Hi Fernando, Thank you for your help. I will check rand(). When you said "the disassembled code", which code do you mean?
Yuchen On Wed, Mar 19, 2014 at 1:44 AM, Fernando Endo <[email protected]>wrote: > Hello, > > I'm my opinion, you have to check what is done in the rand() function, it > may be completely integer. Usually, one should look at the disassembled > code to verify that gem5 stats are ok. > > Regards, > > -- > Fernando A. Endo, PhD student and researcher > > Université de Grenoble, UJF > France > > > > 2014-03-12 20:22 GMT+01:00 Yuchen Hou <[email protected]>: > >> Hi, >> I am using gem5 to profile a piece of C code but I am not sure if I am on >> the right track. >> >> I need to measure the numbers of alpha instructions executed in an >> experiment introduced by the following two lines C code: >> { >> r = (double)rand() / (double)RAND_MAX; // line 2 >> r = -log(r) / log(2.71828) / p; // line 3 >> } >> >> The way I setup the experiment is that I wrap the two lines like this: >> { >> m5_dumpreset_stats(0,0); /* add this before region of interest */ >> m5_checkpoint(0, 0); /* add this before region of interest */ >> r = (double)rand() / (double)RAND_MAX; >> r = -log(r) / log(2.71828) / p; >> m5_dumpreset_stats(0,0); /* add this after region of interest */ >> } >> , and then run a simulation with a run script in simple cpu, and rerun >> the simulation from the checkpoint with timing cpu. After that, I get these >> parameters out of stats.txt: >> ("system.switch_cpus.num_conditional_control_insts" >> "system.switch_cpus.num_int_insts" "system.switch_cpus.num_fp_insts" >> "system.switch_cpus.num_load_insts" "system.switch_cpus.num_store_insts"), >> with corresponding values is ( 2992 29902 263 6176 3159 ) >> >> Can anyone help me understand the reason of the huge number of >> instructions (especially integer instructions)? Is this experiment >> designed/conducted correctly at all? Thanks! >> >> >> Yuchen >> >> _______________________________________________ >> gem5-users mailing list >> [email protected] >> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >> > > > _______________________________________________ > gem5-users mailing list > [email protected] > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >
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