#4 Glucas fails on G5 with -ffast-math option

[Anonymous]

Today 20060101 I download Glucas and make it on my PowerMac G5
running Mac OS X 10.4.3 and gcc 4.0 using all defaults in "configure".
When I ran the first test "Glucas -s 1" I got the following error:

Selftest 1 (128 K FFT-runlength). 100 iterations for M2457601...
Glucas panic!. Something is wrong. Suiciding at iteration 7...

I finally determined that the problem appears to be due to the -ffast-
math option on the gcc 4.0 compiler (which sets a number of other
options which I did not test individually). When I removed the -ffast-
math option and rebuilt, Glucas ran all tests successfully with the
following results:

PowerMac:~/Desktop/NOBACKUP/glucas-2.9.2-20051226/src rand
$ ./sumGlucas

FFT sec/Iter deviat sec/Iter deviat % (RC=0)
Roundoff_check=1 Roundoff_check=0
--------------------------------------------------
128 0.004 0.000 0.002 0.000 53.8
144 0.005 0.001 0.003 0.001 50.0
160 0.006 0.001 0.003 0.001 54.2
192 0.007 0.001 0.003 0.001 50.0
224 0.009 0.001 0.004 0.001 52.8
256 0.010 0.001 0.005 0.002 51.6
288 0.012 0.001 0.006 0.002 50.0
320 0.014 0.001 0.007 0.002 48.8
384 0.016 0.002 0.008 0.002 50.5
448 0.018 0.002 0.009 0.003 50.9
512 0.021 0.002 0.010 0.003 50.0
576 0.024 0.002 0.012 0.004 50.7
640 0.030 0.003 0.014 0.004 51.7
768 0.036 0.004 0.017 0.005 50.9
896 0.042 0.004 0.021 0.006 50.0
1024 0.049 0.005 0.024 0.007 51.5
1152 0.056 0.005 0.028 0.008 50.0
1280 0.065 0.006 0.032 0.009 50.5
1536 0.077 0.007 0.038 0.011 50.3
1792 0.091 0.009 0.045 0.014 50.5
2048 0.106 0.010 0.052 0.015 50.6
2304 0.122 0.012 0.060 0.018 50.9
2560 0.134 0.013 0.067 0.019 50.5
3072 0.161 0.015 0.080 0.023 50.5
3584 0.190 0.018 0.094 0.028 50.5
4096 0.219 0.020 0.109 0.031 50.4
4608 0.251 0.025 0.124 0.037 50.6
5120 0.303 0.029 0.150 0.044 50.4
6144 0.364 0.035 0.180 0.052 50.5
7168 0.434 0.041 0.215 0.063 50.5
8192 0.493 0.047 0.244 0.071 50.4

Thought you might like to know that -ffast-math appears to cause a
problem on the G5.

Rand Childs