User talk:Waldorf: Difference between revisions
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(New section: Lucas-Lehmer test) |
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To (in hybrid Ada/C at least): |
To (in hybrid Ada/C at least): |
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MP : Long_Long_Integer := 2ULL**Item - 1; |
MP : Long_Long_Integer := 2ULL**Item - 1; |
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(esp if the bit width on Int is ≤ ¼ of Long_Long_Integer's width) |
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The logic is Lucas-Lehmer should be generate n in 2*n-1 where n is |
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"almost" half the bit width of Long_Long_Integer. If this width is |
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128, then n should get to: |
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M2 M3 M5 M7 M13 M17 M19 M31 M61 |
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Unsigned also help get to M127 if Long_Long_Integer is 32 bytes wide, |
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if there is such a thing. |
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