[ModuloSchedule] Add interface call to accept/reject SMS schedules

[dpenry]

Summary

This interface allows a target to reject a proposed
SMS schedule. For Hexagon/PowerPC, all schedules
are accepted, leaving behavior unchanged. For ARM,
schedules which exceed register pressure limits are
rejected.

Also, two RegisterPressureTracker methods now need to be public so
that register pressure can be computed by more callers.

[dmgreen]

At a high level shouldUseSchedule sounds like a useful addition, but much of the logic in the current Arm implementation doesn't seem very Arm specific (correct me if I'm wrong). Would it be beneficial to incorporate the register pressure calculations into SwingSchedulerDAG, which the target could opt into checking.

llvm/include/llvm/CodeGen/TargetInstrInfo.h

734

"should be used"
Perhaps explain that returning false means no pipelined loops too. "Otherwise return false to not pipeline the loop."

llvm/lib/CodeGen/MachinePipeliner.cpp

2098

Perhaps move this below the "Schedule Found?" message below, and adding a debug message explaining that the target opted out of the schedule might be useful for debugging.

llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp

6842

cnt -> Cnt

6843

i -> I

6888

cycle -> Cycle. Same for the rest of the variables,

llvm/test/CodeGen/Thumb2/swp-regpressure.mir

7

This test uses phi nodes to increase the register pressure? Maybe remove the dead phis from dot2.

And maybe rename the tests to make it clear that dot1 has too high pressure, but dot2 is OK and expected to pipeilne.

[dpenry]

In D128941#3627725, @dmgreen wrote:

At a high level shouldUseSchedule sounds like a useful addition, but much of the logic in the current Arm implementation doesn't seem very Arm specific (correct me if I'm wrong). Would it be beneficial to incorporate the register pressure calculations into SwingSchedulerDAG, which the target could opt into checking.

The current logic isn't Arm-specific. This might be useful more generally, but I'd like to see more feedback before adding the calculations in.

llvm/test/CodeGen/Thumb2/swp-regpressure.mir

7

• Renamed the tests, but the point of using the phi nodes in this way -- including the dead phis -- was to have the same set of instructions in each case with the only difference being the register pressure induced by them. Phi nodes are particularly nice because they don't affect RecMII.

[dpenry]

• Changes to comments
• Debug message explaining that target opted out of schedule
• Fixes to variable names
• Naming of functions within test case

[dmgreen]

OK. The logic looks OK to me, and we can always move the code if another target finds a use for it.
LGTM with a few suggestions

llvm/include/llvm/CodeGen/TargetInstrInfo.h

734

"should used" > "should be used"

llvm/lib/CodeGen/MachinePipeliner.cpp

2097

Remove this extra line.

llvm/lib/Target/Hexagon/HexagonInstrInfo.cpp

753 ↗

(On Diff #445641)

You could perhaps just make the default PipelinerLoopInfo::shouldUseSchedule return true to avoid these overrides.

[dpenry]

Responding to comments

[dpenry]

Comments addressed.

[dmgreen]

LGTM

llvm/include/llvm/CodeGen/RegisterPressure.h

public:
   }
 
   bool hasUntiedDef(Register VirtReg) const {
     return UntiedDefs.count(VirtReg);
   }
 
   void dump() const;
 
+  void increaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
+                           LaneBitmask NewMask);
+  void decreaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
+                           LaneBitmask NewMask);
+
 protected:
   /// Add Reg to the live out set and increase max pressure.
   void discoverLiveOut(RegisterMaskPair Pair);
   /// Add Reg to the live in set and increase max pressure.
   void discoverLiveIn(RegisterMaskPair Pair);
 
   /// Get the SlotIndex for the first nondebug instruction including or
   /// after the current position.
   SlotIndex getCurrSlot() const;
 
-  void increaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
-                           LaneBitmask NewMask);
-  void decreaseRegPressure(Register RegUnit, LaneBitmask PreviousMask,
-                           LaneBitmask NewMask);
-
   void bumpDeadDefs(ArrayRef<RegisterMaskPair> DeadDefs);
 
   void bumpUpwardPressure(const MachineInstr *MI);
   void bumpDownwardPressure(const MachineInstr *MI);
 
   void discoverLiveInOrOut(RegisterMaskPair Pair,
                            SmallVectorImpl<RegisterMaskPair> &LiveInOrOut);
 

llvm/include/llvm/CodeGen/TargetInstrInfo.h

 class MCInst;
 struct MCSchedModel;
 class Module;
 class ScheduleDAG;
 class ScheduleDAGMI;
 class ScheduleHazardRecognizer;
 class SDNode;
 class SelectionDAG;
+class SMSchedule;
+class SwingSchedulerDAG;
 class RegScavenger;
 class TargetRegisterClass;
 class TargetRegisterInfo;
 class TargetSchedModel;
 class TargetSubtargetInfo;
 
 template <class T> class SmallVectorImpl;
 
public:
   class PipelinerLoopInfo {
   public:
     virtual ~PipelinerLoopInfo();
     /// Return true if the given instruction should not be pipelined and should
     /// be ignored. An example could be a loop comparison, or induction variable
     /// update with no users being pipelined.
     virtual bool shouldIgnoreForPipelining(const MachineInstr *MI) const = 0;
 
+    /// Return true if the proposed schedule should used.  Otherwise return
+    /// false to not pipeline the loop. This function should be used to ensure
+    /// that pipelined loops meet target-specific quality heuristics.
+    virtual bool shouldUseSchedule(SwingSchedulerDAG &SSD, SMSchedule &SMS) {
+      return true;
+    }
+
     /// Create a condition to determine if the trip count of the loop is greater
     /// than TC, where TC is always one more than for the previous prologue or
     /// 0 if this is being called for the outermost prologue.
     ///
     /// If the trip count is statically known to be greater than TC, return
     /// true. If the trip count is statically known to be not greater than TC,
     /// return false. Otherwise return nullopt and fill out Cond with the test
     /// condition.

llvm/lib/CodeGen/MachinePipeliner.cpp

if (scheduleFound)
       scheduleFound =
           Schedule.normalizeNonPipelinedInstructions(this, LoopPipelinerInfo);
 
