error in compiling cilk plus with gcc-4.7

Question

I get the following error

main.c:107:2: internal compiler error: in extract_for_fields, at cilk-spawn.c:1857
}

and the relevant lines are:

cilk_for (index = 0; table_name[index]!=NULL; ++index )
{
      /* some work*/
}

Line 107 corresponds to the closing braces of cilk_for loop.

Any help is appreciated!

That's a compiler bug. Does it work in 4.6? Are you using some pre-release of 4.7? — Flexo, Jun 20 '12 at 16:19
no. cilk plus can only be build with `gcc-4.7` as intel has added that branch to `gcc-4.7` only. So is there nothing I can do about it except sending the a bug report — Aman Deep Gautam, Jun 20 '12 at 16:21

score 0 · Answer 1 · answered Jun 20 '12 at 17:50

0

Try building with no optimization (omit any optimization flags, or use -O0 explicitely).

If that helps, you can try and see if -O1 (some optimization) works, then -O2, and so on. If you're lucky, you can figure out that way which optimization is causing the problem, and then simply disable that optimization with some -fno-foo flag.

answered Jun 20 '12 at 17:50

Kenneth Hoste

2,816
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I got the fix and posted it above. – Aman Deep Gautam Jun 20 '12 at 18:02

score 0 · Accepted Answer · answered Jun 20 '12 at 18:02

What I did above was not a valid cilk_for loop because the cilk_for loop must test the control variable. Also one must be able to predict how many time the loop will run and in this case this is not possible. So the correct version for this will be

int count=0;
while(table_name[count]!=NULL)
    count++;
cilk_for (index = 0; index!=count; ++index )
{
      /* some work*/
}

error in compiling cilk plus with gcc-4.7

2 Answers2