[llvm][NFC] Move inlining decision-related APIs in InliningAdvisor.

[mtrofin]

Summary

Factoring out in preparation to https://reviews.llvm.org/D79042

[davidxl]

At first I thought may be put inliner advisor and friends into InlineCost.h[cpp], but on second thought, the proposed restructuring is better: we have inline cost analysis in InlineCost.xx, actual inliner transformation in Inliner.xx, and the inline heuristics or ML sits in InlineAdvisor.xx.

Just need to make the naming more consistent : InliningAdvisor --> InlineAdvisor

[mtrofin]

feedback: InliningAdvisor -> InlineAdvisor

[mtrofin]

In D79613#2027187, @davidxl wrote:

At first I thought may be put inliner advisor and friends into InlineCost.h[cpp], but on second thought, the proposed restructuring is better: we have inline cost analysis in InlineCost.xx, actual inliner transformation in Inliner.xx, and the inline heuristics or ML sits in InlineAdvisor.xx.

Just need to make the naming more consistent : InliningAdvisor --> InlineAdvisor

Done.

[mtrofin]

updated name in comments

[davidxl]

lgtm

llvm/include/llvm/Analysis/InliningAdvisor.h

+//===- InliningAdvisor.h - Inlining decision making abstraction -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+#ifndef LLVM_INLININGADVISOR_H_
+#define LLVM_INLININGADVISOR_H_
+
+#include <memory>
+#include <unordered_set>
+#include <vector>
+
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+class BasicBlock;
+class CallBase;
+class Function;
+class OptimizationRemarkEmitter;
+
+// Default (manual policy) decision making helper APIs. Shared with the legacy
+// pass manager inliner.
+
+/// Return true if inlining of CB can block the caller from being
+/// inlined which is proved to be more beneficial. \p IC is the
+/// estimated inline cost associated with callsite \p CB.
+/// \p TotalSecondaryCost will be set to the estimated cost of inlining the
+/// caller if \p CB is suppressed for inlining.
+bool shouldBeDeferred(Function *Caller, InlineCost IC, int &TotalSecondaryCost,
+                      function_ref<InlineCost(CallBase &CB)> GetInlineCost);
+
+/// Return the cost only if the inliner should attempt to inline at the given
+/// CallSite. If we return the cost, we will emit an optimisation remark later
+/// using that cost, so we won't do so from this function. Return None if
+/// inlining should not be attempted.
+Optional<InlineCost>
+shouldInline(CallBase &CB, function_ref<InlineCost(CallBase &CB)> GetInlineCost,
+             OptimizationRemarkEmitter &ORE);
+
+/// Emit ORE message.
+void emitInlinedInto(OptimizationRemarkEmitter &ORE, DebugLoc DLoc,
+                     const BasicBlock *Block, const Function &Callee,
+                     const Function &Caller, const InlineCost &IC);
+
+/// Set the inline-remark attribute.
+void setInlineRemark(CallBase &CB, StringRef Message);
+
+/// Utility for extracting the inline cost message to a string.
+std::string inlineCostStr(const InlineCost &IC);
+} // namespace llvm
+#endif // LLVM_INLININGADVISOR_H_

llvm/lib/Analysis/CMakeLists.txt

add_llvm_component_library(LLVMAnalysis
   EHPersonalities.cpp
   GlobalsModRef.cpp
   GuardUtils.cpp
   HeatUtils.cpp
   IVDescriptors.cpp
   IVUsers.cpp
   IndirectCallPromotionAnalysis.cpp
   InlineCost.cpp
+  InliningAdvisor.cpp
   InstCount.cpp
   InstructionPrecedenceTracking.cpp
   InstructionSimplify.cpp
   Interval.cpp
   IntervalPartition.cpp
   LazyBranchProbabilityInfo.cpp
   LazyBlockFrequencyInfo.cpp
   LazyCallGraph.cpp

