ira.c (update_equiv_regs): Revert to using may_trap_or_fault_p again.

2017-06-23  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        rtl-optimizatoin/79286
        * ira.c (update_equiv_regs): Revert to using may_trap_or_fault_p again.
        * rtlanal.c (rtx_addr_can_trap_p_1): SYMBOL_REF_FUNCTION_P can never
        trap.  PIC register plus a const unspec without offset can never trap.

From-SVN: r249588

gcc/ChangeLog

+2017-06-23  Bernd Edlinger  <bernd.edlinger@hotmail.de>
+
+	rtl-optimizatoin/79286
+	* ira.c (update_equiv_regs): Revert to using may_trap_or_fault_p again.
+	* rtlanal.c (rtx_addr_can_trap_p_1): SYMBOL_REF_FUNCTION_P can never
+	trap.  PIC register plus a const unspec without offset can never trap.
+
 2017-06-23  Marc Glisse  <marc.glisse@inria.fr>
 
 	* tree.h (builtin_structptr_type): New type.

gcc/ira.c

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

gcc/rtlanal.c

@@ -485,7 +485,7 @@ rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
     case SYMBOL_REF:
       if (SYMBOL_REF_WEAK (x))
 	return 1;
-      if (!CONSTANT_POOL_ADDRESS_P (x))
+      if (!CONSTANT_POOL_ADDRESS_P (x) && !SYMBOL_REF_FUNCTION_P (x))
 	{
 	  tree decl;
 	  HOST_WIDE_INT decl_size;
@@ -644,8 +644,11 @@ rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
 
     case PLUS:
       /* An address is assumed not to trap if:
-         - it is the pic register plus a constant.  */
-      if (XEXP (x, 0) == pic_offset_table_rtx && CONSTANT_P (XEXP (x, 1)))
+	 - it is the pic register plus a const unspec without offset.  */
+      if (XEXP (x, 0) == pic_offset_table_rtx
+	  && GET_CODE (XEXP (x, 1)) == CONST
+	  && GET_CODE (XEXP (XEXP (x, 1), 0)) == UNSPEC
+	  && offset == 0)
 	return 0;
 
       /* - or it is an address that can't trap plus a constant integer.  */