From faf8fa566493a3aefb18f784cf706aae6a1e569f Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Thu, 3 Sep 2009 20:35:57 +0000
Subject: [PATCH] There is not any need to copy metadata while merging modules.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80941 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Linker/LinkModules.cpp        | 10 ++--------
 test/Linker/2009-09-03-mdnode.ll  | 30 ++++++++++++++++++++++++++++++
 test/Linker/2009-09-03-mdnode2.ll | 25 +++++++++++++++++++++++++
 3 files changed, 57 insertions(+), 8 deletions(-)
 create mode 100644 test/Linker/2009-09-03-mdnode.ll
 create mode 100644 test/Linker/2009-09-03-mdnode2.ll

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 0fa97c55687..00bb55e9531 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -395,14 +395,8 @@ static Value *RemapOperand(const Value *In,
       assert(!isa<GlobalValue>(CPV) && "Unmapped global?");
       llvm_unreachable("Unknown type of derived type constant value!");
     }
-  } else if (const MDNode *N = dyn_cast<MDNode>(In)) {
-    std::vector<Value*> Elems;
-    for (unsigned i = 0, e = N->getNumElements(); i !=e; ++i)
-      Elems.push_back(RemapOperand(N->getElement(i), ValueMap, Context));
-    if (!Elems.empty())
-      Result = MDNode::get(Context, &Elems[0], Elems.size());
-  } else if (const MDString *MDS = dyn_cast<MDString>(In)) {
-    Result = MDString::get(Context, MDS->getString());
+  } else if (isa<MetadataBase>(In)) {
+    Result = const_cast<Value*>(In);
   } else if (isa<InlineAsm>(In)) {
     Result = const_cast<Value*>(In);
   }
diff --git a/test/Linker/2009-09-03-mdnode.ll b/test/Linker/2009-09-03-mdnode.ll
new file mode 100644
index 00000000000..11862f70b29
--- /dev/null
+++ b/test/Linker/2009-09-03-mdnode.ll
@@ -0,0 +1,30 @@
+; RUN: llvm-as < %s > %t.bc
+; RUN: llvm-as < %p/2009-09-03-mdnode2.ll > %t2.bc
+; RUN: llvm-link %t.bc %t2.bc
+
+declare void @f() nounwind
+
+define i32 @main(...) nounwind {
+entry:
+  %retval = alloca i32                            ; <i32*> [#uses=2]
+  call void @llvm.dbg.func.start(metadata !0)
+  store i32 0, i32* %retval
+  call void @llvm.dbg.stoppoint(i32 4, i32 5, metadata !1)
+  call void @f()
+  br label %return
+
+return:                                           ; preds = %entry
+  %0 = load i32* %retval                          ; <i32> [#uses=1]
+  call void @llvm.dbg.stoppoint(i32 5, i32 1, metadata !1)
+  call void @llvm.dbg.region.end(metadata !0)
+  ret i32 %0
+}
+
+declare void @llvm.dbg.func.start(metadata) nounwind readnone
+
+declare void @llvm.dbg.stoppoint(i32, i32, metadata) nounwind readnone
+
+declare void @llvm.dbg.region.end(metadata) nounwind readnone
+
+!0 = metadata !{i32 458798, i32 0, metadata !1, metadata !"main", metadata !"main", metadata !"main", metadata !1, i32 2, null, i1 false, i1 true}
+!1 = metadata !{i32 458769, i32 0, i32 12, metadata !"a.c", metadata !"/home/rich/ellcc/test/source", metadata !"ellcc 0.1.0", i1 true, i1 true, metadata !"", i32 0}
diff --git a/test/Linker/2009-09-03-mdnode2.ll b/test/Linker/2009-09-03-mdnode2.ll
new file mode 100644
index 00000000000..21589a49b79
--- /dev/null
+++ b/test/Linker/2009-09-03-mdnode2.ll
@@ -0,0 +1,25 @@
+; This file is used by 2009-09-03-mdnode.ll, so it doesn't actually do anything itself
+;
+; RUN: true
+
+define i32 @f(...) nounwind {
+entry:
+  %retval = alloca i32                            ; <i32*> [#uses=1]
+  call void @llvm.dbg.func.start(metadata !0)
+  br label %return
+
+return:                                           ; preds = %entry
+  %0 = load i32* %retval                          ; <i32> [#uses=1]
+  call void @llvm.dbg.stoppoint(i32 3, i32 1, metadata !1)
+  call void @llvm.dbg.region.end(metadata !0)
+  ret i32 %0
+}
+
+declare void @llvm.dbg.func.start(metadata) nounwind readnone
+
+declare void @llvm.dbg.stoppoint(i32, i32, metadata) nounwind readnone
+
+declare void @llvm.dbg.region.end(metadata) nounwind readnone
+
+!0 = metadata !{i32 458798, i32 0, metadata !1, metadata !"f", metadata !"f", metadata !"f", metadata !1, i32 1, null, i1 false, i1 true}
+!1 = metadata !{i32 458769, i32 0, i32 12, metadata !"b.c", metadata !"/home/rich/ellcc/test/source", metadata !"ellcc 0.1.0", i1 true, i1 true, metadata !"", i32 0}
-- 
2.34.1