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[SCEV] Handle unreachable binop when matching shift recurrence

Authored by reames on Wed, Mar 31, 10:29 AM.

Description

[SCEV] Handle unreachable binop when matching shift recurrence

This fixes an issue introduced with my change d4648e, and reported in pr49768.

The root problem is that dominance collapses in unreachable code, and that LoopInfo explicitly only models reachable code. Since the recurrence matcher doesn't filter by reachability (and can't easily because not all consumers have domtree), we need to bailout before assuming that finding a recurrence implies we found a loop.

Details

Committed
reamesWed, Mar 31, 10:33 AM
Parents
rG437958d9fdb6: [X86] Improve SMULO/UMULO codegen for vXi8 vectors.
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