Merge pull request swiftlang#68819 from kubamracek/embedded-osize

[embedded] Fix a compiler crash when using generic classes in -O/-Osize

Author: kubamracek

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -469,10 +469,16 @@ void addFunctionPasses(SILPassPipelinePlan &P,
   // makes a change we'll end up restarting the function passes on the
   // current function (after optimizing any new callees).
   P.addDevirtualizer();
-  P.addGenericSpecializer();
-  // Run devirtualizer after the specializer, because many
-  // class_method/witness_method instructions may use concrete types now.
-  P.addDevirtualizer();
+  // MandatoryPerformanceOptimizations already took care of all specializations
+  // in embedded Swift mode, running the generic specializer might introduce
+  // more generic calls from non-generic functions, which breaks the assumptions
+  // of embedded Swift.
+  if (!P.getOptions().EmbeddedSwift) {
+    P.addGenericSpecializer();
+    // Run devirtualizer after the specializer, because many
+    // class_method/witness_method instructions may use concrete types now.
+    P.addDevirtualizer();
+  }
   P.addARCSequenceOpts();
 
   if (P.getOptions().EnableOSSAModules) {
@@ -754,8 +760,14 @@ static void addMidLevelFunctionPipeline(SILPassPipelinePlan &P) {
 static void addLowLevelPassPipeline(SILPassPipelinePlan &P) {
   P.startPipeline("LowLevel,Function", true /*isFunctionPassPipeline*/);
 
-  // Should be after FunctionSignatureOpts and before the last inliner.
-  P.addReleaseDevirtualizer();
+  // MandatoryPerformanceOptimizations already took care of all specializations
+  // in embedded Swift mode, running the release devirtualizer might introduce
+  // more generic calls from non-generic functions, which breaks the assumptions
+  // of embedded Swift.
+  if (!P.getOptions().EmbeddedSwift) {
+    // Should be after FunctionSignatureOpts and before the last inliner.
+    P.addReleaseDevirtualizer();
+  }
 
   addFunctionPasses(P, OptimizationLevelKind::LowLevel);
 

test/embedded/classes-stack-promotion.swift

@@ -86,9 +86,7 @@ struct Main {
 // CHECK-IR-NEXT:   call {{.*}}@"$s4main5print_10terminatorys12StaticStringV_AEtF"
 // CHECK-IR-NEXT:   call {{.*}}@"$s4main5print_10terminatorys12StaticStringV_AEtF"
 // CHECK-IR-NEXT:   call {{.*}}@"$s4main3bar1oyAA7MyClassC_tF"
-// CHECK-IR-NEXT:   call {{.*}}@swift_setDeallocating
-// CHECK-IR-NEXT:   call {{.*}}@"$s4main5print_10terminatorys12StaticStringV_AEtF"
-// CHECK-IR-NEXT:   call {{.*}}@"$s4main5print_10terminatorys12StaticStringV_AEtF"
+// CHECK-IR-NEXT:   call {{.*}}@swift_release
 // CHECK-IR-NEXT:   call {{.*}}@llvm.lifetime.end.p0
 // CHECK-IR-NEXT:   call {{.*}}@"$s4main5print_10terminatorys12StaticStringV_AEtF"
 // CHECK-IR-NEXT:   call {{.*}}@swift_initStackObject

test/embedded/osize-genericspecializer.swift

@@ -0,0 +1,19 @@
+// RUN: %target-swift-emit-ir -Osize %s -enable-experimental-feature Embedded | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: VENDOR=apple
+// REQUIRES: OS=macosx
+
+public func foo<T>(n: T) {
+    bar(n: 42)
+}
+
+private func bar<T>(n: T) {
+    baz(n: 42)
+}
+
+public func baz<T>(n: T) {
+    let x: ContiguousArray<Int> = .init(repeating: 0, count: 1)
+}
+
+// CHECK: define {{.*}}@main(

test/embedded/osize-releasedevirt.swift

@@ -0,0 +1,14 @@
+// RUN: %target-swift-emit-ir -Osize %s -enable-experimental-feature Embedded | %FileCheck %s
+
+// REQUIRES: swift_in_compiler
+// REQUIRES: VENDOR=apple
+// REQUIRES: OS=macosx
+
+public func foo() {
+    bar([42])
+}
+
+func bar(_: UnsafePointer<UInt?>) {
+}
+
+// CHECK: define {{.*}}@main(