xiangzhangllvm added inline comments.
================ Comment at: llvm/lib/Analysis/ConstantFolding.cpp:101 /// Constant fold bitcast, symbolically evaluating it with DataLayout. /// This always returns a non-null constant, but it may be a /// ConstantExpr if unfoldable. ---------------- clin1 wrote: > xiangzhangllvm wrote: > > clin1 wrote: > > > API for this function always returns non-null: can we return > > > ConstantExpr::getBitCast(C,DestTy) instead? Then the change in SCCP is > > > not needed either. > > I tried, the SCCP will also fold the bitcast into the following instruction. > I see, that makes sense. But are we sure that all callers of FoldBitCast are > doing a null check: for example, FoldReinterpretLoadFromConstPtr calls > FoldBitCast several times, and null is not checked before dereference. Maybe > the AMX type cannot happen in this case? > Alternative: can AMX be checked in SCCP? Right! let me check the callers of FoldBitCast, Luckly, there is only several callers of FoldBitCast, and almost all in this file ConstantFolding.cpp. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D98757/new/ https://reviews.llvm.org/D98757 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