llvm/lib/Analysis/InliningAdvisor.cpp

+//===- InliningAdvisor.cpp - analysis pass implementation -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements InliningAdvisorAnalysis and DefaultInliningAdvisor, and
+// related types.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/InliningAdvisor.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/InlineCost.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <sstream>
+
+using namespace llvm;
+#define DEBUG_TYPE "inline"
+
+// This weirdly named statistic tracks the number of times that, when attempting
+// to inline a function A into B, we analyze the callers of B in order to see
+// if those would be more profitable and blocked inline steps.
+STATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed");
+
+/// Flag to add inline messages as callsite attributes 'inline-remark'.
+static cl::opt<bool>
+    InlineRemarkAttribute("inline-remark-attribute", cl::init(false),
+                          cl::Hidden,
+                          cl::desc("Enable adding inline-remark attribute to"
+                                   " callsites processed by inliner but decided"
+                                   " to be not inlined"));
+
+// An integer used to limit the cost of inline deferral.  The default negative
+// number tells shouldBeDeferred to only take the secondary cost into account.
+static cl::opt<int>
+    InlineDeferralScale("inline-deferral-scale",
+                        cl::desc("Scale to limit the cost of inline deferral"),
+                        cl::init(-1), cl::Hidden);
+
+/// Return true if inlining of CB can block the caller from being
+/// inlined which is proved to be more beneficial. \p IC is the
+/// estimated inline cost associated with callsite \p CB.
+/// \p TotalSecondaryCost will be set to the estimated cost of inlining the
+/// caller if \p CB is suppressed for inlining.
+bool llvm::shouldBeDeferred(
+    Function *Caller, InlineCost IC, int &TotalSecondaryCost,
+    function_ref<InlineCost(CallBase &CB)> GetInlineCost) {
+  // For now we only handle local or inline functions.
+  if (!Caller->hasLocalLinkage() && !Caller->hasLinkOnceODRLinkage())
+    return false;
+  // If the cost of inlining CB is non-positive, it is not going to prevent the
+  // caller from being inlined into its callers and hence we don't need to
+  // defer.
+  if (IC.getCost() <= 0)
+    return false;
+  // Try to detect the case where the current inlining candidate caller (call
+  // it B) is a static or linkonce-ODR function and is an inlining candidate
+  // elsewhere, and the current candidate callee (call it C) is large enough
+  // that inlining it into B would make B too big to inline later. In these
+  // circumstances it may be best not to inline C into B, but to inline B into
+  // its callers.
+  //
+  // This only applies to static and linkonce-ODR functions because those are
+  // expected to be available for inlining in the translation units where they
+  // are used. Thus we will always have the opportunity to make local inlining
+  // decisions. Importantly the linkonce-ODR linkage covers inline functions
+  // and templates in C++.
+  //
+  // FIXME: All of this logic should be sunk into getInlineCost. It relies on
+  // the internal implementation of the inline cost metrics rather than
+  // treating them as truly abstract units etc.
+  TotalSecondaryCost = 0;
+  // The candidate cost to be imposed upon the current function.
+  int CandidateCost = IC.getCost() - 1;
+  // If the caller has local linkage and can be inlined to all its callers, we
+  // can apply a huge negative bonus to TotalSecondaryCost.
+  bool ApplyLastCallBonus = Caller->hasLocalLinkage() && !Caller->hasOneUse();
+  // This bool tracks what happens if we DO inline C into B.
+  bool InliningPreventsSomeOuterInline = false;
+  unsigned NumCallerUsers = 0;
+  for (User *U : Caller->users()) {
+    CallBase *CS2 = dyn_cast<CallBase>(U);
+
+    // If this isn't a call to Caller (it could be some other sort
+    // of reference) skip it.  Such references will prevent the caller
+    // from being removed.
+    if (!CS2 || CS2->getCalledFunction() != Caller) {
+      ApplyLastCallBonus = false;
+      continue;
+    }
+
+    InlineCost IC2 = GetInlineCost(*CS2);
+    ++NumCallerCallersAnalyzed;
+    if (!IC2) {
+      ApplyLastCallBonus = false;
+      continue;
+    }
+    if (IC2.isAlways())
+      continue;
+
+    // See if inlining of the original callsite would erase the cost delta of
+    // this callsite. We subtract off the penalty for the call instruction,
+    // which we would be deleting.
+    if (IC2.getCostDelta() <= CandidateCost) {
+      InliningPreventsSomeOuterInline = true;
+      TotalSecondaryCost += IC2.getCost();
+      NumCallerUsers++;
+    }
+  }
+
+  if (!InliningPreventsSomeOuterInline)
+    return false;
+
