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 2013-01-27, 22:09 #1 fivemack (loop (#_fork))     Feb 2006 Cambridge, England 11001001101012 Posts Small mlucas issue on non-x86 I thought I might as well see just how slowly mlucas runs on a last-year's ARM. The current downloadable tarfile of mlucas (Mlucas_10.09.2011; I appreciate this is old, is there a newer place to look?) doesn't build unless USE_SSE2 is defined, because the section around lines 1441 to 1458 of radix16_ditN_cy_dif1.c (only) uses *bjmodn0 which is incorrect if !USE_SSE2 I did #if !defined(USE_SSE2) #define BJSTAR #else #define BJSTAR * #endif then replaced *bjmodn0 with BJSTAR modn0 but I appreciate that makes the code a bit ugly. It's really not terribly fast: Code: M2614999: using FFT length 128K = 131072 8-byte floats. this gives an average 19.950859069824219 bits per digit Using complex FFT radices 8 16 32 16 1000 iterations of M2614999 with FFT length 131072 = 128 K Res64: 1A184504D2DE2D3C. AvgMaxErr = 0.000000000. MaxErr = 0.000000000. Program: E3.0x Res mod 2^36 = 20717645116 Res mod 2^35 - 1 = 5934292942 Res mod 2^36 - 1 = 4090378120 Clocks = 00:00:45.939 M42643801: using FFT length 2304K = 2359296 8-byte floats. this gives an average 18.074799007839626 bits per digit Using complex FFT radices 9 8 8 8 16 16 10 iterations of M42643801 with FFT length 2359296 = 2304 K Res64: 9BDB491DF4C00002. AvgMaxErr N/A. MaxErr = 0.000000000. Program: E3.0x Res mod 2^36 = 59940798466 Res mod 2^35 - 1 = 11033316518 Res mod 2^36 - 1 = 15286304084 Clocks = 00:00:10.410 (for comparison, a 3.4GHz Sandy Bridge machine gave 0.045s/i for 42643801 and 0.0021s/i for 2614999; so about 22 times faster) I'm trying different compiler options; I tried enabling multi-threading but got a message saying that the sensitivity list for radix44 needed updating. Have you got a newer version of that? Last fiddled with by fivemack on 2013-01-28 at 14:51