     // If a schedule is found, check if it is a valid schedule too.
     if (scheduleFound)
       scheduleFound = Schedule.isValidSchedule(this);
   }
 
   LLVM_DEBUG(dbgs() << "Schedule Found? " << scheduleFound
                     << " (II=" << Schedule.getInitiationInterval()
                     << ")\n");
 
   if (scheduleFound) {
+    scheduleFound = LoopPipelinerInfo->shouldUseSchedule(*this, Schedule);
+    if (!scheduleFound)
+      dbgs() << "Target rejected schedule\n";
+  }
+
+  if (scheduleFound) {
     Schedule.finalizeSchedule(this);
     Pass.ORE->emit([&]() {
       return MachineOptimizationRemarkAnalysis(
                  DEBUG_TYPE, "schedule", Loop.getStartLoc(), Loop.getHeader())
              << "Schedule found with Initiation Interval: "
              << ore::NV("II", Schedule.getInitiationInterval())
              << ", MaxStageCount: "
              << ore::NV("MaxStageCount", Schedule.getMaxStageCount());

llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp

 #include "MCTargetDesc/ARMAddressingModes.h"
 #include "MCTargetDesc/ARMBaseInfo.h"
 #include "MVETailPredUtils.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/CodeGen/DFAPacketizer.h"
 #include "llvm/CodeGen/LiveVariables.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"
+#include "llvm/CodeGen/MachinePipeliner.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/MachineScheduler.h"
 #include "llvm/CodeGen/MultiHazardRecognizer.h"
 #include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
 #include "llvm/CodeGen/SelectionDAGNodes.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSchedule.h"

 }
 
 namespace {
 class ARMPipelinerLoopInfo : public TargetInstrInfo::PipelinerLoopInfo {
   MachineInstr *EndLoop, *LoopCount;
   MachineFunction *MF;
   const TargetInstrInfo *TII;
 
+  // Bitset[0 .. MAX_STAGES-1] ... iterations needed
+  //       [LAST_IS_USE] : last reference to register in schedule is a use
+  //       [SEEN_AS_LIVE] : Normal pressure algorithm believes register is live
+  static int constexpr MAX_STAGES = 30;
+  static int constexpr LAST_IS_USE = MAX_STAGES;
+  static int constexpr SEEN_AS_LIVE = MAX_STAGES + 1;
+  typedef std::bitset<MAX_STAGES + 2> IterNeed;
+  typedef std::map<unsigned, IterNeed> IterNeeds;
+
+  void bumpCrossIterationPressure(RegPressureTracker &RPT,
+                                  const IterNeeds &CIN);
+  bool tooMuchRegisterPressure(SwingSchedulerDAG &SSD, SMSchedule &SMS);
+
   // Meanings of the various stuff with loop types:
   // t2Bcc:
   //   EndLoop = branch at end of original BB that will become a kernel
   //   LoopCount = CC setter live into branch
   // t2LoopEnd:
   //   EndLoop = branch at end of original BB
   //   LoopCount = t2LoopDec
 public:
   ARMPipelinerLoopInfo(MachineInstr *EndLoop, MachineInstr *LoopCount)
       : EndLoop(EndLoop), LoopCount(LoopCount),
         MF(EndLoop->getParent()->getParent()),
         TII(MF->getSubtarget().getInstrInfo()) {}
 
   bool shouldIgnoreForPipelining(const MachineInstr *MI) const override {
     // Only ignore the terminator.
     return MI == EndLoop || MI == LoopCount;
   }
 
+  bool shouldUseSchedule(SwingSchedulerDAG &SSD, SMSchedule &SMS) override {
+    if (tooMuchRegisterPressure(SSD, SMS))
+      return false;
+
+    return true;
+  }
+
   Optional<bool> createTripCountGreaterCondition(
       int TC, MachineBasicBlock &MBB,
       SmallVectorImpl<MachineOperand> &Cond) override {
 
     if (isCondBranchOpcode(EndLoop->getOpcode())) {
       Cond.push_back(EndLoop->getOperand(1));
       Cond.push_back(EndLoop->getOperand(2));
       if (EndLoop->getOperand(0).getMBB() == EndLoop->getParent()) {
public:
   }
 
