Message ID | 20200612201056.228614-3-hjl.tools@gmail.com |
---|---|
State | Superseded |
Headers | show |
Series | [1/4] strncmp: Add a testcase for page boundary [BZ #25933] | expand |
On 6/12/20 4:10 PM, H.J. Lu via Libc-alpha wrote: > Add strncmp workloads on page boundary. This benchmark need some work. Please post v2. > --- > benchtests/bench-strncmp.c | 117 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 117 insertions(+) > > diff --git a/benchtests/bench-strncmp.c b/benchtests/bench-strncmp.c > index 95a59c9465..065c7e7789 100644 > --- a/benchtests/bench-strncmp.c > +++ b/benchtests/bench-strncmp.c > @@ -27,6 +27,7 @@ > > #ifdef WIDE > # define L(str) L##str > +# define STRDUP wcsdup OK. > # define SIMPLE_STRNCMP simple_wcsncmp > > /* Wcsncmp uses signed semantics for comparison, not unsigned. > @@ -48,6 +49,7 @@ simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n) > > #else > # define L(str) str > +# define STRDUP strdup OK. > # define SIMPLE_STRNCMP simple_strncmp > > /* Strncmp uses unsigned semantics for comparison. */ > @@ -190,6 +192,118 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t > json_element_object_end (json_ctx); > } > > +static void > +do_test_page_boundary_1 (json_ctx_t *json_ctx, CHAR *s1, CHAR *s2, Rename to "do_one_test_page_boundary" > + size_t align1, size_t align2, size_t len, > + size_t n, int exp_result) > +{ > + json_element_object_begin (json_ctx); > + json_attr_uint (json_ctx, "strlen", (double) len); > + json_attr_uint (json_ctx, "len", (double) n); > + json_attr_uint (json_ctx, "align1", (double) align1); > + json_attr_uint (json_ctx, "align2", (double) align2); > + json_array_begin (json_ctx, "timings"); > + FOR_EACH_IMPL (impl, 0) > + do_one_test (json_ctx, impl, s1, s2, n, exp_result); > + json_array_end (json_ctx); > + json_element_object_end (json_ctx); OK. > +} > + Add a comment: /* To trigger bug 25933 we need a size that is equal to the vector length times 4. In the case of AVX2 for Intel we need 32 * 4. We make this test generic and run it for all architectures as additional boundary testing for such related algorithms. */ > +static void > +do_test_page_boundary (json_ctx_t *json_ctx) OK. > +{ > + size_t size = 32 * 4; > + size_t len; > + CHAR *s1 = (CHAR *) (buf1 + (BUF1PAGES - 1) * page_size); > + CHAR *s2 = (CHAR *) (buf2 + (BUF1PAGES - 1) * page_size); > + int exp_result; > + > + memset (s1, 'a', page_size); > + memset (s2, 'a', page_size); > + > + s1[(page_size / CHARBYTES) - 1] = (CHAR) 0; > + Add comment: /* Iterate over a size that is just below where we expect the bug to trigger up to the size we expect will trigger the bug e.g. [99-128]. Likewise iterate the start of two strings between 30 and 31 bytes away from the boundary to simulate alignment changes. */ > + for (size_t s = 99; s <= size; s++) > + for (size_t s1a = 31; s1a < 32; s1a++) Please make s1a iterate over [30,32) like s2a. > + for (size_t s2a = 30; s2a < 32; s2a++) > + { > + size_t align1 = (page_size / CHARBYTES - s) - s1a; > + size_t align2 = (page_size / CHARBYTES - s) - s2a; > + CHAR *s1p = s1 + align1; > + CHAR *s2p = s2 + align2; > + len = (page_size / CHARBYTES) - 1 - align1; > + exp_result = SIMPLE_STRNCMP (s1p, s2p, s); > + do_test_page_boundary_1 (json_ctx, s1p, s2p, align1, align2, > + len, s, exp_result); > + } > +} > + > +static void > +do_page_test (json_ctx_t *json_ctx, size_t offset1, size_t offset2, Rename to do_one_test_page() > + CHAR *s2) > +{ > + CHAR *s1; > + int exp_result; > + > + if (offset1 * CHARBYTES >= page_size > + || offset2 * CHARBYTES >= page_size) > + return; OK. Nothing bigger than a page size because we only have one page to work within. > + > + s1 = (CHAR *) buf1; > + s1 += offset1; > + s2 += offset2; > + > + size_t len = (page_size / CHARBYTES) - offset1; > + > + exp_result= *s1; > + > + json_element_object_begin (json_ctx); > + json_attr_uint (json_ctx, "strlen", (double) len); > + json_attr_uint (json_ctx, "len", (double) page_size); > + json_attr_uint (json_ctx, "align1", (double) offset1); > + json_attr_uint (json_ctx, "align2", (double) offset2); > + json_array_begin (json_ctx, "timings"); > + { > + FOR_EACH_IMPL (impl, 0) > + do_one_test (json_ctx, impl, s1, s2, page_size, -exp_result); > + } > + json_array_end (json_ctx); > + json_element_object_end (json_ctx); > + > + json_element_object_begin (json_ctx); > + json_attr_uint (json_ctx, "strlen", (double) len); > + json_attr_uint (json_ctx, "len", (double) page_size); > + json_attr_uint (json_ctx, "align1", (double) offset1); > + json_attr_uint (json_ctx, "align2", (double) offset2); > + json_array_begin (json_ctx, "timings"); > + { > + FOR_EACH_IMPL (impl, 0) > + do_one_test (json_ctx, impl, s1, s2, page_size, exp_result); > + } > + json_array_end (json_ctx); > + json_element_object_end (json_ctx); > +} OK. > + > +static void > +do_test_page (json_ctx_t *json_ctx) > +{ > + size_t i; > + CHAR *s1, *s2; > + > + s1 = (CHAR *) buf1; > + for (i = 0; i < (page_size / CHARBYTES) - 1; i++) > + s1[i] = 23; Add a comment for this magic fill number. > + s1[i] = 0; > + > + s2 = STRDUP (s1); > + > + for (i = 0; i < 64; ++i) Add a comment for these magic numbers. > + do_page_test (json_ctx, (3988 / CHARBYTES) + i, > + (2636 / CHARBYTES), s2); Call do_one_test_page() > + > + free (s2); > +} > + > int > test_main (void) > { > @@ -267,6 +381,9 @@ test_main (void) > do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, -1); > } > > + do_test_page_boundary (&json_ctx); > + do_test_page (&json_ctx); OK. > + > json_array_end (&json_ctx); > json_attr_object_end (&json_ctx); > json_attr_object_end (&json_ctx); >
diff --git a/benchtests/bench-strncmp.c b/benchtests/bench-strncmp.c index 95a59c9465..065c7e7789 100644 --- a/benchtests/bench-strncmp.c +++ b/benchtests/bench-strncmp.c @@ -27,6 +27,7 @@ #ifdef WIDE # define L(str) L##str +# define STRDUP wcsdup # define SIMPLE_STRNCMP simple_wcsncmp /* Wcsncmp uses signed semantics for comparison, not unsigned. @@ -48,6 +49,7 @@ simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n) #else # define L(str) str +# define STRDUP strdup # define SIMPLE_STRNCMP simple_strncmp /* Strncmp uses unsigned semantics for comparison. */ @@ -190,6 +192,118 @@ do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t json_element_object_end (json_ctx); } +static void +do_test_page_boundary_1 (json_ctx_t *json_ctx, CHAR *s1, CHAR *s2, + size_t align1, size_t align2, size_t