Merge pull request #81837 from atrick/builtin-addressof

LifetimeDependenceInsertion: allow dependency on Builtin.addressof()

Author: atrick

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LifetimeDependenceInsertion.swift

@@ -413,6 +413,11 @@ struct VariableIntroducerUseDefWalker : LifetimeDependenceUseDefValueWalker, Lif
   }
 
   mutating func introducer(_ value: Value, _ owner: Value?) -> WalkResult {
+    if let addrToPtr = value as? AddressToPointerInst {
+      // AddressToPointer introduces the value dependence. To handle Builtin.addressOfBorrow, follow the address that
+      // the pointer is derived from.
+      return walkUp(address: addrToPtr.address)
+    }
     return visitorClosure(value)
   }
 

test/SILOptimizer/lifetime_dependence/dependence_insertion.swift

@@ -81,6 +81,39 @@ func bv_pointer_convert(p: UnsafePointer<Int>) -> BV {
   BV(p, 0)
 }
 
+// =============================================================================
+// Builtin.addressOfBorrow
+// =============================================================================
+
+// swift-frontend -emit-sil -enable-builtin-module -enable-experimental-feature LifetimeDependence -enable-experimental-feature AddressableParameters -Xllvm -sil-print-function=test ./dependsOnAddress.swift
+
+import Builtin
+
+struct IntHolder {
+  var field: Int
+}
+
+struct NERawPointer: ~Escapable {
+  var p: Builtin.RawPointer
+}
+
+@lifetime(borrow x)
+func pointerDepends(on x: Builtin.RawPointer) -> NERawPointer {
+  NERawPointer(p: x)
+}
+
+// CHECK-LABEL: sil hidden [ossa] @$s4test0A22BuiltinAddressOfBorrow6holderAA12NERawPointerVAA9IntHolderVz_tF : $@convention(thin) (@inout IntHolder) -> @lifetime(borrow 0) @owned NERawPointer {
+// CHECK: bb0(%0 : $*IntHolder):
+// CHECK: [[ACCESS:%[0-9]+]] = begin_access [read] [static] %0
+// CHECK: [[PTR:%[0-9]+]] = address_to_pointer [stack_protection] %2 to $Builtin.RawPointer
+// CHECK: [[NE:%[0-9]+]] = apply %{{.*}}([[PTR]]) : $@convention(thin) (Builtin.RawPointer) -> @lifetime(borrow 0) @owned NERawPointer
+// CHECK: mark_dependence [unresolved] [[NE]] on %0
+// CHECK-LABEL: } // end sil function '$s4test0A22BuiltinAddressOfBorrow6holderAA12NERawPointerVAA9IntHolderVz_tF'
+@lifetime(borrow holder)
+func testBuiltinAddressOfBorrow(holder: inout IntHolder) -> NERawPointer {
+  pointerDepends(on: Builtin.addressOfBorrow(holder))
+}
+
 // =============================================================================
 // @_addressableForDependencies
 // =============================================================================