[llvm] [InstCombine] Convert load from LUT into a select (PR #98339)

[Nikita Popov via llvm-commits]

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@@ -1,5 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -passes=instcombine -S -data-layout="p:32:32:32-p1:16:16:16-p2:128:128:128:32-n8:16:32:64" < %s | FileCheck %s
+; RUN: opt -passes="instcombine<max-iterations=2>" -S -data-layout="p:32:32:32-p1:16:16:16-p2:128:128:128:32-n8:16:32:64" < %s | FileCheck %s
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nikic wrote:

Hm, I think this may be because ConstantFoldConstant first does recursive folding, and probably infers an inbounds that needed to fold the icmp. Maybe should explicitly call ConstantFoldConstant on the arms? We're not guaranteed that global initializers are fully folded inside InstCombine.

https://github.com/llvm/llvm-project/pull/98339