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bench-strncmp.c: Add workloads on page boundary

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Add strncmp workloads on page boundary.
This commit is contained in:
H.J. Lu 2020-06-11 08:52:42 -07:00
parent 659c041188
commit c4277ba234
1 changed files with 128 additions and 0 deletions
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128
benchtests/bench-strncmp.c
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@ -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 +192,129 @@ 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_one_test_page_boundary (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)
{
/* 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. */
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;
/* 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 = 30; 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_one_test_page_boundary (json_ctx, s1p, s2p, align1, align2,
len, s, exp_result);
}
}
static void
do_one_test_page (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;
/* Fill buf1 with 23. */
for (i = 0; i < (page_size / CHARBYTES) - 1; i++)
s1[i] = 23;
s1[i] = 0;
/* Make a copy of buf1. */
s2 = STRDUP (s1);
/* Test should terminate within the page boundary. */
for (i = 0; i < (108 / CHARBYTES); ++i)
do_one_test_page (json_ctx, ((page_size - 108) / CHARBYTES) + i,
((page_size - 1460) / CHARBYTES), s2);
free (s2);
}
int
test_main (void)
{
@ -267,6 +392,9 @@ 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);