[ObjC][ARC] Upgrade calls to ARC runtime functions to intrinsic calls if

the bitcode has the arm64 retainAutoreleasedReturnValue marker

The ARC middle-end passes stopped optimizing or transforming bitcode
that has been compiled with old compilers after we started emitting
calls to ARC runtime functions as intrinsic calls instead of normal
function calls in the front-end and made changes to teach the ARC
middle-end passes about those intrinsics (see r349534). This patch
converts calls to ARC runtime functions that are not intrinsic functions
to intrinsic function calls if the bitcode has the arm64
retainAutoreleasedReturnValue marker. Checking for the presence of the
marker is necessary to make sure we aren't changing ARC function calls
that were originally MRR message sends (see r349952).

rdar://problem/53280660

Differential Revision: https://reviews.llvm.org/D65902

llvm-svn: 368311

include/llvm/IR/AutoUpgrade.h

@@ -58,6 +58,10 @@ namespace llvm {
   /// returns true if module is modified.
   bool UpgradeRetainReleaseMarker(Module &M);
 
+  /// Convert calls to ARC runtime functions to intrinsic calls if the bitcode
+  /// has the arm64 retainAutoreleasedReturnValue marker.
+  bool UpgradeARCRuntimeCalls(Module &M);
+
   void UpgradeSectionAttributes(Module &M);
 
   /// If the given TBAA tag uses the scalar TBAA format, create a new node

lib/Bitcode/Reader/BitcodeReader.cpp

@@ -5313,6 +5313,7 @@ Error BitcodeReader::materializeModule() {
   UpgradeModuleFlags(*TheModule);
 
   UpgradeRetainReleaseMarker(*TheModule);
+  UpgradeARCRuntimeCalls(*TheModule);
 
   return Error::success();
 }

lib/IR/AutoUpgrade.cpp

@@ -490,12 +490,6 @@ static bool UpgradeX86IntrinsicFunction(Function *F, StringRef Name,
 static bool UpgradeIntrinsicFunction1(Function *F, Function *&NewFn) {
   assert(F && "Illegal to upgrade a non-existent Function.");
 
-  // Upgrade intrinsics "clang.arc.use" which doesn't start with "llvm.".
-  if (F->getName() == "clang.arc.use") {
-    NewFn = nullptr;
-    return true;
-  }
-
   // Quickly eliminate it, if it's not a candidate.
   StringRef Name = F->getName();
   if (Name.size() <= 8 || !Name.startswith("llvm."))
@@ -1661,14 +1655,6 @@ void llvm::UpgradeIntrinsicCall(CallInst *CI, Function *NewFn) {
     // Get the Function's name.
     StringRef Name = F->getName();
 
-    // clang.arc.use is an old name for llvm.arc.clang.arc.use. It is dropped
-    // from upgrader because the optimizer now only recognizes intrinsics for
-    // ARC runtime calls.
-    if (Name == "clang.arc.use") {
-      CI->eraseFromParent();
-      return;
-    }
-
     assert(Name.startswith("llvm.") && "Intrinsic doesn't start with 'llvm.'");
     Name = Name.substr(5);
 
@@ -3868,6 +3854,74 @@ bool llvm::UpgradeRetainReleaseMarker(Module &M) {
   return Changed;
 }
 
