[PATCH] D29872: Do not legalize large add with addc/adde, introduce addcarry and do it with uaddo/addcarry

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: include/llvm/CodeGen/ISDOpcodes.h:236
+    /// a glue, which allows further optimisation.
+    ADDCARRY, SUBCARRY,
+
----------------
Please explicitly note that the carry input to SUBCARRY supposed to be the output of USUBO; the "carry" bit is defined differently on some architectures.


https://reviews.llvm.org/D29872