[llvm] [DeadStoreElimination] Optimize tautological assignments (PR #75744)

[Shreyansh Chouhan via llvm-commits]

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@@ -1926,6 +1926,43 @@ struct DSEState {
       if (InitC && InitC == StoredConstant)
         return MSSA.isLiveOnEntryDef(
             MSSA.getSkipSelfWalker()->getClobberingMemoryAccess(Def, BatchAA));
+
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BK1603 wrote:

https://godbolt.org/z/TMsbYhPe6

Looks like we already handle this for cases when the second operand is not a constant?

https://github.com/llvm/llvm-project/pull/75744