1 files changed, 11 insertions, 1 deletions
diff --git a/gcc/web.c b/gcc/web.c
index 9b849249b0d..e57bb37570f 100644
--- a/gcc/web.c
+++ b/gcc/web.c
@@ -377,7 +377,17 @@ web_main (void)
     FOR_BB_INSNS (bb, insn)
     {
       unsigned int uid = INSN_UID (insn);
-      if (NONDEBUG_INSN_P (insn))
+
+      if (NONDEBUG_INSN_P (insn)
+	  /* Ignore naked clobber.  For example, reg 134 in the second insn
+	     of the following sequence will not be replaced.
+
+	       (insn (clobber (reg:SI 134)))
+
+	       (insn (set (reg:SI 0 r0) (reg:SI 134)))
+
+	     Thus the later passes can optimize them away.  */
+	  && GET_CODE (PATTERN (insn)) != CLOBBER)
 	{
 	  df_ref *use_rec;
 	  df_ref *def_rec;