Handle calls and invokes in GlobalStatus.

This patch teaches GlobalStatus to analyze a call that uses the global value as
a callee, not as an argument.

With this change internalize call handle the common use of linkonce_odr
functions. This reduces the number of linkonce_odr functions in a LTO build of
clang (checked with the emit-llvm gold plugin option) from 1730 to 60.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193436 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 42 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/GlobalStatus.cpp b/lib/Transforms/Utils/GlobalStatus.cpp
index 8fb79aa87b..5f0a563cee 100644
--- a/lib/Transforms/Utils/GlobalStatus.cpp
+++ b/lib/Transforms/Utils/GlobalStatus.cpp
@@ -11,6 +11,7 @@
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/Support/CallSite.h"
 #include "llvm/Transforms/Utils/GlobalStatus.h"
 
 using namespace llvm;
@@ -148,6 +149,10 @@ static bool analyzeGlobalAux(const Value *V, GlobalStatus &GS,
         if (MSI->isVolatile())
           return true;
         GS.StoredType = GlobalStatus::Stored;
+      } else if (ImmutableCallSite C = I) {
+        if (!C.isCallee(UI))
+          return true;
+        GS.IsLoaded = true;
       } else {
         return true; // Any other non-load instruction might take address!
       }
diff --git a/test/Transforms/Internalize/linkonce_odr_func.ll b/test/Transforms/Internalize/linkonce_odr_func.ll
new file mode 100644
index 0000000000..c82acc0174
--- /dev/null
+++ b/test/Transforms/Internalize/linkonce_odr_func.ll
@@ -0,0 +1,37 @@
+; RUN: opt < %s -internalize -internalize-dso-list foo1,foo2,foo3,foo4 -S | FileCheck %s
+
+; CHECK: define internal void @foo1(
+define linkonce_odr void @foo1() noinline {
+  ret void
+}
+
+; CHECK: define linkonce_odr void @foo2(
+define linkonce_odr void @foo2() noinline {
+  ret void
+}
+
+; CHECK: define internal void @foo3(
+define linkonce_odr void @foo3() noinline {
+  ret void
+}
+
+; CHECK: define linkonce_odr void @foo4(
+define linkonce_odr void @foo4() noinline {
+  ret void
+}
+
+declare void @f(void()*)
+
+define void @bar() {
+bb0:
+  call void @foo1()
+  call void @f(void()* @foo2)
+  invoke void @foo3() to label %bb1 unwind label %clean
+bb1:
+  invoke void @f(void()* @foo4) to label %bb2 unwind label %clean
+bb2:
+  ret void
+clean:
+  landingpad i32 personality i8* null cleanup
+  ret void
+}