[ThinLTO] Internalize readonly globals
An attempt to recommit r346584 after failure on OSX build bot.
Fixed cache key computation in ThinLTOCodeGenerator and added
test case
llvm-svn: 347033
diff --git a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
index 479816a..dd952ea 100644
--- a/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
+++ b/llvm/lib/Transforms/Utils/FunctionImportUtils.cpp
@@ -204,8 +204,9 @@
// Check the summaries to see if the symbol gets resolved to a known local
// definition.
+ ValueInfo VI;
if (GV.hasName()) {
- ValueInfo VI = ImportIndex.getValueInfo(GV.getGUID());
+ VI = ImportIndex.getValueInfo(GV.getGUID());
if (VI && VI.isDSOLocal()) {
GV.setDSOLocal(true);
if (GV.hasDLLImportStorageClass())
@@ -213,6 +214,22 @@
}
}
+ // Mark read-only variables which can be imported with specific attribute.
+ // We can't internalize them now because IRMover will fail to link variable
+ // definitions to their external declarations during ThinLTO import. We'll
+ // internalize read-only variables later, after import is finished.
+ // See internalizeImmutableGVs.
+ //
+ // If global value dead stripping is not enabled in summary then
+ // propagateConstants hasn't been run. We can't internalize GV
+ // in such case.
+ if (!GV.isDeclaration() && VI && ImportIndex.withGlobalValueDeadStripping()) {
+ const auto &SL = VI.getSummaryList();
+ auto *GVS = SL.empty() ? nullptr : dyn_cast<GlobalVarSummary>(SL[0].get());
+ if (GVS && GVS->isReadOnly())
+ cast<GlobalVariable>(&GV)->addAttribute("thinlto-internalize");
+ }
+
bool DoPromote = false;
if (GV.hasLocalLinkage() &&
((DoPromote = shouldPromoteLocalToGlobal(&GV)) || isPerformingImport())) {
@@ -230,7 +247,7 @@
// Remove functions imported as available externally defs from comdats,
// as this is a declaration for the linker, and will be dropped eventually.
// It is illegal for comdats to contain declarations.
- auto *GO = dyn_cast_or_null<GlobalObject>(&GV);
+ auto *GO = dyn_cast<GlobalObject>(&GV);
if (GO && GO->isDeclarationForLinker() && GO->hasComdat()) {
// The IRMover should not have placed any imported declarations in
// a comdat, so the only declaration that should be in a comdat