[PATCH] D158673: [SDAG][RISCV] Avoid neg instructions when lowering atomic_load_sub with a constant rhs

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

In D158673#4615369 <https://reviews.llvm.org/D158673#4615369>, @jrtc27 wrote:

> (But AArch64 does mark ATOMIC_LOAD_ADD as LibCall already)

So AArch64 would fail your suggestion "just check if add is legal, use that if so, otherwise fall back on a libcall?" since add wouldn't be legal it would be libcall.


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https://reviews.llvm.org/D158673