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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2017-04-09 23:19:47 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2017-04-09 23:19:47 +0200 |
| commit | c804d4ec5cb222c842644bb99d9b077f5c6576f2 (patch) | |
| tree | c772695425022592894deab2058ecf41ef81228e /coreutils/factor.c | |
| parent | 7e5f2f3b5163a3c7c6b20a311f1177f9c4f04b81 (diff) | |
| download | busybox-w32-c804d4ec5cb222c842644bb99d9b077f5c6576f2.tar.gz busybox-w32-c804d4ec5cb222c842644bb99d9b077f5c6576f2.tar.bz2 busybox-w32-c804d4ec5cb222c842644bb99d9b077f5c6576f2.zip | |
factor: factor2 variable is unused now, drop it
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'coreutils/factor.c')
| -rw-r--r-- | coreutils/factor.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/coreutils/factor.c b/coreutils/factor.c index 1c01e3f27..85284aa27 100644 --- a/coreutils/factor.c +++ b/coreutils/factor.c | |||
| @@ -89,7 +89,6 @@ static NOINLINE half_t isqrt_odd(wide_t N) | |||
| 89 | 89 | ||
| 90 | static NOINLINE void factorize(wide_t N) | 90 | static NOINLINE void factorize(wide_t N) |
| 91 | { | 91 | { |
| 92 | wide_t factor2; | ||
| 93 | half_t factor; | 92 | half_t factor; |
| 94 | half_t max_factor; | 93 | half_t max_factor; |
| 95 | unsigned count3; | 94 | unsigned count3; |
| @@ -105,7 +104,6 @@ static NOINLINE void factorize(wide_t N) | |||
| 105 | max_factor = isqrt_odd(N); | 104 | max_factor = isqrt_odd(N); |
| 106 | count3 = 3; | 105 | count3 = 3; |
| 107 | factor = 3; | 106 | factor = 3; |
| 108 | factor2 = 3 * 3; | ||
| 109 | for (;;) { | 107 | for (;;) { |
| 110 | /* The division is the most costly part of the loop. | 108 | /* The division is the most costly part of the loop. |
| 111 | * On 64bit CPUs, takes at best 12 cycles, often ~20. | 109 | * On 64bit CPUs, takes at best 12 cycles, often ~20. |
| @@ -118,10 +116,6 @@ static NOINLINE void factorize(wide_t N) | |||
| 118 | next_factor: | 116 | next_factor: |
| 119 | if (factor >= max_factor) | 117 | if (factor >= max_factor) |
| 120 | break; | 118 | break; |
| 121 | /* (f + 2)^2 = f^2 + 4*f + 4 = f^2 + 4*(f+1) */ | ||
| 122 | factor2 = factor2 + 4 * (factor + 1); | ||
| 123 | /* overflow is impossible due to max_factor check */ | ||
| 124 | /* (factor2 > N) is impossible due to max_factor check */ | ||
| 125 | factor += 2; | 119 | factor += 2; |
| 126 | /* Rudimentary wheel sieving: skip multiples of 3: | 120 | /* Rudimentary wheel sieving: skip multiples of 3: |
| 127 | * Every third odd number is divisible by three and thus isn't a prime: | 121 | * Every third odd number is divisible by three and thus isn't a prime: |