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			710 lines
		
	
	
		
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|   | //===- HexagonNewValueJump.cpp - Hexagon Backend New Value Jump -----------===//
 | ||
|  | //
 | ||
|  | //                     The LLVM Compiler Infrastructure
 | ||
|  | //
 | ||
|  | // This file is distributed under the University of Illinois Open Source
 | ||
|  | // License. See LICENSE.TXT for details.
 | ||
|  | //
 | ||
|  | //===----------------------------------------------------------------------===//
 | ||
|  | //
 | ||
|  | // This implements NewValueJump pass in Hexagon.
 | ||
|  | // Ideally, we should merge this as a Peephole pass prior to register
 | ||
|  | // allocation, but because we have a spill in between the feeder and new value
 | ||
|  | // jump instructions, we are forced to write after register allocation.
 | ||
|  | // Having said that, we should re-attempt to pull this earlier at some point
 | ||
|  | // in future.
 | ||
|  | 
 | ||
|  | // The basic approach looks for sequence of predicated jump, compare instruciton
 | ||
|  | // that genereates the predicate and, the feeder to the predicate. Once it finds
 | ||
|  | // all, it collapses compare and jump instruction into a new valu jump
 | ||
|  | // intstructions.
 | ||
|  | //
 | ||
|  | //===----------------------------------------------------------------------===//
 | ||
|  | 
 | ||
|  | #include "Hexagon.h"
 | ||
|  | #include "HexagonInstrInfo.h"
 | ||
|  | #include "HexagonRegisterInfo.h"
 | ||
|  | #include "llvm/ADT/Statistic.h"
 | ||
|  | #include "llvm/CodeGen/MachineBasicBlock.h"
 | ||
|  | #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
 | ||
|  | #include "llvm/CodeGen/MachineFunction.h"
 | ||
|  | #include "llvm/CodeGen/MachineFunctionPass.h"
 | ||
|  | #include "llvm/CodeGen/MachineInstr.h"
 | ||
|  | #include "llvm/CodeGen/MachineInstrBuilder.h"
 | ||
|  | #include "llvm/CodeGen/MachineOperand.h"
 | ||
|  | #include "llvm/CodeGen/MachineRegisterInfo.h"
 | ||
|  | #include "llvm/CodeGen/TargetOpcodes.h"
 | ||
|  | #include "llvm/CodeGen/TargetRegisterInfo.h"
 | ||
|  | #include "llvm/CodeGen/TargetSubtargetInfo.h"
 | ||
|  | #include "llvm/IR/DebugLoc.h"
 | ||
|  | #include "llvm/MC/MCInstrDesc.h"
 | ||
|  | #include "llvm/Pass.h"
 | ||
|  | #include "llvm/Support/BranchProbability.h"
 | ||
|  | #include "llvm/Support/CommandLine.h"
 | ||
|  | #include "llvm/Support/Debug.h"
 | ||
|  | #include "llvm/Support/ErrorHandling.h"
 | ||
|  | #include "llvm/Support/MathExtras.h"
 | ||
|  | #include "llvm/Support/raw_ostream.h"
 | ||
|  | #include <cassert>
 | ||
|  | #include <cstdint>
 | ||
|  | #include <iterator>
 | ||
|  | 
 | ||
|  | using namespace llvm; | ||
|  | 
 | ||
|  | #define DEBUG_TYPE "hexagon-nvj"
 | ||
|  | 
 | ||
|  | STATISTIC(NumNVJGenerated, "Number of New Value Jump Instructions created"); | ||
|  | 
 | ||
|  | static cl::opt<int> DbgNVJCount("nvj-count", cl::init(-1), cl::Hidden, | ||
|  |     cl::desc("Maximum number of predicated jumps to be converted to " | ||
|  |     "New Value Jump")); | ||
|  | 
 | ||
|  | static cl::opt<bool> DisableNewValueJumps("disable-nvjump", cl::Hidden, | ||
|  |     cl::ZeroOrMore, cl::init(false), | ||
|  |     cl::desc("Disable New Value Jumps")); | ||
