Pierre-vh wrote: > > Where and how should that be implemented ? I struggled with that. I tried > > adding a new special case in TableGen but I just couldn't find the right > > way to do it. Do I just add it in C++ InstructionSelector before it checks > > the patterns? Or should it be some kind of post-processing step after the > > shift has been selected, but before the G_ZEXT is selected? > > It already exists as a complex pattern, isUnneededShiftMask. The combiners > should be trying to get the clamping code into this form which expects the and
I tried it but the DAG immediately transforms `(and x, 0xFF)` into a zext and it seems pretty stubborn about it as it's a basic transform. I don't mind trying to make it work a bit longer, but I could also just bring this back. What do you think? https://github.com/llvm/llvm-project/pull/131310 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
