Add some swift SIL+Optimizer infrastructure

SwiftCompilerSources/Sources/Optimizer/CMakeLists.txt

@@ -16,4 +16,5 @@ add_subdirectory(DataStructures)
 add_subdirectory(InstructionPasses)
 add_subdirectory(PassManager)
 add_subdirectory(FunctionPasses)
+add_subdirectory(TestPasses)
 add_subdirectory(Utilities)

SwiftCompilerSources/Sources/Optimizer/DataStructures/BasicBlockRange.swift

@@ -78,8 +78,7 @@ struct BasicBlockRange : CustomStringConvertible, CustomReflectable {
 
   /// Insert a potential end block.
   mutating func insert(_ block: BasicBlock) {
-    if !wasInserted.contains(block) {
-      wasInserted.insert(block)
+    if wasInserted.insert(block) {
       inserted.append(block)
     }
     worklist.pushIfNotVisited(block)

SwiftCompilerSources/Sources/Optimizer/DataStructures/BasicBlockWorklist.swift

@@ -34,8 +34,7 @@ struct BasicBlockWorklist : CustomStringConvertible, CustomReflectable {
 
   /// Pushes \p block onto the worklist if \p block has never been pushed before.
   mutating func pushIfNotVisited(_ block: BasicBlock) {
-    if !pushedBlocks.contains(block) {
-      pushedBlocks.insert(block);
+    if pushedBlocks.insert(block) {
       worklist.append(block)
     }
   }

SwiftCompilerSources/Sources/Optimizer/DataStructures/CMakeLists.txt

@@ -9,6 +9,7 @@
 swift_compiler_sources(Optimizer
   BasicBlockRange.swift
   BasicBlockWorklist.swift
+  FunctionUses.swift
   InstructionRange.swift
   Set.swift
   Stack.swift)

SwiftCompilerSources/Sources/Optimizer/DataStructures/FunctionUses.swift

@@ -0,0 +1,166 @@
+//===--- FunctionUses.swift -----------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SIL
+
+/// Provides a list of instructions, which reference a function.
+///
+/// A function "use" is an instruction in another (or the same) function which
+/// references the function. In most cases those are `function_ref` instructions,
+/// but can also be e.g. `keypath` instructions.
+///
+/// 'FunctionUses' performs an analysis of all functions in the module and collects
+/// instructions which reference other functions. This utility can be used to do
+/// inter-procedural caller-analysis.
+///
+/// In order to use `FunctionUses`, first call `collect()` and then get use-lists of
+/// functions with `getUses(of:)`.
+struct FunctionUses {
+
+  // Function uses are stored in a single linked list, whereas the "next" is not a pointer
+  // but an index into `FunctionUses.useStorage`.
+  fileprivate struct Use {
+    // The index of the next use in `FunctionUses.useStorage`.
+    let next: Int?
+
+    // The instruction which references the function.
+    let usingInstruction: Instruction
+  }
+
+  // The head of the single-linked list of function uses.
+  fileprivate struct FirstUse {
+    // The head of the use-list.
+    var first: Int?
+
+    // True if the function has unknown uses
+    var hasUnknownUses: Bool
+
+    init(of function: Function) {
+      self.hasUnknownUses = function.isPossiblyUsedExternally || function.isAvailableExternally
+    }
+
+    mutating func insert(_ inst: Instruction, _ uses: inout [Use]) {
+      let newFirst = uses.count
+      uses.append(Use(next: first, usingInstruction: inst))
+      first = newFirst
+    }
+  }
+
+  /// The list of uses of a function.
+  struct UseList : CollectionLikeSequence, CustomStringConvertible {
+    struct Iterator : IteratorProtocol {
+      fileprivate let useStorage: [Use]
+      fileprivate var currentUseIdx: Int?
+
+      mutating func next() -> Instruction? {
+        if let useIdx = currentUseIdx {
+          let use = useStorage[useIdx]
+          currentUseIdx = use.next
+          return use.usingInstruction
+        }
+        return nil
+      }
+    }
+
+    // The "storage" for all function uses.
+    fileprivate let useStorage: [Use]
+
+    // The head of the single-linked use list.
+    fileprivate let firstUse: FirstUse
+
+    /// True if the function has unknown uses in addition to the list of referencing instructions.
+    ///
+    /// This is the case, e.g. if the function has public linkage or if the function
+    /// is referenced from a vtable or witness table.
+    var hasUnknownUses: Bool { firstUse.hasUnknownUses }
+
+    func makeIterator() -> Iterator {
+      return Iterator(useStorage: useStorage, currentUseIdx: firstUse.first)
+    }
+
+    var description: String {
+      var result = "[\n"
+      if hasUnknownUses {
+        result += "<unknown uses>\n"
+      }
+      for inst in self {
+        result += "@\(inst.function.name): \(inst)\n"
+
+      }
+      result += "]"
+      return result
+    }
+
+    var customMirror: Mirror { Mirror(self, children: []) }
+  }
+
+  // The "storage" for all function uses.
+  private var useStorage: [Use] = []
+
+  // The use-list head for each function.
+  private var uses: [Function: FirstUse] = [:]
+
+  init() {
+    // Already start with a reasonable big capacity to reduce the number of
+    // re-allocations when appending to the data structures.
+    useStorage.reserveCapacity(128)
+    uses.reserveCapacity(64)
+  }
+
+  /// Returns the use-list of `function`.
+  ///
+  /// Note that `collect` must be called before `getUses` can be used.
+  func getUses(of function: Function) -> UseList {
+    UseList(useStorage: useStorage, firstUse: uses[function, default: FirstUse(of: function)])
+  }
+
+  /// Collects all uses of all function in the module.
+  mutating func collect(context: ModulePassContext) {
+
+    // Mark all functions, which are referenced from tables, to have "unknown" uses.
+
+    for vTable in context.vTables {
+      for entry in vTable.entries {
+        markUnknown(entry.function)
+      }
+    }
+
+    for witnessTable in context.witnessTables {
+      for entry in witnessTable.entries {
+        if entry.kind == .method, let f = entry.methodFunction {
+          markUnknown(f)
+        }
+      }
+    }
+
+    for witnessTable in context.defaultWitnessTables {
+      for entry in witnessTable.entries {
+        if entry.kind == .method, let f = entry.methodFunction {
+          markUnknown(f)
+        }
+      }
+    }
+
+    // Collect all instructions, which reference functions, in the module.
+    for function in context.functions {
+      for inst in function.instructions {
+        inst.visitReferencedFunctions { referencedFunc in
+          uses[referencedFunc, default: FirstUse(of: referencedFunc)].insert(inst, &useStorage)
+        }
+      }
+    }
+  }
+
+  private mutating func markUnknown(_ function: Function) {
+    uses[function, default: FirstUse(of: function)].hasUnknownUses = true
+  }
+}