|  | 
 | ||
|  | namespace llvm { | ||
|  | 
 | ||
|  | FunctionPass *createHexagonNewValueJump(); | ||
|  | void initializeHexagonNewValueJumpPass(PassRegistry&); | ||
|  | 
 | ||
|  | } // end namespace llvm
 | ||
|  | 
 | ||
|  | namespace { | ||
|  | 
 | ||
|  |   struct HexagonNewValueJump : public MachineFunctionPass { | ||
|  |     static char ID; | ||
|  | 
 | ||
|  |     HexagonNewValueJump() : MachineFunctionPass(ID) {} | ||
|  | 
 | ||
|  |     void getAnalysisUsage(AnalysisUsage &AU) const override { | ||
|  |       AU.addRequired<MachineBranchProbabilityInfo>(); | ||
|  |       MachineFunctionPass::getAnalysisUsage(AU); | ||
|  |     } | ||
|  | 
 | ||
|  |     StringRef getPassName() const override { return "Hexagon NewValueJump"; } | ||
|  | 
 | ||
|  |     bool runOnMachineFunction(MachineFunction &Fn) override; | ||
|  | 
 | ||
|  |     MachineFunctionProperties getRequiredProperties() const override { | ||
|  |       return MachineFunctionProperties().set( | ||
|  |           MachineFunctionProperties::Property::NoVRegs); | ||
|  |     } | ||
|  | 
 | ||
|  |   private: | ||
|  |     const HexagonInstrInfo *QII; | ||
|  |     const HexagonRegisterInfo *QRI; | ||
|  | 
 | ||
|  |     /// \brief A handle to the branch probability pass.
 | ||
|  |     const MachineBranchProbabilityInfo *MBPI; | ||
|  | 
 | ||
|  |     bool isNewValueJumpCandidate(const MachineInstr &MI) const; | ||
|  |   }; | ||
|  | 
 | ||
|  | } // end anonymous namespace
 | ||
|  | 
 | ||
|  | char HexagonNewValueJump::ID = 0; | ||
|  | 
 | ||
|  | INITIALIZE_PASS_BEGIN(HexagonNewValueJump, "hexagon-nvj", | ||
|  |                       "Hexagon NewValueJump", false, false) | ||
|  | INITIALIZE_PASS_DEPENDENCY(MachineBranchProbabilityInfo) | ||
|  | INITIALIZE_PASS_END(HexagonNewValueJump, "hexagon-nvj", | ||
|  |                     "Hexagon NewValueJump", false, false) | ||
|  | 
 | ||
|  | // We have identified this II could be feeder to NVJ,
 | ||
|  | // verify that it can be.
 | ||
|  | static bool canBeFeederToNewValueJump(const HexagonInstrInfo *QII, | ||
|  |                                       const TargetRegisterInfo *TRI, | ||
|  |                                       MachineBasicBlock::iterator II, | ||
|  |                                       MachineBasicBlock::iterator end, | ||
|  |                                       MachineBasicBlock::iterator skip, | ||
|  |                                       MachineFunction &MF) { | ||
|  |   // Predicated instruction can not be feeder to NVJ.
 | ||
|  |   if (QII->isPredicated(*II)) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   // Bail out if feederReg is a paired register (double regs in
 | ||
|  |   // our case). One would think that we can check to see if a given
 | ||
|  |   // register cmpReg1 or cmpReg2 is a sub register of feederReg
 | ||
|  |   // using -- if (QRI->isSubRegister(feederReg, cmpReg1) logic
 | ||
|  |   // before the callsite of this function
 | ||
|  |   // But we can not as it comes in the following fashion.
 | ||
|  |   //    %d0 = Hexagon_S2_lsr_r_p killed %d0, killed %r2
 | ||
|  |   //    %r0 = KILL %r0, implicit killed %d0
 | ||
|  |   //    %p0 = CMPEQri killed %r0, 0
 | ||
|  |   // Hence, we need to check if it's a KILL instruction.
