Awesome, thanks!
Ethan
On Tue, Aug 7, 2012 at 2:06 PM, Ben Pfaff <b...@nicira.com> wrote:
> On Tue, Jul 31, 2012 at 10:40:13AM -0700, Ethan Jackson wrote:
>> Oh one more thing:
>>
>> This seems like the kind of thing that's both easy to get wrong, and
>> easy to unit test. Does it make sense to add one?
>
> Yes, I folded this in, thanks:
>
> diff --git a/tests/library.at b/tests/library.at
> index 70660a2..0765c3f 100644
> --- a/tests/library.at
> +++ b/tests/library.at
> @@ -103,12 +103,14 @@ AT_CLEANUP
> m4_foreach(
> [testname],
> [[ctz],
> + [popcount],
> [log_2_floor],
> [bitwise_copy],
> [bitwise_zero],
> [bitwise_one],
> [bitwise_is_all_zeros]],
> [AT_SETUP([testname[()] function])
> + AT_KEYWORDS([testname])
> AT_CHECK([test-util testname], [0], [], [])
> AT_CLEANUP])
>
> diff --git a/tests/test-util.c b/tests/test-util.c
> index 71a7f21..b98fc79 100644
> --- a/tests/test-util.c
> +++ b/tests/test-util.c
> @@ -26,6 +26,9 @@
> #include "random.h"
> #include "util.h"
>
> +#undef NDEBUG
> +#include <assert.h>
> +
> static void
> check_log_2_floor(uint32_t x, int n)
> {
> @@ -85,6 +88,59 @@ test_ctz(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
> check_ctz(0, 32);
> }
>
> +static void
> +shuffle(unsigned int *p, size_t n)
> +{
> + for (; n > 1; n--, p++) {
> + unsigned int *q = &p[rand() % n];
> + unsigned int tmp = *p;
> + *p = *q;
> + *q = tmp;
> + }
> +}
> +
> +static void
> +check_popcount(uint32_t x, int n)
> +{
> + if (popcount(x) != n) {
> + fprintf(stderr, "popcount(%#"PRIx32") is %d but should be %d\n",
> + x, popcount(x), n);
> + abort();
> + }
> +}
> +
> +static void
> +test_popcount(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
> +{
> + unsigned int bits[32];
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(bits); i++) {
> + bits[i] = 1u << i;
> + }
> +
> + check_popcount(0, 0);
> +
> + for (i = 0; i < 1000; i++) {
> + uint32_t x = 0;
> + int j;
> +
> + shuffle(bits, ARRAY_SIZE(bits));
> + for (j = 0; j < 32; j++) {
> + x |= bits[j];
> + check_popcount(x, j + 1);
> + }
> + assert(x == UINT32_MAX);
> +
> + shuffle(bits, ARRAY_SIZE(bits));
> + for (j = 31; j >= 0; j--) {
> + x &= ~bits[j];
> + check_popcount(x, j);
> + }
> + assert(x == 0);
> + }
> +}
> +
> /* Returns the sum of the squares of the first 'n' positive integers. */
> static unsigned int
> sum_of_squares(int n)
> @@ -282,6 +338,7 @@ test_follow_symlinks(int argc, char *argv[])
>
> static const struct command commands[] = {
> {"ctz", 0, 0, test_ctz},
> + {"popcount", 0, 0, test_popcount},
> {"log_2_floor", 0, 0, test_log_2_floor},
> {"bitwise_copy", 0, 0, test_bitwise_copy},
> {"bitwise_zero", 0, 0, test_bitwise_zero},
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