   void setPreheader(MachineBasicBlock *NewPreheader) override {}
 
   void adjustTripCount(int TripCountAdjust) override {}
 
   void disposed() override {}
 };
+
+void ARMPipelinerLoopInfo::bumpCrossIterationPressure(RegPressureTracker &RPT,
+                                                      const IterNeeds &CIN) {
+  // Increase pressure by the amounts in CrossIterationNeeds
+  for (const auto &N : CIN) {
+    int Cnt = N.second.count() - N.second[SEEN_AS_LIVE] * 2;
+    for (int I = 0; I < Cnt; ++I)
+      RPT.increaseRegPressure(Register(N.first), LaneBitmask::getNone(),
+                              LaneBitmask::getAll());
+  }
+  // Decrease pressure by the amounts in CrossIterationNeeds
+  for (const auto &N : CIN) {
+    int Cnt = N.second.count() - N.second[SEEN_AS_LIVE] * 2;
+    for (int I = 0; I < Cnt; ++I)
+      RPT.decreaseRegPressure(Register(N.first), LaneBitmask::getAll(),
+                              LaneBitmask::getNone());
+  }
+}
+
+bool ARMPipelinerLoopInfo::tooMuchRegisterPressure(SwingSchedulerDAG &SSD,
+                                                   SMSchedule &SMS) {
+  IterNeeds CrossIterationNeeds;
+
+  // Determine which values will be loop-carried after the schedule is
+  // applied
+
+  for (auto &SU : SSD.SUnits) {
+    const MachineInstr *MI = SU.getInstr();
+    int Stg = SMS.stageScheduled(const_cast<SUnit *>(&SU));
+    for (auto &S : SU.Succs)
+      if (MI->isPHI() && S.getKind() == SDep::Anti) {
+        Register Reg = S.getReg();
+        if (Register::isVirtualRegister(Reg))
+          CrossIterationNeeds.insert(std::make_pair(Reg.id(), IterNeed()))
+              .first->second.set(0);
+      } else if (S.isAssignedRegDep()) {
+        int OStg = SMS.stageScheduled(S.getSUnit());
+        if (OStg >= 0 && OStg != Stg) {
+          Register Reg = S.getReg();
+          if (Register::isVirtualRegister(Reg))
+            CrossIterationNeeds.insert(std::make_pair(Reg.id(), IterNeed()))
+                .first->second |= ((1 << (OStg - Stg)) - 1);
+        }
+      }
+  }
+
+  // Determine more-or-less what the proposed schedule (reversed) is going to
+  // be; it might not be quite the same because the within-cycle ordering
+  // created by SMSchedule depends upon changes to help with address offsets and
+  // the like.
+  std::vector<SUnit *> ProposedSchedule;
+  for (int Cycle = SMS.getFinalCycle(); Cycle >= SMS.getFirstCycle(); --Cycle)
+    for (int Stage = 0, StageEnd = SMS.getMaxStageCount(); Stage <= StageEnd;
+         ++Stage) {
+      std::deque<SUnit *> Instrs =
+          SMS.getInstructions(Cycle + Stage * SMS.getInitiationInterval());
+      std::sort(Instrs.begin(), Instrs.end(),
+                [](SUnit *A, SUnit *B) { return A->NodeNum > B->NodeNum; });
+      for (SUnit *SU : Instrs)
+        ProposedSchedule.push_back(SU);
+    }
+
+  // Learn whether the last use/def of each cross-iteration register is a use or
+  // def. If it is a def, RegisterPressure will implicitly increase max pressure
+  // and we do not have to add the pressure.
+  for (auto SU : ProposedSchedule)
+    for (ConstMIBundleOperands OperI(*SU->getInstr()); OperI.isValid();
+         ++OperI) {
+      auto MO = *OperI;
+      if (!MO.isReg() || !MO.getReg())
+        continue;
+      Register Reg = MO.getReg();
+      auto CIter = CrossIterationNeeds.find(Reg.id());
+      if (CIter == CrossIterationNeeds.end() || CIter->second[LAST_IS_USE] ||
+          CIter->second[SEEN_AS_LIVE])
+        continue;
+      if (MO.isDef() && !MO.isDead())
+        CIter->second.set(SEEN_AS_LIVE);
+      else if (MO.isUse())
+        CIter->second.set(LAST_IS_USE);
+    }
+  for (auto &CI : CrossIterationNeeds)
+    CI.second.reset(LAST_IS_USE);
+
+  RegionPressure RecRegPressure;
+  RegPressureTracker RPTracker(RecRegPressure);
+  RegisterClassInfo RegClassInfo;
+  RegClassInfo.runOnMachineFunction(*MF);
+  RPTracker.init(MF, &RegClassInfo, nullptr, EndLoop->getParent(),
+                 EndLoop->getParent()->end(), false, false);
+  const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
+
+  bumpCrossIterationPressure(RPTracker, CrossIterationNeeds);
+
+  for (auto SU : ProposedSchedule) {
+    MachineBasicBlock::const_iterator CurInstI = SU->getInstr();
+    RPTracker.setPos(std::next(CurInstI));
+    RPTracker.recede();
+
+    // Track what cross-iteration registers would be seen as live
+    for (ConstMIBundleOperands OperI(*CurInstI); OperI.isValid(); ++OperI) {
+      auto MO = *OperI;
+      if (!MO.isReg() || !MO.getReg())
+        continue;
+      Register Reg = MO.getReg();
+      if (MO.isDef() && !MO.isDead()) {
+        auto CIter = CrossIterationNeeds.find(Reg.id());
+        if (CIter != CrossIterationNeeds.end()) {
+          CIter->second.reset(0);
+          CIter->second.reset(SEEN_AS_LIVE);
+        }
+      }
+    }
+    for (auto &S : SU->Preds) {
+      auto Stg = SMS.stageScheduled(SU);
+      if (S.isAssignedRegDep()) {
+        Register Reg = S.getReg();
+        auto CIter = CrossIterationNeeds.find(Reg.id());
+        if (CIter != CrossIterationNeeds.end()) {
+          auto Stg2 = SMS.stageScheduled(const_cast<SUnit *>(S.getSUnit()));
+          assert(Stg2 <= Stg && "Data dependence upon earlier stage");
+          if (Stg - Stg2 < MAX_STAGES)
+            CIter->second.set(1u << (Stg - Stg2));
+          CIter->second.set(SEEN_AS_LIVE);
+        }
+      }
+    }
+
+    bumpCrossIterationPressure(RPTracker, CrossIterationNeeds);
+  }
+
+  auto &P = RPTracker.getPressure().MaxSetPressure;
+  for (unsigned I = 0, E = P.size(); I < E; ++I)
+    if (P[I] > TRI->getRegPressureSetLimit(*MF, I)) {
+      return true;
+    }
+  return false;
+}
+
 } // namespace
 
 std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
 ARMBaseInstrInfo::analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const {
   MachineBasicBlock::iterator I = LoopBB->getFirstTerminator();
   MachineBasicBlock *Preheader = *LoopBB->pred_begin();
   if (Preheader == LoopBB)
     Preheader = *std::next(LoopBB->pred_begin());

