available_externall linkage is not local, this was confusing the codegenerator,

and it wasn't generating calls through @PLT for these functions.
hasLocalLinkage() is now false for available_externally,
I attempted to fix the inliner and dce to handle available_externally properly.
It passed make check.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72328 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 28 insertions, 7 deletions

diff --git a/include/llvm/GlobalValue.h b/include/llvm/GlobalValue.h
index 50c613ef6a..3b7f67d5d0 100644
--- a/include/llvm/GlobalValue.h
+++ b/include/llvm/GlobalValue.h
@@ -123,8 +123,7 @@ public:
   bool hasInternalLinkage() const { return Linkage == InternalLinkage; }
   bool hasPrivateLinkage() const { return Linkage == PrivateLinkage; }
   bool hasLocalLinkage() const {
-    return Linkage == InternalLinkage || Linkage == PrivateLinkage ||
-           Linkage == AvailableExternallyLinkage;
+    return Linkage == InternalLinkage || Linkage == PrivateLinkage;
   }
   bool hasDLLImportLinkage() const { return Linkage == DLLImportLinkage; }
   bool hasDLLExportLinkage() const { return Linkage == DLLExportLinkage; }
diff --git a/lib/Transforms/IPO/GlobalDCE.cpp b/lib/Transforms/IPO/GlobalDCE.cpp
index 4f97ae175b..db378b0d0b 100644
--- a/lib/Transforms/IPO/GlobalDCE.cpp
+++ b/lib/Transforms/IPO/GlobalDCE.cpp
@@ -64,7 +64,7 @@ bool GlobalDCE::runOnModule(Module &M) {
     Changed |= RemoveUnusedGlobalValue(*I);
     // Functions with external linkage are needed if they have a body
     if (!I->hasLocalLinkage() && !I->hasLinkOnceLinkage() &&
-        !I->isDeclaration())
+        !I->isDeclaration() && !I->hasAvailableExternallyLinkage())
       GlobalIsNeeded(I);
   }
 
@@ -74,7 +74,7 @@ bool GlobalDCE::runOnModule(Module &M) {
     // Externally visible & appending globals are needed, if they have an
     // initializer.
     if (!I->hasLocalLinkage() && !I->hasLinkOnceLinkage() &&
-        !I->isDeclaration())
+        !I->isDeclaration() && !I->hasAvailableExternallyLinkage())
       GlobalIsNeeded(I);
   }
 
diff --git a/lib/Transforms/IPO/Inliner.cpp b/lib/Transforms/IPO/Inliner.cpp
index b589792022..b382837289 100644
--- a/lib/Transforms/IPO/Inliner.cpp
+++ b/lib/Transforms/IPO/Inliner.cpp
@@ -69,7 +69,8 @@ bool Inliner::InlineCallIfPossible(CallSite CS, CallGraph &CG,
 
   // If we inlined the last possible call site to the function, delete the
   // function body now.
-  if (Callee->use_empty() && Callee->hasLocalLinkage() &&
+  if (Callee->use_empty() && (Callee->hasLocalLinkage() ||
+                              Callee->hasAvailableExternallyLinkage()) &&
       !SCCFunctions.count(Callee)) {
     DOUT << "    -> Deleting dead function: " << Callee->getName() << "\n";
     CallGraphNode *CalleeNode = CG[Callee];
diff --git a/lib/Transforms/Utils/BasicInliner.cpp b/lib/Transforms/Utils/BasicInliner.cpp
index ef37614997..1650cfa306 100644
--- a/lib/Transforms/Utils/BasicInliner.cpp
+++ b/lib/Transforms/Utils/BasicInliner.cpp
@@ -130,7 +130,8 @@ void BasicInlinerImpl::inlineFunctions() {
         
         // Inline
         if (InlineFunction(CS, NULL, TD)) {
-          if (Callee->use_empty() && Callee->hasLocalLinkage())
+          if (Callee->use_empty() && (Callee->hasLocalLinkage() ||
+                                      Callee->hasAvailableExternallyLinkage()))
             DeadFunctions.insert(Callee);
           Changed = true;
           CallSites.erase(CallSites.begin() + index);
diff --git a/lib/Transforms/Utils/InlineCost.cpp b/lib/Transforms/Utils/InlineCost.cpp
index c9eb0ea1c9..87aff01a58 100644
--- a/lib/Transforms/Utils/InlineCost.cpp
+++ b/lib/Transforms/Utils/InlineCost.cpp
@@ -189,7 +189,8 @@ InlineCost InlineCostAnalyzer::getInlineCost(CallSite CS,
   // If there is only one call of the function, and it has internal linkage,
   // make it almost guaranteed to be inlined.
   //
-  if (Callee->hasLocalLinkage() && Callee->hasOneUse())
+  if ((Callee->hasLocalLinkage() || Callee->hasAvailableExternallyLinkage()) && 
+      Callee->hasOneUse())
     InlineCost -= 15000;
   
   // If this function uses the coldcc calling convention, prefer not to inline
diff --git a/test/CodeGen/X86/2009-05-23-available_externally.ll b/test/CodeGen/X86/2009-05-23-available_externally.ll
new file mode 100644
index 0000000000..f4881bab45
--- /dev/null
+++ b/test/CodeGen/X86/2009-05-23-available_externally.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | llc -relocation-model=pic | grep atoi | grep PLT
+; PR4253
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @foo(i8* %x) nounwind readonly {
+entry:
+	%call = tail call fastcc i32 @atoi(i8* %x) nounwind readonly		; <i32> [#uses=1]
+	ret i32 %call
+}
+
+define available_externally fastcc i32 @atoi(i8* %__nptr) nounwind readonly {
+entry:
+	%call = tail call i64 @strtol(i8* nocapture %__nptr, i8** null, i32 10) nounwind readonly		; <i64> [#uses=1]
+	%conv = trunc i64 %call to i32		; <i32> [#uses=1]
+	ret i32 %conv
+}
+
+declare i64 @strtol(i8*, i8** nocapture, i32) nounwind