SwiftCompilerSources/Sources/Optimizer/DataStructures/Set.swift

@@ -35,8 +35,10 @@ struct BasicBlockSet : CustomStringConvertible, CustomReflectable {
     BasicBlockSet_contains(bridged, block.bridged) != 0
   }
 
-  mutating func insert(_ block: BasicBlock) {
-    BasicBlockSet_insert(bridged, block.bridged)
+  /// Returns true if `block` was not contained in the set before inserting.
+  @discardableResult
+  mutating func insert(_ block: BasicBlock) -> Bool {
+    BasicBlockSet_insert(bridged, block.bridged) != 0
   }
 
   mutating func erase(_ block: BasicBlock) {
@@ -80,8 +82,10 @@ struct ValueSet : CustomStringConvertible, CustomReflectable {
     NodeSet_containsValue(bridged, value.bridged) != 0
   }
 
-  mutating func insert(_ value: Value) {
-    NodeSet_insertValue(bridged, value.bridged)
+  /// Returns true if `value` was not contained in the set before inserting.
+  @discardableResult
+  mutating func insert(_ value: Value) -> Bool {
+    NodeSet_insertValue(bridged, value.bridged) != 0
   }
 
   mutating func erase(_ value: Value) {
@@ -139,8 +143,10 @@ struct InstructionSet : CustomStringConvertible, CustomReflectable {
     NodeSet_containsInstruction(bridged, inst.bridged) != 0
   }
 
-  mutating func insert(_ inst: Instruction) {
-    NodeSet_insertInstruction(bridged, inst.bridged)
+  /// Returns true if `inst` was not contained in the set before inserting.
+  @discardableResult
+  mutating func insert(_ inst: Instruction) -> Bool {
+    NodeSet_insertInstruction(bridged, inst.bridged) != 0
   }
 
   mutating func erase(_ inst: Instruction) {
@@ -150,11 +156,9 @@ struct InstructionSet : CustomStringConvertible, CustomReflectable {
   var description: String {
     let function = NodeSet_getFunction(bridged).function
     var d = "{\n"
-    for block in function.blocks {
-      for inst in block.instructions {
-        if contains(inst) {
-          d += inst.description
-        }
+    for inst in function.instructions {
+      if contains(inst) {
+        d += inst.description
       }
     }
     d += "}\n"

