------- Comment #3 from dmarkman at mac dot com 2008-04-14 21:47 ------- Hi, first of all thanks for your comment I don't use i0 in the program - it's inside of the quotes so test is fine I made all changes you made and still in 4.3 (opt) I'm getting (+Inf, Nan) it looks like that 4.4 fixes that Inconsistence I just don't build 4,4 to check thanks again
> Well, your test case is invalid anyway (i0 is referenced before being > defined). > > Here's a standard conforming portable version that compiles with "-Wall > -pedantic -std=f2003": > > program short_test_inf > implicit none > integer, parameter :: dp = selected_real_kind (15) > complex(dp) nan_inf, normal_number, cmplx_test, i0 > real(dp) tth, pi, zero > data tth /6.66666666666666667e-01_dp/ > data pi /3.1415926535897932385_dp/ > data zero /0.0_dp/ > normal_number = cmplx(tth, zero, dp) > nan_inf = cmplx(pi/zero, zero/zero, dp) > i0 = cmplx(0, 0, dp) > cmplx_test = nan_inf * normal_number > C print *,'nan_inf ',nan_inf > print *,'cmplx_test (inf+iNan)*(2/3+i0) ',cmplx_test > cmplx_test = nan_inf * tth > C print *,'tth ',tth > print *,'cmplx_test (inf+iNan)*(2/3)',cmplx_test > end program > > Results with this program comparing 4.1 and 4.4 (trunk): > > $ ./gf41-opt > cmplx_test (inf+iNan)*(2/3+i0) ( NaN, > NaN) > cmplx_test (inf+iNan)*(2/3) ( +Infinity, > NaN) > $ ./gf41-nonopt > cmplx_test (inf+iNan)*(2/3+i0) ( NaN, > NaN) > cmplx_test (inf+iNan)*(2/3) ( NaN, > NaN) > $ ./gf44-opt > cmplx_test (inf+iNan)*(2/3+i0) ( +Infinity, > > NaN) > cmplx_test (inf+iNan)*(2/3) ( +Infinity, > NaN) > $ ./gf44-nonopt > cmplx_test (inf+iNan)*(2/3+i0) ( NaN, > > NaN) > cmplx_test (inf+iNan)*(2/3) ( NaN, > NaN) > > Basically, I'd like to close this as wontfix. IIRC once you get an FP > exception, all bets are off and the result of further computation can be > anything. Of course it would be nice if results were the same regardless of > optimization level. > > For a related issue where being excessively anal about complex arithmetic > resulted in a factor of 5 slowdown, see PR 29549 > -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35877
