[llvm] [PowerPC] Add flag to DAG combiner to improve compile time. (PR #86884)

[Stefan Pintilie via llvm-commits]

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@@ -150,6 +150,11 @@ static cl::opt<bool> EnableVectorFCopySignExtendRound(
     cl::desc(
         "Enable merging extends and rounds into FCOPYSIGN on vector types"));
 
+static cl::opt<bool>
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stefanp-ibm wrote:

I know what you mean about these options being mostly for debug. However, this compile time issue is more of a special case. My fear with adding a threshold is that this is target indep code and it can negatively impact performance on a whole set of targets. To avoid this I would still prefer to keep the default as it is now and add an option that would add a threshold value. So, either way, I get a debug option like this one.

https://github.com/llvm/llvm-project/pull/86884