[PR,68064] Testcase and an assert for an already fixed bug

Hi,

PR 68064 has been fixed by Richi's revision 231246.  I would still
like to add the testcase to the testsuite and add a checking assert
so that if ever get zero alignment again, we catch it in the analysis
part of IPA-CP (which with LTO means in compilation and not linking
phase which makes a big difference for debugging).

I have tossed this into a bootstrap and test run on an x86_64-linux
and found no issues.  I believe the patch is quite obvious and so will
go ahead and commit it to trunk.

Thanks,

Martin


Add asssert and testcase for PR 68064

2015-12-09  Martin Jambor  <mjambor@suse.cz>

	* ipa-prop.c (ipa_compute_jump_functions_for_edge): Add checking
	assert that align is nonzero.

testsuite/
	* g++.dg/torture/pr68064.C: New test.
---
 gcc/ipa-prop.c                         |  1 +
 gcc/testsuite/g++.dg/torture/pr68064.C | 35 ++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/torture/pr68064.C

On Fri, Dec 11, 2015 at 12:16 PM, Martin Jambor <mjambor@suse.cz> wrote:
> Hi,
>
> PR 68064 has been fixed by Richi's revision 231246.  I would still
> like to add the testcase to the testsuite and add a checking assert
> so that if ever get zero alignment again, we catch it in the analysis
> part of IPA-CP (which with LTO means in compilation and not linking
> phase which makes a big difference for debugging).
>
> I have tossed this into a bootstrap and test run on an x86_64-linux
> and found no issues.  I believe the patch is quite obvious and so will
> go ahead and commit it to trunk.
>
> Thanks,
>
> Martin
>
>
> Add asssert and testcase for PR 68064
>
> 2015-12-09  Martin Jambor  <mjambor@suse.cz>
>
>         * ipa-prop.c (ipa_compute_jump_functions_for_edge): Add checking
>         assert that align is nonzero.
>
> testsuite/
>         * g++.dg/torture/pr68064.C: New test.
> ---
>  gcc/ipa-prop.c                         |  1 +
>  gcc/testsuite/g++.dg/torture/pr68064.C | 35 ++++++++++++++++++++++++++++++++++
>  2 files changed, 36 insertions(+)
>  create mode 100644 gcc/testsuite/g++.dg/torture/pr68064.C
>
> diff --git a/gcc/ipa-prop.c b/gcc/ipa-prop.c
> index f379ea7..d0a3501 100644
> --- a/gcc/ipa-prop.c
> +++ b/gcc/ipa-prop.c
> @@ -1646,6 +1646,7 @@ ipa_compute_jump_functions_for_edge (struct ipa_func_body_info *fbi,
>               && align % BITS_PER_UNIT == 0
>               && hwi_bitpos % BITS_PER_UNIT == 0)
>             {
> +             gcc_checking_assert (align != 0);
>               jfunc->alignment.known = true;
>               jfunc->alignment.align = align / BITS_PER_UNIT;

don't you want to assert align / BITS_PER_UNIT is not 0?

>               jfunc->alignment.misalign = hwi_bitpos / BITS_PER_UNIT;
> diff --git a/gcc/testsuite/g++.dg/torture/pr68064.C b/gcc/testsuite/g++.dg/torture/pr68064.C
> new file mode 100644
> index 0000000..59b6897
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/torture/pr68064.C
> @@ -0,0 +1,35 @@
> +// { dg-do compile }
> +
> +template <class Config> class A {
> +public:
> +  class B;
> +  typedef typename Config::template D<A>::type TypeHandle;
> +  static A *Tagged() { return B::New(B::kTagged); }
> +  static TypeHandle Union(TypeHandle);
> +  static TypeHandle Representation(TypeHandle, typename Config::Region *);
> +  bool Is();
> +};
> +
> +template <class Config> class A<Config>::B {
> +  friend A;
> +  enum { kTaggedPointer = 1 << 31, kTagged = kTaggedPointer };
> +  static A *New(int p1) { return Config::from_bitset(p1); }
> +};
> +
> +struct C {
> +  typedef int Region;
> +  template <class> struct D { typedef A<C> *type; };
> +  static A<C> *from_bitset(unsigned);
> +};
> +A<C> *C::from_bitset(unsigned p1) { return reinterpret_cast<A<C> *>(p1); }
> +
> +namespace {
> +int *a;
> +void fn1(A<C> *p1) { A<C>::Union(A<C>::Representation(p1, a)); }
> +}
> +
> +void fn2() {
> +  A<C> b;
> +  A<C> *c = b.Is() ? 0 : A<C>::Tagged();
> +  fn1(c);
> +}
> --
> 2.6.3
>