Message ID | 000001d0da84$c84110f0$58c332d0$@com |
---|---|
State | New |
Headers | show |
Sorry, I assumed someone else (Carlos?) was reviewing this and then forgot about it. I've put review comments inline. The major concern I have is that you're duplicating contents of math_private.h to compare it against the gcc builtins, which is fine as a first hack if you want to avoid changing actual code for the tests, but may not be a good idea in the long term. That is, there is a risk that the inlines may be modified but this test doesn't realize that. I don't mind this going in as a first revision (with other changes recommended below) provided you're willing to remedy this situation in the next iteration so that there is at least a failure in running the benchtest if the definitions of the inlines change in any way. Siddhesh On Wed, 2015-08-19 at 14:41 +0100, Wilco Dijkstra wrote: > 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 > + Unnecessary hunk. > 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..1251935 > --- /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 > + <http://www.gnu.org/licenses/>. */ > + > +#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 <stdlib.h> > +#include <math.h> > +#include <stdint.h> > + > +#define BOOLTEST(func) \ > +int __attribute__((noinline)) \ Make this function and others below static. > +func ## _f (double d, int i) \ > +{ \ > + if (func (d)) \ > + return (int)d + i; \ Space after (int). > + 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)) \ Avoid implicit boolean coercion. > + 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. */ If seems a bit ugly to duplicate code from sysdeps/ieee754/dbl -64/wordsize-64/math_private.h to test them. Can you look at another way to massage math_private.h so that you can do something as simple as include the file and rewrite the function names using macros? If it's too hard or you want to do it in a second pass then please enhance the comment to reflect that. > + > +extern __always_inline int static __always_inline for this and everything else below. > +__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 double > +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 double > +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) > + > +VALUETEST (remainder_test1) > +VALUETEST (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[] = static 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"); Use the TEST_NAME macro. > + > + /* 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. */ How do you know that this is the ratio of generated inputs? Please enhance the comment to describe that. > + > + 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 <inttypes.h> > #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.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 > + <http://www.gnu.org/licenses/>. */ > + > + > +#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);
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..1251935 --- /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 + <http://www.gnu.org/licenses/>. */ + +#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 <stdlib.h> +#include <math.h> +#include <stdint.h> + +#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 double +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 double +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) + +VALUETEST (remainder_test1) +VALUETEST (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 <inttypes.h> #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.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 + <http://www.gnu.org/licenses/>. */ + + +#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); -- 1.9.1 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 + <http://www.gnu.org/licenses/>. */ + + +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; +}