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

Amaury SECHET via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 18 07:43:09 PDT 2017


deadalnix added inline comments.


================
Comment at: lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp:1968
+    // Calculate the overflow: addition overflows iff a + b < a, and subtraction
+    // overflows iff a - b > a.
+    auto Cond = N->getOpcode() == ISD::UADDO ? ISD::SETULT : ISD::SETUGT;
----------------
mkazantsev wrote:
> iff -> if?
iff is a shorthand for if and only if, to indicate bijection. it is commonly used in the comment int hat file, so I think this is fine.


https://reviews.llvm.org/D29872





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