From nobody Tue Feb 10 08:41:08 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=linaro.org ARC-Seal: i=1; a=rsa-sha256; t=1712598939; cv=none; d=zohomail.com; s=zohoarc; b=PKNanXlw1MwW7qm80KJrZS17YO4IHif4rCIl0kyBk3yeKaAx2AaguLC5wRaG3bh5dZz0kT9tA0lLmRogdwe0rtTyEgTrT2E8k3U/z7iajw+X+LCGRTAtDX//MI9mnO9w0seK8EMzh4CF/3gAMyXYYWkMtvCqCvIoki5klqrGu0k= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1712598939; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=r70v09Z1jYUdUmudZIEve8pIi40latYcxErAtIALfYA=; b=JHyREeLMiyUr/u2yhb1pa7IiUPxY592LmRLi6T7ypGMnimwgPQtE7d9u1FU1IMqNgTbt+TePv4YaN/hmcTG7LjU8mw4FBNuZ3wTw2DX4CXG4O09nFu50HD+Q8WVW/Se2UFi0qEsrFR1B3+Pc6CxpQ1PXVLO64ubf0UmMwYfTT/A= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 171259893934967.93038569359351; Mon, 8 Apr 2024 10:55:39 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rtt8N-00027K-0O; Mon, 08 Apr 2024 13:50:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rtt8M-00027B-BU for qemu-devel@nongnu.org; Mon, 08 Apr 2024 13:50:18 -0400 Received: from mail-pg1-x52b.google.com ([2607:f8b0:4864:20::52b]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rtt8J-0003k4-EJ for qemu-devel@nongnu.org; Mon, 08 Apr 2024 13:50:18 -0400 Received: by mail-pg1-x52b.google.com with SMTP id 41be03b00d2f7-5e4613f2b56so3665145a12.1 for ; Mon, 08 Apr 2024 10:50:15 -0700 (PDT) Received: from stoup.. (098-147-007-212.res.spectrum.com. [98.147.7.212]) by smtp.gmail.com with ESMTPSA id ga15-20020a17090b038f00b0029c3bac0aa8sm8658432pjb.4.2024.04.08.10.50.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Apr 2024 10:50:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1712598614; x=1713203414; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=r70v09Z1jYUdUmudZIEve8pIi40latYcxErAtIALfYA=; b=wrA720sPrA8Nm+OQoSIqkjj9BW8Hgk8o3vq4sjrYWHqth0Ucp7DXEL/6QaDY4x2x00 Qzj68v95fcVY3h/Fz9bs16FogQlmb7lGIzMNe/T53qjc5I8NW8ETnfp+TtIb6RVbbCo9 GOwVjOJTht3gtMwUgCImHCRxpQhmN8/nk7rzBSgV619Wcg9+CFlVsfgklgwwfr7U01OY x+tYqK21NkwSmh3SaEsai6O5lqEDOWnradH/W6XdDz1yonnE1jNGPp2FJJbjNDDaJ2dl RtcoxZVyFaLytocQ4xguXj8MKg/lBzGxE6RYS7JNIzqZhvwsiJkszfj8QfmHGso6QURP RQ5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712598614; x=1713203414; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=r70v09Z1jYUdUmudZIEve8pIi40latYcxErAtIALfYA=; b=OxAEHIKoYt9/9am5W6Dqe654NM00q1DETauFvuRgS3t3riCIlIoTqXU3BgsFkmjLMK 9XppxTs+RqB0K01DHj/CdjfL3Daty+nYx3u+dY/eiInoQAF5QTbAhK+g2L8rhzbsJsmh RnGqo1fB69BUqu8PiCpmJNtVR4FeWeuete4/Zu3S/p1cfq0BNhP3xsC/GhMwxutBYVj6 mIScrPphb2RFp+rSrievR+bEE5YFeGS1VhMJeOH1/kGF8Cm1D6tCFUZVtghiU/pTOmXy Mp+fcELwqEH4nWFomHXGiwRumQf+sol/HpbwJgWh5eb9SyfoCybL/gM2gv+jMQzwdPf8 dYhw== X-Gm-Message-State: AOJu0Yy/Fpk2Y7BReynK29dq7k3CHnHX/WMS3phrhNvI0J3y14UemJSb z7+yqjJCQoRyB65+Kt6rxTXkOvwat5kWKIM3LsmHk9n7RhMk7C1NOV56IWLFZnYKu5YBACn1Kug F X-Google-Smtp-Source: AGHT+IE80lerOFer8W/g3BtOG55khwBtNttI6YF0ABRTth2WipfaIEoACLdRRtcktw5n+RSlePjXbQ== X-Received: by 2002:a17:90b:1bcc:b0:2a0:2fb3:c1ff with SMTP id