From c054822027a4a6895bc95979c6c10ff5763c7c7e Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 13 Apr 2017 10:51:13 +0200 Subject: [PATCH] factor: tweak comments Signed-off-by: Denys Vlasenko --- coreutils/factor.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/coreutils/factor.c b/coreutils/factor.c index 66d6a7cae..7adc2385a 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; -- 2.25.1