len, + size_t n, int exp_result) +{ + json_element_object_begin (json_ctx); + json_attr_uint (json_ctx, "strlen", (double) len); + json_attr_uint (json_ctx, "len", (double) n); + json_attr_uint (json_ctx, "align1", (double) align1); + json_attr_uint (json_ctx, "align2", (double) align2); + json_array_begin (json_ctx, "timings"); + FOR_EACH_IMPL (impl, 0) + do_one_test (json_ctx, impl, s1, s2, n, exp_result); + json_array_end (json_ctx); + json_element_object_end (json_ctx); +} + +static void +do_test_page_boundary (json_ctx_t *json_ctx) +{ + size_t size = 32 * 4; + size_t len; + CHAR *s1 = (CHAR *) (buf1 + (BUF1PAGES - 1) * page_size); + CHAR *s2 = (CHAR *) (buf2 + (BUF1PAGES - 1) * page_size); + int exp_result; + + memset (s1, 'a', page_size); + memset (s2, 'a', page_size); + + s1[(page_size / CHARBYTES) - 1] = (CHAR) 0; + + for (size_t s = 99; s <= size; s++) + for (size_t s1a = 31; s1a < 32; s1a++) + for (size_t s2a = 30; s2a < 32; s2a++) + { + size_t align1 = (page_size / CHARBYTES - s) - s1a; + size_t align2 = (page_size / CHARBYTES - s) - s2a; + CHAR *s1p = s1 + align1; + CHAR *s2p = s2 + align2; + len = (page_size / CHARBYTES) - 1 - align1; + exp_result = SIMPLE_STRNCMP (s1p, s2p, s); + do_test_page_boundary_1 (json_ctx, s1p, s2p, align1, align2, + len, s, exp_result); + } +} + +static void +do_page_test (json_ctx_t *json_ctx, size_t offset1, size_t offset2, + CHAR *s2) +{ + CHAR *s1; + int exp_result; + + if (offset1 * CHARBYTES >= page_size + || offset2 * CHARBYTES >= page_size) + return; + + s1 = (CHAR *) buf1; + s1 += offset1; + s2 += offset2; + + size_t len = (page_size / CHARBYTES) - offset1; + + exp_result= *s1; + + json_element_object_begin (json_ctx); + json_attr_uint (json_ctx, "strlen", (double) len); + json_attr_uint (json_ctx, "len", (double) page_size); + json_attr_uint (json_ctx, "align1", (double) offset1); + json_attr_uint (json_ctx, "align2", (double) offset2); + json_array_begin (json_ctx, "timings"); + { + FOR_EACH_IMPL (impl, 0) + do_one_test (json_ctx, impl, s1, s2, page_size, -exp_result); + } + json_array_end (json_ctx); + json_element_object_end (json_ctx); + + json_element_object_begin (json_ctx); + json_attr_uint (json_ctx, "strlen", (double) len); + json_attr_uint (json_ctx, "len", (double) page_size); + json_attr_uint (json_ctx, "align1", (double) offset1); + json_attr_uint (json_ctx, "align2", (double) offset2); + json_array_begin (json_ctx, "timings"); + { + FOR_EACH_IMPL (impl, 0) + do_one_test (json_ctx, impl, s1, s2, page_size, exp_result); + } + json_array_end (json_ctx); + json_element_object_end (json_ctx); +} + +static void +do_test_page (json_ctx_t *json_ctx) +{ + size_t i; + CHAR *s1, *s2; + + s1 = (CHAR *) buf1; + for (i = 0; i < (page_size / CHARBYTES) - 1; i++) + s1[i] = 23; + s1[i] = 0; + + s2 = STRDUP (s1); + + for (i = 0; i < 64; ++i) + do_page_test (json_ctx, (3988 / CHARBYTES) + i, + (2636 / CHARBYTES), s2); + + free (s2); +} + int test_main (void) { @@ -267,6 +381,9 @@ test_main (void) do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, -1); } + do_test_page_boundary (&json_ctx); + do_test_page (&json_ctx); + json_array_end (&json_ctx); json_attr_object_end (&json_ctx); json_attr_object_end (&json_ctx);