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[174.21.72.5]) by smtp.gmail.com with ESMTPSA id p10-20020a170902c70a00b001e81c778784sm3366611plp.67.2024.05.03.08.13.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 May 2024 08:13:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1714749203; x=1715354003; 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=j2qk0rBcBkKKFEgVV+rMjuUu0W/Dg2i9vyIUDLqamH4=; b=BIE5RkmNEdnNaZkd0yv5E3GlkPOEyXoWOE+xt/mAEXv8pC90L7FFw+uFZtMg2BENaX 2RumZrpG65+41G14yWfkJm8MFNuyEnLXgZjQCST8u7KoZyZ2T0fYHAawLUTTSnT+pcXp INNq0ynkd6Wl4xikOxfwXQaRxxbm6vabRYz7dag+RnzKllCvlwzKEubxOmVOVWfx8B4w +MYEFTvmBLFLwaPSTymwpv1cc+kjveuQHSDUzROingC0zx+KwBnR9MubSwF5MgBgftWO u6MTDKWKRIcQo/hShmQJg/DaEeRdSqx3fX0QIvIYQ1Y0Cwh4hYH6iEJSpL8G0maob8Ie trbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714749203; x=1715354003; 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=j2qk0rBcBkKKFEgVV+rMjuUu0W/Dg2i9vyIUDLqamH4=; b=qlshUi0hmz4MMxfSdEGJ/DVodBglGh4ImhmSfxKqr3Tsi1+JKDY2kdp5K1lTbpG/JG bR0YN8rNTMuP4OuKiEJAZz5/1vF9ujMT3CHTNJZPHQmj4ZWTX9yRNJL7rIQnF6ClZbNJ L2sx4c04YBLZfzUX1LdyoqDm20JGrMdSvw9zEMDxWAzhvuMzOhymmSQY9KR7qLxvlcgg ewMQ3y0RIj1cko4uMR31eQKB7URR1hh0pCK2MUqEZ9axAnWCM3TaYgM9sMOFagto2b7+ 4jOLBuJAr8k/k31fEwi8p/iSDjyLHT83dXZUV+4VPSHSS4JMo3yox8e3+9DKv5HbPt4k FzXg== X-Gm-Message-State: AOJu0YzbB5uc887Babp+1oKhQvQ8ePegTsi6NxQ60KyL1sbMGXBP2GXK RnnRwhfHQlqC3yne+LomoDmfP5LUTFn8QoxiImfNzUVD4vFF098hagpa6+/42sYXG8De40oZUlG W X-Google-Smtp-Source: AGHT+IEXRSKnBTz6oqGwJR8uM2WDbBCAMaq4Ef7p0eLFDF30TKAzoaLgm0AuoTcb3UBZWNjxGyyGrQ== X-Received: by 2002:a17:903:11d0:b0:1e5:5bd7:87a4 with SMTP id q16-20020a17090311d000b001e55bd787a4mr3582066plh.16.1714749203332; Fri, 03 May 2024 08:13:23 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Cc: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Subject: [PULL 08/10] util/bufferiszero: Simplify test_buffer_is_zero_next_accel Date: Fri, 3 May 2024 08:13:12 -0700 Message-Id: <20240503151314.336357-9-richard.henderson@linaro.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240503151314.336357-1-richard.henderson@linaro.org> References: <20240503151314.336357-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::631; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x631.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+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1714749224304100003 Because the three alternatives are monotonic, we don't need to keep a couple of bitmasks, just identify the strongest alternative at startup. Generalize test_buffer_is_zero_next_accel and init_accel by always defining an accel_table array. Reviewed-by: Philippe Mathieu-Daud=C3=A9 Signed-off-by: Richard Henderson --- util/bufferiszero.c | 81 ++++++++++++++++++++------------------------- 1 file changed, 35 insertions(+), 46 deletions(-) diff --git a/util/bufferiszero.c b/util/bufferiszero.c index f9af7841ba..7218154a13 100644 --- a/util/bufferiszero.c +++ b/util/bufferiszero.c @@ -27,7 +27,6 @@ #include "host/cpuinfo.h" =20 typedef bool (*biz_accel_fn)(const void *, size_t); -static biz_accel_fn buffer_is_zero_accel; =20 static bool buffer_is_zero_int_lt256(const void *buf, size_t len) { @@ -179,60 +178,35 @@ buffer_zero_avx2(const void *buf, size_t len) } #endif /* CONFIG_AVX2_OPT */ =20 -static unsigned __attribute__((noinline)) -select_accel_cpuinfo(unsigned info) -{ - /* Array is sorted in order of algorithm preference. */ - static const struct { - unsigned bit; - biz_accel_fn fn; - } all[] =3D { +static biz_accel_fn const accel_table[] =3D { + buffer_is_zero_int_ge256, + buffer_zero_sse2, #ifdef CONFIG_AVX2_OPT - { CPUINFO_AVX2, buffer_zero_avx2 }, + buffer_zero_avx2, #endif - { CPUINFO_SSE2, buffer_zero_sse2 }, - { CPUINFO_ALWAYS, buffer_is_zero_int_ge256 }, - }; +}; =20 - for (unsigned i =3D 0; i < ARRAY_SIZE(all); ++i) { - if (info & all[i].bit) { - buffer_is_zero_accel =3D all[i].fn; - return all[i].bit; - } +static unsigned best_accel(void) +{ + unsigned info =3D cpuinfo_init(); + +#ifdef CONFIG_AVX2_OPT + if (info & CPUINFO_AVX2) { + return 2; } - return 0; +#endif + return info & CPUINFO_SSE2 ? 1 : 0; } =20 -static unsigned used_accel; - -static void __attribute__((constructor)) init_accel(void) -{ - used_accel =3D select_accel_cpuinfo(cpuinfo_init()); -} - -#define INIT_ACCEL NULL - -bool test_buffer_is_zero_next_accel(void) -{ - /* - * Accumulate the accelerators that we've already tested, and - * remove them from the set to test this round. We'll get back - * a zero from select_accel_cpuinfo when there are no more. - */ - unsigned used =3D select_accel_cpuinfo(cpuinfo & ~used_accel); - used_accel |=3D used; - return used; -} #else -bool test_buffer_is_zero_next_accel(void) -{ - return false; -} - -#define INIT_ACCEL buffer_is_zero_int_ge256 +#define best_accel() 0 +static biz_accel_fn const accel_table[1] =3D { + buffer_is_zero_int_ge256 +}; #endif =20 -static biz_accel_fn buffer_is_zero_accel =3D INIT_ACCEL; +static biz_accel_fn buffer_is_zero_accel; +static unsigned accel_index; =20 bool buffer_is_zero_ool(const void *buf, size_t len) { @@ -257,3 +231,18 @@ bool buffer_is_zero_ge256(const void *buf, size_t len) { return buffer_is_zero_accel(buf, len); } + +bool test_buffer_is_zero_next_accel(void) +{ + if (accel_index !=3D 0) { + buffer_is_zero_accel =3D accel_table[--accel_index]; + return true; + } + return false; +} + +static void __attribute__((constructor)) init_accel(void) +{ + accel_index =3D best_accel(); + buffer_is_zero_accel =3D accel_table[accel_index]; +} --=20 2.34.1