re PR rtl-optimization/11440 (gcc-3.3.1 miscompiles c++ code with -O2, -fno-gcse cures it)

2003-07-14  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>

	PR optimization/11440
	* gcse.c (try_replace_reg): Don't attach notes to ZERO_EXTRACT or
	SIGN_EXTRACT SETs.

From-SVN: r69325

gcc/ChangeLog

+2003-07-14  Franz Sirl  <Franz.Sirl-kernel@lauterbach.com>
+
+	PR optimization/11440
+	* gcse.c (try_replace_reg): Don't attach notes to ZERO_EXTRACT or
+	SIGN_EXTRACT SETs.
+
 2003-07-14  Alan Modra  <amodra@bigpond.net.au>
 
 	* doc/tm.texi (BLOCK_REG_PADDING): Describe.

gcc/gcse.c

@@ -3856,9 +3856,12 @@ try_replace_reg (rtx from, rtx to, rtx insn)
 	  && validate_change (insn, &SET_SRC (set), src, 0))
 	success = 1;
 
-      /* If we've failed to do replacement, have a single SET, and don't already
-	 have a note, add a REG_EQUAL note to not lose information.  */
-      if (!success && note == 0 && set != 0)
+      /* If we've failed to do replacement, have a single SET, don't already
+	 have a note, and have no special SET, add a REG_EQUAL note to not
+	 lose information.  */
+      if (!success && note == 0 && set != 0
+	  && GET_CODE (XEXP (set, 0)) != ZERO_EXTRACT
+	  && GET_CODE (XEXP (set, 0)) != SIGN_EXTRACT)
 	note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
     }