From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-xb2f.google.com (mail-yb1-xb2f.google.com [IPv6:2607:f8b0:4864:20::b2f]) by sourceware.org (Postfix) with ESMTPS id 0F2E03858D35 for ; Thu, 12 Jan 2023 11:30:45 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 0F2E03858D35 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=jp-hosting.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=jp-hosting.net Received: by mail-yb1-xb2f.google.com with SMTP id g4so18271100ybg.7 for ; Thu, 12 Jan 2023 03:30:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jp-hosting.net; s=google; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=7L3f3UvtaeSAlU5nzUPT7FquLSFsjegoMkU0BYRyG/c=; b=LIcyeYao1LetLKcYU3QX/Qc7E/USU6yG8eVjluE41LcoYklrT7d6h5HppmaHipUXmk PTKNMC/Xorv6s6H8Zc5MfgRB0zud1UVMIWRz2pjFUwERBFEEmG89G1YvOgpYJBCi7XsT Db1Xb9xpmaOMmV2kLMRDvTFfbEyqv90OFavnh09scD8bB+668bI+E0nsFgeUUBzV3k6J kq/ihX8+TElsCyLfUuZCTCFk6WMUJvogN/x6TomV1/j/w0g3HueQw7UIAYhenVrJ/FNn GDiYYYARVfJrSleoHM1FEXU3nynZ8sYI9FZLRIg/mr3yR8o2YWPx7m20bCk4cOCMuqDx Zp6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7L3f3UvtaeSAlU5nzUPT7FquLSFsjegoMkU0BYRyG/c=; b=x0h1dfrINXDM0w+555B+wF+ycfQJnf1KBbrOUjC2SDKQ39gdafHZ2xA79lt+VnQbmx 6taALxCbmE/dDiNJNtDM7UiqoarercrNtRVMFqeb+2ZHTT9NCe+TH9LPvuAP3d6OqEXG VkEENd1QE1lTQlePT9EiX6RTR775vqBFxED+fhj+/Xweww3tgWKUdT9tv3KaDo4WQbXj MQbJamQqLPhGIIWkeJOwWTAxf6r58INm2skOdmJ1i4yy9LzYKbCd5zDVN/OAQCjSvx7t leOzYDDmRny/Fjt1LcJfGKG/NZlcNQ3w9qW2H+Jv8dr7BVxXF04c3el24pMbS7Z1JhHc vA4Q== X-Gm-Message-State: AFqh2kpd2dTX7G2utI4psmLOJ2w/6p9XRqcchH4kZ2AYq1USjn/YQfN6 +eFAfALPOsiyLAaVwBRe4mhq9VbQaQtracWBLBixbA== X-Google-Smtp-Source: AMrXdXvLV2fjFNCd6xApvQgY7vx52sdkoLjrNtAOQQECtj9r1BVtnVFdxboUqtgbHdnhU5OQd5tkLsuwSU9rxtjXABk= X-Received: by 2002:a25:b7d0:0:b0:707:3f66:a611 with SMTP id u16-20020a25b7d0000000b007073f66a611mr11071320ybj.216.1673523044241; Thu, 12 Jan 2023 03:30:44 -0800 (PST) MIME-Version: 1.0 References: <7D444AFD-A62E-450E-A80F-CA0C2EB9ECD4@gentoo.org> In-Reply-To: <7D444AFD-A62E-450E-A80F-CA0C2EB9ECD4@gentoo.org> From: James Addison Date: Thu, 12 Jan 2023 11:30:32 +0000 Message-ID: Subject: Re: avx512erintrin.h: uninitialized variable warning (optimized build) To: Sam James Cc: gcc@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_SHORT,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Thanks, Sam, Yep, that does seem closely related. The problems mentioned there look similar enough that it may be possible to resolve an entire class of these problems in the same area of the code in a single pass. I'll add some more details there soon. On Thu, 12 Jan 2023 at 06:51, Sam James wrote: > > > > > On 12 Jan 2023, at 00:26, James Addison via Gcc wrote= : > > > > Hi, > > > > During GCC 12.2.0 compilation of a file that includes[1] immintrin.h > > with both code-optimization and uninitialized-variable-warnings > > enabled, a warning is emitted: > > > > /usr/lib/gcc/x86_64-linux-gnu/12/include/avx512erintrin.h:55:20: > > warning: =E2=80=98__W=E2=80=99 is used uninitialized [-Wuninitialized] > > > > The minimal repro compilation command appears to be: > > > > gcc -O -Wuninitialized -mavx512er -mavx512pf > > ./numpy/distutils/checks/cpu_avx512_knl.c > > > > My question is: does the warning indicate a possible bug that should > > be reported, or is there a reason that the relevant code[2] does not > > initialize the variable (for example, for performance reasons)? > > See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105593, might > be the same thing?