factor: fix comments

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/coreutils/factor.c b/coreutils/factor.c
index 8ca3de71aafce2e11d9c60d535193bde95e194bb..4e521dbc02cf424727acc7d7e4d4f7ab7ba8d2d9 100644 (file)
--- a/coreutils/factor.c
+++ b/coreutils/factor.c
@@ -54,7 +54,7 @@ static inline half_t isqrt(wide_t N)
 //     if (N == 0)
 //             return 0;
 
-       /* First approximation x > sqrt(N) - half as many bits:
+       /* First approximation of x+1 > sqrt(N) - all-ones, half as many bits:
         * 1xxxxx -> 111 (six bits to three)
         * 01xxxx -> 111
         * 001xxx -> 011
@@ -125,7 +125,7 @@ static NOINLINE void factorize(wide_t N)
                if (factor >= max_factor)
                        break;
                factor += 2;
-               /* Rudimentary wheel sieving: skip multiples of 3:
+               /* Rudimentary wheel sieving: skip multiples of 3, 5 and 7:
                 * Every third odd number is divisible by three and thus isn't a prime:
                 * 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47...
                 * ^ ^   ^  ^     ^  ^     ^  _     ^  ^     _  ^     ^  ^     ^