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author | Daisuke Nojiri <dnojiri@chromium.org> | 2014-02-28 16:03:04 -0800 |
---|---|---|
committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-03-01 20:15:59 +0000 |
commit | e381585619778c4952ada5f3118ec4fcf304eb66 (patch) | |
tree | 412fadab6f9d52a25fe328bc5f6e34cddbf88d04 /test/utils.c | |
parent | a35bfd69e9a749fbaa152937dd91a6ed407a9005 (diff) | |
download | chrome-ec-e381585619778c4952ada5f3118ec4fcf304eb66.tar.gz |
Optimize memset
This speeds up memset by copying a word at a time.
Ran the unit test on Peppy:
> runtest
...
Running test_memset... (speed gain: 141532 -> 32136 us) OK
...
Ran make buildall:
...
Running test_memset... (speed gain: 1338 -> 280 us) OK
...
TEST=Described above.
BUG=chrome-os-partner:23720
BRANCH=none
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Change-Id: If34b06ad70f448d950535a4bea4f6556627a9b6f
Tested-by: Daisuke Nojiri <dnojiri@google.com>
Reviewed-on: https://chromium-review.googlesource.com/185936
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Daisuke Nojiri <dnojiri@google.com>
Diffstat (limited to 'test/utils.c')
-rw-r--r-- | test/utils.c | 59 |
1 files changed, 55 insertions, 4 deletions
diff --git a/test/utils.c b/test/utils.c index 9e1138074f..5d4a88d0fe 100644 --- a/test/utils.c +++ b/test/utils.c @@ -161,6 +161,58 @@ static int test_memcpy(void) return EC_SUCCESS; } +/* Plain memset, used as a reference to measure speed gain */ +static void *dumb_memset(void *dest, int c, int len) +{ + char *d = (char *)dest; + while (len > 0) { + *(d++) = c; + len--; + } + return dest; +} + +static int test_memset(void) +{ + int i; + timestamp_t t0, t1, t2, t3; + char *buf; + const int buf_size = 1000; + const int len = 400; + const int iteration = 1000; + + TEST_ASSERT(shared_mem_acquire(buf_size, &buf) == EC_SUCCESS); + + t0 = get_time(); + for (i = 0; i < iteration; ++i) + dumb_memset(buf, 1, len); + t1 = get_time(); + TEST_ASSERT_MEMSET(buf, (char)1, len); + ccprintf(" (speed gain: %d ->", t1.val-t0.val); + + t2 = get_time(); + for (i = 0; i < iteration; ++i) + memset(buf, 1, len); + t3 = get_time(); + TEST_ASSERT_MEMSET(buf, (char)1, len); + ccprintf(" %d us) ", t3.val-t2.val); + + /* Expected about 4x speed gain. Use 3x because it fluctuates */ + TEST_ASSERT((t1.val-t0.val) > (t3.val-t2.val) * 3); + + memset(buf, 128, len); + TEST_ASSERT_MEMSET(buf, (char)128, len); + + memset(buf, -2, len); + TEST_ASSERT_MEMSET(buf, (char)-2, len); + + memset(buf + 1, 1, len - 2); + TEST_ASSERT_MEMSET(buf + 1, (char)1, len - 2); + + shared_mem_release(buf); + return EC_SUCCESS; +} + static int test_strzcpy(void) { char dest[10]; @@ -248,7 +300,7 @@ static int test_get_next_bit(void) static int test_shared_mem(void) { - int i, j; + int i; int sz = shared_mem_size(); char *mem; @@ -257,9 +309,7 @@ static int test_shared_mem(void) for (i = 0; i < 256; ++i) { memset(mem, i, sz); - for (j = 0; j < sz; ++j) - TEST_ASSERT(mem[j] == (char)i); - + TEST_ASSERT_MEMSET(mem, (char)i, sz); if ((i & 0xf) == 0) msleep(20); /* Yield to other tasks */ } @@ -384,6 +434,7 @@ void run_test(void) RUN_TEST(test_parse_bool); RUN_TEST(test_memmove); RUN_TEST(test_memcpy); + RUN_TEST(test_memset); RUN_TEST(test_strzcpy); RUN_TEST(test_strlen); RUN_TEST(test_strcasecmp); |