[PATCH] D35192: [ARM] Use ADDCARRY / SUBCARRY

[Roger Ferrer Ibanez via Phabricator via llvm-commits]

rogfer01 added inline comments.


================
Comment at: lib/Target/ARM/ARMISelLowering.cpp:9891-9894
+  // If HiAdd is a predecessor of ADDC, the replacement below will create a
+  // cycle.
+  if (AddcNode->isPredecessorOf(HiAdd->getNode()))
+    return SDValue();
----------------
This fixes the problem in PR34045.

I wonder if `AddeNode` + `LowAdd` might have the same problem but I don't think it can happen.

The rest of boringssl has built correctly using `-mthumb`, though.


https://reviews.llvm.org/D35192