[llvm] [InstCombine] optimize powi(X,Y)/X with Ofast (PR #67236)

[Nikita Popov via llvm-commits]

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@@ -258,3 +259,23 @@ define double @different_types_powi(double %x, i32 %y, i64 %z) {
   %mul = fmul reassoc double %p2, %p1
   ret double %mul
 }
+
+define nofpclass(nan inf) double @fdiv_pow_powi(double %x) {
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nikic wrote:

What is the purpose of the nofpclass here?

https://github.com/llvm/llvm-project/pull/67236