[PATCH] D141275: [AArch64] Sink to umull if we know tops bits are zero.

[Sam Tebbs via Phabricator via llvm-commits]

samtebbs accepted this revision.
samtebbs added inline comments.
This revision is now accepted and ready to land.


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Comment at: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:14092
+    // Is it profitable to sink if we found two of the same type of extends.
+    return !Ops.empty() && (NumSExts == 2 || NumZExts == 2);
   }
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dmgreen wrote:
> samtebbs wrote:
> > Would an early return within the loop in the case of `NumSExts > 2 && NumZExts > 2` make sense?
> I'm working under the assumption that a mul can only have 2 operands. The loop is just checking both of them.
I see, cool. Semantically an early return and not is the same thing when assuming 2 operands so LGTM.


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https://reviews.llvm.org/D141275