Add invariant.load metadata to loads from selector references. Allows these loads to later be moved/combined in the optimizer. Fixes <rdar://problem/6027699>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144318 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 84277f6..1cbcc58 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -5887,7 +5887,12 @@
if (lval)
return Entry;
- return Builder.CreateLoad(Entry);
+ llvm::LoadInst* LI = Builder.CreateLoad(Entry);
+
+ LI->setMetadata(CGM.getModule().getMDKindID("invariant.load"),
+ llvm::MDNode::get(VMContext,
+ ArrayRef<llvm::Value*>()));
+ return LI;
}
/// EmitObjCIvarAssign - Code gen for assigning to a __strong object.
/// objc_assign_ivar (id src, id *dst, ptrdiff_t)
diff --git a/test/CodeGenObjC/selector-ref-invariance.m b/test/CodeGenObjC/selector-ref-invariance.m
new file mode 100644
index 0000000..e356419
--- /dev/null
+++ b/test/CodeGenObjC/selector-ref-invariance.m
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin11 -emit-llvm -fblocks -o - %s | FileCheck %s
+
+// rdar://6027699
+
+void test(id x) {
+// CHECK: load i8** @"\01L_OBJC_SELECTOR_REFERENCES_", !invariant.load
+// CHECK: @objc_msgSend
+ [x foo];
+}