[llvm] PreISelIntrinsicLowering: Lower llvm.exp to a loop if scalable vec arg (PR #117568)

[Matt Arsenault via llvm-commits]

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@@ -335,6 +335,59 @@ bool PreISelIntrinsicLowering::expandMemIntrinsicUses(Function &F) const {
   return Changed;
 }
 
+static bool lowerExpIntrinsicToLoop(Module &M, Function &F, CallInst *CI) {
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arsenm wrote:

Should generalize this over the intrinsic. Probably should put it in utils

https://github.com/llvm/llvm-project/pull/117568