From patchwork Thu Jul 23 12:54:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wilco X-Patchwork-Id: 499375 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id C588114099F for ; Thu, 23 Jul 2015 22:54:48 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b=FKef1jMK; dkim-atps=neutral DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:mime-version :content-type; q=dns; s=default; b=IB10n7hpnlTBM/t108jP7luFPYbSy XRk0NYg3LjK8TDtI7oKEkjHiviVei+nlpElCaV9aMVg8YO0TO2+9POqTs8DVhtLg XwCxzynZL6mAp2uK9FvPHEgQ7QEy+FQ/Z5QWde+P4qKEXB5LHWyv8+HUKdpecMAY IuTzz4FJgKLmdQ= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:mime-version :content-type; s=default; bh=kZmoTuk0l/dk+3zWCgBdGcZBIOA=; b=FKe f1jMK2XR/eP4dftZaWKZDD8Vuk18Z5x4mc6mPGgRIleXq81ie1vyFaemI39MDuDc N+cLeW4JbQ1RGNYpeEqvO+W62Q0b/8OLJDA8XuduFYU7TVo83szIbQePLq0SaXcV ThxRFdzUuYrJmwWon1Hkmt+VXp+bGEqNi5fq+KRA= Received: (qmail 106959 invoked by alias); 23 Jul 2015 12:54:42 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 106936 invoked by uid 89); 23 Jul 2015 12:54:40 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL, BAYES_00, SPF_PASS autolearn=ham version=3.3.2 X-HELO: eu-smtp-delivery-143.mimecast.com From: "Wilco Dijkstra" To: "'GNU C Library'" Subject: [PATCH v3] Add math-inline benchmark Date: Thu, 23 Jul 2015 13:54:27 +0100 Message-ID: <003601d0c546$b559d3d0$200d7b70$@com> MIME-Version: 1.0 X-MC-Unique: 8AHIgDfRQeaWZ1mpV-ciaA-1 Add a benchmark for isinf/isnan/isnormal/isfinite/fpclassify. The test uses 2 arrays with 1024 doubles, one with 99% finite FP numbers (10% zeroes, 10% negative) and 1% inf/NaN, the other with 50% inf, and 50% Nan. This version removes various tests that caused confusion and only leaves the existing GLIBC definitions and inlines for comparison with the GCC builtins. I changed the tests to not inline inside the loop and use a branch on the boolean result. The 64-bit immediates used by the GLIBC inlines seem very expensive on some microarchitectures, so this shows even more clearly that using the built-ins results in a significant performance gain (see x64 results below). ChangeLog: 2015-07-23 Wilco Dijkstra * benchtests/Makefile: Add bench-math-inlines, link with libm. * benchtests/bench-math-inlines.c: New benchmark. * benchtests/bench-util.h: New file. * benchtests/bench-util.c: New file. * benchtests/bench-skeleton.c: Add include of bench-util.c/h. "__isnan_t": { "normal": { "duration": 5.32475e+06, "iterations": 500, "mean": 10649 } }, "__isnan_inl_t": { "normal": { "duration": 2.74296e+06, "iterations": 500, "mean": 5485 } }, "__isnan_builtin_t": { "normal": { "duration": 2.35589e+06, "iterations": 500, "mean": 4711 } }, "isnan_t": { "normal": { "duration": 2.25889e+06, "iterations": 500, "mean": 4517 } }, "__isinf_t": { "normal": { "duration": 5.7671e+06, "iterations": 500, "mean": 11534 } }, "__isinf_ns_t": { "normal": { "duration": 2.70963e+06, "iterations": 500, "mean": 5419 } }, "__isinf_ns_builtin_t": { "normal": { "duration": 2.70841e+06, "iterations": 500, "mean": 5416 } }, "__isinf_builtin_t": { "normal": { "duration": 2.26255e+06, "iterations": 500, "mean": 4525 } }, "isinf_t": { "normal": { "duration": 2.26428e+06, "iterations": 500, "mean": 4528 } }, "__finite_t": { "normal": { "duration": 5.82567e+06, "iterations": 500, "mean": 11651 } }, "__finite_inl_t": { "normal": { "duration": 3.2019e+06, "iterations": 500, "mean": 6403 } }, "__isfinite_builtin_t": { "normal": { "duration": 3.17892e+06, "iterations": 500, "mean": 6357 } }, "isfinite_t": { "normal": { "duration": 2.75324e+06, "iterations": 500, "mean": 5506 } }, "__isnormal_inl_t": { "normal": { "duration": 