Nimit Sachdeva 2297e0d316 [MoveAutoInit] Fix for miscompilation for #150120 (#173961) ...

Fixes the miscompilation discussed for the PR #164882 as part of
generalizing the optimization for the issue #150120.

Without this commit, MoveAutoInit moves the store instruction to a
different branch which does not dominate the user dominator node. This
results in UB at runtime. The example in the test case is specifically
for an irreducible loop, in which all the predecessor may not dominate
user dominator head.

To fix this problem, we've introduced a new check to verify if the
predecessor of the user dominator node does in fact dominate user
dominator node before deciding that it is the node where the instruction
will be moved to.

2026-01-25 16:21:52 +01:00

7.9 KiB

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