[llvm] c8626cd - [LoopSink] Don't sort BBs if there is only 1 of them (NFC)

[Nikita Popov via llvm-commits]

Author: Danila Kutenin
Date: 2023-08-16T10:03:21+02:00
New Revision: c8626cd916ac07f6e6c4e3ba20c089589b878847

URL: https://github.com/llvm/llvm-project/commit/c8626cd916ac07f6e6c4e3ba20c089589b878847
DIFF: https://github.com/llvm/llvm-project/commit/c8626cd916ac07f6e6c4e3ba20c089589b878847.diff

LOG: [LoopSink] Don't sort BBs if there is only 1 of them (NFC)

This was trigerred by the debug check when comp(a, a) was called.
On line 216 it's checked that LoopBlockNumber should contain
all if there are more than 1. NFC for end users

Differential Revision: https://reviews.llvm.org/D157954

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LoopSink.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/LoopSink.cpp b/llvm/lib/Transforms/Scalar/LoopSink.cpp
index 597c159682c5c0..4d51f0566310c1 100644
--- a/llvm/lib/Transforms/Scalar/LoopSink.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSink.cpp
@@ -222,9 +222,11 @@ static bool sinkInstruction(
   // order. No need to stable sort as the block numbers are a total ordering.
   SmallVector<BasicBlock *, 2> SortedBBsToSinkInto;
   llvm::append_range(SortedBBsToSinkInto, BBsToSinkInto);
-  llvm::sort(SortedBBsToSinkInto, [&](BasicBlock *A, BasicBlock *B) {
-    return LoopBlockNumber.find(A)->second < LoopBlockNumber.find(B)->second;
-  });
+  if (SortedBBsToSinkInto.size() > 1) {
+    llvm::sort(SortedBBsToSinkInto, [&](BasicBlock *A, BasicBlock *B) {
+      return LoopBlockNumber.find(A)->second < LoopBlockNumber.find(B)->second;
+    });
+  }
 
   BasicBlock *MoveBB = *SortedBBsToSinkInto.begin();
   // FIXME: Optimize the efficiency for cloned value replacement. The current