commit d2c49ab726c20fd51a2c3df4689636a56812c355
author Pete Cooper <peter_cooper@apple.com> Tue Dec 18 22:31:34 2018 +0000
committer Pete Cooper <peter_cooper@apple.com> Tue Dec 18 22:31:34 2018 +0000
tree 7b868a8433b2d941d1df228889db402844b9004e
parent efdc43373b87804857f4c43184f5b6824731d66a

Add nonlazybind to objc_retain/objc_release when converting from intrinsics.

For performance reasons, clang set nonlazybind on these functions.  Now that we
are using intrinsics instead of runtime calls, we should set this attribute when
creating the runtime functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349558 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/PreISelIntrinsicLowering.cpp

diff --git a/lib/CodeGen/PreISelIntrinsicLowering.cpp b/lib/CodeGen/PreISelIntrinsicLowering.cpp
index cd15f6b..3689dab 100644
--- a/lib/CodeGen/PreISelIntrinsicLowering.cpp
+++ b/lib/CodeGen/PreISelIntrinsicLowering.cpp
@@ -57,7 +57,8 @@
   return Changed;
 }
 
-static bool lowerObjCCall(Function &F, const char *NewFn) {
+static bool lowerObjCCall(Function &F, const char *NewFn,
+                          bool setNonLazyBind = false) {
   if (F.use_empty())
     return false;
 
@@ -65,6 +66,12 @@
   // program already contains a function with this name.
   Module *M = F.getParent();
   Constant* FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());
+  
+  // If we have Native ARC, set nonlazybind attribute for these APIs for
+  // performance.
+  if (setNonLazyBind)
+    if (Function* Fn = dyn_cast<Function>(FCache))
+      Fn->addFnAttr(Attribute::NonLazyBind);
 
   for (auto I = F.use_begin(), E = F.use_end(); I != E;) {
     auto *CI = dyn_cast<CallInst>(I->getUser());
@@ -125,10 +132,10 @@
       Changed |= lowerObjCCall(F, "objc_moveWeak");
       break;
     case Intrinsic::objc_release:
-      Changed |= lowerObjCCall(F, "objc_release");
+      Changed |= lowerObjCCall(F, "objc_release", true);
       break;
     case Intrinsic::objc_retain:
-      Changed |= lowerObjCCall(F, "objc_retain");
+      Changed |= lowerObjCCall(F, "objc_retain", true);
       break;
     case Intrinsic::objc_retainAutorelease:
       Changed |= lowerObjCCall(F, "objc_retainAutorelease");

test/Transforms/PreISelIntrinsicLowering/objc-arc.ll

diff --git a/test/Transforms/PreISelIntrinsicLowering/objc-arc.ll b/test/Transforms/PreISelIntrinsicLowering/objc-arc.ll
index be852df..235ef65 100644
--- a/test/Transforms/PreISelIntrinsicLowering/objc-arc.ll
+++ b/test/Transforms/PreISelIntrinsicLowering/objc-arc.ll
@@ -279,3 +279,8 @@
 declare i8* @llvm.objc.retain.autorelease(i8*)
 declare i32 @llvm.objc.sync.enter(i8*)
 declare i32 @llvm.objc.sync.exit(i8*)
+
+; CHECK: declare void @objc_release(i8*) [[NLB:#[0-9]+]]
+; CHECK: declare i8* @objc_retain(i8*) [[NLB]]
+
+; CHECK: attributes [[NLB]] = { nonlazybind }