+  // If all outer calls to Caller would get inlined, the cost for the last
+  // one is set very low by getInlineCost, in anticipation that Caller will
+  // be removed entirely.  We did not account for this above unless there
+  // is only one caller of Caller.
+  if (ApplyLastCallBonus)
+    TotalSecondaryCost -= InlineConstants::LastCallToStaticBonus;
+
+  // If InlineDeferralScale is negative, then ignore the cost of primary
+  // inlining -- IC.getCost() multiplied by the number of callers to Caller.
+  if (InlineDeferralScale < 0)
+    return TotalSecondaryCost < IC.getCost();
+
+  int TotalCost = TotalSecondaryCost + IC.getCost() * NumCallerUsers;
+  int Allowance = IC.getCost() * InlineDeferralScale;
+  return TotalCost < Allowance;
+}
+
+namespace llvm {
+static std::basic_ostream<char> &operator<<(std::basic_ostream<char> &R,
+                                            const ore::NV &Arg) {
+  return R << Arg.Val;
+}
+
+template <class RemarkT>
+RemarkT &operator<<(RemarkT &&R, const InlineCost &IC) {
+  using namespace ore;
+  if (IC.isAlways()) {
+    R << "(cost=always)";
+  } else if (IC.isNever()) {
+    R << "(cost=never)";
+  } else {
+    R << "(cost=" << ore::NV("Cost", IC.getCost())
+      << ", threshold=" << ore::NV("Threshold", IC.getThreshold()) << ")";
+  }
+  if (const char *Reason = IC.getReason())
+    R << ": " << ore::NV("Reason", Reason);
+  return R;
+}
+} // namespace llvm
+
+std::string llvm::inlineCostStr(const InlineCost &IC) {
+  std::stringstream Remark;
+  Remark << IC;
+  return Remark.str();
+}
+
+void llvm::setInlineRemark(CallBase &CB, StringRef Message) {
+  if (!InlineRemarkAttribute)
+    return;
+
+  Attribute Attr = Attribute::get(CB.getContext(), "inline-remark", Message);
+  CB.addAttribute(AttributeList::FunctionIndex, Attr);
+}
+
+/// Return the cost only if the inliner should attempt to inline at the given
+/// CallSite. If we return the cost, we will emit an optimisation remark later
+/// using that cost, so we won't do so from this function. Return None if
+/// inlining should not be attempted.
+Optional<InlineCost>
+llvm::shouldInline(CallBase &CB,
+                   function_ref<InlineCost(CallBase &CB)> GetInlineCost,
+                   OptimizationRemarkEmitter &ORE) {
+  using namespace ore;
+
+  InlineCost IC = GetInlineCost(CB);
+  Instruction *Call = &CB;
+  Function *Callee = CB.getCalledFunction();
+  Function *Caller = CB.getCaller();
+
+  if (IC.isAlways()) {
+    LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC)
+                      << ", Call: " << CB << "\n");
+    return IC;
+  }
+
+  if (!IC) {
+    LLVM_DEBUG(dbgs() << "    NOT Inlining " << inlineCostStr(IC)
+                      << ", Call: " << CB << "\n");
+    if (IC.isNever()) {
+      ORE.emit([&]() {
+        return OptimizationRemarkMissed(DEBUG_TYPE, "NeverInline", Call)
+               << NV("Callee", Callee) << " not inlined into "
+               << NV("Caller", Caller) << " because it should never be inlined "
+               << IC;
+      });
+    } else {
+      ORE.emit([&]() {
+        return OptimizationRemarkMissed(DEBUG_TYPE, "TooCostly", Call)
+               << NV("Callee", Callee) << " not inlined into "
+               << NV("Caller", Caller) << " because too costly to inline "
+               << IC;
+      });
+    }
+    setInlineRemark(CB, inlineCostStr(IC));
+    return None;
+  }
+
+  int TotalSecondaryCost = 0;
+  if (shouldBeDeferred(Caller, IC, TotalSecondaryCost, GetInlineCost)) {
+    LLVM_DEBUG(dbgs() << "    NOT Inlining: " << CB
+                      << " Cost = " << IC.getCost()
+                      << ", outer Cost = " << TotalSecondaryCost << '\n');
+    ORE.emit([&]() {
+      return OptimizationRemarkMissed(DEBUG_TYPE, "IncreaseCostInOtherContexts",
+                                      Call)
+             << "Not inlining. Cost of inlining " << NV("Callee", Callee)
+             << " increases the cost of inlining " << NV("Caller", Caller)
+             << " in other contexts";
+    });
+    setInlineRemark(CB, "deferred");
+    // IC does not bool() to false, so get an InlineCost that will.
+    // This will not be inspected to make an error message.
+    return None;
+  }
+
+  LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC) << ", Call: " << CB
+                    << '\n');
+  return IC;
+}
+
+void llvm::emitInlinedInto(OptimizationRemarkEmitter &ORE, DebugLoc DLoc,
+                           const BasicBlock *Block, const Function &Callee,
+                           const Function &Caller, const InlineCost &IC) {
+  ORE.emit([&]() {
+    bool AlwaysInline = IC.isAlways();
+    StringRef RemarkName = AlwaysInline ? "AlwaysInline" : "Inlined";
+    return OptimizationRemark(DEBUG_TYPE, RemarkName, DLoc, Block)
+           << ore::NV("Callee", &Callee) << " inlined into "
+           << ore::NV("Caller", &Caller) << " with " << IC;
+  });
+}

