Add a new method to create SimpleInliner instance and make pre-inliner use this

[eraman]

Summary

This adds a createFunctionInliningPass pass that takes an InlineParams object and use this to create the pre-inliner pass. This prevents the regular inliner's threshold flag from influencing the preinliner. We could make the callers of createFunctionInliningPass(Threshold) and createFunctionInliningPass(OptLevel, SizeOptLevel) use this instead, but I suppose we can't remove them because there may be other external users.

[davidxl]

lib/Transforms/IPO/PassManagerBuilder.cpp

264

I think it is better to make these two as optional field in InlineParams.

[eraman]

lib/Transforms/IPO/PassManagerBuilder.cpp

264

Ok, it make sense. I'm sending a separate NFC patch soon.

[chandlerc]

FWIW, LGTM with the obvious simplification provided by the patch Easwaran has already sent out. Make sure David is happy with it as well, as I've not been following the PGO instrumentation pipeline stuff as closely. But I'm happy with the inliner parts of this.

[eraman]

Rebase and do not set HotCallsiteThreshold as it is now an Optional.

[xur]

LGTM.

include/llvm/Transforms/IPO.h

 #ifndef LLVM_TRANSFORMS_IPO_H
 #define LLVM_TRANSFORMS_IPO_H
 
 #include <functional>
 #include <vector>
 
 namespace llvm {
 
+class InlineParams;
 class StringRef;
 class ModuleSummaryIndex;
 class ModulePass;
 class Pass;
 class Function;
 class BasicBlock;
 class GlobalValue;
 

 /// The Threshold can be passed directly, or asked to be computed from the
 /// given optimization and size optimization arguments.
 ///
 /// The -inline-threshold command line option takes precedence over the
 /// threshold given here.
 Pass *createFunctionInliningPass();
 Pass *createFunctionInliningPass(int Threshold);
 Pass *createFunctionInliningPass(unsigned OptLevel, unsigned SizeOptLevel);
+Pass *createFunctionInliningPass(InlineParams &Params);
 
 //===----------------------------------------------------------------------===//
 /// createAlwaysInlinerPass - Return a new pass object that inlines only
 /// functions that are marked as "always_inline".
 Pass *createAlwaysInlinerPass();
 Pass *createAlwaysInlinerPass(bool InsertLifetime);
 
 //===----------------------------------------------------------------------===//

lib/Transforms/IPO/InlineSimple.cpp

Pass *llvm::createFunctionInliningPass(int Threshold) {
   return new SimpleInliner(llvm::getInlineParams(Threshold));
 }
 
 Pass *llvm::createFunctionInliningPass(unsigned OptLevel,
                                        unsigned SizeOptLevel) {
   return new SimpleInliner(llvm::getInlineParams(OptLevel, SizeOptLevel));
 }
 
+Pass *llvm::createFunctionInliningPass(InlineParams &Params) {
+  return new SimpleInliner(Params);
+}
+
 bool SimpleInliner::runOnSCC(CallGraphSCC &SCC) {
   TTIWP = &getAnalysis<TargetTransformInfoWrapperPass>();
   return Inliner::runOnSCC(SCC);
 }
 
 void SimpleInliner::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<TargetTransformInfoWrapperPass>();
   Inliner::getAnalysisUsage(AU);
 }

lib/Transforms/IPO/PassManagerBuilder.cpp

 
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm-c/Transforms/PassManagerBuilder.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/CFLAndersAliasAnalysis.h"
 #include "llvm/Analysis/CFLSteensAliasAnalysis.h"
 #include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/InlineCost.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/ScopedNoAliasAA.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/IR/Verifier.h"

 
 // Do PGO instrumentation generation or use pass as the option specified.
 void PassManagerBuilder::addPGOInstrPasses(legacy::PassManagerBase &MPM) {
   if (!EnablePGOInstrGen && PGOInstrUse.empty())
     return;
   // Perform the preinline and cleanup passes for O1 and above.
   // And avoid doing them if optimizing for size.
   if (OptLevel > 0 && SizeLevel == 0 && !DisablePreInliner) {
-    // Create preinline pass.
-    MPM.add(createFunctionInliningPass(PreInlineThreshold));
+    // Create preinline pass. We construct an InlineParams object and specify
+    // the threshold here to avoid the command line options of the regular
+    // inliner to influence pre-inlining. The only fields of InlineParams we
+    // care about are DefaultThreshold and HintThreshold.
+    InlineParams IP;
+    IP.DefaultThreshold = PreInlineThreshold;
+    // FIXME: The hint threshold has the same value used by the regular inliner.
+    // This should probably be lowered after performance testing.
+    IP.HintThreshold = 325;
+
+    MPM.add(createFunctionInliningPass(IP));
     MPM.add(createSROAPass());
     MPM.add(createEarlyCSEPass());             // Catch trivial redundancies
     MPM.add(createCFGSimplificationPass());    // Merge & remove BBs
     MPM.add(createInstructionCombiningPass()); // Combine silly seq's
     addExtensionsToPM(EP_Peephole, MPM);
   }
   if (EnablePGOInstrGen) {
     MPM.add(createPGOInstrumentationGenLegacyPass());