8.65908e+06, "iterations": 500, "mean": 17318 } }, "__isnormal_builtin_t": { "normal": { "duration": 3.68589e+06, "iterations": 500, "mean": 7371 } }, "isnormal_t": { "normal": { "duration": 3.76085e+06, "iterations": 500, "mean": 7521 } }, "__fpclassify_t": { "normal": { "duration": 6.63574e+06, "iterations": 500, "mean": 13271 } }, "__fpclassify_builtin_t": { "normal": { "duration": 4.48757e+06, "iterations": 500, "mean": 8975 } }, "fpclassify_t": { "normal": { "duration": 4.48033e+06, "iterations": 500, "mean": 8960 } }, "remainder_test1_t": { "normal": { "duration": 2.10051e+07, "iterations": 500, "mean": 42010 } }, "remainder_test2_t": { "normal": { "duration": 1.9933e+07, "iterations": 500, "mean": 39865 } } } --- benchtests/Makefile | 7 +- benchtests/bench-math-inlines.c | 284 ++++++++++++++++++++++++++++++++++++++++ benchtests/bench-skeleton.c | 18 +-- benchtests/bench-util.c | 34 +++++ benchtests/bench-util.h | 28 ++++ 5 files changed, 355 insertions(+), 16 deletions(-) create mode 100644 benchtests/bench-math-inlines.c create mode 100644 benchtests/bench-util.c create mode 100644 benchtests/bench-util.h diff --git a/benchtests/Makefile b/benchtests/Makefile index 8e615e5..91970f8 100644 --- a/benchtests/Makefile +++ b/benchtests/Makefile @@ -36,6 +36,7 @@ string-bench := bcopy bzero memccpy memchr memcmp memcpy memmem memmove \ strncasecmp strncat strncmp strncpy strnlen strpbrk strrchr \ strspn strstr strcpy_chk stpcpy_chk memrchr strsep strtok \ strcoll + string-bench-all := $(string-bench) # We have to generate locales @@ -50,7 +51,10 @@ stdlib-bench := strtod stdio-common-bench := sprintf -benchset := $(string-bench-all) $(stdlib-bench) $(stdio-common-bench) +math-benchset := math-inlines + +benchset := $(string-bench-all) $(stdlib-bench) $(stdio-common-bench) \ + $(math-benchset) CFLAGS-bench-ffs.c += -fno-builtin CFLAGS-bench-ffsll.c += -fno-builtin @@ -58,6 +62,7 @@ CFLAGS-bench-ffsll.c += -fno-builtin bench-malloc := malloc-thread $(addprefix $(objpfx)bench-,$(bench-math)): $(libm) +$(addprefix $(objpfx)bench-,$(math-benchset)): $(libm) $(addprefix $(objpfx)bench-,$(bench-pthread)): $(shared-thread-library) $(objpfx)bench-malloc-thread: $(shared-thread-library) diff --git a/benchtests/bench-math-inlines.c b/benchtests/bench-math-inlines.c new file mode 100644 index 0000000..cc4f008 --- /dev/null +++ b/benchtests/bench-math-inlines.c @@ -0,0 +1,284 @@ +/* Measure math inline functions. + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#define SIZE 1024 +#define TEST_MAIN +#define TEST_NAME "math-inlines" +#define TEST_FUNCTION test_main () +#include "bench-timing.h" +#include "json-lib.h" +#include "bench-util.h" + +#include +#include +#include + +#define BOOLTEST(func) \ +int __attribute__((noinline)) \ +func ## _f (double d, int i) \ +{ \ + if (func (d)) \ + return (int)d + i; \ + else \ + return 5; \ +} \ +int \ +func ## _t (volatile double *p, size_t n, size_t iters) \ +{ \ + int i, j; \ + int res = 0; \ + for (j = 0; j < iters; j++) \ + for (i = 0; i < n; i++) \ + if (func ## _f (p[i] * 2.0, i)) \ + res += 5; \ + return res; \ +} + +#define VALUETEST(func) \ +int __attribute__((noinline)) \ +func ## _f (double d) \ +{ \ + return func (d); \ +} \ +int \ +func ## _t (volatile double *p, size_t n, size_t iters) \ +{ \ + int i, j; \ + int res = 0; \ + for (j = 0; j < iters; j++) \ + for (i = 0; i < n; i++) \ + res += func ## _f (p[i] * 2.0); \ + return res; \ +} + +typedef union +{ + double value; + uint64_t word; +} ieee_double_shape_type; + +#define EXTRACT_WORDS64(i,d) \ +do { \ + ieee_double_shape_type gh_u; \ + gh_u.value = (d); \ + (i) = gh_u.word; \ +} while (0) + +/* Inlines similar to existing math_private.h versions. */ + +extern __always_inline int +__isnan_inl (double d) +{ + uint64_t di; + EXTRACT_WORDS64 (di, d); + return (di & 0x7fffffffffffffffull) > 0x7ff0000000000000ull; +} + +extern __always_inline int +__isinf_ns (double d) +{ + uint64_t di; + EXTRACT_WORDS64 (di, d); + return (di & 0x7fffffffffffffffull) == 0x7ff0000000000000ull; +} +extern __always_inline int +__finite_inl (double d) +{ + uint64_t di; + EXTRACT_WORDS64 (di, d); + return (di & 0x7fffffffffffffffull) < 0x7ff0000000000000ull; +} + +#define __isnormal_inl(X) (__fpclassify (X) == FP_NORMAL) + +/* Inlines for the builtin functions. */ + +#define __isnan_builtin(X) __builtin_isnan (X) +#define __isinf_ns_builtin(X) __builtin_isinf (X) +#define __isinf_builtin(X) __builtin_isinf_sign (X) +#define __isfinite_builtin(X) __builtin_isfinite (X) +#define __isnormal_builtin(X) __builtin_isnormal (X) +#define __fpclassify_builtin(X) __builtin_fpclassify (FP_NAN, FP_INFINITE, \ + FP_NORMAL, FP_SUBNORMAL, FP_ZERO, (X)) + +double __attribute ((noinline)) +kernel_standard (double x, double y, int z) +{ + return x * y + z; +} + +volatile double rem1 = 2.5; + +extern __always_inline int +remainder_test1 (double x) +{ + double y = rem1; + if (((__builtin_expect (y == 0.0, 0) && !__isnan_inl (x)) + || (__builtin_expect (__isinf_ns (x), 0) && !__isnan_inl (y)))) + return kernel_standard (x, y, 10); + + return remainder (x, y); +} + +extern __always_inline int +remainder_test2 (double x) +{ + double y = rem1; + if (((__builtin_expect (y == 0.0, 0) && !__builtin_isnan (x)) + || (__builtin_expect (__builtin_isinf (x), 0) && !__builtin_isnan (y)))) + return kernel_standard (x, y, 10); + + return remainder (x, y); +} + +/* Create test functions for each possibility. */ + +BOOLTEST (__isnan) +BOOLTEST (__isnan_inl) +BOOLTEST (__isnan_builtin) +BOOLTEST (isnan) + +BOOLTEST (__isinf) +BOOLTEST (__isinf_builtin) +BOOLTEST (__isinf_ns) +BOOLTEST (__isinf_ns_builtin) +BOOLTEST (isinf) + +BOOLTEST (__finite) +BOOLTEST (__finite_inl) +BOOLTEST (__isfinite_builtin) +BOOLTEST (isfinite) + +BOOLTEST (__isnormal_inl) +BOOLTEST (__isnormal_builtin) +BOOLTEST (isnormal) + +VALUETEST (__fpclassify) +VALUETEST (__fpclassify_builtin) +VALUETEST (fpclassify) + +BOOLTEST (remainder_test1) +BOOLTEST (remainder_test2) + +typedef int (*proto_t) (volatile double *p, size_t n, size_t iters); + +typedef struct +{ + const char *name; + proto_t fn; +} impl_t; + +#define IMPL(name) { #name, name ## _t } + +impl_t test_list[] = +{ + IMPL (__isnan), + IMPL (__isnan_inl), + IMPL (__isnan_builtin), + IMPL (isnan), + + IMPL (__isinf), + IMPL (__isinf_ns), + IMPL (__isinf_ns_builtin), + IMPL (__isinf_builtin), + IMPL (isinf), + + IMPL (__finite), + IMPL (__finite_inl), + IMPL (__isfinite_builtin), + IMPL (isfinite), + + IMPL (__isnormal_inl), + IMPL (__isnormal_builtin), + IMPL (isnormal), + + IMPL (__fpclassify), + IMPL (__fpclassify_builtin), + IMPL (fpclassify), + + IMPL (remainder_test1), + IMPL (remainder_test2) +}; + +static void +do_one_test (json_ctx_t *json_ctx, proto_t test_fn, volatile double *arr, + size_t len, const char *testname) +{ + size_t iters = 500; + timing_t start, stop, cur; + + json_attr_object_begin (json_ctx, testname); + + TIMING_NOW (start); + test_fn (arr, len, iters); + TIMING_NOW (stop); + TIMING_DIFF (cur, start, stop); + + json_attr_double (json_ctx, "duration", cur); + json_attr_double (json_ctx, "iterations", iters); + json_attr_double (json_ctx, "mean", cur / iters); + json_attr_object_end (json_ctx); +} + +static volatile double arr1[SIZE]; +static volatile double arr2[SIZE]; + +int +test_main (void) +{ + json_ctx_t json_ctx; + size_t i; + + bench_start (); + + json_init (&json_ctx, 2, stdout); + json_attr_object_begin (&json_ctx, "math-inlines"); + + /* Create 2 test arrays, one with 10% zeroes, 10% negative values, + 79% positive values and 1% infinity/NaN. The other contains + 50% inf, 50% NaN. */ + + for (i = 0; i < SIZE; i++) + { + int x = rand () & 255; + arr1[i] = (x < 25) ? 