From: Jan Hubicka <jh@suse.cz>
Date: Wed, 9 Jan 2002 21:49:02 +0000 (+0100)
Subject: * gcse.c (cprop_jump): Delete insn if simplified jump is no-op.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7d5ab30eb3543198da068bb2b4757fdbf5ba9a8c;p=gcc.git

* gcse.c (cprop_jump): Delete insn if simplified jump is no-op.

From-SVN: r48694
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3b5deaa929a..6f13ad2f65b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2002-01-09  Jan Hubicka  <jh@suse.cz>
+
+	* gcse.c (cprop_jump): Delete insn if simplified jump is no-op.
+
 2002-01-09  Richard Henderson  <rth@redhat.com>
 
 	* config/arm/arm.c (arm_gen_constant): Use trunc_int_for_mode.
diff --git a/gcc/gcse.c b/gcc/gcse.c
index e91b61a4845..e8361fc5aab 100644
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -4037,28 +4037,20 @@ cprop_jump (bb, insn, from, src)
   if (rtx_equal_p (new, SET_SRC (set)))
     return 0;
  
-  /* If this is now a no-op leave it that way, but update LABEL_NUSED if
-     necessary.  */
+  /* If this is now a no-op delete it, otherwise this must be a valid insn.  */
   if (new == pc_rtx)
+    delete_insn (insn);
+  else
     {
-      SET_SRC (set) = new;
-
-      if (JUMP_LABEL (insn) != 0)
-	{
-	  --LABEL_NUSES (JUMP_LABEL (insn));
-	  JUMP_LABEL (insn) = NULL_RTX;
-	}
-    }
-
-  /* Otherwise, this must be a valid instruction.  */
-  else if (! validate_change (insn, &SET_SRC (set), new, 0))
-    return 0;
+      if (! validate_change (insn, &SET_SRC (set), new, 0))
+	return 0;
 
-  /* If this has turned into an unconditional jump,
-     then put a barrier after it so that the unreachable
-     code will be deleted.  */
-  if (GET_CODE (SET_SRC (set)) == LABEL_REF)
-    emit_barrier_after (insn);
+      /* If this has turned into an unconditional jump,
+	 then put a barrier after it so that the unreachable
+	 code will be deleted.  */
+      if (GET_CODE (SET_SRC (set)) == LABEL_REF)
+	emit_barrier_after (insn);
+     }
 
   run_jump_opt_after_gcse = 1;