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| author | Denys Vlasenko | 2017-04-13 10:51:13 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2017-04-13 10:51:13 +0200 |
| commit | c054822027a4a6895bc95979c6c10ff5763c7c7e (patch) | |
| tree | 20fb208d1e2bab309b76b007551b344e6ed34133 | |
| parent | 6c149f4d9afaed9edb75c88b784ad900c1f40700 (diff) | |
| download | busybox-c054822027a4a6895bc95979c6c10ff5763c7c7e.zip busybox-c054822027a4a6895bc95979c6c10ff5763c7c7e.tar.gz | |
factor: tweak comments
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | coreutils/factor.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/coreutils/factor.c b/coreutils/factor.c index 66d6a7c..7adc238 100644 --- a/coreutils/factor.c +++ b/coreutils/factor.c @@ -58,7 +58,7 @@ static NOINLINE void factorize(wide_t N) // unsigned count3; // unsigned count5; // unsigned count7; - // ^^^^^^^^^^^^^^^ commented-out simple siving code (easier to grasp). + // ^^^^^^^^^^^^^^^ commented-out simple sieving code (easier to grasp). // Faster sieving, using one word for potentially up to 6 counters: // count upwards in each mask, counter "triggers" when it sets its mask to "100[0]..." // 10987654321098765432109876543210 - bits 31-0 in 32-bit word @@ -94,6 +94,8 @@ static NOINLINE void factorize(wide_t N) * 18446744073709551601 = 53 348051774975651917 * the last factor requires testing up to * 589959129 - about 100 million iterations. + * The slowest case (largest prime) for N < 2^64 is + * factor 18446744073709551557 (0xffffffffffffffc5). */ max_factor = isqrt_odd(N); // count3 = 3; |