re PR rtl-optimization/79286 (ira and lra wrong code at -O2 and -Os on i686-linux)

	PR rtl-optimizatoin/79286
	* ira.c (update_equiv_regs): Drop may_trap_p exception to
	dominance test.

From-SVN: r245714

gcc/ChangeLog

+2017-02-24  Jeff Law  <law@redhat.com>
+
+	PR rtl-optimizatoin/79286
+	* ira.c (update_equiv_regs): Drop may_trap_p exception to
+	dominance test.
+
 2017-02-24  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/79389

gcc/ira.c

@@ -3551,8 +3551,7 @@ update_equiv_regs (void)
 	  if (DF_REG_DEF_COUNT (regno) == 1
 	      && note
 	      && !rtx_varies_p (XEXP (note, 0), 0)
-	      && (!may_trap_p (XEXP (note, 0))
-		  || def_dominates_uses (regno)))
+	      && def_dominates_uses (regno))
 	    {
 	      rtx note_value = XEXP (note, 0);
 	      remove_note (insn, note);