1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 4798d4e88d8..18d321b3106 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -651,6 +651,16 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) {
   PM.add(createJumpThreadingPass());
 }
 
+void PassManagerBuilder::addEarlyLTOOptimizationPasses(
+    legacy::PassManagerBase &PM) {
+  // Remove unused virtual tables to improve the quality of code generated by
+  // whole-program devirtualization and bitset lowering.
+  PM.add(createGlobalDCEPass());
+
+  // Apply whole-program devirtualization and virtual constant propagation.
+  PM.add(createWholeProgramDevirtPass());
+}
+
 void PassManagerBuilder::addLateLTOOptimizationPasses(
     legacy::PassManagerBase &PM) {
   // Delete basic blocks, which optimization passes may have killed.
@@ -675,6 +685,9 @@ void PassManagerBuilder::populateLTOPassManager(legacy::PassManagerBase &PM) {
   if (VerifyInput)
     PM.add(createVerifierPass());
 
+  if (OptLevel != 0)
+    addEarlyLTOOptimizationPasses(PM);
+
   if (OptLevel > 1)
     addLTOOptimizationPasses(PM);