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--- ms-20240504.cu [2024/06/20 00:09] – mino
+++ ms-20240504.cu [2024/10/16 15:05] (current) – mino
@@ Line 20: / Line 20: @@
   sys     0m0.272s
-== Note added on 2024.06.19 ==
+== Note added on 2024.06.20 ==
-The function void LastCols( ) in the code contains the following doubtful comparison:
+The function void LastCols( ) in the code contains the following questionable comparison:
       psingl = psingl
@@ Line 32: / Line 32: @@
                  or rev_max32_c == unsigned( v2 )
-because the upper 32 bits of v2 should be ignored in the comparison.
+because the upper 32 bits of v2 should be ignored when compared with the 32bit unsigned rev_max32_c.
-However, this flaw is irrelevant to the validity of the result because this comparison is totally unnecessary for even N (including 6). The result of the comparison should be always false for even N, and omitting the cast never turns a false case into true.
+However, this flaw is irrelevant to the validity of the result because this logical operation is totally unnecessary and has no effect for even N (including 6) because complements of any rows never appear as columns in even order magic squares. And for N < 6, the upper 32 bits of v2 are always 0s and the cast has no effect in any way.
-For odd N, this flaw can be relevant, but for N < 6, the upper 32 bits of v2 are always 0s and the cast has no effect in any way. You have to be careful if you want to use this code for N=7.
+This part of the code and other parts related to the self complemenarity check should be removed from functions MakeCols() and LastCols() in order to optimize the performance for N=6.
+We will gain 3% improvement of the performance by this optimization.
 <file cpp ms-20240504.cu>