 | ||
|  |   if (II->getOpcode() == TargetOpcode::KILL) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   if (II->isImplicitDef()) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   if (QII->isSolo(*II)) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   // Make sure there there is no 'def' or 'use' of any of the uses of
 | ||
|  |   // feeder insn between it's definition, this MI and jump, jmpInst
 | ||
|  |   // skipping compare, cmpInst.
 | ||
|  |   // Here's the example.
 | ||
|  |   //    r21=memub(r22+r24<<#0)
 | ||
|  |   //    p0 = cmp.eq(r21, #0)
 | ||
|  |   //    r4=memub(r3+r21<<#0)
 | ||
|  |   //    if (p0.new) jump:t .LBB29_45
 | ||
|  |   // Without this check, it will be converted into
 | ||
|  |   //    r4=memub(r3+r21<<#0)
 | ||
|  |   //    r21=memub(r22+r24<<#0)
 | ||
|  |   //    p0 = cmp.eq(r21, #0)
 | ||
|  |   //    if (p0.new) jump:t .LBB29_45
 | ||
|  |   // and result WAR hazards if converted to New Value Jump.
 | ||
|  |   for (unsigned i = 0; i < II->getNumOperands(); ++i) { | ||
|  |     if (II->getOperand(i).isReg() && | ||
|  |         (II->getOperand(i).isUse() || II->getOperand(i).isDef())) { | ||
|  |       MachineBasicBlock::iterator localII = II; | ||
|  |       ++localII; | ||
|  |       unsigned Reg = II->getOperand(i).getReg(); | ||
|  |       for (MachineBasicBlock::iterator localBegin = localII; localBegin != end; | ||
|  |            ++localBegin) { | ||
|  |         if (localBegin == skip) | ||
|  |           continue; | ||
|  |         // Check for Subregisters too.
 | ||
|  |         if (localBegin->modifiesRegister(Reg, TRI) || | ||
|  |             localBegin->readsRegister(Reg, TRI)) | ||
|  |           return false; | ||
|  |       } | ||
|  |     } | ||
|  |   } | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | // These are the common checks that need to performed
 | ||
|  | // to determine if
 | ||
|  | // 1. compare instruction can be moved before jump.
 | ||
|  | // 2. feeder to the compare instruction can be moved before jump.
 | ||
|  | static bool commonChecksToProhibitNewValueJump(bool afterRA, | ||
|  |                           MachineBasicBlock::iterator MII) { | ||
|  |   // If store in path, bail out.
 | ||
|  |   if (MII->mayStore()) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   // if call in path, bail out.
 | ||
|  |   if (MII->isCall()) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   // if NVJ is running prior to RA, do the following checks.
 | ||
|  |   if (!afterRA) { | ||
|  |     // The following Target Opcode instructions are spurious
 | ||
|  |     // to new value jump. If they are in the path, bail out.
 | ||
|  |     // KILL sets kill flag on the opcode. It also sets up a
 | ||
|  |     // single register, out of pair.
 | ||
|  |     //    %d0 = S2_lsr_r_p killed %d0, killed %r2
 | ||
|  |     //    %r0 = KILL %r0, implicit killed %d0
 | ||
|  |     //    %p0 = C2_cmpeqi killed %r0, 0
 | ||
|  |     // PHI can be anything after RA.
 | ||
|  |     // COPY can remateriaze things in between feeder, compare and nvj.
 | ||
|  |     if (MII->getOpcode() == TargetOpcode::KILL || | ||
|  |         MII->getOpcode() == TargetOpcode::PHI || | ||
|  |         MII->getOpcode() == TargetOpcode::COPY) | ||
|  |       return false; | ||
|  | 
 | ||
|  |     // The following pseudo Hexagon instructions sets "use" and "def"
 | ||
|  |     // of registers by individual passes in the backend. At this time,
 | ||
|  |     // we don't know the scope of usage and definitions of these
 | ||
|  |     // instructions.
