[llvm] [DAGCombiner] Freeze maybe poison operands when folding select to logic (PR #84924)

[Nikita Popov via llvm-commits]

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@@ -6,21 +6,14 @@
 
 ; (x0 < x1) && (x2 > x3)
 define i32 @cmp_and2(i32 %0, i32 %1, i32 %2, i32 %3) {
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nikic wrote:

Does SDAG ever look through CopyFromReg in some way? If not, we could assume that the value is frozen.

We can definitely treat function arguments as frozen in SDAG, I'm just not familiar with where else CopyFromReg gets used...

https://github.com/llvm/llvm-project/pull/84924