factor: factor2 variable is unused now, drop it
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
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@ -89,7 +89,6 @@ static NOINLINE half_t isqrt_odd(wide_t N)
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static NOINLINE void factorize(wide_t N)
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{
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wide_t factor2;
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half_t factor;
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half_t max_factor;
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unsigned count3;
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@ -105,7 +104,6 @@ static NOINLINE void factorize(wide_t N)
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max_factor = isqrt_odd(N);
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count3 = 3;
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factor = 3;
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factor2 = 3 * 3;
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for (;;) {
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/* The division is the most costly part of the loop.
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* On 64bit CPUs, takes at best 12 cycles, often ~20.
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@ -118,10 +116,6 @@ static NOINLINE void factorize(wide_t N)
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next_factor:
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if (factor >= max_factor)
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break;
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/* (f + 2)^2 = f^2 + 4*f + 4 = f^2 + 4*(f+1) */
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factor2 = factor2 + 4 * (factor + 1);
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/* overflow is impossible due to max_factor check */
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/* (factor2 > N) is impossible due to max_factor check */
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factor += 2;
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/* Rudimentary wheel sieving: skip multiples of 3:
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* Every third odd number is divisible by three and thus isn't a prime:
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