Re: [Patch, rtl] PR middle-end/78016, keep REG_NOTE order during insn copy

[Jiong Wang]

On 21/10/16 13:30, Bernd Schmidt wrote:

On 10/21/2016 02:04 PM, Jiong Wang wrote:

+  /* Locate the end of existing REG_NOTES in NEW_RTX.  */
+  rtx *ptail = &REG_NOTES (new_rtx);
+  while (*ptail != NULL_RTX)
+    ptail = &XEXP (*ptail, 1);

I was thinking along the lines of something like this (untested, emit-rtl.c part omitted). Eric can choose whether he likes either of these or wants something else.

Hi Eric,

  What's your decision on this?

  Thanks.

Regards,
Jiong

Bernd

Index: gcc/rtl.h
===================================================================
--- gcc/rtl.h    (revision 241233)
+++ gcc/rtl.h    (working copy)
@@ -3008,6 +3008,7 @@ extern rtx alloc_reg_note (enum reg_note
 extern void add_reg_note (rtx, enum reg_note, rtx);
 extern void add_int_reg_note (rtx, enum reg_note, int);
 extern void add_shallow_copy_of_reg_note (rtx_insn *, rtx);
+extern rtx duplicate_reg_note (rtx_insn *, rtx);
 extern void remove_note (rtx, const_rtx);
 extern void remove_reg_equal_equiv_notes (rtx_insn *);
 extern void remove_reg_equal_equiv_notes_for_regno (unsigned int);
Index: gcc/rtlanal.c
===================================================================
--- gcc/rtlanal.c    (revision 241233)
+++ gcc/rtlanal.c    (working copy)
@@ -2304,6 +2304,21 @@ add_shallow_copy_of_reg_note (rtx_insn *
     add_reg_note (insn, REG_NOTE_KIND (note), XEXP (note, 0));
 }

+/* Duplicate NOTE and return the copy.  */
+rtx
+duplicate_reg_note (rtx note)
+{
+  rtx n;
+  reg_note_kind kind = REG_NOTE_KIND (note);
+
+  if (GET_CODE (note) == INT_LIST)

+ return gen_rtx_INT_LIST ((machine_mode) kind, XINT (note, 0), NULL_RTX);

+  else if (GET_CODE (note) == EXPR_LIST)

+ return alloc_reg_note (kind, copy_insn_1 (XEXP (note, 0)), NULL_RTX);

+  else
+    return alloc_reg_note (kind, XEXP (note, 0), NULL_RTX);
+}
+
 /* Remove register note NOTE from the REG_NOTES of INSN.  */

 void
Index: gcc/sel-sched-ir.c
===================================================================
--- gcc/sel-sched-ir.c    (revision 241233)
+++ gcc/sel-sched-ir.c    (working copy)
@@ -5762,6 +5762,11 @@ create_copy_of_insn_rtx (rtx insn_rtx)
   res = create_insn_rtx_from_pattern (copy_rtx (PATTERN (insn_rtx)),
                                       NULL_RTX);

+  /* Locate the end of existing REG_NOTES in NEW_RTX.  */
+  rtx *ptail = &REG_NOTES (new_rtx);
+  while (*ptail != NULL_RTX)
+    ptail = &XEXP (*ptail, 1);
+
   /* Copy all REG_NOTES except REG_EQUAL/REG_EQUIV and REG_LABEL_OPERAND

since mark_jump_label will make them. REG_LABEL_TARGETs are created

      there too, but are supposed to be sticky, so we copy them. */
@@ -5770,11 +5775,8 @@ create_copy_of_insn_rtx (rtx insn_rtx)
     && REG_NOTE_KIND (link) != REG_EQUAL
     && REG_NOTE_KIND (link) != REG_EQUIV)
       {
-    if (GET_CODE (link) == EXPR_LIST)
-      add_reg_note (res, REG_NOTE_KIND (link),
-            copy_insn_1 (XEXP (link, 0)));
-    else
-      add_reg_note (res, REG_NOTE_KIND (link), XEXP (link, 0));
+    *ptail = duplicate_reg_note (link);
+    ptail = &XEXP (*ptail, 1);
       }

   return res;