[Bug ipa/111922] [11/12/13/14 Regression] ICE in cp with -O2 -fno-tree-fre

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111922

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amacleod at redhat dot com,
                   |                            |jakub at gcc dot gnu.org

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Slightly cleaned up:
void f2 (void);
void f4 (int, int, int);
struct A { int a; };
struct B { struct A *b; int c; } v;

static int
f1 (x, y)
  struct C *x;
  struct A *y;
{
  (v.c = v.b->a) || (v.c = v.b->a);
  f2 ();
}

static void
f3 (int x, int y)
{
  int b = f1 (0, ~x);
  f4 (0, 0, v.c);
}

void
f5 (void)
{
  f3 (0, 0);
}

The problem is in the f1 call, given it uses the K&R definition style and the
caller invokes UB by using incompatible types (int vs. pointers), I think
IPA-VRP should punt somewhere on the type mismatch.

I think
      Value_Range vr (operand_type);
      if (TREE_CODE_CLASS (operation) == tcc_unary)
        ipa_vr_operation_and_type_effects (vr,
                                           src_lats->m_value_range.m_vr,
                                           operation, param_type,
                                           operand_type);
should be avoided if param_type is not a compatible type to operand_type,
unless operation is some cast operation (NOP_EXPR, CONVERT_EXPR, dunno if the
float to integral or vice versa ops as well but vrp probably doesn't handle
that yet).
In the above case, param_type is struct A *, i.e. pointer, while operand_type
is int.