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

[Martin Jambor]

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  <mjam...@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;
              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