llvm/test/CodeGen/Thumb2/swp-regpressure.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=thumbv7m-none-eabi -mcpu=cortex-m7 -run-pass=pipeliner -o - %s | FileCheck %s --check-prefix=CHECK
+
+# This test checks that too much register pressure will cause the modulo
+# schedule to be rejected and that a test with the same resource usage
+# but without register pressure is not rejected.
+
+--- |
+  define hidden float @high_pressure(float* nocapture noundef readonly %a, float* nocapture noundef readonly %b, i32 noundef %sz) local_unnamed_addr #0 {
+  entry:
+    %cmp8 = icmp sgt i32 %sz, 0
+    br i1 %cmp8, label %for.body.preheader, label %for.end
+
+  for.body.preheader:                               ; preds = %entry
+    %scevgep = getelementptr float, float* %b, i32 -1
+    %scevgep4 = getelementptr float, float* %a, i32 -1
+    br label %for.body
+
+  for.body:                                         ; preds = %for.body.preheader, %for.body
+    %lsr.iv5 = phi float* [ %scevgep4, %for.body.preheader ], [ %scevgep6, %for.body ]
+    %lsr.iv1 = phi float* [ %scevgep, %for.body.preheader ], [ %scevgep2, %for.body ]
+    %lsr.iv = phi i32 [ %sz, %for.body.preheader ], [ %lsr.iv.next, %for.body ]
+    %sum.010 = phi float [ %add, %for.body ], [ 0.000000e+00, %for.body.preheader ]
+    %scevgep7 = getelementptr float, float* %lsr.iv5, i32 1
+    %0 = load float, float* %scevgep7, align 4
+    %scevgep3 = getelementptr float, float* %lsr.iv1, i32 1
+    %1 = load float, float* %scevgep3, align 4
+    %mul = fmul fast float %1, %0
+    %add = fadd fast float %mul, %sum.010
+    %lsr.iv.next = add i32 %lsr.iv, -1
+    %scevgep2 = getelementptr float, float* %lsr.iv1, i32 1
+    %scevgep6 = getelementptr float, float* %lsr.iv5, i32 1
+    %exitcond.not = icmp eq i32 %lsr.iv.next, 0
+    br i1 %exitcond.not, label %for.end, label %for.body, !llvm.loop !0
+
+  for.end:                                          ; preds = %for.body, %entry
+    %sum.0.lcssa = phi float [ 0.000000e+00, %entry ], [ %add, %for.body ]
+    ret float %sum.0.lcssa
+  }
+
+  !0 = distinct !{!0, !1, !2, !3}
+  !1 = !{!"llvm.loop.mustprogress"}
+  !2 = !{!"llvm.loop.unroll.disable"}
+  !3 = !{!"llvm.loop.pipeline.initiationinterval", i32 3}
+
+
+  define hidden float @low_pressure(float* nocapture noundef readonly %a, float* nocapture noundef readonly %b, i32 noundef %sz) local_unnamed_addr #0 {
+  entry:
+    %cmp8 = icmp sgt i32 %sz, 0
+    br i1 %cmp8, label %for.body.preheader, label %for.end
+
+  for.body.preheader:                               ; preds = %entry
+    %scevgep = getelementptr float, float* %b, i32 -1
+    %scevgep4 = getelementptr float, float* %a, i32 -1
+    br label %for.body
+
+  for.body:                                         ; preds = %for.body.preheader, %for.body
+    %lsr.iv5 = phi float* [ %scevgep4, %for.body.preheader ], [ %scevgep6, %for.body ]
+    %lsr.iv1 = phi float* [ %scevgep, %for.body.preheader ], [ %scevgep2, %for.body ]
+    %lsr.iv = phi i32 [ %sz, %for.body.preheader ], [ %lsr.iv.next, %for.body ]
+    %sum.010 = phi float [ %add, %for.body ], [ 0.000000e+00, %for.body.preheader ]
+    %scevgep7 = getelementptr float, float* %lsr.iv5, i32 1
+    %0 = load float, float* %scevgep7, align 4
+    %scevgep3 = getelementptr float, float* %lsr.iv1, i32 1
+    %1 = load float, float* %scevgep3, align 4
+    %mul = fmul fast float %1, %0
+    %add = fadd fast float %mul, %sum.010
+    %lsr.iv.next = add i32 %lsr.iv, -1
+    %scevgep2 = getelementptr float, float* %lsr.iv1, i32 1
+    %scevgep6 = getelementptr float, float* %lsr.iv5, i32 1
+    %exitcond.not = icmp eq i32 %lsr.iv.next, 0
+    br i1 %exitcond.not, label %for.end, label %for.body, !llvm.loop !4
+
+  for.end:                                          ; preds = %for.body, %entry
+    %sum.0.lcssa = phi float [ 0.000000e+00, %entry ], [ %add, %for.body ]
+    ret float %sum.0.lcssa
+  }
+
+  !4 = distinct !{!4, !5, !6, !7}
+  !5 = !{!"llvm.loop.mustprogress"}
+  !6 = !{!"llvm.loop.unroll.disable"}
+  !7 = !{!"llvm.loop.pipeline.initiationinterval", i32 3}
+
+...
+---
+name:            high_pressure
+alignment:       2
+tracksRegLiveness: true
+constants:
+  - id:              0
+    value:           'float 0.000000e+00'
+    alignment:       4
+    isTargetSpecific: false
+body:             |
+  ; CHECK-LABEL: name: high_pressure
+  ; CHECK: bb.0.entry:
+  ; CHECK-NEXT:   successors: %bb.2(0x50000000), %bb.1(0x30000000)
+  ; CHECK-NEXT:   liveins: $r0, $r1, $r2
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gprnopc = COPY $r2
+  ; CHECK-NEXT:   [[COPY1:%[0-9]+]]:gprnopc = COPY $r1
+  ; CHECK-NEXT:   [[COPY2:%[0-9]+]]:gprnopc = COPY $r0
+  ; CHECK-NEXT:   t2CMPri [[COPY]], 1, 14 /* CC::al */, $noreg, implicit-def $cpsr
+  ; CHECK-NEXT:   t2Bcc %bb.2, 10 /* CC::ge */, $cpsr
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.4(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[VLDRS:%[0-9]+]]:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+  ; CHECK-NEXT:   t2B %bb.4, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.2.for.body.preheader:
+  ; CHECK-NEXT:   successors: %bb.3(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[t2SUBri:%[0-9]+]]:rgpr = t2SUBri [[COPY1]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[COPY3:%[0-9]+]]:gpr = COPY [[t2SUBri]]