llvm/lib/Transforms/IPO/Inliner.cpp

 #include "llvm/ADT/StringRef.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/BlockFrequencyInfo.h"
 #include "llvm/Analysis/CGSCCPassManager.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/InlineCost.h"
+#include "llvm/Analysis/InliningAdvisor.h"
 #include "llvm/Analysis/LazyCallGraph.h"
 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DataLayout.h"

 
 #define DEBUG_TYPE "inline"
 
 STATISTIC(NumInlined, "Number of functions inlined");
 STATISTIC(NumCallsDeleted, "Number of call sites deleted, not inlined");
 STATISTIC(NumDeleted, "Number of functions deleted because all callers found");
 STATISTIC(NumMergedAllocas, "Number of allocas merged together");
 
-// This weirdly named statistic tracks the number of times that, when attempting
-// to inline a function A into B, we analyze the callers of B in order to see
-// if those would be more profitable and blocked inline steps.
-STATISTIC(NumCallerCallersAnalyzed, "Number of caller-callers analyzed");
-
 /// Flag to disable manual alloca merging.
 ///
 /// Merging of allocas was originally done as a stack-size saving technique
 /// prior to LLVM's code generator having support for stack coloring based on
 /// lifetime markers. It is now in the process of being removed. To experiment
 /// with disabling it and relying fully on lifetime marker based stack
 /// coloring, you can pass this flag to LLVM.
 static cl::opt<bool>
     DisableInlinedAllocaMerging("disable-inlined-alloca-merging",
                                 cl::init(false), cl::Hidden);
 
-// An integer used to limit the cost of inline deferral.  The default negative
-// number tells shouldBeDeferred to only take the secondary cost into account.
-static cl::opt<int>
-    InlineDeferralScale("inline-deferral-scale",
-                        cl::desc("Scale to limit the cost of inline deferral"),
-                        cl::init(-1), cl::Hidden);
-
 namespace {
 
 enum class InlinerFunctionImportStatsOpts {
   No = 0,
   Basic = 1,
   Verbose = 2,
 };
 
 } // end anonymous namespace
 
 static cl::opt<InlinerFunctionImportStatsOpts> InlinerFunctionImportStats(
     "inliner-function-import-stats",
     cl::init(InlinerFunctionImportStatsOpts::No),
     cl::values(clEnumValN(InlinerFunctionImportStatsOpts::Basic, "basic",
                           "basic statistics"),
                clEnumValN(InlinerFunctionImportStatsOpts::Verbose, "verbose",
                           "printing of statistics for each inlined function")),
     cl::Hidden, cl::desc("Enable inliner stats for imported functions"));
 
-/// Flag to add inline messages as callsite attributes 'inline-remark'.
-static cl::opt<bool>
-    InlineRemarkAttribute("inline-remark-attribute", cl::init(false),
-                          cl::Hidden,
-                          cl::desc("Enable adding inline-remark attribute to"
-                                   " callsites processed by inliner but decided"
-                                   " to be not inlined"));
-
 LegacyInlinerBase::LegacyInlinerBase(char &ID) : CallGraphSCCPass(ID) {}
 
 LegacyInlinerBase::LegacyInlinerBase(char &ID, bool InsertLifetime)
     : CallGraphSCCPass(ID), InsertLifetime(InsertLifetime) {}
 
 /// For this class, we declare that we require and preserve the call graph.
 /// If the derived class implements this method, it should
 /// always explicitly call the implementation here.
static InlineResult inlineCallIfPossible(
   AttributeFuncs::mergeAttributesForInlining(*Caller, *Callee);
 
   if (!DisableInlinedAllocaMerging)
     mergeInlinedArrayAllocas(Caller, IFI, InlinedArrayAllocas, InlineHistory);
 
