From ec304151b74f9254d7029ee4d197ce1f7cbe501a Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Sat, 31 Jan 2015 19:27:28 +0000
Subject: Vendor import of llvm RELEASE_360/rc2 tag r227651 (effectively, 3.6.0
 RC2): https://llvm.org/svn/llvm-project/llvm/tags/RELEASE_360/rc2@227651

---
 lib/IR/Core.cpp | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

(limited to 'lib/IR/Core.cpp')

diff --git a/lib/IR/Core.cpp b/lib/IR/Core.cpp
index a25c4d66d3bb..753d9c229eca 100644
--- a/lib/IR/Core.cpp
+++ b/lib/IR/Core.cpp
@@ -563,9 +563,23 @@ LLVMValueRef LLVMGetMetadata(LLVMValueRef Inst, unsigned KindID) {
   return nullptr;
 }
 
-void LLVMSetMetadata(LLVMValueRef Inst, unsigned KindID, LLVMValueRef MD) {
-  MDNode *N =
-      MD ? cast<MDNode>(unwrap<MetadataAsValue>(MD)->getMetadata()) : nullptr;
+// MetadataAsValue uses a canonical format which strips the actual MDNode for
+// MDNode with just a single constant value, storing just a ConstantAsMetadata
+// This undoes this canonicalization, reconstructing the MDNode.
+static MDNode *extractMDNode(MetadataAsValue *MAV) {
+  Metadata *MD = MAV->getMetadata();
+  assert((isa<MDNode>(MD) || isa<ConstantAsMetadata>(MD)) &&
+      "Expected a metadata node or a canonicalized constant");
+
+  if (MDNode *N = dyn_cast<MDNode>(MD))
+    return N;
+
+  return MDNode::get(MAV->getContext(), MD);
+}
+
+void LLVMSetMetadata(LLVMValueRef Inst, unsigned KindID, LLVMValueRef Val) {
+  MDNode *N = Val ? extractMDNode(unwrap<MetadataAsValue>(Val)) : nullptr;
+
   unwrap<Instruction>(Inst)->setMetadata(KindID, N);
 }
 
@@ -795,7 +809,7 @@ void LLVMAddNamedMetadataOperand(LLVMModuleRef M, const char* name,
     return;
   if (!Val)
     return;
-  N->addOperand(cast<MDNode>(unwrap<MetadataAsValue>(Val)->getMetadata()));
+  N->addOperand(extractMDNode(unwrap<MetadataAsValue>(Val)));
 }
 
 /*--.. Operations on scalar constants ......................................--*/
-- 
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