[PATCH] D129995: [AArch64] isDesirableToCommuteWithShift - fix UBFX masked shift comment. NFC.

[Dave Green via Phabricator via llvm-commits]

dmgreen added a reviewer: efriedma.
dmgreen added a comment.

I don't know this code very well. It looks like `N = N->getOperand(0).getNode();` was added later than the original code.
The code seems to be checking for a AND with an operand that is a SRL. So in that regards matches the original comment. That pattern will itself be shifted by the original N, IIUC?
I expect the "((x >> C) & mask)" is meant to be the "extract of some number of bits from x". Those bits are then shifted into where they belong in the final value.


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https://reviews.llvm.org/D129995