failed make check using gcc 4.1.0 after applying the toom3 patch

Juergen Bullinger juergen.bullinger at
Sat Feb 18 00:46:43 CET 2006

Hi all,

I encountered a problem after I installed the toom3 patch from the
tid-bits site on a newly extracted gmp source directory and try to
compile it using gcc 4.1.0.
make check reported problems on four of the tests (segmentation fault).
One of the tests which failed was t-fdiv.

The strange thing is, that gmp compiles well without this patch on the
same compiler and gmp with the patch compiles also well on other
versions of gcc. I guess my previous version was gcc 4.0.0 which worked.
But when I read that it produces improper code, I updated to the latest
Has somebody had this problem before?

I did some analysis on what happens before t-fdiv fails. I put some
printfs in t-fdiv.c and also some in mpn/generic/mul_n.c. I added one
printf at the end of the mul_n function (mul_n.c) and one printf before
the first call to mpz_mul_n and one behind the first call to mpz_mul_n
in t-fdiv.c.
>From the output it looks like the last line in mpn_mul_n is reached but
before the printf after the call of mpz_mul_n is executed an error

Could this be a problem with the stack?
Is mpz_mul_n just a synonym for mpn_mul_n, or is it not the same?
I know that if it is not the same, at least mpz_mul_n calls mpn_mul_n
and in this case probably there is a bug in the code which is executed
after mpn_mul_n is called.

Is this a bug in gcc?

Thank you for your help.

kind regards

Juergen Bullinger <juergen.bullinger at>

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