 | ||
|  |     if (MII->getOpcode() == Hexagon::LDriw_pred || | ||
|  |         MII->getOpcode() == Hexagon::STriw_pred) | ||
|  |       return false; | ||
|  |   } | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | static bool canCompareBeNewValueJump(const HexagonInstrInfo *QII, | ||
|  |                                      const TargetRegisterInfo *TRI, | ||
|  |                                      MachineBasicBlock::iterator II, | ||
|  |                                      unsigned pReg, | ||
|  |                                      bool secondReg, | ||
|  |                                      bool optLocation, | ||
|  |                                      MachineBasicBlock::iterator end, | ||
|  |                                      MachineFunction &MF) { | ||
|  |   MachineInstr &MI = *II; | ||
|  | 
 | ||
|  |   // If the second operand of the compare is an imm, make sure it's in the
 | ||
|  |   // range specified by the arch.
 | ||
|  |   if (!secondReg) { | ||
|  |     const MachineOperand &Op2 = MI.getOperand(2); | ||
|  |     if (!Op2.isImm()) | ||
|  |       return false; | ||
|  | 
 | ||
|  |     int64_t v = Op2.getImm(); | ||
|  |     bool Valid = false; | ||
|  | 
 | ||
|  |     switch (MI.getOpcode()) { | ||
|  |       case Hexagon::C2_cmpeqi: | ||
|  |       case Hexagon::C4_cmpneqi: | ||
|  |       case Hexagon::C2_cmpgti: | ||
|  |       case Hexagon::C4_cmpltei: | ||
|  |         Valid = (isUInt<5>(v) || v == -1); | ||
|  |         break; | ||
|  |       case Hexagon::C2_cmpgtui: | ||
|  |       case Hexagon::C4_cmplteui: | ||
|  |         Valid = isUInt<5>(v); | ||
|  |         break; | ||
|  |       case Hexagon::S2_tstbit_i: | ||
|  |       case Hexagon::S4_ntstbit_i: | ||
|  |         Valid = (v == 0); | ||
|  |         break; | ||
|  |     } | ||
|  | 
 | ||
|  |     if (!Valid) | ||
|  |       return false; | ||
|  |   } | ||
|  | 
 | ||
|  |   unsigned cmpReg1, cmpOp2 = 0; // cmpOp2 assignment silences compiler warning.
 | ||
|  |   cmpReg1 = MI.getOperand(1).getReg(); | ||
|  | 
 | ||
|  |   if (secondReg) { | ||
|  |     cmpOp2 = MI.getOperand(2).getReg(); | ||
|  | 
 | ||
|  |     // If the same register appears as both operands, we cannot generate a new
 | ||
|  |     // value compare. Only one operand may use the .new suffix.
 | ||
|  |     if (cmpReg1 == cmpOp2) | ||
|  |       return false; | ||
|  | 
 | ||
|  |     // Make sure that that second register is not from COPY
 | ||
|  |     // At machine code level, we don't need this, but if we decide
 | ||
|  |     // to move new value jump prior to RA, we would be needing this.
 | ||
|  |     MachineRegisterInfo &MRI = MF.getRegInfo(); | ||
|  |     if (secondReg && !TargetRegisterInfo::isPhysicalRegister(cmpOp2)) { | ||
|  |       MachineInstr *def = MRI.getVRegDef(cmpOp2); | ||
|  |       if (def->getOpcode() == TargetOpcode::COPY) | ||
|  |         return false; | ||
|  |     } | ||
|  |   } | ||
|  | 
 | ||
|  |   // Walk the instructions after the compare (predicate def) to the jump,
 | ||
|  |   // and satisfy the following conditions.
 | ||
|  |   ++II; | ||
|  |   for (MachineBasicBlock::iterator localII = II; localII != end; ++localII) { | ||
|  |     if (localII->isDebugValue()) | ||
|  |       continue; | ||
|  | 
 | ||
|  |     // Check 1.
 | ||
|  |     // If "common" checks fail, bail out.
 | ||
|  |     if (!commonChecksToProhibitNewValueJump(optLocation, localII)) | ||
|  |       return false; | ||
|  | 
 | ||
|  |     // Check 2.
