[llvm] [InstCombine] Simplify nonnull phi nodes (PR #128466)

[Nikita Popov via llvm-commits]

================
@@ -996,7 +996,7 @@ Value *InstCombinerImpl::simplifyNonNullOperand(Value *V,
   if (!V->hasOneUse())
     return nullptr;
 
-  if (Depth == 1)
+  if (Depth == 2)
----------------
nikic wrote:

Can you please land this separately, with a test for nested GEP?

It might make sense to directly go to MaxAnalysisRecursionDepth, which will also help inform how other code is written. In particular, if the depth is increased, then your phi handling as currently implemented would become very expensive.

https://github.com/llvm/llvm-project/pull/128466