+  ; CHECK-NEXT:   [[t2SUBri1:%[0-9]+]]:rgpr = t2SUBri [[COPY2]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS1:%[0-9]+]]:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+  ; CHECK-NEXT:   [[COPY4:%[0-9]+]]:gpr = COPY [[t2SUBri1]]
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.3.for.body:
+  ; CHECK-NEXT:   successors: %bb.4(0x04000000), %bb.3(0x7c000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[PHI:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %10, %bb.3
+  ; CHECK-NEXT:   [[PHI1:%[0-9]+]]:gprnopc = PHI [[COPY3]], %bb.2, %12, %bb.3
+  ; CHECK-NEXT:   [[PHI2:%[0-9]+]]:gprnopc = PHI [[COPY]], %bb.2, %14, %bb.3
+  ; CHECK-NEXT:   [[PHI3:%[0-9]+]]:spr = PHI [[VLDRS1]], %bb.2, %16, %bb.3
+  ; CHECK-NEXT:   [[PHI4:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %18, %bb.3
+  ; CHECK-NEXT:   [[PHI5:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %20, %bb.3
+  ; CHECK-NEXT:   [[PHI6:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %22, %bb.3
+  ; CHECK-NEXT:   [[PHI7:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %24, %bb.3
+  ; CHECK-NEXT:   [[PHI8:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %26, %bb.3
+  ; CHECK-NEXT:   [[PHI9:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %28, %bb.3
+  ; CHECK-NEXT:   [[PHI10:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %30, %bb.3
+  ; CHECK-NEXT:   [[PHI11:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %32, %bb.3
+  ; CHECK-NEXT:   [[PHI12:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %34, %bb.3
+  ; CHECK-NEXT:   [[PHI13:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %36, %bb.3
+  ; CHECK-NEXT:   [[PHI14:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %38, %bb.3
+  ; CHECK-NEXT:   [[PHI15:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %40, %bb.3
+  ; CHECK-NEXT:   [[PHI16:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %42, %bb.3
+  ; CHECK-NEXT:   [[PHI17:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %44, %bb.3
+  ; CHECK-NEXT:   [[PHI18:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %46, %bb.3
+  ; CHECK-NEXT:   [[PHI19:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %48, %bb.3
+  ; CHECK-NEXT:   [[PHI20:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %50, %bb.3
+  ; CHECK-NEXT:   [[PHI21:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %52, %bb.3
+  ; CHECK-NEXT:   [[PHI22:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.2, %54, %bb.3
+  ; CHECK-NEXT:   [[t2ADDri:%[0-9]+]]:rgpr = t2ADDri [[PHI]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS2:%[0-9]+]]:spr = VLDRS [[PHI]], 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep7)
+  ; CHECK-NEXT:   [[t2ADDri1:%[0-9]+]]:rgpr = t2ADDri [[PHI1]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS3:%[0-9]+]]:spr = VLDRS [[PHI1]], 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep3)
+  ; CHECK-NEXT:   [[VMULS:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VMULS [[VLDRS3]], [[VLDRS2]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   [[VADDS:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VADDS [[VMULS]], [[PHI3]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   [[t2SUBri2:%[0-9]+]]:rgpr = t2SUBri [[PHI2]], 1, 14 /* CC::al */, $noreg, def $cpsr
+  ; CHECK-NEXT:   [[COPY5:%[0-9]+]]:gpr = COPY [[t2SUBri2]]
+  ; CHECK-NEXT:   [[COPY6:%[0-9]+]]:gpr = COPY [[t2ADDri1]]
+  ; CHECK-NEXT:   [[COPY7:%[0-9]+]]:gpr = COPY [[t2ADDri]]
+  ; CHECK-NEXT:   [[COPY8:%[0-9]+]]:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   [[COPY9:%[0-9]+]]:rgpr = COPY [[PHI5]]
+  ; CHECK-NEXT:   [[COPY10:%[0-9]+]]:rgpr = COPY [[PHI6]]
+  ; CHECK-NEXT:   [[COPY11:%[0-9]+]]:rgpr = COPY [[PHI7]]
+  ; CHECK-NEXT:   [[COPY12:%[0-9]+]]:rgpr = COPY [[PHI8]]
+  ; CHECK-NEXT:   [[COPY13:%[0-9]+]]:rgpr = COPY [[PHI9]]
+  ; CHECK-NEXT:   [[COPY14:%[0-9]+]]:rgpr = COPY [[PHI10]]
+  ; CHECK-NEXT:   [[COPY15:%[0-9]+]]:rgpr = COPY [[PHI11]]
+  ; CHECK-NEXT:   [[COPY16:%[0-9]+]]:rgpr = COPY [[PHI12]]
+  ; CHECK-NEXT:   [[COPY17:%[0-9]+]]:rgpr = COPY [[PHI13]]
+  ; CHECK-NEXT:   [[COPY18:%[0-9]+]]:rgpr = COPY [[PHI14]]
+  ; CHECK-NEXT:   [[COPY19:%[0-9]+]]:rgpr = COPY [[PHI15]]
+  ; CHECK-NEXT:   [[COPY20:%[0-9]+]]:rgpr = COPY [[PHI16]]
+  ; CHECK-NEXT:   [[COPY21:%[0-9]+]]:rgpr = COPY [[PHI17]]
+  ; CHECK-NEXT:   [[COPY22:%[0-9]+]]:rgpr = COPY [[PHI18]]
+  ; CHECK-NEXT:   [[COPY23:%[0-9]+]]:rgpr = COPY [[PHI19]]
+  ; CHECK-NEXT:   [[COPY24:%[0-9]+]]:rgpr = COPY [[PHI20]]
+  ; CHECK-NEXT:   [[COPY25:%[0-9]+]]:rgpr = COPY [[PHI21]]
+  ; CHECK-NEXT:   [[COPY26:%[0-9]+]]:rgpr = COPY [[PHI22]]
+  ; CHECK-NEXT:   t2Bcc %bb.3, 1 /* CC::ne */, $cpsr
+  ; CHECK-NEXT:   t2B %bb.4, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.4.for.end:
+  ; CHECK-NEXT:   [[PHI23:%[0-9]+]]:spr = PHI [[VLDRS]], %bb.1, [[VADDS]], %bb.3
+  ; CHECK-NEXT:   [[VMOVRS:%[0-9]+]]:gpr = VMOVRS [[PHI23]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   $r0 = COPY [[VMOVRS]]
+  ; CHECK-NEXT:   tBX_RET 14 /* CC::al */, $noreg, implicit $r0
+  bb.0.entry:
+    successors: %bb.1(0x50000000), %bb.4(0x30000000)
+    liveins: $r0, $r1, $r2
+
+    %13:gprnopc = COPY $r2
+    %12:gprnopc = COPY $r1
+    %11:gprnopc = COPY $r0
+    t2CMPri %13, 1, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    t2Bcc %bb.1, 10 /* CC::ge */, $cpsr
+
+  bb.4:
+    successors: %bb.3(0x80000000)
+
+    %14:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+    t2B %bb.3, 14 /* CC::al */, $noreg
+
+  bb.1.for.body.preheader:
+    successors: %bb.2(0x80000000)
+
