[flang-commits] [clang] [flang] [llvm] Introduce -fexperimental-loop-fuse to clang and flang (PR #142686)

[Madhur Amilkanthwar via flang-commits]

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@@ -65,6 +65,9 @@ class PipelineTuningOptions {
   /// false.
   bool LoopInterchange;
 
+  /// Tuning option to enable/disable loop fusion. Its default value is false.
+  bool LoopFusion;
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madhur13490 wrote:

In `ThinLTOCodeGenerator.cpp`, I need to do `PTO.LoopFusion = False`. Such change is also needed in `mlir/lib/ExecutionEngine/OptUtils.cpp`. 

This is required at each site which is using `PipelineTuningOptions`. For `LoopInterchange` and others, initialization occurs in `PassBuilderPipelines.cpp`, but for LoopFusion, I can't do this because the definition of the LoopFusion variable is in `NewPMDriver.cpp`, as suggested by @kasuga-fj. 

I am inclined to follow the way LoopInterchange is initialized (and thus move the definition of LoopFusion from `NewPMDriver.cpp` to `PassBuilderPipelines.cpp`)

What do you think?

https://github.com/llvm/llvm-project/pull/142686