From patchwork Wed Sep 7 09:38:59 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Monakov X-Patchwork-Id: 113732 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) by ozlabs.org (Postfix) with SMTP id CFCC1B6F99 for ; Wed, 7 Sep 2011 19:39:18 +1000 (EST) Received: (qmail 24014 invoked by alias); 7 Sep 2011 09:39:17 -0000 Received: (qmail 24005 invoked by uid 22791); 7 Sep 2011 09:39:16 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from smtp.ispras.ru (HELO smtp.ispras.ru) (83.149.198.202) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 07 Sep 2011 09:39:01 +0000 Received: from ispserv.ispras.ru (ispserv.ispras.ru [83.149.198.72]) by smtp.ispras.ru (Postfix) with ESMTP id D54355D4040; Wed, 7 Sep 2011 13:27:38 +0400 (MSD) Received: from monoid.intra.ispras.ru (winnie.ispras.ru [83.149.198.236]) by ispserv.ispras.ru (Postfix) with ESMTP id A091F3FC48; Wed, 7 Sep 2011 13:38:59 +0400 (MSD) Date: Wed, 7 Sep 2011 13:38:59 +0400 (MSD) From: Alexander Monakov To: gcc-patches@gcc.gnu.org cc: "Vladimir N. Makarov" Subject: [PATCH] sel-sched: forbid differing modes in substitution (PR 50205) Message-ID: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org Hello, The patch repairs a problem when we attempt to substitute an insn like (... (cmp (mem (reg:DI ax)) (reg:SI ax))) (note different modes) through (set (reg:DI ax) (reg:DI dx)), which leaves the (reg:SI ax) part of the comparison intact, causing an ICE later on when we notice that the dependency on ax is still present. As this is quite rare, we can simply forbid substitution in such circumstances, much like substitution of multiple hard reg references is forbidden now. En passant, the patch simplifes the code a little, as we never try to substitute anything but registers. Bootstrapped and regtested on x86_64-linux with sel-sched enabled at -O2, OK? (I'll add the testcase from Bugzilla when committing) 2011-09-07 Alexander Monakov PR rtl-optimization/50205 * sel-sched.c (count_occurrences_1): Simplify on the assumption that p->x is a register. Forbid substitution when the same register is found in a different mode. (count_occurrences_equiv): Assert that 'what' is a register. diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c index f11faca..2af01ae 100644 --- a/gcc/sel-sched.c +++ b/gcc/sel-sched.c @@ -813,18 +813,12 @@ count_occurrences_1 (rtx *cur_rtx, void *arg) { rtx_search_arg_p p = (rtx_search_arg_p) arg; - /* The last param FOR_GCSE is true, because otherwise it performs excessive - substitutions like - r8 = r33 - r16 = r33 - for the last insn it presumes r33 equivalent to r8, so it changes it to - r33. Actually, there's no change, but it spoils debugging. */ - if (exp_equiv_p (*cur_rtx, p->x, 0, true)) - { - /* Bail out if we occupy more than one register. */ - if (REG_P (*cur_rtx) - && HARD_REGISTER_P (*cur_rtx) - && hard_regno_nregs[REGNO(*cur_rtx)][GET_MODE (*cur_rtx)] > 1) + if (REG_P (*cur_rtx) && REGNO (*cur_rtx) == REGNO (p->x)) + { + /* Bail out if mode is different or more than one register is used. */ + if (GET_MODE (*cur_rtx) != GET_MODE (p->x) + || (HARD_REGISTER_P (*cur_rtx) + && hard_regno_nregs[REGNO(*cur_rtx)][GET_MODE (*cur_rtx)] > 1)) { p->n = 0; return 1; @@ -837,7 +831,6 @@ count_occurrences_1 (rtx *cur_rtx, void *arg) } if (GET_CODE (*cur_rtx) == SUBREG - && REG_P (p->x) && (!REG_P (SUBREG_REG (*cur_rtx)) || REGNO (SUBREG_REG (*cur_rtx)) == REGNO (p->x))) { @@ -859,6 +852,7 @@ count_occurrences_equiv (rtx what, rtx where) { struct rtx_search_arg arg; + gcc_assert (REG_P (what)); arg.x = what; arg.n = 0;