AccessUtils: use the begin_apply result instead of the begin_apply instruction for a yield access base

A begin_apply can yield multiple addresses. We need to store the result of the apply in order to distinguish between two AccessBases with different results from the same begin_apply.

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/Utilities/AccessUtils.swift

@@ -28,6 +28,7 @@
 // %l = load %s                               the access
 // ```
 //===----------------------------------------------------------------------===//
+
 import SIL
 
 /// AccessBase describes the base address of a memory access (e.g. of a `load` or `store``).
@@ -68,7 +69,7 @@ enum AccessBase : CustomStringConvertible, Hashable {
   case argument(FunctionArgument)
 
   /// An indirect result of a `begin_apply`.
-  case yield(BeginApplyInst)
+  case yield(MultipleValueInstructionResult)
 
   /// An address which is derived from a `Builtin.RawPointer`.
   case pointer(PointerToAddressInst)
@@ -86,8 +87,8 @@ enum AccessBase : CustomStringConvertible, Hashable {
     case let arg as FunctionArgument     : self = .argument(arg)
     case let ga as GlobalAddrInst        : self = .global(ga.global)
     case let mvr as MultipleValueInstructionResult:
-      if let ba = mvr.parentInstruction as? BeginApplyInst, baseAddress.type.isAddress {
-        self = .yield(ba)
+      if mvr.parentInstruction is BeginApplyInst && baseAddress.type.isAddress {
+        self = .yield(mvr)
       } else {
         self = .unidentified
       }
@@ -105,7 +106,7 @@ enum AccessBase : CustomStringConvertible, Hashable {
       case .class(let rea):    return "class  - \(rea)"
       case .tail(let rta):     return "tail - \(rta.instance)"
       case .argument(let arg): return "argument - \(arg)"
-      case .yield(let ba):     return "yield - \(ba)"
+      case .yield(let result): return "yield - \(result)"
       case .pointer(let p):    return "pointer - \(p)"
     }
   }
@@ -180,8 +181,8 @@ enum AccessBase : CustomStringConvertible, Hashable {
       return gl1 == gl2
     case (.argument(let arg1), .argument(let arg2)):
       return arg1 == arg2
-    case (.yield(let ba1), .yield(let ba2)):
-      return ba1 == ba2
+    case (.yield(let baResult1), .yield(let baResult2)):
+      return baResult1 == baResult2
     case (.pointer(let p1), .pointer(let p2)):
       return p1 == p2
     default:

SwiftCompilerSources/Sources/SIL/Instruction.swift

@@ -165,7 +165,7 @@ public class SingleValueInstruction : Instruction, Value {
   }
 }
 
-public final class MultipleValueInstructionResult : Value {
+public final class MultipleValueInstructionResult : Value, Hashable {
   public var parentInstruction: MultipleValueInstruction {
     bridged.getParent().getAs(MultipleValueInstruction.self)
   }
@@ -179,6 +179,14 @@ public final class MultipleValueInstructionResult : Value {
   var bridged: BridgedMultiValueResult {
     BridgedMultiValueResult(obj: SwiftObject(self))
   }
+
+  public static func ==(lhs: MultipleValueInstructionResult, rhs: MultipleValueInstructionResult) -> Bool {
+    lhs === rhs
+  }
+
+  public func hash(into hasher: inout Hasher) {
+    hasher.combine(ObjectIdentifier(self))
+  }
 }
 
 extension BridgedMultiValueResult {

test/SILOptimizer/accessutils.sil

@@ -338,6 +338,32 @@ bb0(%0 : $MyArray<String>):
   return %14 : $()
 }
 
+sil @yieldTwoAddresses : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64)
+
+// CHECK-LABEL: Accesses for testBeginApply
+// CHECK-NEXT: Value: (**%1**, %2, %3) = begin_apply %0() : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64) // user: %4
+// CHECK-NEXT:   Scope: base
+// CHECK-NEXT:   Base: yield - (**%1**, %2, %3) = begin_apply %0() : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64) // user: %4
+// CHECK-NEXT:   Path: ""
+// CHECK-NEXT:    no Storage paths
+// CHECK-NEXT: Value: (%1, **%2**, %3) = begin_apply %0() : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64) // user: %5
+// CHECK-NEXT:   Scope: base
+// CHECK-NEXT:   Base: yield - (%1, **%2**, %3) = begin_apply %0() : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64) // user: %5
+// CHECK-NEXT:   Path: ""
+// CHECK-NEXT:    no Storage paths
+// CHECK-NEXT:  End accesses for testBeginApply
+sil @testBeginApply : $@convention(thin) () -> () {
+bb0:
+  %0 = function_ref @yieldTwoAddresses : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64)
+  (%1, %2, %3) = begin_apply %0() : $@yield_once @convention(thin) () -> (@yields @in_guaranteed String, @yields @in_guaranteed Int64)
+  %4 = load %1 : $*String
+  %5 = load %2 : $*Int64
+  end_apply %3
+  %7 = tuple ()
+  return %7 : $()
+}
+
+
 sil_global @global1 : $Int64
 sil_global @global2 : $Int64