[llvm] r191313 - MemoryBuiltins: Fix operator new bits.

[Hal Finkel]

----- Original Message -----
> 
> On 24.09.2013, at 19:38, Hal Finkel <hfinkel at anl.gov> wrote:
> 
> > Ben,
> > 
> > Kind of off topic, but since you're looking at this code, can you
> > see why posix_memalign is in this list:
> > 
> >  {LibFunc::posix_memalign,      MallocLike,  3, 2,  -1},
> > 
> > As far as I can tell, getAllocationData will always fail on it
> > because of this check:
> > 
> > if (FTy->getReturnType() == Type::getInt8PtrTy(FTy->getContext())
> > && ...
> 
> Thanks for noticing this. posix_memalign doesn't make any sense
> there, the infrastructure isn't ready for it. Just fixing the check
> wouldn't work either because code calling isMallocLikeFn relies on
> the return value being a pointer. I'll replace the entry with a TODO
> for now.

Great, thanks!

 -Hal

> 
> - Ben
> 
> > 
> > Thanks,
> > Hal
> > 
> > 
> > ----- Original Message -----
> >> Author: d0k
> >> Date: Tue Sep 24 12:15:14 2013
> >> New Revision: 191313
> >> 
> >> URL: http://llvm.org/viewvc/llvm-project?rev=191313&view=rev
> >> Log:
> >> MemoryBuiltins: Fix operator new bits.
> >> 
> >> We really don't want to optimize malloc return value checks away.
> >> 
> >> Modified:
> >>    llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
> >>    llvm/trunk/test/Transforms/InstSimplify/call.ll
> >> 
> >> Modified: llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
> >> URL:
> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryBuiltins.cpp?rev=191313&r1=191312&r2=191313&view=diff
> >> ==============================================================================
> >> --- llvm/trunk/lib/Analysis/MemoryBuiltins.cpp (original)
> >> +++ llvm/trunk/lib/Analysis/MemoryBuiltins.cpp Tue Sep 24 12:15:14
> >> 2013
> >> @@ -35,9 +35,9 @@ enum AllocType {
> >>   CallocLike         = 1<<1, // allocates + bzero
> >>   ReallocLike        = 1<<2, // reallocates
> >>   StrDupLike         = 1<<3,
> >> -  OpNewLike          = MallocLike | (1<<4), // allocates; never
> >> returns null
> >> -  AllocLike          = MallocLike | CallocLike | StrDupLike,
> >> -  AnyAlloc           = MallocLike | CallocLike | ReallocLike |
> >> StrDupLike
> >> +  OpNewLike          = 1<<4, // allocates; never returns null
> >> +  AllocLike          = MallocLike | CallocLike | StrDupLike |
> >> OpNewLike,
> >> +  AnyAlloc           = AllocLike | ReallocLike
> >> };
> >> 
> >> struct AllocFnsTy {
> >> 
> >> Modified: llvm/trunk/test/Transforms/InstSimplify/call.ll
> >> URL:
> >> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/call.ll?rev=191313&r1=191312&r2=191313&view=diff
> >> ==============================================================================
> >> --- llvm/trunk/test/Transforms/InstSimplify/call.ll (original)
> >> +++ llvm/trunk/test/Transforms/InstSimplify/call.ll Tue Sep 24
> >> 12:15:14 2013
> >> @@ -121,3 +121,23 @@ cast.end:
> >> }
> >> 
> >> declare noalias i8* @_Znwm(i64)
> >> +
> >> +define i8* @malloc_can_return_null() {
> >> +entry:
> >> +  %call = tail call noalias i8* @malloc(i64 8)
> >> +  %cmp = icmp eq i8* %call, null
> >> +  br i1 %cmp, label %cast.end, label %cast.notnull
> >> +
> >> +cast.notnull:                                     ; preds =
> >> %entry
> >> +  %add.ptr = getelementptr inbounds i8* %call, i64 4
> >> +  br label %cast.end
> >> +
> >> +cast.end:                                         ; preds =
> >> %cast.notnull, %entry
> >> +  %cast.result = phi i8* [ %add.ptr, %cast.notnull ], [ null,
> >> %entry
> >> ]
> >> +  ret i8* %cast.result
> >> +
> >> +; CHECK-LABEL: @malloc_can_return_null
> >> +; CHECK: br i1 %cmp, label %cast.end, label %cast.notnull
> >> +}
> >> +
> >> +declare noalias i8* @malloc(i64)
> >> 
> >> 
> >> _______________________________________________
> >> llvm-commits mailing list
> >> llvm-commits at cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> >> 
> > 
> > --
> > Hal Finkel
> > Assistant Computational Scientist
> > Leadership Computing Facility
> > Argonne National Laboratory
> 
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory