Add a new pass FunctionTargetTransformInfo. This pass serves as a

shim between the TargetTransformInfo immutable pass and the Subtarget
via the TargetMachine and Function. Migrate a single call from
BasicTargetTransformInfo as an example and provide shims where TargetMachine
begins taking a Function to determine the subtarget.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218004 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/FunctionTargetTransformInfo.cpp

@@ -0,0 +1,50 @@
+//===- llvm/Analysis/FunctionTargetTransformInfo.h --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass wraps a TargetTransformInfo in a FunctionPass so that it can
+// forward along the current Function so that we can make target specific
+// decisions based on the particular subtarget specified for each Function.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/InitializePasses.h"
+#include "llvm/Analysis/FunctionTargetTransformInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "function-tti"
+static const char ftti_name[] = "Function TargetTransformInfo";
+INITIALIZE_PASS_BEGIN(FunctionTargetTransformInfo, "function_tti", ftti_name, false, true)
+INITIALIZE_AG_DEPENDENCY(TargetTransformInfo)
+INITIALIZE_PASS_END(FunctionTargetTransformInfo, "function_tti", ftti_name, false, true)
+char FunctionTargetTransformInfo::ID = 0;
+
+namespace llvm {
+FunctionPass *createFunctionTargetTransformInfoPass() {
+  return new FunctionTargetTransformInfo();
+}
+}
+
+FunctionTargetTransformInfo::FunctionTargetTransformInfo()
+  : FunctionPass(ID), Fn(nullptr), TTI(nullptr) {
+  initializeFunctionTargetTransformInfoPass(*PassRegistry::getPassRegistry());
+}
+
+void FunctionTargetTransformInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.setPreservesAll();
+  AU.addRequired<TargetTransformInfo>();
+}
+
+void FunctionTargetTransformInfo::releaseMemory() {}
+
+bool FunctionTargetTransformInfo::runOnFunction(Function &F) {
+  Fn = &F;
+  TTI = &getAnalysis<TargetTransformInfo>();
+  return false;
+}