Give Multiversion-inline functions linkonce linkage

Since multiversion variant functions can be inline, in C they become
available-externally linkage.  This ends up causing the variants to not
be emitted, and not available to the linker.

The solution is to make sure that multiversion functions are always
emitted by marking them linkonce.

Change-Id: I897aa37c7cbba0c1eb2c57ee881d5000a2113b75

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@344957 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index c8aea635a7e71771a90fa54a50c5ef27cd6fde7b..c8e672a56728c0af5d78ee7833d14a92c1034973 100644 (file)
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -3669,6 +3669,10 @@ llvm::GlobalValue::LinkageTypes CodeGenModule::getLLVMLinkageForDeclarator(
       return llvm::GlobalVariable::WeakAnyLinkage;
   }
 
+  if (const auto *FD = D->getAsFunction())
+    if (FD->isMultiVersion() && Linkage == GVA_AvailableExternally)
+      return llvm::GlobalVariable::LinkOnceAnyLinkage;
+
   // We are guaranteed to have a strong definition somewhere else,
   // so we can use available_externally linkage.
   if (Linkage == GVA_AvailableExternally)

diff --git a/test/CodeGen/attr-target-mv.c b/test/CodeGen/attr-target-mv.c
index 48e1558356977a1c65d8533442cd5b62ce5af63a..3ccb5b319954132b19ee9a800e10f8c17405e8f8 100644 (file)
--- a/test/CodeGen/attr-target-mv.c
+++ b/test/CodeGen/attr-target-mv.c
@@ -88,19 +88,19 @@ void bar4() {
 
 // CHECK: declare i32 @foo.arch_sandybridge()
 
-// CHECK: define available_externally i32 @foo_inline.sse4.2()
+// CHECK: define linkonce i32 @foo_inline.sse4.2()
 // CHECK: ret i32 0
 
 // CHECK: declare i32 @foo_inline.arch_sandybridge()
 //
-// CHECK: define available_externally i32 @foo_inline.arch_ivybridge()
+// CHECK: define linkonce i32 @foo_inline.arch_ivybridge()
 // CHECK: ret i32 1
-// CHECK: define available_externally i32 @foo_inline()
+// CHECK: define linkonce i32 @foo_inline()
 // CHECK: ret i32 2
 
-// CHECK: define available_externally void @foo_decls()
-// CHECK: define available_externally void @foo_decls.sse4.2()
+// CHECK: define linkonce void @foo_decls()
+// CHECK: define linkonce void @foo_decls.sse4.2()
 
-// CHECK: define available_externally void @foo_multi.avx_sse4.2()
-// CHECK: define available_externally void @foo_multi.fma4_sse4.2()
-// CHECK: define available_externally void @foo_multi.arch_ivybridge_fma4_sse4.2()
+// CHECK: define linkonce void @foo_multi.avx_sse4.2()
+// CHECK: define linkonce void @foo_multi.fma4_sse4.2()
+// CHECK: define linkonce void @foo_multi.arch_ivybridge_fma4_sse4.2()