 | ||
|  |     // If there is a def or use of predicate (result of compare), bail out.
 | ||
|  |     if (localII->modifiesRegister(pReg, TRI) || | ||
|  |         localII->readsRegister(pReg, TRI)) | ||
|  |       return false; | ||
|  | 
 | ||
|  |     // Check 3.
 | ||
|  |     // If there is a def of any of the use of the compare (operands of compare),
 | ||
|  |     // bail out.
 | ||
|  |     // Eg.
 | ||
|  |     //    p0 = cmp.eq(r2, r0)
 | ||
|  |     //    r2 = r4
 | ||
|  |     //    if (p0.new) jump:t .LBB28_3
 | ||
|  |     if (localII->modifiesRegister(cmpReg1, TRI) || | ||
|  |         (secondReg && localII->modifiesRegister(cmpOp2, TRI))) | ||
|  |       return false; | ||
|  |   } | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | // Given a compare operator, return a matching New Value Jump compare operator.
 | ||
|  | // Make sure that MI here is included in isNewValueJumpCandidate.
 | ||
|  | static unsigned getNewValueJumpOpcode(MachineInstr *MI, int reg, | ||
|  |                                       bool secondRegNewified, | ||
|  |                                       MachineBasicBlock *jmpTarget, | ||
|  |                                       const MachineBranchProbabilityInfo | ||
|  |                                       *MBPI) { | ||
|  |   bool taken = false; | ||
|  |   MachineBasicBlock *Src = MI->getParent(); | ||
|  |   const BranchProbability Prediction = | ||
|  |     MBPI->getEdgeProbability(Src, jmpTarget); | ||
|  | 
 | ||
|  |   if (Prediction >= BranchProbability(1,2)) | ||
|  |     taken = true; | ||
|  | 
 | ||
|  |   switch (MI->getOpcode()) { | ||
|  |     case Hexagon::C2_cmpeq: | ||
|  |       return taken ? Hexagon::J4_cmpeq_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpeq_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C2_cmpeqi: | ||
|  |       if (reg >= 0) | ||
|  |         return taken ? Hexagon::J4_cmpeqi_t_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpeqi_t_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpeqn1_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpeqn1_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmpneqi: | ||
|  |       if (reg >= 0) | ||
|  |         return taken ? Hexagon::J4_cmpeqi_f_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpeqi_f_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpeqn1_f_jumpnv_t : | ||
|  |                      Hexagon::J4_cmpeqn1_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C2_cmpgt: | ||
|  |       if (secondRegNewified) | ||
|  |         return taken ? Hexagon::J4_cmplt_t_jumpnv_t | ||
|  |                      : Hexagon::J4_cmplt_t_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgt_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgt_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C2_cmpgti: | ||
|  |       if (reg >= 0) | ||
|  |         return taken ? Hexagon::J4_cmpgti_t_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpgti_t_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgtn1_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtn1_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C2_cmpgtu: | ||
|  |       if (secondRegNewified) | ||
|  |         return taken ? Hexagon::J4_cmpltu_t_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpltu_t_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgtu_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtu_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C2_cmpgtui: | ||
|  |       return taken ? Hexagon::J4_cmpgtui_t_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtui_t_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmpneq: | ||
|  |       return taken ? Hexagon::J4_cmpeq_f_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpeq_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmplte: | ||