oa12-20020a17090b1bcc00b002a02fb3c1ffmr7520545pjb.15.1712598613747; Mon, 08 Apr 2024 10:50:13 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: Alexander Monakov , Mikhail Romanov Subject: [PULL 28/35] util/bufferiszero: Remove SSE4.1 variant Date: Mon, 8 Apr 2024 07:49:22 -1000 Message-Id: <20240408174929.862917-29-richard.henderson@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240408174929.862917-1-richard.henderson@linaro.org> References: <20240408174929.862917-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::52b; envelope-from=richard.henderson@linaro.org; helo=mail-pg1-x52b.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1712598941358100009 Content-Type: text/plain; charset="utf-8" From: Alexander Monakov The SSE4.1 variant is virtually identical to the SSE2 variant, except for using 'PTEST+JNZ' in place of 'PCMPEQB+PMOVMSKB+CMP+JNE' for testing if an SSE register is all zeroes. The PTEST instruction decodes to two uops, so it can be handled only by the complex decoder, and since CMP+JNE are macro-fused, both sequences decode to three uops. The uops comprising the PTEST instruction dispatch to p0 and p5 on Intel CPUs, so PCMPEQB+PMOVMSKB is comparatively more flexible from dispatch standpoint. Hence, the use of PTEST brings no benefit from throughput standpoint. Its latency is not important, since it feeds only a conditional jump, which terminates the dependency chain. I never observed PTEST variants to be faster on real hardware. Signed-off-by: Alexander Monakov Signed-off-by: Mikhail Romanov Reviewed-by: Richard Henderson Message-Id: <20240206204809.9859-2-amonakov@ispras.ru> --- util/bufferiszero.c | 29 ----------------------------- 1 file changed, 29 deletions(-) diff --git a/util/bufferiszero.c b/util/bufferiszero.c index 3e6a5dfd63..f5a3634f9a 100644 --- a/util/bufferiszero.c +++ b/util/bufferiszero.c @@ -100,34 +100,6 @@ buffer_zero_sse2(const void *buf, size_t len) } =20 #ifdef CONFIG_AVX2_OPT -static bool __attribute__((target("sse4"))) -buffer_zero_sse4(const void *buf, size_t len) -{ - __m128i t =3D _mm_loadu_si128(buf); - __m128i *p =3D (__m128i *)(((uintptr_t)buf + 5 * 16) & -16); - __m128i *e =3D (__m128i *)(((uintptr_t)buf + len) & -16); - - /* Loop over 16-byte aligned blocks of 64. */ - while (likely(p <=3D e)) { - __builtin_prefetch(p); - if (unlikely(!_mm_testz_si128(t, t))) { - return false; - } - t =3D p[-4] | p[-3] | p[-2] | p[-1]; - p +=3D 4; - } - - /* Finish the aligned tail. */ - t |=3D e[-3]; - t |=3D e[-2]; - t |=3D e[-1]; - - /* Finish the unaligned tail. */ - t |=3D _mm_loadu_si128(buf + len - 16); - - return _mm_testz_si128(t, t); -} - static bool __attribute__((target("avx2"))) buffer_zero_avx2(const void *buf, size_t len) { @@ -221,7 +193,6 @@ select_accel_cpuinfo(unsigned info) #endif #ifdef CONFIG_AVX2_OPT { CPUINFO_AVX2, 128, buffer_zero_avx2 }, - { CPUINFO_SSE4, 64, buffer_zero_sse4 }, #endif { CPUINFO_SSE2, 64, buffer_zero_sse2 }, { CPUINFO_ALWAYS, 0, buffer_zero_int }, --=20 2.34.1