+bool llvm::UpgradeARCRuntimeCalls(Module &M) {
+  auto UpgradeToIntrinsic = [&](const char *OldFunc,
+                                llvm::Intrinsic::ID IntrinsicFunc) {
+    Function *Fn = M.getFunction(OldFunc);
+
+    if (!Fn)
+      return false;
+
+    Function *NewFn = llvm::Intrinsic::getDeclaration(&M, IntrinsicFunc);
+    Fn->replaceAllUsesWith(NewFn);
+    Fn->eraseFromParent();
+    return true;
+  };
+
+  // Unconditionally convert "clang.arc.use" to "llvm.objc.clang.arc.use".
+  bool Changed =
+      UpgradeToIntrinsic("clang.arc.use", llvm::Intrinsic::objc_clang_arc_use);
+
+  // Return if the bitcode doesn't have the arm64 retainAutoreleasedReturnValue
+  // marker. We don't know for sure that it was compiled with ARC in that case.
+  if (!M.getModuleFlag("clang.arc.retainAutoreleasedReturnValueMarker"))
+    return false;
+
+  std::pair<const char *, llvm::Intrinsic::ID> RuntimeFuncs[] = {
+      {"objc_autorelease", llvm::Intrinsic::objc_autorelease},
+      {"objc_autoreleasePoolPop", llvm::Intrinsic::objc_autoreleasePoolPop},
+      {"objc_autoreleasePoolPush", llvm::Intrinsic::objc_autoreleasePoolPush},
+      {"objc_autoreleaseReturnValue",
+       llvm::Intrinsic::objc_autoreleaseReturnValue},
+      {"objc_copyWeak", llvm::Intrinsic::objc_copyWeak},
+      {"objc_destroyWeak", llvm::Intrinsic::objc_destroyWeak},
+      {"objc_initWeak", llvm::Intrinsic::objc_initWeak},
+      {"objc_loadWeak", llvm::Intrinsic::objc_loadWeak},
+      {"objc_loadWeakRetained", llvm::Intrinsic::objc_loadWeakRetained},
+      {"objc_moveWeak", llvm::Intrinsic::objc_moveWeak},
+      {"objc_release", llvm::Intrinsic::objc_release},
+      {"objc_retain", llvm::Intrinsic::objc_retain},
+      {"objc_retainAutorelease", llvm::Intrinsic::objc_retainAutorelease},
+      {"objc_retainAutoreleaseReturnValue",
+       llvm::Intrinsic::objc_retainAutoreleaseReturnValue},
+      {"objc_retainAutoreleasedReturnValue",
+       llvm::Intrinsic::objc_retainAutoreleasedReturnValue},
+      {"objc_retainBlock", llvm::Intrinsic::objc_retainBlock},
+      {"objc_storeStrong", llvm::Intrinsic::objc_storeStrong},
+      {"objc_storeWeak", llvm::Intrinsic::objc_storeWeak},
+      {"objc_unsafeClaimAutoreleasedReturnValue",
+       llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue},
+      {"objc_retainedObject", llvm::Intrinsic::objc_retainedObject},
+      {"objc_unretainedObject", llvm::Intrinsic::objc_unretainedObject},
+      {"objc_unretainedPointer", llvm::Intrinsic::objc_unretainedPointer},
+      {"objc_retain_autorelease", llvm::Intrinsic::objc_retain_autorelease},
+      {"objc_sync_enter", llvm::Intrinsic::objc_sync_enter},
+      {"objc_sync_exit", llvm::Intrinsic::objc_sync_exit},
+      {"objc_arc_annotation_topdown_bbstart",
+       llvm::Intrinsic::objc_arc_annotation_topdown_bbstart},
+      {"objc_arc_annotation_topdown_bbend",
+       llvm::Intrinsic::objc_arc_annotation_topdown_bbend},
+      {"objc_arc_annotation_bottomup_bbstart",
+       llvm::Intrinsic::objc_arc_annotation_bottomup_bbstart},
+      {"objc_arc_annotation_bottomup_bbend",
+       llvm::Intrinsic::objc_arc_annotation_bottomup_bbend}};
+
+  for (auto &I : RuntimeFuncs)
+    Changed |= UpgradeToIntrinsic(I.first, I.second);
+
+  return Changed;
+}
+
 bool llvm::UpgradeModuleFlags(Module &M) {
   NamedMDNode *ModFlags = M.getModuleFlagsMetadata();
   if (!ModFlags)

