[NFC] Add ApplySite.parameterDependence(target:source:)

Author: atrick

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LifetimeDependenceDiagnostics.swift

@@ -184,7 +184,8 @@ private struct DiagnoseDependence {
       if inoutArg == sourceArg {
         return .continueWalk
       }
-      if function.argumentConventions.getDependence(target: inoutArg.index, source: sourceArg.index) != nil {
+      if function.argumentConventions.parameterDependence(targetArgumentIndex: inoutArg.index,
+                                                          sourceArgumentIndex: sourceArg.index) != nil {
         // The inout result depends on a lifetime that is inherited or borrowed in the caller.
         log("  has dependent inout argument: \(inoutArg)")
         return .continueWalk

SwiftCompilerSources/Sources/Optimizer/Utilities/FunctionSignatureTransforms.swift

@@ -26,7 +26,7 @@ private extension ArgumentConventions {
 
     // Check if `argIndex` is a lifetime source in parameterDependencies
     for targetIndex in firstParameterIndex..<self.count {
-      if getDependence(target: targetIndex, source: argIndex) != nil {
+      if parameterDependence(targetArgumentIndex: targetIndex, sourceArgumentIndex: argIndex) != nil {
         return true
       }
     }

SwiftCompilerSources/Sources/SIL/ApplySite.swift

@@ -79,6 +79,15 @@ public struct ApplyOperandConventions : Collection {
       calleeArgumentIndex(ofOperandIndex: operandIndex)!]
   }
 
+  public func parameterDependence(targetOperandIndex: Int, sourceOperandIndex: Int) -> LifetimeDependenceConvention? {
+    guard let targetArgIdx = calleeArgumentIndex(ofOperandIndex: targetOperandIndex),
+          let sourceArgIdx = calleeArgumentIndex(ofOperandIndex: sourceOperandIndex) else {
+      return nil
+    }
+    return calleeArgumentConventions.parameterDependence(targetArgumentIndex: targetArgIdx,
+                                                         sourceArgumentIndex: sourceArgIdx)
+  }
+
   public var firstParameterOperandIndex: Int {
     return ApplyOperandConventions.firstArgumentIndex +
       calleeArgumentConventions.firstParameterIndex
@@ -247,6 +256,10 @@ extension ApplySite {
       : operandConventions[parameterDependencies: idx]
   }
 
+  public func parameterDependence(target: Operand, source: Operand) -> LifetimeDependenceConvention? {
+    return operandConventions.parameterDependence(targetOperandIndex: target.index, sourceOperandIndex: source.index)
+  }
+
   public var yieldConventions: YieldConventions {
     YieldConventions(convention: functionConvention)
   }

SwiftCompilerSources/Sources/SIL/Argument.swift

@@ -318,17 +318,16 @@ public struct ArgumentConventions : Collection, CustomStringConvertible {
     return convention.parameterDependencies(for: targetParamIdx)
   }
 
+  /// Return a parameter dependence of the target argument on the source argument.
+  public func parameterDependence(targetArgumentIndex: Int, sourceArgumentIndex: Int) -> LifetimeDependenceConvention? {
+    findDependence(source: sourceArgumentIndex, in: self[parameterDependencies: targetArgumentIndex])
+  }
+
   /// Return a dependence of the function results on the indexed parameter.
   public subscript(resultDependsOn argumentIndex: Int) -> LifetimeDependenceConvention? {
     findDependence(source: argumentIndex, in: convention.resultDependencies)
   }
 
-  /// Return a dependence of the target argument on the source argument.
-  public func getDependence(target targetArgumentIndex: Int, source sourceArgumentIndex: Int)
-    -> LifetimeDependenceConvention? {
-    findDependence(source: sourceArgumentIndex, in: self[parameterDependencies: targetArgumentIndex])
-  }
-
   /// Number of SIL arguments for the function type's results
   /// including the error result. Use this to avoid lazy iteration
   /// over indirectSILResults to find the count.