From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by sourceware.org (Postfix) with ESMTPS id 0B54F3858D20 for ; Wed, 9 Aug 2023 09:53:02 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 0B54F3858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-ed1-x533.google.com with SMTP id 4fb4d7f45d1cf-5233deb7cb9so3464711a12.3 for ; Wed, 09 Aug 2023 02:53:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691574781; x=1692179581; 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=ff4QABKNmlGA0XpK7Ltn3rwSWyT/Va/GBdobHr3+FOU=; b=AzZici7PJ0HfMmrxclpz+anu9EaoAv+gtZ1hyPU+f7f2u0BJoWzUlt0Rg6amzQWT7M r61DBXVwsXOeoEm1aAf1+FAAqC77Dy7iXfxYSIHLkqZX4Uj/1pNWXdCpGhCg7MxQIBll cFH8qx+ckNPKNb7IGrX/3KOr2B54snK95Bmqz9F2KH4QcH+5yaqNmNCAr7pLgthDb1Lj r1Rm14dz4m2kBYLxk5s0utcSI1jSoSQPVJ1RdHMZh6FdiGJL5ZJ6SCfcZCU6nrVfsEen TsBWUXJ+u6tz+uevzTuiPLDR7r26oqRrvXY+k131+7YdFZFyBJnXF6ymoQeQ5sjhMpl0 ZdhA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691574781; x=1692179581; 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=ff4QABKNmlGA0XpK7Ltn3rwSWyT/Va/GBdobHr3+FOU=; b=WI1tT5YDycWrMIrTr3bi/b+/LdJicJiPDfGUAeCCuct6vXwaCEybyonYU+hxdgS6zr DaTc0N9jT+wK1l5yRr9fNlEzocFPIqQollkehGvOMm+17zkV3ndzG/p7DgOd2jVdc6EZ exhyJ7VHa8sR86socobUBPZuCvLRzTuLZAuNa596X8r/EnB42z7Y2mRmQ6ClJxntAyfs m9K/mnEJ469HRGalsJVXtwuY7snE3O/J2/p+5FFm/+m2z2VcQNOXXldNiY0jeNA1bVk6 uLtuLX0cbLCD4fEvnhP2/24K3OV3wd6EFnQKVMhoDtoLF1lMT0iCKGz6FnghVCW99UM7 ORgg== X-Gm-Message-State: AOJu0YxiNVvQSwrzxiUj8SYbvEus5Jf0nEoWVbbTRdKlq9hv0aSPgVSv +iHtcXRZjs+UL4bQCMhOs/+KK6FHVYOdjmiiCZ8= X-Google-Smtp-Source: AGHT+IE7F3bQPgGOUMzgonb63N6mxVgjEqnvGi0cDNgiLHST9ck8/4jwYTNoA6YlXpo4HvzRttwxabFla9SQ9z/UphI= X-Received: by 2002:aa7:c643:0:b0:523:471e:681a with SMTP id z3-20020aa7c643000000b00523471e681amr1820396edr.41.1691574780493; Wed, 09 Aug 2023 02:53:00 -0700 (PDT) MIME-Version: 1.0 References: <20230807085701.302936-1-hongtao.liu@intel.com> In-Reply-To: From: Uros Bizjak Date: Wed, 9 Aug 2023 11:52:49 +0200 Message-ID: Subject: Re: [PATCH] i386: Clear upper bits of XMM register for V4HFmode/V2HFmode operations [PR110762] To: Richard Biener Cc: liuhongt , gcc-patches@gcc.gnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-2.3 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,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: On Mon, Aug 7, 2023 at 1:20=E2=80=AFPM Richard Biener wrote: > > Please also note the RFC patch [1] that relaxes clears for V2SFmode > > with -fno-trapping-math. The patched compiler will then emit the same > > code as clang does for -O2. Which raises another question - should gcc > > default to -fno-trapping-math? > > I think we discussed this before and yes, IMHO we should default to > -fno-trapping-math at least for C/C++ to be consistent with our other > handling of the FP environment (default to -fno-rounding-math) and > lack of proper FENV access barriers for inspecting the exceptions. > > Note Fortran has the -ffpe-trap=3D option which would then need to make > sure to also enable -ftrapping-math. Ada might have similar constraints > (it also uses -fnon-call-exceptions, but unless it enables CPU traps for > FP exceptions that would be a no-op). Note this also shows we should > possibly separate maintaining the IEEE exception state and considering > changes in the IEEE exception states to cause CPU traps (that's also > a source of common confusion on the user side). FTR: PR54192, "-fno-trapping-math by default?" [1] [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D54192 Uros.