test/Bitcode/upgrade-arc-runtime-calls.ll

@@ -0,0 +1,75 @@
+; Test that calls to ARC runtime functions are converted to intrinsic calls if
+; the bitcode has the arm64 retainAutoreleasedReturnValueMarker metadata.
+
+; upgrade-arc-runtime-calls.bc and upgrade-mrr-runtime-calls.bc are identical
+; except that the former has the arm64 retainAutoreleasedReturnValueMarker
+; metadata.
+
+; RUN: llvm-dis < %S/upgrade-arc-runtime-calls.bc | FileCheck -check-prefixes=ARC %s
+; RUN: llvm-dis < %S/upgrade-mrr-runtime-calls.bc | FileCheck -check-prefixes=MRR %s
+
+// ARC: define void @testRuntimeCalls(i8* %[[A:.*]], i8** %[[B:.*]], i8** %[[C:.*]]) {
+// ARC: %[[V0:.*]] = tail call i8* @llvm.objc.autorelease(i8* %[[A]])
+// ARC-NEXT: tail call void @llvm.objc.autoreleasePoolPop(i8* %[[A]])
+// ARC-NEXT: %[[V1:.*]] = tail call i8* @llvm.objc.autoreleasePoolPush()
+// ARC-NEXT: %[[V2:.*]] = tail call i8* @llvm.objc.autoreleaseReturnValue(i8* %[[A]])
+// ARC-NEXT: tail call void @llvm.objc.copyWeak(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: tail call void @llvm.objc.destroyWeak(i8** %[[B]])
+// ARC-NEXT: %[[V3:.*]] = tail call i8* @llvm.objc.initWeak(i8** %[[B]], i8* %[[A]])
+// ARC-NEXT: %[[V4:.*]] = tail call i8* @llvm.objc.loadWeak(i8** %[[B]])
+// ARC-NEXT: %[[V5:.*]] = tail call i8* @llvm.objc.loadWeakRetained(i8** %[[B]])
+// ARC-NEXT: tail call void @llvm.objc.moveWeak(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: tail call void @llvm.objc.release(i8* %[[A]])
+// ARC-NEXT: %[[V6:.*]] = tail call i8* @llvm.objc.retain(i8* %[[A]])
+// ARC-NEXT: %[[V7:.*]] = tail call i8* @llvm.objc.retainAutorelease(i8* %[[A]])
+// ARC-NEXT: %[[V8:.*]] = tail call i8* @llvm.objc.retainAutoreleaseReturnValue(i8* %[[A]])
+// ARC-NEXT: %[[V9:.*]] = tail call i8* @llvm.objc.retainAutoreleasedReturnValue(i8* %[[A]])
+// ARC-NEXT: %[[V10:.*]] = tail call i8* @llvm.objc.retainBlock(i8* %[[A]])
+// ARC-NEXT: tail call void @llvm.objc.storeStrong(i8** %[[B]], i8* %[[A]])
+// ARC-NEXT: %[[V11:.*]] = tail call i8* @llvm.objc.storeWeak(i8** %[[B]], i8* %[[A]])
+// ARC-NEXT: tail call void (...) @llvm.objc.clang.arc.use(i8* %[[A]])
+// ARC-NEXT: %[[V12:.*]] = tail call i8* @llvm.objc.unsafeClaimAutoreleasedReturnValue(i8* %[[A]])
+// ARC-NEXT: %[[V13:.*]] = tail call i8* @llvm.objc.retainedObject(i8* %[[A]])
+// ARC-NEXT: %[[V14:.*]] = tail call i8* @llvm.objc.unretainedObject(i8* %[[A]])
+// ARC-NEXT: %[[V15:.*]] = tail call i8* @llvm.objc.unretainedPointer(i8* %[[A]])
+// ARC-NEXT: %[[V16:.*]] = tail call i8* @objc_retain.autorelease(i8* %[[A]])
+// ARC-NEXT: %[[V17:.*]] = tail call i32 @objc_sync.enter(i8* %[[A]])
+// ARC-NEXT: %[[V18:.*]] = tail call i32 @objc_sync.exit(i8* %[[A]])
+// ARC-NEXT: tail call void @llvm.objc.arc.annotation.topdown.bbstart(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: tail call void @llvm.objc.arc.annotation.topdown.bbend(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: tail call void @llvm.objc.arc.annotation.bottomup.bbstart(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: tail call void @llvm.objc.arc.annotation.bottomup.bbend(i8** %[[B]], i8** %[[C]])
