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| author | Xi Wang <xi.wang@gmail.com> | 2012-08-14 18:54:40 -0400 |
|---|---|---|
| committer | Werner Koch <wk@gnupg.org> | 2012-08-16 10:48:03 +0200 |
| commit | 2c54c4da19d3a79e9f749740828026dd41f0521a (patch) | |
| tree | acd346d2c038018c59db3697cc07e8fb0d36e073 /mpi/mpih-div.c | |
| parent | 2196728e2252917849c1be94417258076767021b (diff) | |
| download | libgcrypt-2c54c4da19d3a79e9f749740828026dd41f0521a.tar.gz | |
Replace deliberate division by zero with _gcry_divide_by_zero.
* mpi/mpi-pow.c: Replace 1 / msize.
* mpi/mpih-div.c: Replace 1 / dsize.
* src/misc.c: Add _gcry_divide_by_zero.
--
1) Division by zero doesn't "provoke a signal" on architectures
like PowerPC.
2) C compilers like clang will optimize away these divisions, even
though the code tries "to make the compiler not remove" them.
This patch redirects these cases to _gcry_divide_by_zero.
Diffstat (limited to 'mpi/mpih-div.c')
| -rw-r--r-- | mpi/mpih-div.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/mpi/mpih-div.c b/mpi/mpih-div.c index 224b8108..b33dcbfa 100644 --- a/mpi/mpih-div.c +++ b/mpi/mpih-div.c @@ -212,9 +212,8 @@ _gcry_mpih_divrem( mpi_ptr_t qp, mpi_size_t qextra_limbs, switch(dsize) { case 0: - /* We are asked to divide by zero, so go ahead and do it! (To make - the compiler not remove this statement, return the value.) */ - return 1 / dsize; + _gcry_divide_by_zero(); + break; case 1: { |