[Mlir-commits] [mlir] ea294e3 - [MLIR][Affine] Make isValidLoopInterchangePermutation efficient (#128863)

[llvmlistbot at llvm.org]

Author: Arnab Dutta
Date: 2025-02-26T20:43:50+05:30
New Revision: ea294e3f1d3ca03a3a7e65a61d6b3945cc405200

URL: https://github.com/llvm/llvm-project/commit/ea294e3f1d3ca03a3a7e65a61d6b3945cc405200
DIFF: https://github.com/llvm/llvm-project/commit/ea294e3f1d3ca03a3a7e65a61d6b3945cc405200.diff

LOG: [MLIR][Affine] Make isValidLoopInterchangePermutation efficient (#128863)

Avoid doing dependency checks for the trivial case when size of `loops`
is 1.

Added: 
    

Modified: 
    mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp

Removed: 
    


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diff  --git a/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp b/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
index 82b96e9876a6f..6833d6583c27a 100644
--- a/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
+++ b/mlir/lib/Dialect/Affine/Utils/LoopUtils.cpp
@@ -1351,10 +1351,12 @@ static bool checkLoopInterchangeDependences(
 /// nested sequence of loops in 'loops' would violate dependences.
 bool mlir::affine::isValidLoopInterchangePermutation(
     ArrayRef<AffineForOp> loops, ArrayRef<unsigned> loopPermMap) {
+  assert(loopPermMap.size() == loops.size() && "invalid loop perm map");
+  unsigned maxLoopDepth = loops.size();
+  if (maxLoopDepth == 1)
+    return true;
   // Gather dependence components for dependences between all ops in loop nest
   // rooted at 'loops[0]', at loop depths in range [1, maxLoopDepth].
-  assert(loopPermMap.size() == loops.size());
-  unsigned maxLoopDepth = loops.size();
   std::vector<SmallVector<DependenceComponent, 2>> depCompsVec;
   getDependenceComponents(loops[0], maxLoopDepth, &depCompsVec);
   return checkLoopInterchangeDependences(depCompsVec, loops, loopPermMap);