Fix infinite recursion (was: Re: Ping: [PATCH] PR 30315 Canonicalize overflow checks in simplify-rtx.c)

Hans-Peter Nilsson hans-peter.nilsson@axis.com
Mon Sep 10 08:06:00 GMT 2007


> Date: Mon, 10 Sep 2007 02:55:06 +0200
> From: Hans-Peter Nilsson <hp@axis.com>

> (I'll commit as obvious after trunk fails on my x86_64 host or
> if it passes regtest.  I won't be sorry if someone beats me to
> it.)

No regressions or changes in warnings for
x86_64-unknown-linux-gnu, fixed the problem for cris-elf, so
committed.

	* simplify-rtx.c (simplify_relational_operation_1): For recent
        canonicalization, don't recurse if op1 equals both PLUS arguments. 

Index: simplify-rtx.c
===================================================================
--- simplify-rtx.c	(revision 128320)
+++ simplify-rtx.c	(working copy)
@@ -3816,7 +3816,9 @@
   /* Canonicalize (LTU/GEU (PLUS a b) b) as (LTU/GEU (PLUS a b) a).  */
   if ((code == LTU || code == GEU)
       && GET_CODE (op0) == PLUS
-      && rtx_equal_p (op1, XEXP (op0, 1)))
+      && rtx_equal_p (op1, XEXP (op0, 1))
+      /* Don't recurse "infinitely" for (LTU/GEU (PLUS b b) b).  */
+      && !rtx_equal_p (op1, XEXP (op0, 0)))
     return simplify_gen_relational (code, mode, cmp_mode, op0, XEXP (op0, 0));
 
   if (op1 == const0_rtx)

brgds, H-P



More information about the Gcc-patches mailing list