PR target/78614

	* rtl.c (copy_rtx): Don't clear used flag here.
	(shallow_copy_rtx_stat): Clear used flag here unless code the rtx
	is shareable.
	* simplify-rtx.c (simplify_replace_fn_rtx): When copying rtx with
	'E' in format, copy all vectors.
	* emit-rtl.c (copy_insn_1): Don't clear used flag here.
	* valtrack.c (cleanup_auto_inc_dec): Likewise.
	* config/rs6000/rs6000.c (rs6000_frame_related): Likewise.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@243194 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 23 insertions, 5 deletions

diff --git a/gcc/rtl.c b/gcc/rtl.c
index 3fac1931f3f..0410f019e51 100644
--- a/gcc/rtl.c
+++ b/gcc/rtl.c
@@ -318,10 +318,6 @@ copy_rtx (rtx orig)
      us to explicitly document why we are *not* copying a flag.  */
   copy = shallow_copy_rtx (orig);
 
-  /* We do not copy the USED flag, which is used as a mark bit during
-     walks over the RTL.  */
-  RTX_FLAG (copy, used) = 0;
-
   format_ptr = GET_RTX_FORMAT (GET_CODE (copy));
 
   for (i = 0; i < GET_RTX_LENGTH (GET_CODE (copy)); i++)
@@ -367,7 +363,29 @@ shallow_copy_rtx_stat (const_rtx orig MEM_STAT_DECL)
 {
   const unsigned int size = rtx_size (orig);
   rtx const copy = ggc_alloc_rtx_def_stat (size PASS_MEM_STAT);
-  return (rtx) memcpy (copy, orig, size);
+  memcpy (copy, orig, size);
+  switch (GET_CODE (orig))
+    {
+      /* RTX codes copy_rtx_if_shared_1 considers are shareable,
+	 the used flag is often used for other purposes.  */
+    case REG:
+    case DEBUG_EXPR:
+    case VALUE:
+    CASE_CONST_ANY:
+    case SYMBOL_REF:
+    case CODE_LABEL:
+    case PC:
+    case CC0:
+    case RETURN:
+    case SIMPLE_RETURN:
+    case SCRATCH:
+      break;
+    default:
+      /* For all other RTXes clear the used flag on the copy.  */
+      RTX_FLAG (copy, used) = 0;
+      break;
+    }
+  return copy;
 }
 
 /* Nonzero when we are generating CONCATs.  */