From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8918 invoked by alias); 10 Apr 2003 15:47:29 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 8904 invoked from network); 10 Apr 2003 15:47:28 -0000 Received: from unknown (HELO nikam.ms.mff.cuni.cz) (195.113.18.106) by sources.redhat.com with SMTP; 10 Apr 2003 15:47:28 -0000 Received: from camelot.ms.mff.cuni.cz (kampanus.ms.mff.cuni.cz [195.113.18.107]) by nikam.ms.mff.cuni.cz (Postfix) with SMTP id 5FA6D4DE86; Thu, 10 Apr 2003 17:47:29 +0200 (CEST) Received: by camelot.ms.mff.cuni.cz (sSMTP sendmail emulation); Thu, 10 Apr 2003 17:47:30 +0200 Date: Thu, 10 Apr 2003 16:35:00 -0000 From: Jan Hubicka To: Jan Hubicka Cc: Eric Botcazou , gcc@gcc.gnu.org Subject: Re: Reload bug Message-ID: <20030410154730.GH9319@kam.mff.cuni.cz> References: <200304081937.16859.ebotcazou@libertysurf.fr> <200304091105.24896.ebotcazou@libertysurf.fr> <20030409112544.GA12755@kam.mff.cuni.cz> <200304101201.50800.ebotcazou@libertysurf.fr> <20030410153230.GD9319@kam.mff.cuni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030410153230.GD9319@kam.mff.cuni.cz> User-Agent: Mutt/1.3.28i X-SW-Source: 2003-04/txt/msg00428.txt.bz2 > > > Concerning this testcase, the reload used to manage to get around this > > > problem. It didn't get around intentionally and just because the > > > instruction contrain does not accept SSE register so reload is needed > > > anyway. > > > > I think you're completely right: the reload pass has no specific > > infrastructure for dealing with invalid subregs. It may "fix" these subregs, > > but only if it happens that the operand needs reloading because of the insn > > constraints. > > > > I now have an example: PR target/10286 > > > > We pass > > > > (insn 33 30 35 (set (subreg:SI (reg/v:DI 67) 4) > > (mem/f:SI (plus:SI (reg/f:SI 16 argp) > > (const_int 4 [0x4])) [0 hi+0 S4 A32])) 45 {*movsi_1} > > (insn_list 30 (nil)) > > > > to reload, which produces > > > > (insn 33 30 35 (set (reg:SI 29 emm0) > > (mem/f:SI (plus:SI (reg/f:SI 6 ebp) > > (const_int 12 [0xc])) [0 hi+0 S4 A32])) 45 {*movsi_1} > > (insn_list 30 (nil)) > > (nil)) > > > > that is, the only reload for insn 33 is > > > > Reloads for insn # 33 > > Reload 0: reload_in (SI) = (mem/f:SI (plus:SI (reg/f:SI 6 ebp) > > (const_int 12 [0xc])) > > [0 hi+0 S4 A32]) > > GENERAL_REGS, RELOAD_FOR_INPUT (opnum = 1), optional > > reload_in_reg: (mem/f:SI (plus:SI (reg/f:SI 6 ebp) > > (const_int 12 [0xc])) > > [0 hi+0 S4 A32]) > > > > > > Incidentally, PR target/10286 is a regression from GCC 3.2 present in > > GCC 3.2.1 and later. The culprit is this patch: > > > > Sat Oct 19 15:49:14 CEST 2002 Jan Hubicka > > > > * mmintrin.h (__m64): typedef it to v2si. > > (_mm_cvtsi32_si64, _mm_cvtsi32_si64_mm_sll_pi16, > > _mm_sll_pi32, _mm_sll_pi64, _mm_slli_pi64, _mm_sra_pi16, > > _mm_sra_pi32, _mm_srl_pi16, _mm_srl_pi32, _mm_srl_pi64, > > _mm_srli_pi64, _mm_and_si64, _mm_andnot_si64, > > _mm_or_si64, _mm_xor_si64): Add neccesary casts. > > * xmmintrin.h (_mm_setzero_si64): Likewise. > > > > See http://gcc.gnu.org/ml/gcc-patches/2002-10/msg01091.html > > > > Before the patch, __m64 was defined as 'unsigned long long' so (%eax, %edx) > > was used instead of %rmm0 and we didn't produce invalid subregs. I think > > this patch has opened a can of worms and the MMX intrinsics are seriously > > broken on the 3.2 branch now. > > They always have been - I've fixed 50+ different bugs exposed by simple > testsuite executing each individual intrincisc with few diferent args, > so I would not brother about this on the 3.2. 3.3 is different issue > and should be the first GCC where intrincisc are generaly usable. I > hope. > > Will look into this in the detail this evening, now I have about -10 > minutes of time. Thanks! Perhaps I would vote for simply disabling the xmm intrincisc support in the 3.2.x compiler by adding #error into the headers. It is better than confusing user by completely broken interface especially one so dificult to use as xmm/mmx intrincisc are. Honza > > Honza > > > > -- > > Eric Botcazou