[clang] [llvm] [clang-tools-extra] Remove unused LoopInfo from InlineSpiller and SpillPlacement (NFC) (PR #71874)

[Matthias Braun via cfe-commits]

https://github.com/MatzeB updated https://github.com/llvm/llvm-project/pull/71874

>From 3b502f8cc14456b325efc3017a4a114391284b37 Mon Sep 17 00:00:00 2001
From: Matthias Braun <matze at braunis.de>
Date: Wed, 19 Oct 2022 10:58:40 -0700
Subject: [PATCH] Remove unused LoopInfo from InlineSpiller and SpillPlacement

---
 llvm/lib/CodeGen/CalcSpillWeights.cpp | 5 ++---
 llvm/lib/CodeGen/InlineSpiller.cpp    | 9 ++-------
 llvm/lib/CodeGen/SpillPlacement.cpp   | 4 ----
 llvm/lib/CodeGen/SpillPlacement.h     | 2 --
 4 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/llvm/lib/CodeGen/CalcSpillWeights.cpp b/llvm/lib/CodeGen/CalcSpillWeights.cpp
index bf114921a7d220a..0d819e0298213b9 100644
--- a/llvm/lib/CodeGen/CalcSpillWeights.cpp
+++ b/llvm/lib/CodeGen/CalcSpillWeights.cpp
@@ -163,8 +163,6 @@ float VirtRegAuxInfo::weightCalcHelper(LiveInterval &LI, SlotIndex *Start,
   const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo();
   const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
   MachineBasicBlock *MBB = nullptr;
-  MachineLoop *Loop = nullptr;
-  bool IsExiting = false;
   float TotalWeight = 0;
   unsigned NumInstr = 0; // Number of instructions using LI
   SmallPtrSet<MachineInstr *, 8> Visited;
@@ -260,9 +258,10 @@ float VirtRegAuxInfo::weightCalcHelper(LiveInterval &LI, SlotIndex *Start,
     float Weight = 1.0f;
     if (IsSpillable) {
       // Get loop info for mi.
+      bool IsExiting = false;
       if (MI->getParent() != MBB) {
         MBB = MI->getParent();
-        Loop = Loops.getLoopFor(MBB);
+        const MachineLoop *Loop = Loops.getLoopFor(MBB);
         IsExiting = Loop ? Loop->isLoopExiting(MBB) : false;
       }
 
diff --git a/llvm/lib/CodeGen/InlineSpiller.cpp b/llvm/lib/CodeGen/InlineSpiller.cpp
index 71d58b2e9e18d7d..e6d6fff96fbc519 100644
--- a/llvm/lib/CodeGen/InlineSpiller.cpp
+++ b/llvm/lib/CodeGen/InlineSpiller.cpp
@@ -33,7 +33,6 @@
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineInstrBundle.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/SlotIndexes.h"
@@ -86,7 +85,6 @@ class HoistSpillHelper : private LiveRangeEdit::Delegate {
   LiveIntervals &LIS;
   LiveStacks &LSS;
   MachineDominatorTree &MDT;
-  MachineLoopInfo &Loops;
   VirtRegMap &VRM;
   MachineRegisterInfo &MRI;
   const TargetInstrInfo &TII;
@@ -138,8 +136,7 @@ class HoistSpillHelper : private LiveRangeEdit::Delegate {
                    VirtRegMap &vrm)
       : MF(mf), LIS(pass.getAnalysis<LiveIntervals>()),
         LSS(pass.getAnalysis<LiveStacks>()),
-        MDT(pass.getAnalysis<MachineDominatorTree>()),
-        Loops(pass.getAnalysis<MachineLoopInfo>()), VRM(vrm),
+        MDT(pass.getAnalysis<MachineDominatorTree>()), VRM(vrm),
         MRI(mf.getRegInfo()), TII(*mf.getSubtarget().getInstrInfo()),
         TRI(*mf.getSubtarget().getRegisterInfo()),
         MBFI(pass.getAnalysis<MachineBlockFrequencyInfo>()),
@@ -157,7 +154,6 @@ class InlineSpiller : public Spiller {
   LiveIntervals &LIS;
   LiveStacks &LSS;
   MachineDominatorTree &MDT;
-  MachineLoopInfo &Loops;
   VirtRegMap &VRM;
   MachineRegisterInfo &MRI;
   const TargetInstrInfo &TII;
@@ -197,8 +193,7 @@ class InlineSpiller : public Spiller {
                 VirtRegAuxInfo &VRAI)
       : MF(MF), LIS(Pass.getAnalysis<LiveIntervals>()),
         LSS(Pass.getAnalysis<LiveStacks>()),
-        MDT(Pass.getAnalysis<MachineDominatorTree>()),
-        Loops(Pass.getAnalysis<MachineLoopInfo>()), VRM(VRM),
+        MDT(Pass.getAnalysis<MachineDominatorTree>()), VRM(VRM),
         MRI(MF.getRegInfo()), TII(*MF.getSubtarget().getInstrInfo()),
         TRI(*MF.getSubtarget().getRegisterInfo()),
         MBFI(Pass.getAnalysis<MachineBlockFrequencyInfo>()),
diff --git a/llvm/lib/CodeGen/SpillPlacement.cpp b/llvm/lib/CodeGen/SpillPlacement.cpp
index 6e74e51d678285b..cdb8099e354bba1 100644
--- a/llvm/lib/CodeGen/SpillPlacement.cpp
+++ b/llvm/lib/CodeGen/SpillPlacement.cpp
@@ -32,7 +32,6 @@
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
@@ -52,7 +51,6 @@ char &llvm::SpillPlacementID = SpillPlacement::ID;
 INITIALIZE_PASS_BEGIN(SpillPlacement, DEBUG_TYPE,
                       "Spill Code Placement Analysis", true, true)
 INITIALIZE_PASS_DEPENDENCY(EdgeBundles)
-INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
 INITIALIZE_PASS_END(SpillPlacement, DEBUG_TYPE,
                     "Spill Code Placement Analysis", true, true)
 
@@ -60,7 +58,6 @@ void SpillPlacement::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequired<MachineBlockFrequencyInfo>();
   AU.addRequiredTransitive<EdgeBundles>();
-  AU.addRequiredTransitive<MachineLoopInfo>();
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
@@ -195,7 +192,6 @@ struct SpillPlacement::Node {
 bool SpillPlacement::runOnMachineFunction(MachineFunction &mf) {
   MF = &mf;
   bundles = &getAnalysis<EdgeBundles>();
-  loops = &getAnalysis<MachineLoopInfo>();
 
   assert(!nodes && "Leaking node array");
   nodes = new Node[bundles->getNumBundles()];
diff --git a/llvm/lib/CodeGen/SpillPlacement.h b/llvm/lib/CodeGen/SpillPlacement.h
index 2a298c7a74aa61a..5fd9b085259d1d4 100644
--- a/llvm/lib/CodeGen/SpillPlacement.h
+++ b/llvm/lib/CodeGen/SpillPlacement.h
@@ -38,13 +38,11 @@ class BitVector;
 class EdgeBundles;
 class MachineBlockFrequencyInfo;
 class MachineFunction;
-class MachineLoopInfo;
 
 class SpillPlacement : public MachineFunctionPass {
   struct Node;
   const MachineFunction *MF = nullptr;
   const EdgeBundles *bundles = nullptr;
-  const MachineLoopInfo *loops = nullptr;
   const MachineBlockFrequencyInfo *MBFI = nullptr;
   Node *nodes = nullptr;