[multiversion] Implement the old pass manager's TTI wrapper pass in

terms of the new pass manager's TargetIRAnalysis.

Yep, this is one of the nicer bits of the new pass manager's design.
Passes can in many cases operate in a vacuum and so we can just nest
things when convenient. This is particularly convenient here as I can
now consolidate all of the TargetMachine logic on this analysis.

The most important change here is that this pushes the function we need
TTI for all the way into the TargetMachine, and re-creates the TTI
object for each function rather than re-using it for each function.
We're now prepared to teach the targets to produce function-specific TTI
objects with specific subtargets cached, etc.

One piece of feedback I'd love here is whether its worth renaming any of
this stuff. None of the names really seem that awesome to me at this
point, but TargetTransformInfoWrapperPass is particularly ... odd.
TargetIRAnalysisWrapper might make more sense. I would want to do that
rename separately anyways, but let me know what you think.

llvm-svn: 227731

llvm/include/llvm/Analysis/TargetTransformInfo.h

@@ -22,6 +22,7 @@
 #ifndef LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
 #define LLVM_ANALYSIS_TARGETTRANSFORMINFO_H
 
+#include "llvm/ADT/Optional.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/Pass.h"
@@ -791,7 +792,8 @@ private:
 /// This pass can be constructed from a TTI object which it stores internally
 /// and is queried by passes.
 class TargetTransformInfoWrapperPass : public ImmutablePass {
-  TargetTransformInfo TTI;
+  TargetIRAnalysis TIRA;
+  Optional<TargetTransformInfo> TTI;
 
   virtual void anchor();
 
@@ -804,16 +806,16 @@ public:
   /// Use the constructor below or call one of the creation routines.
   TargetTransformInfoWrapperPass();
 
-  explicit TargetTransformInfoWrapperPass(TargetTransformInfo TTI);
+  explicit TargetTransformInfoWrapperPass(TargetIRAnalysis TIRA);
 
-  TargetTransformInfo &getTTI(Function &F) { return TTI; }
+  TargetTransformInfo &getTTI(Function &F);
 };
 
 /// \brief Create an analysis pass wrapper around a TTI object.
 ///
 /// This analysis pass just holds the TTI instance and makes it available to
 /// clients.
-ImmutablePass *createTargetTransformInfoWrapperPass(TargetTransformInfo TTI);
+ImmutablePass *createTargetTransformInfoWrapperPass(TargetIRAnalysis TIRA);
 
 } // End llvm namespace
 

llvm/lib/Analysis/TargetTransformInfo.cpp

@@ -280,19 +280,24 @@ char TargetTransformInfoWrapperPass::ID = 0;
 void TargetTransformInfoWrapperPass::anchor() {}
 
 TargetTransformInfoWrapperPass::TargetTransformInfoWrapperPass()
-    : ImmutablePass(ID), TTI(NoTTIImpl(/*DataLayout*/ nullptr)) {
+    : ImmutablePass(ID) {
   initializeTargetTransformInfoWrapperPassPass(
       *PassRegistry::getPassRegistry());
 }
 
 TargetTransformInfoWrapperPass::TargetTransformInfoWrapperPass(
-    TargetTransformInfo TTI)
-    : ImmutablePass(ID), TTI(std::move(TTI)) {
+    TargetIRAnalysis TIRA)
+    : ImmutablePass(ID), TIRA(std::move(TIRA)) {
   initializeTargetTransformInfoWrapperPassPass(
       *PassRegistry::getPassRegistry());
 }
 
-ImmutablePass *
-llvm::createTargetTransformInfoWrapperPass(TargetTransformInfo TTI) {
-  return new TargetTransformInfoWrapperPass(std::move(TTI));
+TargetTransformInfo &TargetTransformInfoWrapperPass::getTTI(Function &F) {
+  TTI = TIRA.run(F);
+  return *TTI;
+}
+
+ImmutablePass *
+llvm::createTargetTransformInfoWrapperPass(TargetIRAnalysis TIRA) {
+  return new TargetTransformInfoWrapperPass(std::move(TIRA));
 }

llvm/lib/CodeGen/LLVMTargetMachine.cpp

@@ -90,7 +90,7 @@ static MCContext *addPassesToGenerateCode(LLVMTargetMachine *TM,
                                           AnalysisID StopAfter) {
 
   // Add internal analysis passes from the target machine.
-  PM.add(createTargetTransformInfoWrapperPass(TM->getTTI()));
+  PM.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
 
   // Targets may override createPassConfig to provide a target-specific
   // subclass.

llvm/lib/LTO/LTOCodeGenerator.cpp

@@ -490,7 +490,8 @@ bool LTOCodeGenerator::generateObjectFile(raw_ostream &out,
   mergedModule->setDataLayout(TargetMach->getDataLayout());
 
   passes.add(new DataLayoutPass());
-  passes.add(createTargetTransformInfoWrapperPass(TargetMach->getTTI()));
+  passes.add(
+      createTargetTransformInfoWrapperPass(TargetMach->getTargetIRAnalysis()));
 
   Triple TargetTriple(TargetMach->getTargetTriple());
   PassManagerBuilder PMB;

llvm/lib/Target/TargetMachineC.cpp

@@ -256,5 +256,6 @@ char *LLVMGetDefaultTargetTriple(void) {
 }
 
 void LLVMAddAnalysisPasses(LLVMTargetMachineRef T, LLVMPassManagerRef PM) {
-  unwrap(PM)->add(createTargetTransformInfoWrapperPass(unwrap(T)->getTTI()));
+  unwrap(PM)->add(
+      createTargetTransformInfoWrapperPass(unwrap(T)->getTargetIRAnalysis()));
 }

llvm/tools/opt/opt.cpp

@@ -427,8 +427,8 @@ int main(int argc, char **argv) {
     Passes.add(new DataLayoutPass());
 
   // Add internal analysis passes from the target machine.
-  Passes.add(createTargetTransformInfoWrapperPass(
-      TM ? TM->getTTI() : TargetTransformInfo(DL)));
+  Passes.add(createTargetTransformInfoWrapperPass(TM ? TM->getTargetIRAnalysis()
+                                                     : TargetIRAnalysis()));
 
   std::unique_ptr<FunctionPassManager> FPasses;
   if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) {
@@ -436,7 +436,7 @@ int main(int argc, char **argv) {
     if (DL)
       FPasses->add(new DataLayoutPass());
     FPasses->add(createTargetTransformInfoWrapperPass(
-        TM ? TM->getTTI() : TargetTransformInfo(DL)));
+        TM ? TM->getTargetIRAnalysis() : TargetIRAnalysis()));
   }
 
   if (PrintBreakpoints) {