>
Date:   Sat Apr 11 15:22:43 2020 +0800

    v3 split reg which is used before define

Diff:
---
 gcc/loop-unroll.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 8891a796f82..312deced921 100644
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -1650,7 +1650,9 @@ analyze_insn_to_split_def (class loop *loop, rtx_insn *insn)
   
   if (dump_file)
     {
-      fprintf (dump_file, "\n;; Split assignment ");
+      fprintf (dump_file,
+	       "\n;; Split assignment %s: ",
+	       use_before_set ? "use leads def" : "");
       print_rtl (dump_file, dest);
       fprintf (dump_file, "\n");
     }
@@ -2358,7 +2360,6 @@ apply_opt_in_copies (struct opt_info *opt_info,
 		    end_sequence ();
 		    emit_insn_before (seq, ins);
 		    delete_insn (ins);
-		    dts->insn = insn;
 		    new_insn_list.safe_push (insn);
 		    ins = insn;
 		  }
@@ -2387,6 +2388,7 @@ apply_opt_in_copies (struct opt_info *opt_info,
 	    end_sequence ();
 	    emit_insn_before (seq, BB_END (BLOCK_FOR_INSN (dts->last_insn)));
 	  }
+      apply_change_group();
     }  
 }