SwiftCompilerSources/Sources/Optimizer/DataStructures/Stack.swift

@@ -26,7 +26,7 @@ import SIL
 /// destruct this data structure, e.g. in a `defer {}` block.
 struct Stack<Element> : CollectionLikeSequence {
 
-  private let context: PassContext
+  private let bridgedContext: BridgedPassContext
   private var firstSlab = BridgedSlab(data: nil)
   private var lastSlab = BridgedSlab(data: nil)
   private var endIndex: Int = 0
@@ -61,7 +61,8 @@ struct Stack<Element> : CollectionLikeSequence {
     }
   }
 
-  init(_ context: PassContext) { self.context = context }
+  init(_ context: PassContext) { self.bridgedContext = context._bridged }
+  init(_ context: ModulePassContext) { self.bridgedContext = context._bridged }
 
   func makeIterator() -> Iterator {
     return Iterator(slab: firstSlab, index: 0, lastSlab: lastSlab, endIndex: endIndex)
@@ -77,11 +78,11 @@ struct Stack<Element> : CollectionLikeSequence {
 
   mutating func push(_ element: Element) {
     if endIndex >= Stack.slabCapacity {
-      lastSlab = PassContext_allocSlab(context._bridged, lastSlab)
+      lastSlab = PassContext_allocSlab(bridgedContext, lastSlab)
       endIndex = 0
     } else if firstSlab.data == nil {
       assert(endIndex == 0)
-      firstSlab = PassContext_allocSlab(context._bridged, lastSlab)
+      firstSlab = PassContext_allocSlab(bridgedContext, lastSlab)
       lastSlab = firstSlab
     }
     (Stack.bind(lastSlab) + endIndex).initialize(to: element)
@@ -109,12 +110,12 @@ struct Stack<Element> : CollectionLikeSequence {
 
     if endIndex == 0 {
       if lastSlab.data == firstSlab.data {
-        _ = PassContext_freeSlab(context._bridged, lastSlab)
+        _ = PassContext_freeSlab(bridgedContext, lastSlab)
         firstSlab.data = nil
         lastSlab.data = nil
         endIndex = 0
       } else {
-        lastSlab = PassContext_freeSlab(context._bridged, lastSlab)
+        lastSlab = PassContext_freeSlab(bridgedContext, lastSlab)
         endIndex = Stack.slabCapacity
       }
     }

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/AssumeSingleThreaded.swift

@@ -29,12 +29,10 @@ import SIL
 
 let assumeSingleThreadedPass = FunctionPass(
   name: "sil-assume-single-threaded", { function, context in
-    for block in function.blocks {
-      for inst in block.instructions {
-        guard let rcInst = inst as? RefCountingInst else { continue }
+    for inst in function.instructions {
+      guard let rcInst = inst as? RefCountingInst else { continue }
 
-        rcInst.setAtomicity(isAtomic: false, context)
-      }
+      rcInst.setAtomicity(isAtomic: false, context)
     }
   }
 )

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/CMakeLists.txt

@@ -8,14 +8,9 @@
 
 swift_compiler_sources(Optimizer
   AssumeSingleThreaded.swift
-  AccessDumper.swift
   ComputeEffects.swift
-  EscapeInfoDumper.swift
   ObjCBridgingOptimization.swift
-  SILPrinter.swift
   MergeCondFails.swift
-  RangeDumper.swift
   ReleaseDevirtualizer.swift
-  RunUnitTests.swift
   StackPromotion.swift
 )

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/ObjCBridgingOptimization.swift

@@ -48,12 +48,10 @@ let objCBridgingOptimization = FunctionPass(name: "objc-bridging-opt", {
   }
 
   // Now try to optimize non-optional and optional -> non-optional bridging.
-  for block in function.blocks {
-    for inst in block.instructions {
-      if let apply = inst as? ApplyInst {
-        if !optimizeNonOptionalBridging(apply, context) {
-          return
-        }
+  for inst in function.instructions {
+    if let apply = inst as? ApplyInst {
+      if !optimizeNonOptionalBridging(apply, context) {
+        return
       }
     }
   }