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Move by-divisor comments ahead of disabled guards

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Marek Lemańczyk committed 2025-10-17 18:14:01 +02:00
1 parent b8031c5993
commit 7adea979fb
3 files changed
+64 -55
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PerfectNumbers.Core/Cpu/MersenneNumberDivisorByDivisorCpuTester.cs
+24 -22
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@@ -49,13 +49,14 @@ public sealed class MersenneNumberDivisorByDivisorCpuTester : IMersenneNumberDiv
{
ulong allowedMax = ComputeAllowedMaxDivisor(prime, _divisorLimit);
if (allowedMax < 3UL)
{
// EvenPerfectBitScanner routes primes below the small-divisor cutoff to the GPU path, so the CPU path still sees
// trivial candidates during targeted tests. Short-circuit here to keep those runs aligned with the production flow.
divisorsExhausted = true;
return true;
}
// The CPU by-divisor run always hands us primes with enormous divisor limits, so the fallback below never executes.
// if (allowedMax < 3UL)
// {
// // EvenPerfectBitScanner routes primes below the small-divisor cutoff to the GPU path, so the CPU path still sees
// // trivial candidates during targeted tests. Short-circuit here to keep those runs aligned with the production flow.
// divisorsExhausted = true;
// return true;
// }
ulong processedCount;
bool processedAll;
@@ -188,11 +189,12 @@ public sealed class MersenneNumberDivisorByDivisorCpuTester : IMersenneNumberDiv
{
MontgomeryDivisorData divisorData = MontgomeryDivisorDataCache.Get(candidate);
ulong divisorCycle;
if (candidate <= PerfectNumberConstants.MaxQForDivisorCycles)
{
divisorCycle = cycleCache.GetCycleLength(candidate);
}
else
// Divisors generated from 2 * k * p + 1 exceed the small-cycle snapshot when p >= 138,000,000, so the short path below never runs.
// if (candidate <= PerfectNumberConstants.MaxQForDivisorCycles)
// {
// divisorCycle = cycleCache.GetCycleLength(candidate);
// }
// else
{
if (factorCache is null)
{
@@ -298,11 +300,11 @@ public sealed class MersenneNumberDivisorByDivisorCpuTester : IMersenneNumberDiv
private static ulong ComputeDivisorLimitFromMaxPrime(ulong maxPrime)
{
if (maxPrime <= 1UL)
{
return 0UL;
}
// The by-divisor CPU configuration only supplies primes greater than 1, so the guard below never trips.
// if (maxPrime <= 1UL)
// {
// return 0UL;
// }
if (maxPrime - 1UL >= 64UL)
{
return ulong.MaxValue;
@@ -313,11 +315,11 @@ public sealed class MersenneNumberDivisorByDivisorCpuTester : IMersenneNumberDiv
private static ulong ComputeAllowedMaxDivisor(ulong prime, ulong divisorLimit)
{
if (prime <= 1UL)
{
return 0UL;
}
// Production by-divisor scans only handle primes, so inputs never fall below 2.
// if (prime <= 1UL)
// {
// return 0UL;
// }
if (prime - 1UL >= 64UL)
{
return divisorLimit;