Volodymyr Vasylkun 21e3a212c5 [InstCombine] Replace an integer comparison of a phi node with multiple ucmp/scmp operands and a constant with phi of individual comparisons of original intrinsic's arguments (#107769) ...

When we have a `phi` instruction with more than one of its incoming
values being a call to `ucmp` or `scmp`, which is then compared with an
integer constant, we can move the comparison through the `phi` into the
incoming basic blocks because we know that a comparison of `ucmp`/`scmp`
with a constant will be simplified by the next iteration of InstCombine.

There's a high chance that other similar patterns can be identified, in
which case they can be easily handled by the same code by moving the
check for "simplifiable" instructions into a lambda.

2024-09-13 19:50:27 +01:00

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