|  |       if (secondRegNewified) | ||
|  |         return taken ? Hexagon::J4_cmplt_f_jumpnv_t | ||
|  |                      : Hexagon::J4_cmplt_f_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgt_f_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgt_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmplteu: | ||
|  |       if (secondRegNewified) | ||
|  |         return taken ? Hexagon::J4_cmpltu_f_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpltu_f_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgtu_f_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtu_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmpltei: | ||
|  |       if (reg >= 0) | ||
|  |         return taken ? Hexagon::J4_cmpgti_f_jumpnv_t | ||
|  |                      : Hexagon::J4_cmpgti_f_jumpnv_nt; | ||
|  |       return taken ? Hexagon::J4_cmpgtn1_f_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtn1_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     case Hexagon::C4_cmplteui: | ||
|  |       return taken ? Hexagon::J4_cmpgtui_f_jumpnv_t | ||
|  |                    : Hexagon::J4_cmpgtui_f_jumpnv_nt; | ||
|  | 
 | ||
|  |     default: | ||
|  |        llvm_unreachable("Could not find matching New Value Jump instruction."); | ||
|  |   } | ||
|  |   // return *some value* to avoid compiler warning
 | ||
|  |   return 0; | ||
|  | } | ||
|  | 
 | ||
|  | bool HexagonNewValueJump::isNewValueJumpCandidate( | ||
|  |     const MachineInstr &MI) const { | ||
|  |   switch (MI.getOpcode()) { | ||
|  |   case Hexagon::C2_cmpeq: | ||
|  |   case Hexagon::C2_cmpeqi: | ||
|  |   case Hexagon::C2_cmpgt: | ||
|  |   case Hexagon::C2_cmpgti: | ||
|  |   case Hexagon::C2_cmpgtu: | ||
|  |   case Hexagon::C2_cmpgtui: | ||
|  |   case Hexagon::C4_cmpneq: | ||
|  |   case Hexagon::C4_cmpneqi: | ||
|  |   case Hexagon::C4_cmplte: | ||
|  |   case Hexagon::C4_cmplteu: | ||
|  |   case Hexagon::C4_cmpltei: | ||
|  |   case Hexagon::C4_cmplteui: | ||
|  |     return true; | ||
|  | 
 | ||
|  |   default: | ||
|  |     return false; | ||
|  |   } | ||
|  | } | ||
|  | 
 | ||
|  | bool HexagonNewValueJump::runOnMachineFunction(MachineFunction &MF) { | ||
|  |   DEBUG(dbgs() << "********** Hexagon New Value Jump **********\n" | ||
|  |                << "********** Function: " << MF.getName() << "\n"); | ||
|  | 
 | ||
|  |   if (skipFunction(MF.getFunction())) | ||
|  |     return false; | ||
|  | 
 | ||
|  |   // If we move NewValueJump before register allocation we'll need live variable
 | ||
|  |   // analysis here too.
 | ||
|  | 
 | ||
|  |   QII = static_cast<const HexagonInstrInfo *>(MF.getSubtarget().getInstrInfo()); | ||
|  |   QRI = static_cast<const HexagonRegisterInfo *>( | ||
|  |       MF.getSubtarget().getRegisterInfo()); | ||
|  |   MBPI = &getAnalysis<MachineBranchProbabilityInfo>(); | ||
|  | 
 | ||
|  |   if (DisableNewValueJumps) { | ||
|  |     return false; | ||
|  |   } | ||
|  | 
 | ||
|  |   int nvjCount = DbgNVJCount; | ||
|  |   int nvjGenerated = 0; | ||
|  | 
 | ||
|  |   // Loop through all the bb's of the function
 | ||
|  |   for (MachineFunction::iterator MBBb = MF.begin(), MBBe = MF.end(); | ||
|  |        MBBb != MBBe; ++MBBb) { | ||
|  |     MachineBasicBlock *MBB = &*MBBb; | ||
|  | 
 | ||
|  |     DEBUG(dbgs() << "** dumping bb ** " << MBB->getNumber() << "\n"); | ||
|  |     DEBUG(MBB->dump()); | ||
|  |     DEBUG(dbgs() << "\n" << "********** dumping instr bottom up **********\n"); | ||
|  |     bool foundJump    = false; | ||
|  |     bool foundCompare = false; | ||
|  |     bool invertPredicate = false; | ||
|  |     unsigned predReg = 0; // predicate reg of the jump.
