From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-x32a.google.com (mail-ot1-x32a.google.com [IPv6:2607:f8b0:4864:20::32a]) by sourceware.org (Postfix) with ESMTPS id 87C473938C07 for ; Mon, 8 Feb 2021 14:09:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 87C473938C07 Received: by mail-ot1-x32a.google.com with SMTP id k25so12161720otb.4 for ; Mon, 08 Feb 2021 06:09:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=xukM2sLiJJk4gTJ5SiQOH6492pxlcTPIAXHXJ4U6lFQ=; b=UQeeNunbEq/zbOAXVFOVkw1pbslfw/cC1uz8ZYFjhqxjXpplNQTx/z/SB+Xhd4XD7d TightF3uxe338dmqQiqt+u/NNe8gMEjq5odhSglTGQYlODuK1m5GN21VKdyowuiwK+cj wqQKxJgvQMAoNCKcs2fh9WVfrZHsYGgrxo6Z4dvqobbk+QyqOk9pB2x/DghEHJcK0itf x/y1gnQzEm84ZjvG2kvho8Mo8LLHo7zxjMoHIhhK32eFezEyi16TCafu3emulSSd55BZ QOdkyPeycM+YPn4bI69YE/bIDowXa3kOX0rI5FxzMjHre6rbWOycxnPkiZEzopW9NqMb K4eA== X-Gm-Message-State: AOAM531ow/Q1/zmMnatMhd91VHgi3KQtPhnZGFOVEOGGp2FZBfNjZsmE DAh6KM66bsrWEv9D0ppczIqMqbRuHg5/pVttYPSL+WSb X-Google-Smtp-Source: ABdhPJwSEBrByYpgggWxbjYg+jfGDjQDpFiq1hZyhI2od/oF3OhAqlhUTqLqg79vOdbdJbzA3sE80qaIYKSRiiz6eEc= X-Received: by 2002:a05:6830:1285:: with SMTP id z5mr3495463otp.90.1612793375903; Mon, 08 Feb 2021 06:09:35 -0800 (PST) MIME-Version: 1.0 References: <20210203053900.4125403-1-goldstein.w.n@gmail.com> <20210203053900.4125403-2-goldstein.w.n@gmail.com> In-Reply-To: <20210203053900.4125403-2-goldstein.w.n@gmail.com> From: "H.J. Lu" Date: Mon, 8 Feb 2021 06:08:59 -0800 Message-ID: Subject: Re: [PATCH v4 2/2] x86: Add additional benchmarks and tests for strchr To: noah Cc: GNU C Library , "Carlos O'Donell" Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3037.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Feb 2021 14:09:38 -0000 On Tue, Feb 2, 2021 at 9:39 PM wrote: > > From: noah > > This patch adds additional benchmarks and tests for string size of > 4096 and several benchmarks for string size 256 with different > alignments. > > Signed-off-by: noah > --- > Added 2 additional benchmark and test sizes: > > 4096: Just feels like a natural "large" size to test > > 256 with multiple alignments: This essentially is to test how > expensive the initial work prior to the 4x loop is depending on > different alignments. > > results from bench-strchr: All times are in seconds and the medium of > 100 runs. Old is current strchr-avx2.S implementation. New is this > patch. > > Summary: New is definetly faster for medium -> large sizes. Once the > 4x loop is hit there is a 10%+ speedup and New always wins out. For > smaller sizes there is more variance as to which is faster and the > differences are small. Generally it seems the New version wins > out. This is likely because 0 - 31 sized strings are the fast path for > new (no jmp). Also something that is neat is the significant > performance improved for alignment 96 and 112. This is because the 5x > vectors before 4x loop really favor that alignment. > > Benchmarking CPU: > Icelake: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz > > size, algn, Old T , New T -------- Win Dif > 0 , 0 , 2.54 , 2.52 -------- New -0.02 > 1 , 0 , 2.57 , 2.52 -------- New -0.05 > 2 , 0 , 2.56 , 2.52 -------- New -0.04 > 3 , 0 , 2.58 , 2.54 -------- New -0.04 > 4 , 0 , 2.61 , 2.55 -------- New -0.06 > 5 , 0 , 2.65 , 2.62 -------- New -0.03 > 6 , 0 , 2.73 , 2.74 -------- Old -0.01 > 7 , 0 , 2.75 , 2.74 -------- New -0.01 > 8 , 0 , 2.62 , 2.6 -------- New -0.02 > 9 , 0 , 2.73 , 2.75 -------- Old -0.02 > 10 , 0 , 2.74 , 2.74 -------- Eq N/A > 11 , 0 , 2.76 , 2.72 -------- New -0.04 > 12 , 0 , 2.74 , 2.72 -------- New -0.02 > 13 , 0 , 2.75 , 2.72 -------- New -0.03 > 14 , 0 , 2.74 , 2.73 -------- New -0.01 > 15 , 0 , 2.74 , 2.73 -------- New -0.01 > 16 , 0 , 2.74 , 2.73 -------- New -0.01 > 17 , 0 , 2.74 , 2.74 -------- Eq N/A > 18 , 0 , 2.73 , 2.73 -------- Eq N/A > 19 , 0 , 2.73 , 2.73 -------- Eq N/A > 20 , 0 , 2.73 , 2.73 -------- Eq N/A > 21 , 0 , 2.73 , 2.72 -------- New -0.01 > 22 , 0 , 2.71 , 2.74 -------- Old -0.03 > 23 , 0 , 2.71 , 2.69 -------- New -0.02 > 24 , 0 , 2.68 , 2.67 -------- New -0.01 > 25 , 0 , 2.66 , 2.62 -------- New -0.04 > 26 , 0 , 2.64 , 2.62 -------- New -0.02 > 27 , 0 , 2.71 , 2.64 -------- New -0.07 > 28 , 0 , 2.67 , 2.69 -------- Old -0.02 > 29 , 0 , 2.72 , 2.72 -------- Eq N/A > 30 , 0 , 2.68 , 2.69 -------- Old -0.01 > 31 , 0 , 2.68 , 2.68 -------- Eq N/A > 32 , 0 , 3.51 , 3.52 -------- Old -0.01 > 32 , 1 , 3.52 , 3.51 -------- New -0.01 > 64 , 0 , 3.97 , 3.93 -------- New -0.04 > 64 , 2 , 3.95 , 3.9 -------- New -0.05 > 64 , 1 , 4.0 , 3.93 -------- New -0.07 > 64 , 3 , 3.97 , 3.88 -------- New -0.09 > 64 , 4 , 3.95 , 3.89 -------- New -0.06 > 64 , 5 , 3.94 , 3.9 -------- New -0.04 > 64 , 6 , 3.97 , 3.9 -------- New -0.07 > 64 , 7 , 3.97 , 3.91 -------- New -0.06 > 96 , 0 , 4.74 , 4.52 -------- New -0.22 > 128 , 0 , 5.29 , 5.19 -------- New -0.1 > 128 , 2 , 5.29 , 5.15 -------- New -0.14 > 128 , 3 , 5.31 , 5.22 -------- New -0.09 > 256 , 0 , 11.19 , 9.81 -------- New -1.38 > 256 , 3 , 11.19 , 9.84 -------- New -1.35 > 256 , 4 , 11.2 , 9.88 -------- New -1.32 > 256 , 16 , 11.21 , 9.79 -------- New -1.42 > 256 , 32 , 11.39 , 10.34 -------- New -1.05 > 256 , 48 , 11.88 , 10.56 -------- New -1.32 > 256 , 64 , 11.82 , 10.83 -------- New -0.99 > 256 , 80 , 11.85 , 10.86 -------- New -0.99 > 256 , 96 , 9.56 , 8.76 -------- New -0.8 > 256 , 112 , 9.55 , 8.9 -------- New -0.65 > 512 , 0 , 15.76 , 13.72 -------- New -2.04 > 512 , 4 , 15.72 , 13.74 -------- New -1.98 > 512 , 5 , 15.73 , 13.74 -------- New -1.99 > 1024, 0 , 24.85 , 21.33 -------- New -3.52 > 1024, 5 , 24.86 , 21.27 -------- New -3.59 > 1024, 6 , 24.87 , 21.32 -------- New -3.55 > 2048, 0 , 45.75 , 36.7 -------- New -9.05 > 2048, 6 , 43.91 , 35.42 -------- New -8.49 > 2048, 7 , 44.43 , 36.37 -------- New -8.06 > 4096, 0 , 96.94 , 81.34 -------- New -15.6 > 4096, 7 , 97.01 , 81.32 -------- New -15.69 > > benchtests/bench-strchr.c | 26 +++++++++++++++++++++++++- > string/test-strchr.c | 26 +++++++++++++++++++++++++- > 2 files changed, 50 insertions(+), 2 deletions(-) > > diff --git a/benchtests/bench-strchr.c b/benchtests/bench-strchr.c > index bf493fe458..4ce2369d9b 100644 > --- a/benchtests/bench-strchr.c > +++ b/benchtests/bench-strchr.c > @@ -100,7 +100,7 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char) > size_t i; > CHAR *result; > CHAR *buf = (CHAR *) buf1; > - align &= 15; > + align &= 127; > if ((align + len) * sizeof (CHAR) >= page_size) > return; > > @@ -151,12 +151,24 @@ test_main (void) > do_test (i, 16 << i, 2048, SMALL_CHAR, MIDDLE_CHAR); > } > > + for (i = 1; i < 8; ++i) > + { > + do_test (0, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > + do_test (i, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > + } > + > for (i = 1; i < 8; ++i) > { > do_test (i, 64, 256, SMALL_CHAR, MIDDLE_CHAR); > do_test (i, 64, 256, SMALL_CHAR, BIG_CHAR); > } > > + for (i = 0; i < 8; ++i) > + { > + do_test (16 * i, 256, 512, SMALL_CHAR, MIDDLE_CHAR); > + do_test (16 * i, 256, 512, SMALL_CHAR, BIG_CHAR); > + } > + > for (i = 0; i < 32; ++i) > { > do_test (0, i, i + 1, SMALL_CHAR, MIDDLE_CHAR); > @@ -169,12 +181,24 @@ test_main (void) > do_test (i, 16 << i, 2048, 0, MIDDLE_CHAR); > } > > + for (i = 1; i < 8; ++i) > + { > + do_test (0, 16 << i, 4096, 0, MIDDLE_CHAR); > + do_test (i, 16 << i, 4096, 0, MIDDLE_CHAR); > + } > + > for (i = 1; i < 8; ++i) > { > do_test (i, 64, 256, 0, MIDDLE_CHAR); > do_test (i, 64, 256, 0, BIG_CHAR); > } > > + for (i = 0; i < 8; ++i) > + { > + do_test (16 * i, 256, 512, 0, MIDDLE_CHAR); > + do_test (16 * i, 256, 512, 0, BIG_CHAR); > + } > + > for (i = 0; i < 32; ++i) > { > do_test (0, i, i + 1, 0, MIDDLE_CHAR); > diff --git a/string/test-strchr.c b/string/test-strchr.c > index 5b6022746c..2cf4ea2add 100644 > --- a/string/test-strchr.c > +++ b/string/test-strchr.c > @@ -130,7 +130,7 @@ do_test (size_t align, size_t pos, size_t len, int seek_char, int max_char) > size_t i; > CHAR *result; > CHAR *buf = (CHAR *) buf1; > - align &= 15; > + align &= 127; > if ((align + len) * sizeof (CHAR) >= page_size) > return; > > @@ -259,12 +259,24 @@ test_main (void) > do_test (i, 16 << i, 2048, SMALL_CHAR, MIDDLE_CHAR); > } > > + for (i = 1; i < 8; ++i) > + { > + do_test (0, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > + do_test (i, 16 << i, 4096, SMALL_CHAR, MIDDLE_CHAR); > + } > + > for (i = 1; i < 8; ++i) > { > do_test (i, 64, 256, SMALL_CHAR, MIDDLE_CHAR); > do_test (i, 64, 256, SMALL_CHAR, BIG_CHAR); > } > > + for (i = 0; i < 8; ++i) > + { > + do_test (16 * i, 256, 512, SMALL_CHAR, MIDDLE_CHAR); > + do_test (16 * i, 256, 512, SMALL_CHAR, BIG_CHAR); > + } > + > for (i = 0; i < 32; ++i) > { > do_test (0, i, i + 1, SMALL_CHAR, MIDDLE_CHAR); > @@ -277,12 +289,24 @@ test_main (void) > do_test (i, 16 << i, 2048, 0, MIDDLE_CHAR); > } > > + for (i = 1; i < 8; ++i) > + { > + do_test (0, 16 << i, 4096, 0, MIDDLE_CHAR); > + do_test (i, 16 << i, 4096, 0, MIDDLE_CHAR); > + } > + > for (i = 1; i < 8; ++i) > { > do_test (i, 64, 256, 0, MIDDLE_CHAR); > do_test (i, 64, 256, 0, BIG_CHAR); > } > > + for (i = 0; i < 8; ++i) > + { > + do_test (16 * i, 256, 512, 0, MIDDLE_CHAR); > + do_test (16 * i, 256, 512, 0, BIG_CHAR); > + } > + > for (i = 0; i < 32; ++i) > { > do_test (0, i, i + 1, 0, MIDDLE_CHAR); > -- > 2.29.2 > LGTM. Thanks. -- H.J.