Revert "Define the ThinLTO Pipeline"

This reverts commit r260604.
I didn't intend to push this now.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 260606

diff --git a/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h b/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
index 0353439..2f96a58 100644 (file)
--- a/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
+++ b/llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h
@@ -133,8 +133,6 @@ public:
   bool VerifyOutput;
   bool MergeFunctions;
   bool PrepareForLTO;
-  bool PrepareForThinLTO;
-  bool PerformThinLTO;
 
   /// Profile data file name that the instrumentation will be written to.
   std::string PGOInstrGen;
@@ -172,7 +170,6 @@ public:
   /// populateModulePassManager - This sets up the primary pass manager.
   void populateModulePassManager(legacy::PassManagerBase &MPM);
   void populateLTOPassManager(legacy::PassManagerBase &PM);
-  void populateThinLTOPassManager(legacy::PassManagerBase &PM);
 };
 
 /// Registers a function for adding a standard set of passes.  This should be

diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 5bb82ef..46a0d1d 100644 (file)
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -140,8 +140,6 @@ PassManagerBuilder::PassManagerBuilder() {
     PrepareForLTO = false;
     PGOInstrGen = RunPGOInstrGen;
     PGOInstrUse = RunPGOInstrUse;
-    PrepareForThinLTO = false;
-    PerformThinLTO = false;
 }
 
 PassManagerBuilder::~PassManagerBuilder() {
@@ -235,11 +233,6 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   MPM.add(createTailCallEliminationPass()); // Eliminate tail calls
   MPM.add(createCFGSimplificationPass());     // Merge & remove BBs
   MPM.add(createReassociatePass());           // Reassociate expressions
-  if (PrepareForThinLTO) {
-    MPM.add(createAggressiveDCEPass());        // Delete dead instructions
-    MPM.add(createInstructionCombiningPass()); // Combine silly seq's
-    return;
-  }
   // Rotate Loop - disable header duplication at -Oz
   MPM.add(createLoopRotatePass(SizeLevel == 2 ? 0 : -1));
   MPM.add(createLICMPass());                  // Hoist loop invariants
@@ -353,12 +346,6 @@ void PassManagerBuilder::populateModulePassManager(
 
     MPM.add(createIPSCCPPass());              // IP SCCP
     MPM.add(createGlobalOptimizerPass());     // Optimize out global vars
-
-    if (PerformThinLTO)
-      // Linking modules together can lead to duplicated global constants, only
-      // keep one copy of each constant.
-      MPM.add(createConstantMergePass());
-
     // Promote any localized global vars
     MPM.add(createPromoteMemoryToRegisterPass());
 
@@ -391,12 +378,6 @@ void PassManagerBuilder::populateModulePassManager(
 
   addFunctionSimplificationPasses(MPM);
 
-  // If we are planning to perform ThinLTO later, let's not bloat the code with
-  // unrolling/vectorization/... now. We'll first run the inliner + CGSCC passes
-  // during ThinLTO and performs the rest of the optimizations afterward.
-  if (PrepareForThinLTO)
-    return;
-
   // FIXME: This is a HACK! The inliner pass above implicitly creates a CGSCC
   // pass manager that we are specifically trying to avoid. To prevent this
   // we must insert a no-op module pass to reset the pass manager.
@@ -415,7 +396,7 @@ void PassManagerBuilder::populateModulePassManager(
   if (!DisableUnitAtATime)
     MPM.add(createReversePostOrderFunctionAttrsPass());
 
-  if (!DisableUnitAtATime && OptLevel > 1 && !PrepareForLTO)
+  if (!DisableUnitAtATime && OptLevel > 1 && !PrepareForLTO) {
     // Remove avail extern fns and globals definitions if we aren't
     // compiling an object file for later LTO. For LTO we want to preserve
     // these so they are eligible for inlining at link-time. Note if they
@@ -426,15 +407,6 @@ void PassManagerBuilder::populateModulePassManager(
     // globals referenced by available external functions dead
     // and saves running remaining passes on the eliminated functions.
     MPM.add(createEliminateAvailableExternallyPass());
-
-  if (PerformThinLTO) {
-    // Remove dead fns and globals. Removing unreferenced functions could lead
-    // to more opportunities for globalopt
-    MPM.add(createGlobalDCEPass());
-    MPM.add(createGlobalOptimizerPass());
-    // Remove dead fns and globals after globalopt
-    MPM.add(createGlobalDCEPass());
-    addFunctionSimplificationPasses(MPM);
   }
 
   if (EnableNonLTOGlobalsModRef)
@@ -710,20 +682,6 @@ void PassManagerBuilder::addLateLTOOptimizationPasses(
     PM.add(createMergeFunctionsPass());
 }
 
-void PassManagerBuilder::populateThinLTOPassManager(
-    legacy::PassManagerBase &PM) {
-  PerformThinLTO = true;
-
-  if (VerifyInput)
-    PM.add(createVerifierPass());
-
-  populateModulePassManager(PM);
-
-  if (VerifyOutput)
-    PM.add(createVerifierPass());
-  PerformThinLTO = false;
-}
-
 void PassManagerBuilder::populateLTOPassManager(legacy::PassManagerBase &PM) {
   if (LibraryInfo)
     PM.add(new TargetLibraryInfoWrapperPass(*LibraryInfo));