   return IR; // success
 }
 
-/// Return true if inlining of CB can block the caller from being
-/// inlined which is proved to be more beneficial. \p IC is the
-/// estimated inline cost associated with callsite \p CB.
-/// \p TotalSecondaryCost will be set to the estimated cost of inlining the
-/// caller if \p CB is suppressed for inlining.
-static bool
-shouldBeDeferred(Function *Caller, InlineCost IC, int &TotalSecondaryCost,
-                 function_ref<InlineCost(CallBase &CB)> GetInlineCost) {
-  // For now we only handle local or inline functions.
-  if (!Caller->hasLocalLinkage() && !Caller->hasLinkOnceODRLinkage())
-    return false;
-  // If the cost of inlining CB is non-positive, it is not going to prevent the
-  // caller from being inlined into its callers and hence we don't need to
-  // defer.
-  if (IC.getCost() <= 0)
-    return false;
-  // Try to detect the case where the current inlining candidate caller (call
-  // it B) is a static or linkonce-ODR function and is an inlining candidate
-  // elsewhere, and the current candidate callee (call it C) is large enough
-  // that inlining it into B would make B too big to inline later. In these
-  // circumstances it may be best not to inline C into B, but to inline B into
-  // its callers.
-  //
-  // This only applies to static and linkonce-ODR functions because those are
-  // expected to be available for inlining in the translation units where they
-  // are used. Thus we will always have the opportunity to make local inlining
-  // decisions. Importantly the linkonce-ODR linkage covers inline functions
-  // and templates in C++.
-  //
-  // FIXME: All of this logic should be sunk into getInlineCost. It relies on
-  // the internal implementation of the inline cost metrics rather than
-  // treating them as truly abstract units etc.
-  TotalSecondaryCost = 0;
-  // The candidate cost to be imposed upon the current function.
-  int CandidateCost = IC.getCost() - 1;
-  // If the caller has local linkage and can be inlined to all its callers, we
-  // can apply a huge negative bonus to TotalSecondaryCost.
-  bool ApplyLastCallBonus = Caller->hasLocalLinkage() && !Caller->hasOneUse();
-  // This bool tracks what happens if we DO inline C into B.
-  bool InliningPreventsSomeOuterInline = false;
-  unsigned NumCallerUsers = 0;
-  for (User *U : Caller->users()) {
-    CallBase *CS2 = dyn_cast<CallBase>(U);
-
-    // If this isn't a call to Caller (it could be some other sort
-    // of reference) skip it.  Such references will prevent the caller
-    // from being removed.
-    if (!CS2 || CS2->getCalledFunction() != Caller) {
-      ApplyLastCallBonus = false;
-      continue;
-    }
-
-    InlineCost IC2 = GetInlineCost(*CS2);
-    ++NumCallerCallersAnalyzed;
-    if (!IC2) {
-      ApplyLastCallBonus = false;
-      continue;
-    }
-    if (IC2.isAlways())
-      continue;
-
-    // See if inlining of the original callsite would erase the cost delta of
-    // this callsite. We subtract off the penalty for the call instruction,
-    // which we would be deleting.
-    if (IC2.getCostDelta() <= CandidateCost) {
-      InliningPreventsSomeOuterInline = true;
-      TotalSecondaryCost += IC2.getCost();
-      NumCallerUsers++;
-    }
-  }
-
-  if (!InliningPreventsSomeOuterInline)
-    return false;
-
-  // If all outer calls to Caller would get inlined, the cost for the last
-  // one is set very low by getInlineCost, in anticipation that Caller will
-  // be removed entirely.  We did not account for this above unless there
-  // is only one caller of Caller.
-  if (ApplyLastCallBonus)
-    TotalSecondaryCost -= InlineConstants::LastCallToStaticBonus;
-
-  // If InlineDeferralScale is negative, then ignore the cost of primary
-  // inlining -- IC.getCost() multiplied by the number of callers to Caller.
-  if (InlineDeferralScale < 0)
-    return TotalSecondaryCost < IC.getCost();
-
-  int TotalCost = TotalSecondaryCost + IC.getCost() * NumCallerUsers;
-  int Allowance = IC.getCost() * InlineDeferralScale;
-  return TotalCost < Allowance;
-}
-
-static std::basic_ostream<char> &operator<<(std::basic_ostream<char> &R,
-                                            const ore::NV &Arg) {
-  return R << Arg.Val;
-}
-
-template <class RemarkT>
-RemarkT &operator<<(RemarkT &&R, const InlineCost &IC) {
-  using namespace ore;
-  if (IC.isAlways()) {
-    R << "(cost=always)";
-  } else if (IC.isNever()) {
-    R << "(cost=never)";
-  } else {
-    R << "(cost=" << ore::NV("Cost", IC.getCost())
-      << ", threshold=" << ore::NV("Threshold", IC.getThreshold()) << ")";
-  }
-  if (const char *Reason = IC.getReason())
-    R << ": " << ore::NV("Reason", Reason);
-  return R;
-}
-
-static std::string inlineCostStr(const InlineCost &IC) {
-  std::stringstream Remark;
-  Remark << IC;
-  return Remark.str();
-}
-
-static void setInlineRemark(CallBase &CB, StringRef Message) {
-  if (!InlineRemarkAttribute)
-    return;
-
-  Attribute Attr = Attribute::get(CB.getContext(), "inline-remark", Message);
-  CB.addAttribute(AttributeList::FunctionIndex, Attr);
-}
-
-/// Return the cost only if the inliner should attempt to inline at the given
-/// CallSite. If we return the cost, we will emit an optimisation remark later
-/// using that cost, so we won't do so from this function. Return None if
-/// inlining should not be attempted.
-static Optional<InlineCost>
-shouldInline(CallBase &CB, function_ref<InlineCost(CallBase &CB)> GetInlineCost,
-             OptimizationRemarkEmitter &ORE) {
-  using namespace ore;
-
-  InlineCost IC = GetInlineCost(CB);
-  Instruction *Call = &CB;
-  Function *Callee = CB.getCalledFunction();
-  Function *Caller = CB.getCaller();
-
-  if (IC.isAlways()) {
-    LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC)
-                      << ", Call: " << CB << "\n");
-    return IC;
-  }
-
-  if (!IC) {
-    LLVM_DEBUG(dbgs() << "    NOT Inlining " << inlineCostStr(IC)
-                      << ", Call: " << CB << "\n");
-    if (IC.isNever()) {
-      ORE.emit([&]() {
-        return OptimizationRemarkMissed(DEBUG_TYPE, "NeverInline", Call)
-               << NV("Callee", Callee) << " not inlined into "
-               << NV("Caller", Caller) << " because it should never be inlined "
-               << IC;
-      });
-    } else {
-      ORE.emit([&]() {
-        return OptimizationRemarkMissed(DEBUG_TYPE, "TooCostly", Call)
-               << NV("Callee", Callee) << " not inlined into "
-               << NV("Caller", Caller) << " because too costly to inline "
-               << IC;
-      });
-    }
-    setInlineRemark(CB, inlineCostStr(IC));
-    return None;
-  }
-
-  int TotalSecondaryCost = 0;
-  if (shouldBeDeferred(Caller, IC, TotalSecondaryCost, GetInlineCost)) {
-    LLVM_DEBUG(dbgs() << "    NOT Inlining: " << CB
-                      << " Cost = " << IC.getCost()
-                      << ", outer Cost = " << TotalSecondaryCost << '\n');
-    ORE.emit([&]() {
-      return OptimizationRemarkMissed(DEBUG_TYPE, "IncreaseCostInOtherContexts",
-                                      Call)
-             << "Not inlining. Cost of inlining " << NV("Callee", Callee)
-             << " increases the cost of inlining " << NV("Caller", Caller)
-             << " in other contexts";
-    });
-    setInlineRemark(CB, "deferred");
-    // IC does not bool() to false, so get an InlineCost that will.
-    // This will not be inspected to make an error message.
-    return None;
-  }
-
-  LLVM_DEBUG(dbgs() << "    Inlining " << inlineCostStr(IC) << ", Call: " << CB
-                    << '\n');
-  return IC;
-}
-
 /// Return true if the specified inline history ID
 /// indicates an inline history that includes the specified function.
 static bool inlineHistoryIncludes(
     Function *F, int InlineHistoryID,
     const SmallVectorImpl<std::pair<Function *, int>> &InlineHistory) {
   while (InlineHistoryID != -1) {
     assert(unsigned(InlineHistoryID) < InlineHistory.size() &&
            "Invalid inline history ID");