 | ||
|  |     unsigned cmpReg1 = 0; | ||
|  |     int cmpOp2 = 0; | ||
|  |     MachineBasicBlock::iterator jmpPos; | ||
|  |     MachineBasicBlock::iterator cmpPos; | ||
|  |     MachineInstr *cmpInstr = nullptr, *jmpInstr = nullptr; | ||
|  |     MachineBasicBlock *jmpTarget = nullptr; | ||
|  |     bool afterRA = false; | ||
|  |     bool isSecondOpReg = false; | ||
|  |     bool isSecondOpNewified = false; | ||
|  |     // Traverse the basic block - bottom up
 | ||
|  |     for (MachineBasicBlock::iterator MII = MBB->end(), E = MBB->begin(); | ||
|  |          MII != E;) { | ||
|  |       MachineInstr &MI = *--MII; | ||
|  |       if (MI.isDebugValue()) { | ||
|  |         continue; | ||
|  |       } | ||
|  | 
 | ||
|  |       if ((nvjCount == 0) || (nvjCount > -1 && nvjCount <= nvjGenerated)) | ||
|  |         break; | ||
|  | 
 | ||
|  |       DEBUG(dbgs() << "Instr: "; MI.dump(); dbgs() << "\n"); | ||
|  | 
 | ||
|  |       if (!foundJump && (MI.getOpcode() == Hexagon::J2_jumpt || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumptpt || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumpf || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumpfpt || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumptnewpt || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumptnew || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumpfnewpt || | ||
|  |                          MI.getOpcode() == Hexagon::J2_jumpfnew)) { | ||
|  |         // This is where you would insert your compare and
 | ||
|  |         // instr that feeds compare
 | ||
|  |         jmpPos = MII; | ||
|  |         jmpInstr = &MI; | ||
|  |         predReg = MI.getOperand(0).getReg(); | ||
|  |         afterRA = TargetRegisterInfo::isPhysicalRegister(predReg); | ||
|  | 
 | ||
|  |         // If ifconverter had not messed up with the kill flags of the
 | ||
|  |         // operands, the following check on the kill flag would suffice.
 | ||
|  |         // if(!jmpInstr->getOperand(0).isKill()) break;
 | ||
|  | 
 | ||
|  |         // This predicate register is live out out of BB
 | ||
|  |         // this would only work if we can actually use Live
 | ||
|  |         // variable analysis on phy regs - but LLVM does not
 | ||
|  |         // provide LV analysis on phys regs.
 | ||
|  |         //if(LVs.isLiveOut(predReg, *MBB)) break;
 | ||
|  | 
 | ||
|  |         // Get all the successors of this block - which will always
 | ||
|  |         // be 2. Check if the predicate register is live-in in those
 | ||
|  |         // successor. If yes, we can not delete the predicate -
 | ||
|  |         // I am doing this only because LLVM does not provide LiveOut
 | ||
|  |         // at the BB level.
 | ||
|  |         bool predLive = false; | ||
|  |         for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(), | ||
|  |                                                     SIE = MBB->succ_end(); | ||
|  |              SI != SIE; ++SI) { | ||
|  |           MachineBasicBlock *succMBB = *SI; | ||
|  |           if (succMBB->isLiveIn(predReg)) | ||
|  |             predLive = true; | ||
|  |         } | ||
|  |         if (predLive) | ||
|  |           break; | ||
|  | 
 | ||
|  |         if (!MI.getOperand(1).isMBB()) | ||
|  |           continue; | ||
|  |         jmpTarget = MI.getOperand(1).getMBB(); | ||
|  |         foundJump = true; | ||
|  |         if (MI.getOpcode() == Hexagon::J2_jumpf || | ||
|  |             MI.getOpcode() == Hexagon::J2_jumpfnewpt || | ||
|  |             MI.getOpcode() == Hexagon::J2_jumpfnew) { | ||
|  |           invertPredicate = true; | ||
|  |         } | ||
|  |         continue; | ||
|  |       } | ||
|  | 
 | ||
|  |       // No new value jump if there is a barrier. A barrier has to be in its
 | ||
|  |       // own packet. A barrier has zero operands. We conservatively bail out
 | ||
|  |       // here if we see any instruction with zero operands.
