Remove Block.AbsoluteID

Sources/IR/BlockID.swift

@@ -13,11 +13,6 @@ extension Block {
       self.address = address
     }
 
-    /// Creates an instance with the given address.
-    public init(_ b: Block.AbsoluteID) {
-      self.address = b.address
-    }
-
     /// Creates an instance denoting the block containing `i`.
     public init(containing i: InstructionID) {
       self.address = i.block
@@ -41,50 +36,10 @@ extension Block {
 
   }
 
-  /// The absolute ID of a basic block.
-  public struct AbsoluteID: Hashable {
-
-    /// The ID of the function containing the block.
-    public var function: Function.ID
-
-    /// The address of the block in the containing function.
-    public var address: Function.Blocks.Address
-
-    /// Creates an instance with the given properties.
-    public init(_ function: Function.ID, _ address: Function.Blocks.Address) {
-      self.function = function
-      self.address = address
-    }
-
-    /// Creates an instance with the given properties.
-    public init(_ function: Function.ID, _ block: Block.ID) {
-      self.function = function
-      self.address = block.address
-    }
-
-    /// The ID of the `index`-th parameter of the block.
-    public func parameter(_ index: Int) -> Operand {
-      .parameter(Block.ID(self), index)
-    }
-
-    /// The operand denoting the result of the instruction at `instructionAddress` in the block
-    /// identified by `self`.
-    public func result(at instructionAddress: Block.Instructions.Address) -> Operand {
-      .register(InstructionID(address, instructionAddress))
-    }
-
-  }
-
 }
 
 extension Block.ID: CustomStringConvertible {
 
   public var description: String { "b\(address)" }
 
 }
-
-extension Block.AbsoluteID: CustomStringConvertible {
-
-  public var description: String { "b\(address)" }
-
-}

Sources/IR/Emitter.swift

@@ -57,7 +57,7 @@ struct Emitter: Sendable {
   private var loops = LoopIDs()
 
   /// For each block, the state of `frames` where the block was first entered.
-  private var stackOnEntry: [Block.AbsoluteID: Stack] = [:]
+  private var stackOnEntry: [BlockAndFunction: Stack] = [:]
 
   /// Where new instructions are inserted.
   var insertionPoint: InsertionPoint?
@@ -68,6 +68,17 @@ struct Emitter: Sendable {
   /// The source code associated with instructions to be inserted.
   var currentSource: SourceRange
 
+  /// The block's ID across functions.
+  public struct BlockAndFunction: Hashable {
+
+    /// The ID of the function containing the block.
+    public var function: Function.ID
+
+    /// The block's ID inside the function.
+    public var block: Block.ID
+
+  }
+
   /// The program being lowered.
   private var program: TypedProgram {
     module.program
@@ -3592,7 +3603,7 @@ extension Emitter {
   /// This test is used to ensure that all points branching to a block
   /// have consistent stack allocations.
   fileprivate mutating func checkEntryStack(_ b: Block.ID) {
-    modify(&stackOnEntry[Block.AbsoluteID(insertionFunction!, b)]) { x in
+    modify(&stackOnEntry[BlockAndFunction(function: insertionFunction!, block: b)]) { x in
       if let y = x {
         assert(y.hasSameAllocations(as: frames))
       }