Looks good to me, thanks.
On Fri, Jul 12, 2013 at 2:54 PM, Ben Pfaff <b...@nicira.com> wrote:
> Signed-off-by: Ben Pfaff <b...@nicira.com>
> ---
> lib/util.h | 19 +++++++++++++++
> tests/library.at | 2 +
> tests/test-util.c | 65
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 86 insertions(+), 0 deletions(-)
>
> diff --git a/lib/util.h b/lib/util.h
> index ae8bfd7..2159594 100644
> --- a/lib/util.h
> +++ b/lib/util.h
> @@ -108,6 +108,25 @@ is_pow2(uintmax_t x)
> return IS_POW2(x);
> }
>
> +/* Returns X rounded up to a power of 2. X must be a constant
> expression. */
> +#define ROUND_UP_POW2(X) RUP2__(X)
> +#define RUP2__(X) (RUP2_1(X) + 1)
> +#define RUP2_1(X) (RUP2_2(X) | (RUP2_2(X) >> 16))
> +#define RUP2_2(X) (RUP2_3(X) | (RUP2_3(X) >> 8))
> +#define RUP2_3(X) (RUP2_4(X) | (RUP2_4(X) >> 4))
> +#define RUP2_4(X) (RUP2_5(X) | (RUP2_5(X) >> 2))
> +#define RUP2_5(X) (RUP2_6(X) | (RUP2_6(X) >> 1))
> +#define RUP2_6(X) ((X) - 1)
> +
> +/* Returns X rounded down to a power of 2. X must be a constant
> expression. */
> +#define ROUND_DOWN_POW2(X) RDP2__(X)
> +#define RDP2__(X) (RDP2_1(X) - (RDP2_1(X) >> 1))
> +#define RDP2_1(X) (RDP2_2(X) | (RDP2_2(X) >> 16))
> +#define RDP2_2(X) (RDP2_3(X) | (RDP2_3(X) >> 8))
> +#define RDP2_3(X) (RDP2_4(X) | (RDP2_4(X) >> 4))
> +#define RDP2_4(X) (RDP2_5(X) | (RDP2_5(X) >> 2))
> +#define RDP2_5(X) ( (X) | ( (X) >> 1))
> +
> #ifndef MIN
> #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
> #endif
> diff --git a/tests/library.at b/tests/library.at
> index f84a55b..92ec49b 100644
> --- a/tests/library.at
> +++ b/tests/library.at
> @@ -112,6 +112,8 @@ AT_CLEANUP
> m4_foreach(
> [testname],
> [[ctz],
> + [round_up_pow2],
> + [round_down_pow2],
> [popcount],
> [log_2_floor],
> [bitwise_copy],
> diff --git a/tests/test-util.c b/tests/test-util.c
> index 5afe2f7..6bf8ed5 100644
> --- a/tests/test-util.c
> +++ b/tests/test-util.c
> @@ -90,6 +90,69 @@ test_ctz(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
> check_ctz(0, 32);
> }
>
> +/* Returns a random number in the range 'min'...'max' inclusive. */
> +static uint32_t
> +random_in_range(uint32_t min, uint32_t max)
> +{
> + return min == max ? min : min + random_range(max - min + 1);
> +}
> +
> +static void
> +check_rup2(uint32_t x, int n)
> +{
> + uint32_t rup2 = ROUND_UP_POW2(x);
> + if (rup2 != n) {
> + fprintf(stderr, "ROUND_UP_POW2(%#"PRIx32") is %#"PRIx32" "
> + "but should be %#"PRIx32"\n", x, rup2, n);
> + abort();
> + }
> +}
> +
> +static void
> +test_round_up_pow2(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
> +{
> + int n;
> +
> + for (n = 0; n < 32; n++) {
> + /* Min, max value for which ROUND_UP_POW2 should yield (1 << n).
> */
> + uint32_t min = ((1u << n) >> 1) + 1;
> + uint32_t max = 1u << n;
> +
> + check_rup2(min, 1u << n);
> + check_rup2(max, 1u << n);
> + check_rup2(random_in_range(min, max), 1u << n);
> + }
> + check_rup2(0, 0);
> +}
> +
> +static void
> +check_rdp2(uint32_t x, int n)
> +{
> + uint32_t rdp2 = ROUND_DOWN_POW2(x);
> + if (rdp2 != n) {
> + fprintf(stderr, "ROUND_DOWN_POW2(%#"PRIx32") is %#"PRIx32" "
> + "but should be %#"PRIx32"\n", x, rdp2, n);
> + abort();
> + }
> +}
> +
> +static void
> +test_round_down_pow2(int argc OVS_UNUSED, char *argv[] OVS_UNUSED)
> +{
> + int n;
> +
> + for (n = 0; n < 32; n++) {
> + /* Min, max value for which ROUND_DOWN_POW2 should yield (1 <<
> n). */
> + uint32_t min = 1u << n;
> + uint32_t max = ((1u << n) << 1) - 1;
> +
> + check_rdp2(min, 1u << n);
> + check_rdp2(max, 1u << n);
> + check_rdp2(random_in_range(min, max), 1u << n);
> + }
> + check_rdp2(0, 0);
> +}
> +
> static void
> shuffle(unsigned int *p, size_t n)
> {
> @@ -346,6 +409,8 @@ test_assert(int argc OVS_UNUSED, char *argv[]
> OVS_UNUSED)
>
> static const struct command commands[] = {
> {"ctz", 0, 0, test_ctz},
> + {"round_up_pow2", 0, 0, test_round_up_pow2},
> + {"round_down_pow2", 0, 0, test_round_down_pow2},
> {"popcount", 0, 0, test_popcount},
> {"log_2_floor", 0, 0, test_log_2_floor},
> {"bitwise_copy", 0, 0, test_bitwise_copy},
> --
> 1.7.2.5
>
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> http://openvswitch.org/mailman/listinfo/dev
>
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