Merge pull request #66048 from eeckstein/object-outliner

Implement the ObjectOutliner and `load` simplification in Swift

Author: eeckstein

SwiftCompilerSources/Sources/Basic/Utils.swift

@@ -64,11 +64,21 @@ public struct StringRef : CustomStringConvertible, NoReflectionChildren {
 
   public var string: String { _bridged.string }
   public var description: String { string }
-  
+
+  public var count: Int {
+    Int(_bridged.__bytes_endUnsafe() - _bridged.__bytes_beginUnsafe())
+  }
+
+  public subscript(index: Int) -> UInt8 {
+    let buffer = UnsafeBufferPointer<UInt8>(start: _bridged.__bytes_beginUnsafe(),
+                                            count: count)
+    return buffer[index]
+  }
+
   public static func ==(lhs: StringRef, rhs: StaticString) -> Bool {
     let lhsBuffer = UnsafeBufferPointer<UInt8>(
       start: lhs._bridged.__bytes_beginUnsafe(),
-      count: Int(lhs._bridged.__bytes_endUnsafe() - lhs._bridged.__bytes_beginUnsafe()))
+      count: lhs.count)
     return rhs.withUTF8Buffer { (rhsBuffer: UnsafeBufferPointer<UInt8>) in
       if lhsBuffer.count != rhsBuffer.count { return false }
       return lhsBuffer.elementsEqual(rhsBuffer, by: ==)

SwiftCompilerSources/Sources/Optimizer/DataStructures/Worklist.swift

@@ -74,3 +74,4 @@ struct Worklist<Set: IntrusiveSet> : CustomStringConvertible, NoReflectionChildr
 
 typealias BasicBlockWorklist = Worklist<BasicBlockSet>
 typealias InstructionWorklist = Worklist<InstructionSet>
+typealias ValueWorklist = Worklist<ValueSet>

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/CMakeLists.txt

@@ -12,6 +12,7 @@ swift_compiler_sources(Optimizer
   ComputeEscapeEffects.swift
   ComputeSideEffects.swift
   InitializeStaticGlobals.swift
+  ObjectOutliner.swift
   ObjCBridgingOptimization.swift
   MergeCondFails.swift
   NamedReturnValueOptimization.swift

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/InitializeStaticGlobals.swift

@@ -56,8 +56,11 @@ let initializeStaticGlobalsPass = FunctionPass(name: "initialize-static-globals"
     return
   }
 
-  context.createStaticInitializer(for: allocInst.global,
-                                  initValue: storeToGlobal.source as! SingleValueInstruction)
+  var cloner = StaticInitCloner(cloneTo: allocInst.global, context)
+  defer { cloner.deinitialize() }
+
+  _ = cloner.clone(storeToGlobal.source)
+
   context.erase(instruction: allocInst)
   context.erase(instruction: storeToGlobal)
 }