+// ARC-NEXT: ret void
+
+// MRR: define void @testRuntimeCalls(i8* %[[A:.*]], i8** %[[B:.*]], i8** %[[C:.*]]) {
+// MRR: %[[V0:.*]] = tail call i8* @objc_autorelease(i8* %[[A]])
+// MRR-NEXT: tail call void @objc_autoreleasePoolPop(i8* %[[A]])
+// MRR-NEXT: %[[V1:.*]] = tail call i8* @objc_autoreleasePoolPush()
+// MRR-NEXT: %[[V2:.*]] = tail call i8* @objc_autoreleaseReturnValue(i8* %[[A]])
+// MRR-NEXT: tail call void @objc_copyWeak(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: tail call void @objc_destroyWeak(i8** %[[B]])
+// MRR-NEXT: %[[V3:.*]] = tail call i8* @objc_initWeak(i8** %[[B]], i8* %[[A]])
+// MRR-NEXT: %[[V4:.*]] = tail call i8* @objc_loadWeak(i8** %[[B]])
+// MRR-NEXT: %[[V5:.*]] = tail call i8* @objc_loadWeakRetained(i8** %[[B]])
+// MRR-NEXT: tail call void @objc_moveWeak(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: tail call void @objc_release(i8* %[[A]])
+// MRR-NEXT: %[[V6:.*]] = tail call i8* @objc_retain(i8* %[[A]])
+// MRR-NEXT: %[[V7:.*]] = tail call i8* @objc_retainAutorelease(i8* %[[A]])
+// MRR-NEXT: %[[V8:.*]] = tail call i8* @objc_retainAutoreleaseReturnValue(i8* %[[A]])
+// MRR-NEXT: %[[V9:.*]] = tail call i8* @objc_retainAutoreleasedReturnValue(i8* %[[A]])
+// MRR-NEXT: %[[V10:.*]] = tail call i8* @objc_retainBlock(i8* %[[A]])
+// MRR-NEXT: tail call void @objc_storeStrong(i8** %[[B]], i8* %[[A]])
+// MRR-NEXT: %[[V11:.*]] = tail call i8* @objc_storeWeak(i8** %[[B]], i8* %[[A]])
+// MRR-NEXT: tail call void (...) @llvm.objc.clang.arc.use(i8* %[[A]])
+// MRR-NEXT: %[[V12:.*]] = tail call i8* @objc_unsafeClaimAutoreleasedReturnValue(i8* %[[A]])
+// MRR-NEXT: %[[V13:.*]] = tail call i8* @objc_retainedObject(i8* %[[A]])
+// MRR-NEXT: %[[V14:.*]] = tail call i8* @objc_unretainedObject(i8* %[[A]])
+// MRR-NEXT: %[[V15:.*]] = tail call i8* @objc_unretainedPointer(i8* %[[A]])
+// MRR-NEXT: %[[V16:.*]] = tail call i8* @objc_retain.autorelease(i8* %[[A]])
+// MRR-NEXT: %[[V17:.*]] = tail call i32 @objc_sync.enter(i8* %[[A]])
+// MRR-NEXT: %[[V18:.*]] = tail call i32 @objc_sync.exit(i8* %[[A]])
+// MRR-NEXT: tail call void @objc_arc_annotation_topdown_bbstart(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: tail call void @objc_arc_annotation_topdown_bbend(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: tail call void @objc_arc_annotation_bottomup_bbstart(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: tail call void @objc_arc_annotation_bottomup_bbend(i8** %[[B]], i8** %[[C]])
+// MRR-NEXT: ret void

test/Bitcode/upgrade-clang-arc-use.ll

@@ -1,4 +1,4 @@
-; Test upgrade of clang.arc.use by removing it.
+; Test upgrade of clang.arc.use by upgrading to llvm.objc.clang.arc.use.
 ; Bitcode input generated from llvm 6.0
 
 ; RUN: llvm-dis %s.bc -o - | FileCheck %s
@@ -6,7 +6,7 @@
 %0 = type opaque
 define void @foo() {
   %1 = tail call %0* @foo0()
-; CHECK-NOT: clang.arc.use
+; CHECK: call void (...) @llvm.objc.clang.arc.use(
   call void (...) @clang.arc.use(%0* %1)
   ret void
 }