From 469c8057d397f8f20249dc8b9f31c8d0719b854b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Lema=C5=84czyk?= <marek@lemanczyk.eu>
Date: Fri, 31 Oct 2025 22:45:59 +0100
Subject: [PATCH] Flatten heuristic trial division bounds checks

---
 .../Gpu/Kernels/PrimeTesterKernels.cs         | 20 +++++++------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/PerfectNumbers.Core/Gpu/Kernels/PrimeTesterKernels.cs b/PerfectNumbers.Core/Gpu/Kernels/PrimeTesterKernels.cs
index 19b08c9..d6842e0 100644
--- a/PerfectNumbers.Core/Gpu/Kernels/PrimeTesterKernels.cs
+++ b/PerfectNumbers.Core/Gpu/Kernels/PrimeTesterKernels.cs
@@ -92,20 +92,14 @@ internal static class PrimeTesterKernels
 
         int divisorLength = (int)divisorSquares.Length;
         int threadIndex = index;
-        if (threadIndex >= divisorLength)
-        {
-            return;
-        }
+        bool skipThread = threadIndex >= divisorLength;
+        ulong divisorSquare = skipThread ? 0UL : divisorSquares[threadIndex];
+        skipThread = skipThread | (divisorSquare > maxDivisorSquare);
 
-        ulong divisorSquare = divisorSquares[threadIndex];
-        if (divisorSquare > maxDivisorSquare)
-        {
-            return;
-        }
-
-        ulong divisor = divisors[threadIndex];
-        divisor = n % divisor;
-        if (divisor == 0UL)
+        ulong divisor = skipThread ? 1UL : divisors[threadIndex];
+        ulong remainder = skipThread ? 1UL : n % divisor;
+        bool hasFactor = !skipThread & (remainder == 0UL);
+        if (hasFactor)
         {
             resultFlag[0] = 1;
         }