[PATCH] D116816: [instcombine] Delete duplicate object size logic

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp:2578
+  if (getObjectSize(&Call, Size, DL, TLI, Opts) && Size > 0) {
+    // TODO: should be annotating these nonnull
     if (isOpNewLikeFn(&Call, TLI))
----------------
reames wrote:
> xbolva00 wrote:
> > reames wrote:
> > > xbolva00 wrote:
> > > > reames wrote:
> > > > > xbolva00 wrote:
> > > > > > all allocation fns have nonnull attribute, I believe.
> > > > > Er, definitely not.  Malloc can return nullptr on error.  Did you maybe mean that all operator new versions did?  I couldn't find that code, can you point me to it?
> > > > Yeah right, just for new calls.
> > > > 
> > > > Yes, todo is correct here for others
> > > Your wording in last comment is unclear to me, can you rephrase?  
> > That for throwing version of 'new' we already have nonnull.
> > 
> > I am wondering if just “deref(N)” attribute alone is enough for other parts of LLVM to assume also “nonnull” (for addr space 0)
> Can you point me to the code which infers nonnull for the throwing operator new variants?  I did not find it on a quick skim.  In particular, I do not see this in BuildLibCalls.cpp which I would expect.   
> 
> (Regardless, I'd like to leave this cleanup to a separate patch.)
https://clang.llvm.org/doxygen/SemaDecl_8cpp_source.html#l15072


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  https://reviews.llvm.org/D116816/new/

https://reviews.llvm.org/D116816