diff options
| author | Nicolas Boichat <drinkcat@google.com> | 2017-03-03 10:12:07 -0800 |
|---|---|---|
| committer | chrome-bot <chrome-bot@chromium.org> | 2018-05-28 22:46:28 -0700 |
| commit | 49ff62bf0be5cfc88e092f987d77c18a0b21390a (patch) | |
| tree | 4f7fc10f29d02422bcdba81d9964de1bf6d91eb8 /test | |
| parent | 6e364d59c1ae658876b8a0e58a38edd81233655d (diff) | |
| download | chrome-ec-49ff62bf0be5cfc88e092f987d77c18a0b21390a.tar.gz | |
rsa: Optimization of multiplications for Cortex-M0
We multiply 2 32-bit numbers (and not 64-bit numbers), and then add
another 32-bit number, which makes it possible to optimize the
assembly and save a few instructions.
With -O3, 3072-bit exponent, lower verification time from 122 ms to
104 ms on STM32F072 @48Mhz.
Optimized mac function from Dmitry Grinberg <dmitrygr@google.com>.
BRANCH=poppy
BUG=b:35647963
BUG=b:77608104
TEST=On staff, flash, verification successful
TEST=make test-rsa, make test-rsa3
TEST=Flash test-utils and test-rsa to hammer => pass
Change-Id: I584c54c631a3f59f691849a279b308e8d4b4b22d
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/449024
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Diffstat (limited to 'test')
| -rw-r--r-- | test/utils.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/test/utils.c b/test/utils.c index b3ed2fc9dc..7acf238c14 100644 --- a/test/utils.c +++ b/test/utils.c @@ -12,6 +12,7 @@ #include "test_util.h" #include "timer.h" #include "util.h" +#include "watchdog.h" static int test_memmove(void) { @@ -356,6 +357,31 @@ static int test_cond_t(void) return EC_SUCCESS; } +static int test_mula32(void) +{ + uint64_t r = 0x0; + uint32_t b = 0x1; + uint32_t c = 0x1; + uint32_t i; + timestamp_t t0, t1; + + t0 = get_time(); + for (i = 0; i < 5000000; i++) { + r = mula32(b, c, r + (r >> 32)); + b = (b << 13) ^ (b >> 2) ^ i; + c = (c << 16) ^ (c >> 7) ^ i; + watchdog_reload(); + } + t1 = get_time(); + + ccprintf("After %d iterations, r=%08x%08x (time: %d)\n", i, + (uint32_t)(r >> 32), (uint32_t)r, t1.le.lo-t0.le.lo); + TEST_ASSERT(r == 0x9df59b9fb0ab9d96L); + + /* well okay then */ + return EC_SUCCESS; +} + void run_test(void) { test_reset(); @@ -371,6 +397,7 @@ void run_test(void) RUN_TEST(test_shared_mem); RUN_TEST(test_scratchpad); RUN_TEST(test_cond_t); + RUN_TEST(test_mula32); test_print_result(); } |