 }
 
 bool LegacyInlinerBase::runOnSCC(CallGraphSCC &SCC) {
   if (skipSCC(SCC))
     return false;
   return inlineCalls(SCC);
 }
 
-static void emitInlinedInto(OptimizationRemarkEmitter &ORE, DebugLoc &DLoc,
-                            const BasicBlock *Block, const Function &Callee,
-                            const Function &Caller, const InlineCost &IC) {
-  ORE.emit([&]() {
-    bool AlwaysInline = IC.isAlways();
-    StringRef RemarkName = AlwaysInline ? "AlwaysInline" : "Inlined";
-    return OptimizationRemark(DEBUG_TYPE, RemarkName, DLoc, Block)
-           << ore::NV("Callee", &Callee) << " inlined into "
-           << ore::NV("Caller", &Caller) << " with " << IC;
-  });
-}
-
 static bool
 inlineCallsImpl(CallGraphSCC &SCC, CallGraph &CG,
                 std::function<AssumptionCache &(Function &)> GetAssumptionCache,
                 ProfileSummaryInfo *PSI,
                 std::function<const TargetLibraryInfo &(Function &)> GetTLI,
                 bool InsertLifetime,
                 function_ref<InlineCost(CallBase &CB)> GetInlineCost,
                 function_ref<AAResults &(Function &)> AARGetter,