From 7af96a25fc7e3d8648295e313a314433e99cc357 Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Thu, 21 Aug 2014 20:40:56 +0000
Subject: [PATCH] R600/SI: Remove unused SGPR spilling code

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216218 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/R600/SIMachineFunctionInfo.cpp | 61 -------------------------------
 lib/Target/R600/SIMachineFunctionInfo.h   | 19 ----------
 2 files changed, 80 deletions(-)

diff --git a/lib/Target/R600/SIMachineFunctionInfo.cpp b/lib/Target/R600/SIMachineFunctionInfo.cpp
index 086f0908703..b9782038312 100644
--- a/lib/Target/R600/SIMachineFunctionInfo.cpp
+++ b/lib/Target/R600/SIMachineFunctionInfo.cpp
@@ -28,69 +28,8 @@ void SIMachineFunctionInfo::anchor() {}
 SIMachineFunctionInfo::SIMachineFunctionInfo(const MachineFunction &MF)
   : AMDGPUMachineFunction(MF),
     PSInputAddr(0),
-    SpillTracker(),
     NumUserSGPRs(0) { }
 
-static unsigned createLaneVGPR(MachineRegisterInfo &MRI, MachineFunction *MF) {
-  unsigned VGPR = MRI.createVirtualRegister(&AMDGPU::VReg_32RegClass);
-
-  // We need to add this register as live out for the function, in order to
-  // have the live range calculated directly.
-  //
-  // When register spilling begins, we have already calculated the live
-  // live intervals for all the registers.  Since we are spilling SGPRs to
-  // VGPRs, we need to update the Lane VGPR's live interval every time we
-  // spill or restore a register.
-  //
-  // Unfortunately, there is no good way to update the live interval as
-  // the TargetInstrInfo callbacks for spilling and restoring don't give
-  // us access to the live interval information.
-  //
-  // We are lucky, though, because the InlineSpiller calls
-  // LiveRangeEdit::calculateRegClassAndHint() which iterates through
-  // all the new register that have been created when restoring a register
-  // and calls LiveIntervals::getInterval(), which creates and computes
-  // the live interval for the newly created register.  However, once this
-  // live intervals is created, it doesn't change and since we usually reuse
-  // the Lane VGPR multiple times, this means any uses after the first aren't
-  // added to the live interval.
-  //
-  // To work around this, we add Lane VGPRs to the functions live out list,
-  // so that we can guarantee its live range will cover all of its uses.
-
-  for (MachineBasicBlock &MBB : *MF) {
-    if (MBB.back().getOpcode() == AMDGPU::S_ENDPGM) {
-      MBB.back().addOperand(*MF, MachineOperand::CreateReg(VGPR, false, true));
-      return VGPR;
-    }
-  }
-
-  LLVMContext &Ctx = MF->getFunction()->getContext();
-  Ctx.emitError("Could not find S_ENDPGM instruction.");
-
-  return VGPR;
-}
-
-unsigned SIMachineFunctionInfo::RegSpillTracker::reserveLanes(
-    MachineRegisterInfo &MRI, MachineFunction *MF, unsigned NumRegs) {
-  unsigned StartLane = CurrentLane;
-  CurrentLane += NumRegs;
-  if (!LaneVGPR) {
-    LaneVGPR = createLaneVGPR(MRI, MF);
-  } else {
-    if (CurrentLane >= MAX_LANES) {
-      StartLane = CurrentLane = 0;
-      LaneVGPR = createLaneVGPR(MRI, MF);
-    }
-  }
-  return StartLane;
-}
-
-void SIMachineFunctionInfo::RegSpillTracker::addSpilledReg(unsigned FrameIndex,
-                                                           unsigned Reg,
-                                                           int Lane) {
-  SpilledRegisters[FrameIndex] = SpilledReg(Reg, Lane);
-}
 /// \brief Returns a register that is not used at any point in the function.
 ///        If all registers are used, then this function will return
 //         AMDGPU::NoRegister.
diff --git a/lib/Target/R600/SIMachineFunctionInfo.h b/lib/Target/R600/SIMachineFunctionInfo.h
index fcaa23a619b..2917edfcd67 100644
--- a/lib/Target/R600/SIMachineFunctionInfo.h
+++ b/lib/Target/R600/SIMachineFunctionInfo.h
@@ -36,31 +36,12 @@ public:
     bool hasLane() { return Lane != -1;}
   };
 
-  struct RegSpillTracker {
-  private:
-    unsigned CurrentLane;
-    std::map<unsigned, SpilledReg> SpilledRegisters;
-  public:
-    unsigned LaneVGPR;
-    RegSpillTracker() : CurrentLane(0), SpilledRegisters(), LaneVGPR(0) { }
-    /// \p NumRegs The number of consecutive registers what need to be spilled.
-    ///            This function will ensure that all registers are stored in
-    ///            the same VGPR.
-    /// \returns The lane to be used for storing the first register.
-    unsigned reserveLanes(MachineRegisterInfo &MRI, MachineFunction *MF,
-                          unsigned NumRegs = 1);
-    void addSpilledReg(unsigned FrameIndex, unsigned Reg, int Lane = -1);
-    const SpilledReg& getSpilledReg(unsigned FrameIndex);
-    bool programSpillsRegisters() { return !SpilledRegisters.empty(); }
-  };
-
   // SIMachineFunctionInfo definition
 
   SIMachineFunctionInfo(const MachineFunction &MF);
   SpilledReg getSpilledReg(MachineFunction *MF, unsigned FrameIndex,
                            unsigned SubIdx);
   unsigned PSInputAddr;
-  struct RegSpillTracker SpillTracker;
   unsigned NumUserSGPRs;
   std::map<unsigned, unsigned> LaneVGPRs;
 };
-- 
2.11.0