From 8d86f1ba475c2e2adafd7d2e93ac26502de788ce Mon Sep 17 00:00:00 2001
From: Teresa Johnson <tejohnson@google.com>
Date: Thu, 17 Jan 2019 16:05:04 +0000
Subject: Revert "[ThinLTO] Add summary entries for index-based WPD"

Mistaken commit of something still under review!

This reverts commit r351453.

llvm-svn: 351455
---
 llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp | 45 +++++++-----------------
 1 file changed, 12 insertions(+), 33 deletions(-)

(limited to 'llvm/lib/Transforms')

diff --git a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 88b45e03492..510ecb516dc 100644
--- a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -418,55 +418,34 @@ void splitAndWriteThinLTOBitcode(
   }
 }
 
-// Check if the LTO Unit splitting has been enabled.
-bool enableSplitLTOUnit(Module &M) {
+// Returns whether this module needs to be split because splitting is
+// enabled and it uses type metadata.
+bool requiresSplit(Module &M) {
+  // First check if the LTO Unit splitting has been enabled.
   bool EnableSplitLTOUnit = false;
   if (auto *MD = mdconst::extract_or_null<ConstantInt>(
           M.getModuleFlag("EnableSplitLTOUnit")))
     EnableSplitLTOUnit = MD->getZExtValue();
-  return EnableSplitLTOUnit;
-}
+  if (!EnableSplitLTOUnit)
+    return false;
 
-// Returns whether this module needs to be split because it uses type metadata.
-bool hasTypeMetadata(Module &M) {
+  // Module only needs to be split if it contains type metadata.
   for (auto &GO : M.global_objects()) {
     if (GO.hasMetadata(LLVMContext::MD_type))
       return true;
   }
+
   return false;
 }
 
 void writeThinLTOBitcode(raw_ostream &OS, raw_ostream *ThinLinkOS,
                          function_ref<AAResults &(Function &)> AARGetter,
                          Module &M, const ModuleSummaryIndex *Index) {
-  std::unique_ptr<ModuleSummaryIndex> NewIndex = nullptr;
-  // See if this module has any type metadata. If so, we try to split it
-  // or at least promote type ids to enable WPD.
-  if (hasTypeMetadata(M)) {
-    if (enableSplitLTOUnit(M))
-      return splitAndWriteThinLTOBitcode(OS, ThinLinkOS, AARGetter, M);
-    else {
-      // Promote type ids as needed for index-based WPD.
-      std::string ModuleId = getUniqueModuleId(&M);
-      if (!ModuleId.empty()) {
-        promoteTypeIds(M, ModuleId);
-        // Need to rebuild the index so that it contains type metadata
-        // for the newly promoted type ids.
-        // FIXME: Probably should not bother building the index at all
-        // in the caller of writeThinLTOBitcode (which does so via the
-        // ModuleSummaryIndexAnalysis pass), since we have to rebuild it
-        // anyway whenever there is type metadata (here or in
-        // splitAndWriteThinLTOBitcode). Just always build it once via the
-        // buildModuleSummaryIndex when Module(s) are ready.
-        ProfileSummaryInfo PSI(M);
-        NewIndex = llvm::make_unique<ModuleSummaryIndex>(
-            buildModuleSummaryIndex(M, nullptr, &PSI));
-        Index = NewIndex.get();
-      }
-    }
-  }
+  // Split module if splitting is enabled and it contains any type metadata.
+  if (requiresSplit(M))
+    return splitAndWriteThinLTOBitcode(OS, ThinLinkOS, AARGetter, M);
 
-  // Write it out as an unsplit ThinLTO module.
+  // Otherwise we can just write it out as a regular module.
 
   // Save the module hash produced for the full bitcode, which will
   // be used in the backends, and use that in the minimized bitcode
-- 
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