[llvm] 8f4d2e0 - [VectorCombine] scalarizeLoadExtract - add debug message for match + cost-comparison

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2025-03-01T09:57:08Z
New Revision: 8f4d2e02bea6933d7f4c35f577bf5780bad93beb

URL: https://github.com/llvm/llvm-project/commit/8f4d2e02bea6933d7f4c35f577bf5780bad93beb
DIFF: https://github.com/llvm/llvm-project/commit/8f4d2e02bea6933d7f4c35f577bf5780bad93beb.diff

LOG: [VectorCombine] scalarizeLoadExtract - add debug message for match + cost-comparison

Helps with debugging to show to that the fold found the match, and shows the old + new costs to indicate whether the fold was/wasn't profitable.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/VectorCombine.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
index 2e20961b4c912..bb4e1c0f67e79 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -1612,6 +1612,10 @@ bool VectorCombine::scalarizeLoadExtract(Instruction &I) {
     ScalarizedCost += TTI.getAddressComputationCost(VecTy->getElementType());
   }
 
+  LLVM_DEBUG(dbgs() << "Found all extractions of a vector load: " << I
+                    << "\n  LoadExtractCost: " << OriginalCost
+                    << " vs ScalarizedCost: " << ScalarizedCost << "\n");
+
   if (ScalarizedCost >= OriginalCost)
     return false;