+    %16:rgpr = t2SUBri %12, 4, 14 /* CC::al */, $noreg, $noreg
+    %0:gpr = COPY %16
+    %17:rgpr = t2SUBri %11, 4, 14 /* CC::al */, $noreg, $noreg
+    %15:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+    %1:gpr = COPY %17
+
+  bb.2.for.body:
+    successors: %bb.3(0x04000000), %bb.2(0x7c000000)
+
+    %2:gprnopc = PHI %1, %bb.1, %9, %bb.2
+    %3:gprnopc = PHI %0, %bb.1, %8, %bb.2
+    %4:gprnopc = PHI %13, %bb.1, %7, %bb.2
+    %5:spr = PHI %15, %bb.1, %6, %bb.2
+    %101:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %102:gprnopc = PHI %1, %bb.1, %202, %bb.2
+    %103:gprnopc = PHI %1, %bb.1, %203, %bb.2
+    %104:gprnopc = PHI %1, %bb.1, %204, %bb.2
+    %105:gprnopc = PHI %1, %bb.1, %205, %bb.2
+    %106:gprnopc = PHI %1, %bb.1, %206, %bb.2
+    %107:gprnopc = PHI %1, %bb.1, %207, %bb.2
+    %108:gprnopc = PHI %1, %bb.1, %208, %bb.2
+    %109:gprnopc = PHI %1, %bb.1, %209, %bb.2
+    %110:gprnopc = PHI %1, %bb.1, %210, %bb.2
+    %111:gprnopc = PHI %1, %bb.1, %211, %bb.2
+    %112:gprnopc = PHI %1, %bb.1, %212, %bb.2
+    %113:gprnopc = PHI %1, %bb.1, %213, %bb.2
+    %114:gprnopc = PHI %1, %bb.1, %214, %bb.2
+    %115:gprnopc = PHI %1, %bb.1, %215, %bb.2
+    %116:gprnopc = PHI %1, %bb.1, %216, %bb.2
+    %117:gprnopc = PHI %1, %bb.1, %217, %bb.2
+    %118:gprnopc = PHI %1, %bb.1, %218, %bb.2
+    %119:gprnopc = PHI %1, %bb.1, %219, %bb.2
+    %18:rgpr = t2ADDri %2, 4, 14 /* CC::al */, $noreg, $noreg
+    %19:spr = VLDRS %2, 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep7)
+    %20:rgpr = t2ADDri %3, 4, 14 /* CC::al */, $noreg, $noreg
+    %21:spr = VLDRS %3, 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep3)
+    %22:spr = nnan ninf nsz arcp contract afn reassoc VMULS killed %21, killed %19, 14 /* CC::al */, $noreg
+    %6:spr = nnan ninf nsz arcp contract afn reassoc VADDS killed %22, %5, 14 /* CC::al */, $noreg
+    %23:rgpr = t2SUBri %4, 1, 14 /* CC::al */, $noreg, def $cpsr
+    %7:gpr = COPY %23
+    %8:gpr = COPY %20
+    %9:gpr = COPY %18
+    %201:rgpr = COPY %101
+    %202:rgpr = COPY %102
+    %203:rgpr = COPY %103
+    %204:rgpr = COPY %104
+    %205:rgpr = COPY %105
+    %206:rgpr = COPY %106
+    %207:rgpr = COPY %107
+    %208:rgpr = COPY %108
+    %209:rgpr = COPY %109
+    %210:rgpr = COPY %110
+    %211:rgpr = COPY %111
+    %212:rgpr = COPY %112
+    %213:rgpr = COPY %113
+    %214:rgpr = COPY %114
+    %215:rgpr = COPY %115
+    %216:rgpr = COPY %116
+    %217:rgpr = COPY %117
+    %218:rgpr = COPY %118
+    %219:rgpr = COPY %119
+    t2Bcc %bb.2, 1 /* CC::ne */, $cpsr
+    t2B %bb.3, 14 /* CC::al */, $noreg
+
+  bb.3.for.end:
+    %10:spr = PHI %14, %bb.4, %6, %bb.2
+    %24:gpr = VMOVRS %10, 14 /* CC::al */, $noreg
+    $r0 = COPY %24
+    tBX_RET 14 /* CC::al */, $noreg, implicit $r0
+
+
+...
+---
+name:            low_pressure
+alignment:       2
+tracksRegLiveness: true
+constants:
+  - id:              0
+    value:           'float 0.000000e+00'
+    alignment:       4
+    isTargetSpecific: false
+body:             |
+  ; CHECK-LABEL: name: low_pressure
+  ; CHECK: bb.0.entry:
+  ; CHECK-NEXT:   successors: %bb.2(0x50000000), %bb.1(0x30000000)
+  ; CHECK-NEXT:   liveins: $r0, $r1, $r2
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gprnopc = COPY $r2
+  ; CHECK-NEXT:   [[COPY1:%[0-9]+]]:gprnopc = COPY $r1
+  ; CHECK-NEXT:   [[COPY2:%[0-9]+]]:gprnopc = COPY $r0
+  ; CHECK-NEXT:   t2CMPri [[COPY]], 1, 14 /* CC::al */, $noreg, implicit-def $cpsr
+  ; CHECK-NEXT:   t2Bcc %bb.2, 10 /* CC::ge */, $cpsr
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.4(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[VLDRS:%[0-9]+]]:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+  ; CHECK-NEXT:   t2B %bb.4, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.2.for.body.preheader:
+  ; CHECK-NEXT:   successors: %bb.5(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[t2SUBri:%[0-9]+]]:rgpr = t2SUBri [[COPY1]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[COPY3:%[0-9]+]]:gprnopc = COPY [[t2SUBri]]
+  ; CHECK-NEXT:   [[t2SUBri1:%[0-9]+]]:rgpr = t2SUBri [[COPY2]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS1:%[0-9]+]]:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+  ; CHECK-NEXT:   [[COPY4:%[0-9]+]]:gprnopc = COPY [[t2SUBri1]]
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.5.for.body:
+  ; CHECK-NEXT:   successors: %bb.6(0x40000000), %bb.9(0x40000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[t2SUBri2:%[0-9]+]]:rgpr = t2SUBri [[COPY]], 1, 14 /* CC::al */, $noreg, def $cpsr
+  ; CHECK-NEXT:   [[COPY5:%[0-9]+]]:gprnopc = COPY [[t2SUBri2]]
+  ; CHECK-NEXT:   [[COPY6:%[0-9]+]]:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %66:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %67:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %68:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %69:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %70:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %71:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %72:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %73:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %74:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %75:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %76:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %77:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %78:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %79:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %80:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %81:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %82:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   dead %83:rgpr = COPY [[COPY4]]