0.0 : ((x < 50) ? -1 : 100); + if (x == 255) arr1[i] = __builtin_inf (); + if (x == 254) arr1[i] = __builtin_nan ("0"); + arr2[i] = (x < 128) ? __builtin_inf () : __builtin_nan ("0"); + } + + for (i = 0; i < sizeof (test_list) / sizeof (test_list[0]); i++) + { + json_attr_object_begin (&json_ctx, test_list[i].name); + do_one_test (&json_ctx, test_list[i].fn, arr2, SIZE, "inf/nan"); + json_attr_object_end (&json_ctx); + } + + for (i = 0; i < sizeof (test_list) / sizeof (test_list[0]); i++) + { + json_attr_object_begin (&json_ctx, test_list[i].name); + do_one_test (&json_ctx, test_list[i].fn, arr1, SIZE, "normal"); + json_attr_object_end (&json_ctx); + } + + json_attr_object_end (&json_ctx); + return 0; +} + +#include "bench-util.c" +#include "../test-skeleton.c" diff --git a/benchtests/bench-skeleton.c b/benchtests/bench-skeleton.c index e357f0c..bc820df 100644 --- a/benchtests/bench-skeleton.c +++ b/benchtests/bench-skeleton.c @@ -24,21 +24,9 @@ #include #include "bench-timing.h" #include "json-lib.h" +#include "bench-util.h" -volatile unsigned int dontoptimize = 0; - -void -startup (void) -{ - /* This loop should cause CPU to switch to maximal freqency. - This makes subsequent measurement more accurate. We need a side effect - to prevent the loop being deleted by compiler. - This should be enough to cause CPU to speed up and it is simpler than - running loop for constant time. This is used when user does not have root - access to set a constant freqency. */ - for (int k = 0; k < 10000000; k++) - dontoptimize += 23 * dontoptimize + 2; -} +#include "bench-util.c" #define TIMESPEC_AFTER(a, b) \ (((a).tv_sec == (b).tv_sec) ? \ @@ -56,7 +44,7 @@ main (int argc, char **argv) if (argc == 2 && !strcmp (argv[1], "-d")) detailed = true; - startup(); + bench_start (); memset (&runtime, 0, sizeof (runtime)); diff --git a/benchtests/bench-util.c b/benchtests/bench-util.c new file mode 100644 index 0000000..c4149ae --- /dev/null +++ b/benchtests/bench-util.c @@ -0,0 +1,34 @@ +/* Benchmark utility functions. + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + + +static volatile unsigned int dontoptimize = 0; + +void +bench_start (void) +{ + /* This loop should cause CPU to switch to maximal freqency. + This makes subsequent measurement more accurate. We need a side effect + to prevent the loop being deleted by compiler. + This should be enough to cause CPU to speed up and it is simpler than + running loop for constant time. This is used when user does not have root + access to set a constant freqency. */ + + for (int k = 0; k < START_ITER; k++) + dontoptimize += 23 * dontoptimize + 2; +} diff --git a/benchtests/bench-util.h b/benchtests/bench-util.h new file mode 100644 index 0000000..930cecc --- /dev/null +++ b/benchtests/bench-util.h @@ -0,0 +1,28 @@ +/* Benchmark utility functions. + Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + + +#ifndef START_ITER +# define START_ITER (100000000) +#endif + +/* bench_start reduces the random variations due to frequency scaling by + executing a small loop with many memory accesses. START_ITER controls + the number of iterations. */ + +void bench_start (void);