commit 65bb3f92bd5f6d1d32dee43904c56f4f73276e62
author Akira Hatanaka <ahatanaka@apple.com> Thu Mar 21 19:59:49 2019 +0000
committer Akira Hatanaka <ahatanaka@apple.com> Thu Mar 21 19:59:49 2019 +0000
tree 5c039ce629b8e7ee218f1a0682b797be53ed10c5
parent 86559dcb8d519863c16f7b210ca583a34194acef

[CodeGen][ObjC] Annotate calls to objc_retainAutoreleasedReturnValue
with notail on x86-64.

On x86-64, the epilogue code inserted before the tail jump blocks the
autoreleased return optimization.

rdar://problem/38675807

Differential Revision: https://reviews.llvm.org/D59656

llvm-svn: 356705

clang/lib/CodeGen/CGObjC.cpp

diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 561f21a..69ced58 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -1958,10 +1958,10 @@
 /// Perform an operation having the signature
 ///   i8* (i8*)
 /// where a null input causes a no-op and returns null.
-static llvm::Value *
-emitARCValueOperation(CodeGenFunction &CGF, llvm::Value *value,
-                      llvm::Type *returnType, llvm::Function *&fn,
-                      llvm::Intrinsic::ID IntID, bool isTailCall = false) {
+static llvm::Value *emitARCValueOperation(
+    CodeGenFunction &CGF, llvm::Value *value, llvm::Type *returnType,
+    llvm::Function *&fn, llvm::Intrinsic::ID IntID,
+    llvm::CallInst::TailCallKind tailKind = llvm::CallInst::TCK_None) {
   if (isa<llvm::ConstantPointerNull>(value))
     return value;
 
@@ -1976,8 +1976,7 @@
 
   // Call the function.
   llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value);
-  if (isTailCall)
-    call->setTailCall();
+  call->setTailCallKind(tailKind);
 
   // Cast the result back to the original type.
   return CGF.Builder.CreateBitCast(call, origType);
@@ -2187,9 +2186,15 @@
 llvm::Value *
 CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
   emitAutoreleasedReturnValueMarker(*this);
-  return emitARCValueOperation(*this, value, nullptr,
-              CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue,
-                           llvm::Intrinsic::objc_retainAutoreleasedReturnValue);
+  llvm::CallInst::TailCallKind tailKind =
+      CGM.getTargetCodeGenInfo()
+              .shouldSuppressTailCallsOfRetainAutoreleasedReturnValue()
+          ? llvm::CallInst::TCK_NoTail
+          : llvm::CallInst::TCK_None;
+  return emitARCValueOperation(
+      *this, value, nullptr,
+      CGM.getObjCEntrypoints().objc_retainAutoreleasedReturnValue,
+      llvm::Intrinsic::objc_retainAutoreleasedReturnValue, tailKind);
 }
 
 /// Claim a possibly-autoreleased return value at +0.  This is only
@@ -2326,7 +2331,7 @@
   return emitARCValueOperation(*this, value, nullptr,
                             CGM.getObjCEntrypoints().objc_autoreleaseReturnValue,
                                llvm::Intrinsic::objc_autoreleaseReturnValue,
-                               /*isTailCall*/ true);
+                               llvm::CallInst::TCK_Tail);
 }
 
 /// Do a fused retain/autorelease of the given object.
@@ -2336,7 +2341,7 @@
   return emitARCValueOperation(*this, value, nullptr,
                      CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue,
                              llvm::Intrinsic::objc_retainAutoreleaseReturnValue,
-                               /*isTailCall*/ true);
+                               llvm::CallInst::TCK_Tail);
 }
 
 /// Do a fused retain/autorelease of the given object.