+  ; CHECK-NEXT:   t2Bcc %bb.9, 0 /* CC::eq */, $cpsr
+  ; CHECK-NEXT:   t2B %bb.6, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.6.for.body:
+  ; CHECK-NEXT:   successors: %bb.7(0x80000000), %bb.8(0x00000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[t2ADDri:%[0-9]+]]:rgpr = t2ADDri [[COPY4]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS2:%[0-9]+]]:spr = VLDRS [[COPY4]], 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep7)
+  ; CHECK-NEXT:   [[t2ADDri1:%[0-9]+]]:rgpr = t2ADDri [[COPY3]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[VLDRS3:%[0-9]+]]:spr = VLDRS [[COPY3]], 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep3)
+  ; CHECK-NEXT:   [[VMULS:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VMULS [[VLDRS3]], [[VLDRS2]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   [[COPY7:%[0-9]+]]:gpr = COPY [[t2ADDri1]]
+  ; CHECK-NEXT:   [[COPY8:%[0-9]+]]:gpr = COPY [[t2ADDri]]
+  ; CHECK-NEXT:   [[t2SUBri3:%[0-9]+]]:rgpr = t2SUBri [[COPY5]], 1, 14 /* CC::al */, $noreg, def $cpsr
+  ; CHECK-NEXT:   [[COPY9:%[0-9]+]]:gpr = COPY [[t2SUBri3]]
+  ; CHECK-NEXT:   [[COPY10:%[0-9]+]]:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %94:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %95:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %96:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %97:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %98:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %99:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %100:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %101:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %102:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %103:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %104:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %105:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %106:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %107:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %108:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %109:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %110:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   dead %111:rgpr = COPY [[COPY6]]
+  ; CHECK-NEXT:   t2Bcc %bb.8, 0 /* CC::eq */, $cpsr
+  ; CHECK-NEXT:   t2B %bb.7, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.7.for.body:
+  ; CHECK-NEXT:   successors: %bb.8(0x04000000), %bb.7(0x7c000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[PHI:%[0-9]+]]:gprnopc = PHI [[COPY8]], %bb.6, %116, %bb.7
+  ; CHECK-NEXT:   [[PHI1:%[0-9]+]]:gprnopc = PHI [[COPY7]], %bb.6, %117, %bb.7
+  ; CHECK-NEXT:   [[PHI2:%[0-9]+]]:gprnopc = PHI [[COPY9]], %bb.6, %140, %bb.7
+  ; CHECK-NEXT:   [[PHI3:%[0-9]+]]:spr = PHI [[VLDRS1]], %bb.6, %137, %bb.7
+  ; CHECK-NEXT:   [[PHI4:%[0-9]+]]:gprnopc = PHI [[COPY10]], %bb.6, %139, %bb.7
+  ; CHECK-NEXT:   [[PHI5:%[0-9]+]]:spr = PHI [[VMULS]], %bb.6, %118, %bb.7
+  ; CHECK-NEXT:   [[VLDRS4:%[0-9]+]]:spr = VLDRS [[PHI1]], 1, 14 /* CC::al */, $noreg :: (load unknown-size from %ir.scevgep3, align 4)
+  ; CHECK-NEXT:   [[VLDRS5:%[0-9]+]]:spr = VLDRS [[PHI]], 1, 14 /* CC::al */, $noreg :: (load unknown-size from %ir.scevgep7, align 4)
+  ; CHECK-NEXT:   [[t2ADDri2:%[0-9]+]]:rgpr = t2ADDri [[PHI]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[t2ADDri3:%[0-9]+]]:rgpr = t2ADDri [[PHI1]], 4, 14 /* CC::al */, $noreg, $noreg
+  ; CHECK-NEXT:   [[COPY11:%[0-9]+]]:gpr = COPY [[t2ADDri2]]
+  ; CHECK-NEXT:   [[COPY12:%[0-9]+]]:gpr = COPY [[t2ADDri3]]
+  ; CHECK-NEXT:   [[VMULS1:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VMULS [[VLDRS4]], [[VLDRS5]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   dead %119:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %120:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %121:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %122:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %123:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %124:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %125:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %126:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %127:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %128:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %129:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %130:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %131:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %132:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %133:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %134:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %135:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   dead %136:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   [[VADDS:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VADDS [[PHI5]], [[PHI3]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   [[t2SUBri4:%[0-9]+]]:rgpr = t2SUBri [[PHI2]], 1, 14 /* CC::al */, $noreg, def $cpsr
+  ; CHECK-NEXT:   [[COPY13:%[0-9]+]]:rgpr = COPY [[PHI4]]
+  ; CHECK-NEXT:   [[COPY14:%[0-9]+]]:gpr = COPY [[t2SUBri4]]
+  ; CHECK-NEXT:   t2Bcc %bb.7, 1 /* CC::ne */, $cpsr
