Hi, On Thu, Jun 20, 2013 at 05:46:28PM +0200, Martin Jambor wrote: > On Thu, Jun 20, 2013 at 03:47:11PM +0100, Marcus Shawcroft wrote: > > Hi, I've been looking at an issue in mysql compilation which appears > > to be due to this patch. > > > > On 10 May 2013 18:27, Martin Jambor <mjam...@suse.cz> wrote: > > > Hi, > > > > > > as we discover targets of previously indirect calls in ipa-inline and > > > ipa-cp, we sometimes figure out that the targets are not a function. > > > One typical example is when NULL is passed as a function pointer > > > > OK, this part makes sense to me. > > > > > parameter, another is when C++ member-pointer points to a virtual > > > function and the overloaded field of the structure which can also hold > > > pointers to non-virtual methods contains odd integer constants. > > > > I'm struggling to understand why such a member-pointer call would be > > illegal in a well formed program. > > > > Attached is a fragment of code that demonstrates the issue I've been > > looking at. When compiled at -O3 the 047i.inline dump tells me that: > > > > ipa-prop: Discovered direct call to non-function in unsigned int > > A::foo(unsigned int (H::*)() const) const/11, making it unreachable. > > not inlinable: unsigned int A::foo(unsigned int (H::*)() const) > > const/11 -> void __builtin_unreachable()/12, function body not > > available > > > > This behavior appears to be the explicit intent of the original patch, > > the call to the member function pointer has been replaced with > > __builtin_unreachable, but that looks like a legitimate call to me. > > What am I missing? > > Hm, the reason why I did this was that I misremembered that each > branch, the one for virtual calls and the one for direct calls. But > when I checked dumps, I realized it was not so, there is only one call > when the branches join. I'll fix this promptly. > > Thanks for the report,
For the record, this is PR 57670. Martin
