Revert "Fix quadratic performance of the ListMerger in specific usage pattern"

Author: atrick

benchmark/CMakeLists.txt

@@ -40,7 +40,6 @@ set(SWIFT_BENCH_MODULES
     single-source/ArrayRemoveAll
     single-source/ArraySetElement
     single-source/ArraySubscript
-    single-source/AsyncTree
     single-source/BinaryFloatingPointConversionFromBinaryInteger
     single-source/BinaryFloatingPointProperties
     single-source/BitCount

benchmark/single-source/AsyncTree.swift

@@ -28,7 +28,6 @@ import ArrayOfRef
 import ArrayRemoveAll
 import ArraySetElement
 import ArraySubscript
-import AsyncTree
 import BinaryFloatingPointConversionFromBinaryInteger
 import BinaryFloatingPointProperties
 import BitCount
@@ -224,7 +223,6 @@ register(ArrayOfRef.benchmarks)
 register(ArrayRemoveAll.benchmarks)
 register(ArraySetElement.benchmarks)
 register(ArraySubscript.benchmarks)
-register(AsyncTree.benchmarks)
 register(BinaryFloatingPointConversionFromBinaryInteger.benchmarks)
 register(BinaryFloatingPointProperties.benchmarks)
 register(BitCount.benchmarks)

benchmark/utils/main.swift

@@ -2511,32 +2511,6 @@ inline int descendingPriorityOrder(JobPriority lhs,
   return (lhs == rhs ? 0 : lhs > rhs ? -1 : 1);
 }
 
-enum { PriorityBucketCount = 5 };
-
-inline int getPriorityBucketIndex(JobPriority priority) {
-  // Any unknown priorities will be rounded up to a known one.
-  // Priorities higher than UserInteractive are clamped to UserInteractive.
-  // Jobs of unknown priorities will end up in the same bucket as jobs of a
-  // corresponding known priority. Within the bucket they will be sorted in
-  // FIFO order.
-  if (priority > JobPriority::UserInitiated) {
-    // UserInteractive and higher
-    return 0;
-  } else if (priority > JobPriority::Default) {
-    // UserInitiated
-    return 1;
-  } else if (priority > JobPriority::Utility) {
-    // Default
-    return 2;
-  } else if (priority > JobPriority::Background) {
-    // Utility
-    return 3;
-  } else {
-    // Background and lower
-    return 4;
-  }
-}
-
 inline JobPriority withUserInteractivePriorityDowngrade(JobPriority priority) {
   return (priority == JobPriority::UserInteractive) ? JobPriority::UserInitiated
                                                     : priority;