From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30614 invoked by alias); 7 Jan 2015 09:36:05 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 30516 invoked by uid 48); 7 Jan 2015 09:36:01 -0000 From: "chrbr at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug target/64507] SH inlined builtin strncmp doesn't return 0 for 0 length Date: Wed, 07 Jan 2015 09:36:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: target X-Bugzilla-Version: unknown X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: chrbr at gcc dot gnu.org X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-01/txt/msg00361.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D64507 --- Comment #4 from chrbr at gcc dot gnu.org --- Actually, the code could be slightly better by factorizing the return seque= nces ;; check length mov #0,r0 ;; goto .l2 ;; else init r1,r0 ;; goto .l1 .l2: rtx nop .l1: rts=20=20=20=20 sub r1,r0 into ;; check length mov r1,r0 ;; goto l1 ;; else init r1,r0 .l1:=20=20=20=20=20=20=20=20 rts sub r1,r0 however this creates an unitilized mov (which we don=C2=B4t care) but the b= ackend keeps forcing an useless mov #0,r1 >>From gcc-bugs-return-472368-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Wed Jan 07 09:37:41 2015 Return-Path: Delivered-To: listarch-gcc-bugs@gcc.gnu.org Received: (qmail 31750 invoked by alias); 7 Jan 2015 09:37:41 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Delivered-To: mailing list gcc-bugs@gcc.gnu.org Received: (qmail 31710 invoked by uid 48); 7 Jan 2015 09:37:37 -0000 From: "maurits.de.jong at ericsson dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c/64509] _Generic throws error in unselected generic association Date: Wed, 07 Jan 2015 09:37:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c X-Bugzilla-Version: 4.9.2 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: maurits.de.jong at ericsson dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2015-01/txt/msg00362.txt.bz2 Content-length: 645 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64509 --- Comment #4 from Martien de Jong --- I understand. What a shallow and ugly feature it is then. I think it can only usefully be employed using a preprocessor macro, yet it is part of the expression syntax. It is meant to resolve type issues, yet all variants should be type-sane. You can indeed implement something like tgmath.h with it, but only if the types can be implictly converted. BTW, I notice that ./gcc/ginclude/tgmath.h uses __builtin_classify_type __builtin_types_compatible_p __builtin_choose_expr Will it move to using _Generic() ?