[PATCH] D133524: [SLP]Improve reordering of clustered reused scalars.

[Alexey Bataev via Phabricator via llvm-commits]

ABataev added inline comments.


================
Comment at: llvm/lib/IR/Instructions.cpp:2576
+    return false;
+  // If each index is used just once, the sum of such indices is VF * (VF - 1) /
+  // 2 - arithmetic sequence.
----------------
vdmitrie wrote:
> I wonder why you departed from BitVector approach you used in the previous revision?
> The above statement is true. But what you are doing here is applying the opposite statement
> (if sum is VF * (VF-1)/2  then each index is used once in each submask).
> 
> If we have mask "0222 0123" and VF==4 the sum will be 6 in both submasks.
> 
Yeah, you're right, will use bitmask.


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  https://reviews.llvm.org/D133524/new/

https://reviews.llvm.org/D133524