[llvm] f96337e - [VectorCombine] foldConcatOfBoolMasks - add debug message for match + cost-comparison

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2024-12-22T16:21:02Z
New Revision: f96337e04e0290426c72637325424a8be8e8de5d

URL: https://github.com/llvm/llvm-project/commit/f96337e04e0290426c72637325424a8be8e8de5d
DIFF: https://github.com/llvm/llvm-project/commit/f96337e04e0290426c72637325424a8be8e8de5d.diff

LOG: [VectorCombine] foldConcatOfBoolMasks - 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 1e39f9d7be1dc5..b7956e037ad4b1 100644
--- a/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
+++ b/llvm/lib/Transforms/Vectorize/VectorCombine.cpp
@@ -1532,6 +1532,10 @@ bool VectorCombine::foldConcatOfBoolMasks(Instruction &I) {
   if (ShAmtX > 0)
     NewCost += TTI.getArithmeticInstrCost(Instruction::Shl, Ty, CostKind);
 
+  LLVM_DEBUG(dbgs() << "Found a concatenation of bitcasted bool masks: " << I
+                    << "\n  OldCost: " << OldCost << " vs NewCost: " << NewCost
+                    << "\n");
+
   if (NewCost > OldCost)
     return false;