+  ; CHECK-NEXT:   t2B %bb.8, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.8:
+  ; CHECK-NEXT:   successors: %bb.9(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[PHI6:%[0-9]+]]:gprnopc = PHI [[COPY8]], %bb.6, [[COPY11]], %bb.7
+  ; CHECK-NEXT:   [[PHI7:%[0-9]+]]:gprnopc = PHI [[COPY7]], %bb.6, [[COPY12]], %bb.7
+  ; CHECK-NEXT:   [[PHI8:%[0-9]+]]:spr = PHI [[VLDRS1]], %bb.6, [[VADDS]], %bb.7
+  ; CHECK-NEXT:   [[PHI9:%[0-9]+]]:spr = PHI [[VMULS]], %bb.6, [[VMULS1]], %bb.7
+  ; CHECK-NEXT:   [[VADDS1:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VADDS [[PHI9]], [[PHI8]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.9:
+  ; CHECK-NEXT:   successors: %bb.4(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[PHI10:%[0-9]+]]:gprnopc = PHI [[COPY4]], %bb.5, [[PHI6]], %bb.8
+  ; CHECK-NEXT:   [[PHI11:%[0-9]+]]:gprnopc = PHI [[COPY3]], %bb.5, [[PHI7]], %bb.8
+  ; CHECK-NEXT:   [[PHI12:%[0-9]+]]:spr = PHI [[VLDRS1]], %bb.5, [[VADDS1]], %bb.8
+  ; CHECK-NEXT:   [[VLDRS6:%[0-9]+]]:spr = VLDRS [[PHI10]], 1, 14 /* CC::al */, $noreg :: (load unknown-size from %ir.scevgep7, align 4)
+  ; CHECK-NEXT:   [[VLDRS7:%[0-9]+]]:spr = VLDRS [[PHI11]], 1, 14 /* CC::al */, $noreg :: (load unknown-size from %ir.scevgep3, align 4)
+  ; CHECK-NEXT:   [[VMULS2:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VMULS [[VLDRS7]], [[VLDRS6]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   [[VADDS2:%[0-9]+]]:spr = nnan ninf nsz arcp contract afn reassoc VADDS [[VMULS2]], [[PHI12]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   t2B %bb.4, 14 /* CC::al */, $noreg
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.4.for.end:
+  ; CHECK-NEXT:   [[PHI13:%[0-9]+]]:spr = PHI [[VLDRS]], %bb.1, [[VADDS2]], %bb.9
+  ; CHECK-NEXT:   [[VMOVRS:%[0-9]+]]:gpr = VMOVRS [[PHI13]], 14 /* CC::al */, $noreg
+  ; CHECK-NEXT:   $r0 = COPY [[VMOVRS]]
+  ; CHECK-NEXT:   tBX_RET 14 /* CC::al */, $noreg, implicit $r0
+  bb.0.entry:
+    successors: %bb.1(0x50000000), %bb.4(0x30000000)
+    liveins: $r0, $r1, $r2
+
+    %13:gprnopc = COPY $r2
+    %12:gprnopc = COPY $r1
+    %11:gprnopc = COPY $r0
+    t2CMPri %13, 1, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    t2Bcc %bb.1, 10 /* CC::ge */, $cpsr
+
+  bb.4:
+    successors: %bb.3(0x80000000)
+
+    %14:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+    t2B %bb.3, 14 /* CC::al */, $noreg
+
+  bb.1.for.body.preheader:
+    successors: %bb.2(0x80000000)
+
+    %16:rgpr = t2SUBri %12, 4, 14 /* CC::al */, $noreg, $noreg
+    %0:gpr = COPY %16
+    %17:rgpr = t2SUBri %11, 4, 14 /* CC::al */, $noreg, $noreg
+    %15:spr = VLDRS %const.0, 0, 14 /* CC::al */, $noreg :: (load (s32) from constant-pool)
+    %1:gpr = COPY %17
+
+  bb.2.for.body:
+    successors: %bb.3(0x04000000), %bb.2(0x7c000000)
+
+    %2:gprnopc = PHI %1, %bb.1, %9, %bb.2
+    %3:gprnopc = PHI %0, %bb.1, %8, %bb.2
+    %4:gprnopc = PHI %13, %bb.1, %7, %bb.2
+    %5:spr = PHI %15, %bb.1, %6, %bb.2
+    %101:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %102:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %103:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %104:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %105:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %106:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %107:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %108:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %109:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %110:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %111:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %112:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %113:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %114:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %115:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %116:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %117:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %118:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %119:gprnopc = PHI %1, %bb.1, %201, %bb.2
+    %18:rgpr = t2ADDri %2, 4, 14 /* CC::al */, $noreg, $noreg
+    %19:spr = VLDRS %2, 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep7)
+    %20:rgpr = t2ADDri %3, 4, 14 /* CC::al */, $noreg, $noreg
+    %21:spr = VLDRS %3, 1, 14 /* CC::al */, $noreg :: (load (s32) from %ir.scevgep3)
+    %22:spr = nnan ninf nsz arcp contract afn reassoc VMULS killed %21, killed %19, 14 /* CC::al */, $noreg
+    %6:spr = nnan ninf nsz arcp contract afn reassoc VADDS killed %22, %5, 14 /* CC::al */, $noreg
+    %23:rgpr = t2SUBri %4, 1, 14 /* CC::al */, $noreg, def $cpsr
+    %7:gpr = COPY %23
+    %8:gpr = COPY %20
+    %9:gpr = COPY %18
+    %201:rgpr = COPY %101
+    %202:rgpr = COPY %101
+    %203:rgpr = COPY %101
+    %204:rgpr = COPY %101
+    %205:rgpr = COPY %101
+    %206:rgpr = COPY %101
+    %207:rgpr = COPY %101
+    %208:rgpr = COPY %101
+    %209:rgpr = COPY %101
+    %210:rgpr = COPY %101
+    %211:rgpr = COPY %101
+    %212:rgpr = COPY %101
+    %213:rgpr = COPY %101
+    %214:rgpr = COPY %101
+    %215:rgpr = COPY %101
+    %216:rgpr = COPY %101
+    %217:rgpr = COPY %101
+    %218:rgpr = COPY %101
+    %219:rgpr = COPY %101
+    t2Bcc %bb.2, 1 /* CC::ne */, $cpsr
+    t2B %bb.3, 14 /* CC::al */, $noreg
+
+  bb.3.for.end:
+    %10:spr = PHI %14, %bb.4, %6, %bb.2
+    %24:gpr = VMOVRS %10, 14 /* CC::al */, $noreg
+    $r0 = COPY %24
+    tBX_RET 14 /* CC::al */, $noreg, implicit $r0
+
+...