[Mlir-commits] [mlir] [mlir][inliner] Return early if the inliningThreshold is 0U or -1U. (PR #86287)

[llvmlistbot at llvm.org]

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<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir-core

Author: Fabian Tschopp (naibaf7)

<details>
<summary>Changes</summary>

Computing the inlinling profitability can be costly due to walking the graph when counting the number of operations.

This PR addresses that by returning early if the threshold is set to never or always inline.

---
Full diff: https://github.com/llvm/llvm-project/pull/86287.diff


1 Files Affected:

- (modified) mlir/lib/Transforms/InlinerPass.cpp (+6-1) 


``````````diff
diff --git a/mlir/lib/Transforms/InlinerPass.cpp b/mlir/lib/Transforms/InlinerPass.cpp
index 08d8dbf73a6a1d..8be7868b576721 100644
--- a/mlir/lib/Transforms/InlinerPass.cpp
+++ b/mlir/lib/Transforms/InlinerPass.cpp
@@ -93,12 +93,17 @@ InlinerPass::InlinerPass(std::function<void(OpPassManager &)> defaultPipeline,
 // Return true if the inlining ratio does not exceed the threshold.
 static bool isProfitableToInline(const Inliner::ResolvedCall &resolvedCall,
                                  unsigned inliningThreshold) {
+  if (inliningThreshold == 0U)
+    return false;
+  if (inliningThreshold == -1U)
+    return true;
+
   Region *callerRegion = resolvedCall.sourceNode->getCallableRegion();
   Region *calleeRegion = resolvedCall.targetNode->getCallableRegion();
 
   // We should not get external nodes here, but just return true
   // for now to preserve the original behavior of the inliner pass.
-  if (!calleeRegion || !calleeRegion)
+  if (!callerRegion || !calleeRegion)
     return true;
 
   auto countOps = [](Region *region) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/86287