IRGen: Update AllocStackHoisting for macCatalyst.

Teach `inhibitsAllocStackHoisting` about the `targetVariantOSVersionAtLeast`
and `targetOSVersionOrVariantOSVersionAtLeast` builtins.

Author: tshortli

lib/IRGen/AllocStackHoisting.cpp

@@ -442,7 +442,9 @@ bool inhibitsAllocStackHoisting(SILInstruction *I) {
     return Apply->hasSemantics(semantics::AVAILABILITY_OSVERSION);
   }
   if (auto *bi = dyn_cast<BuiltinInst>(I)) {
-    return bi->getBuiltinInfo().ID == BuiltinValueKind::TargetOSVersionAtLeast;
+    return bi->getBuiltinInfo().ID == BuiltinValueKind::TargetOSVersionAtLeast
+        || bi->getBuiltinInfo().ID == BuiltinValueKind::TargetVariantOSVersionAtLeast
+        || bi->getBuiltinInfo().ID == BuiltinValueKind::TargetOSVersionOrVariantOSVersionAtLeast;
   }
   if (isa<HasSymbolInst>(I)) {
     return true;

test/IRGen/availability_maccatalyst.swift

@@ -0,0 +1,65 @@
+// RUN: %target-swift-frontend -target x86_64-apple-ios13.1-macabi -primary-file %s -emit-ir | %FileCheck %s
+// RUN: %target-swift-frontend -target x86_64-apple-ios13.1-macabi -primary-file %s -O -emit-ir | %FileCheck %s --check-prefix=OPT
+
+// REQUIRES: objc_interop
+// REQUIRES: OS=macosx || OS=maccatalyst
+
+import Foundation
+
+
+// We mustn't hoist the alloc_stack for measurement out of the availability
+// guard.
+
+// CHECK-LABEL: define{{.*}} @{{.*}}dontHoist
+// CHECK-NOT: s10Foundation11MeasurementVySo17NSUnitTemperature
+// CHECK: call swiftcc i1 @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"(
+// CHECK: s10Foundation11MeasurementVySo17NSUnitTemperature
+
+// OPT-LABEL: define{{.*}} @{{.*}}dontHoist
+// OPT-NOT: S10Foundation11MeasurementVySo17NSUnitTemperature
+// OPT: call {{.*}} @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"(
+// OPT: s10Foundation11MeasurementVySo17NSUnitTemperature
+
+public func dontHoist() {
+  if #available(macOS 10.15.4, iOS 13.4, watchOS 6.2, tvOS 13.4, *) {
+      let measurement = Measurement<UnitTemperature>(value: Double(42), unit: .celsius)
+      print("\(measurement)")
+  } else {
+      print("Not measurement")
+  }
+}
+
+// The optimizer is weaker for _isVariantOSVersionAtLeast than for _isOSVersionAtLeast
+// because the first is implemented in a runtime call in compiler-rt. We don't want
+// to inline the implementation details of the compiler-rt support into apps, so
+// _isVariantOSVersionAtLeast not marked as inlinable, but we do mark it as
+// _effects(readnone).
+// This means that unlike _isOSVersionAtLeast the optimizer can only coalesce
+// availability checks with the same availability. It does not determine, for example,
+// that a check for iOS 10 is sufficient to guarantee that a check for iOS 9 will also
+// succeed.
+
+// With optimizations on, multiple #availability checks should generate only
+// a single call into _isVariantOSVersionAtLeast.
+
+// CHECK-LABEL: define{{.*}} @{{.*}}multipleAvailabilityChecks
+// CHECK: call swiftcc i1 @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"(
+// CHECK: call swiftcc i1 @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"(
+// CHECK: call swiftcc i1 @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"(
+// CHECK: ret void
+
+// OPT-LABEL: define{{.*}} @{{.*}}multipleAvailabilityChecks
+// OPT: call {{.*}} @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"
+// OPT-NOT: call {{.*}} @"$ss33_stdlib_isVariantOSVersionAtLeastyBi1_Bw_BwBwtF"
+// OPT: ret void
+public func multipleAvailabilityChecks() {
+  if #available(macOS 10.15.4, iOS 13.4, watchOS 6.2, tvOS 13.4, *) {
+    print("test one")
+  }
+  if #available(macOS 10.15.4, iOS 13.4, watchOS 6.2, tvOS 13.4, *) {
+    print("test two")
+  }
+  if #available(macOS 10.15.4, iOS 13.4, watchOS 6.2, tvOS 13.4, *) {
+    print("test three")
+  }
+}

test/IRGen/availability_maccatalyst_zippered.swift

@@ -0,0 +1,30 @@
+// RUN: %target-swift-frontend -primary-file %s -target x86_64-apple-macosx10.50 -target-variant x86_64-apple-ios48.0-macabi -emit-ir | %FileCheck %s
+// RUN: %target-swift-frontend -primary-file %s -target x86_64-apple-macosx10.50 -target-variant x86_64-apple-ios48.0-macabi -O -emit-ir | %FileCheck %s --check-prefix=OPT
+
+// REQUIRES: objc_interop
+// REQUIRES: OS=macosx || OS=maccatalyst
+
+// With optimizations on, multiple #availability checks should generate only
+// a single call into _isVariantOSVersionAtLeast.
+
+// CHECK-LABEL: define{{.*}} @{{.*}}multipleAvailabilityChecks
+// CHECK: call swiftcc i1 @"$ss042_stdlib_isOSVersionAtLeastOrVariantVersiondE0yBi1_Bw_BwBwBwBwBwtF"(
+// CHECK: call swiftcc i1 @"$ss042_stdlib_isOSVersionAtLeastOrVariantVersiondE0yBi1_Bw_BwBwBwBwBwtF"(
+// CHECK: call swiftcc i1 @"$ss042_stdlib_isOSVersionAtLeastOrVariantVersiondE0yBi1_Bw_BwBwBwBwBwtF"(
+// CHECK: ret void
+
+// OPT-LABEL: define{{.*}} @{{.*}}multipleAvailabilityChecks
+// OPT: call {{.*}} @"$ss042_stdlib_isOSVersionAtLeastOrVariantVersiondE0yBi1_Bw_BwBwBwBwBwtF"
+// OPT-NOT: call {{.*}} @"$ss042_stdlib_isOSVersionAtLeastOrVariantVersiondE0yBi1_Bw_BwBwBwBwBwtF"
+// OPT: ret void
+public func multipleAvailabilityChecks() {
+  if #available(OSX 10.52, iOS 50.0, watchOS 43.0, tvOS 50.0, *) {
+    print("test one")
+  }
+  if #available(OSX 10.52, iOS 50.0, watchOS 43.0, tvOS 50.0, *) {
+    print("test two")
+  }
+  if #available(OSX 10.52, iOS 50.0, watchOS 43.0, tvOS 50.0, *) {
+    print("test three")
+  }
+}