 | ||
|  |       if (foundJump && MI.getNumOperands() == 0) | ||
|  |         break; | ||
|  | 
 | ||
|  |       if (foundJump && !foundCompare && MI.getOperand(0).isReg() && | ||
|  |           MI.getOperand(0).getReg() == predReg) { | ||
|  |         // Not all compares can be new value compare. Arch Spec: 7.6.1.1
 | ||
|  |         if (isNewValueJumpCandidate(MI)) { | ||
|  |           assert( | ||
|  |               (MI.getDesc().isCompare()) && | ||
|  |               "Only compare instruction can be collapsed into New Value Jump"); | ||
|  |           isSecondOpReg = MI.getOperand(2).isReg(); | ||
|  | 
 | ||
|  |           if (!canCompareBeNewValueJump(QII, QRI, MII, predReg, isSecondOpReg, | ||
|  |                                         afterRA, jmpPos, MF)) | ||
|  |             break; | ||
|  | 
 | ||
|  |           cmpInstr = &MI; | ||
|  |           cmpPos = MII; | ||
|  |           foundCompare = true; | ||
|  | 
 | ||
|  |           // We need cmpReg1 and cmpOp2(imm or reg) while building
 | ||
|  |           // new value jump instruction.
 | ||
|  |           cmpReg1 = MI.getOperand(1).getReg(); | ||
|  | 
 | ||
|  |           if (isSecondOpReg) | ||
|  |             cmpOp2 = MI.getOperand(2).getReg(); | ||
|  |           else | ||
|  |             cmpOp2 = MI.getOperand(2).getImm(); | ||
|  |           continue; | ||
|  |         } | ||
|  |       } | ||
|  | 
 | ||
|  |       if (foundCompare && foundJump) { | ||
|  |         // If "common" checks fail, bail out on this BB.
 | ||
|  |         if (!commonChecksToProhibitNewValueJump(afterRA, MII)) | ||
|  |           break; | ||
|  | 
 | ||
|  |         bool foundFeeder = false; | ||
|  |         MachineBasicBlock::iterator feederPos = MII; | ||
|  |         if (MI.getOperand(0).isReg() && MI.getOperand(0).isDef() && | ||
|  |             (MI.getOperand(0).getReg() == cmpReg1 || | ||
|  |              (isSecondOpReg && | ||
|  |               MI.getOperand(0).getReg() == (unsigned)cmpOp2))) { | ||
|  | 
 | ||
|  |           unsigned feederReg = MI.getOperand(0).getReg(); | ||
|  | 
 | ||
|  |           // First try to see if we can get the feeder from the first operand
 | ||
|  |           // of the compare. If we can not, and if secondOpReg is true
 | ||
|  |           // (second operand of the compare is also register), try that one.
 | ||
|  |           // TODO: Try to come up with some heuristic to figure out which
 | ||
|  |           // feeder would benefit.
 | ||
|  | 
 | ||
|  |           if (feederReg == cmpReg1) { | ||
|  |             if (!canBeFeederToNewValueJump(QII, QRI, MII, jmpPos, cmpPos, MF)) { | ||
|  |               if (!isSecondOpReg) | ||
|  |                 break; | ||
|  |               else | ||
|  |                 continue; | ||
|  |             } else | ||
|  |               foundFeeder = true; | ||
|  |           } | ||
|  | 
 | ||
|  |           if (!foundFeeder && isSecondOpReg && feederReg == (unsigned)cmpOp2) | ||
|  |             if (!canBeFeederToNewValueJump(QII, QRI, MII, jmpPos, cmpPos, MF)) | ||
|  |               break; | ||
|  | 
 | ||
|  |           if (isSecondOpReg) { | ||
|  |             // In case of CMPLT, or CMPLTU, or EQ with the second register
 | ||
|  |             // to newify, swap the operands.
 | ||
|  |             unsigned COp = cmpInstr->getOpcode(); | ||
|  |             if ((COp == Hexagon::C2_cmpeq || COp == Hexagon::C4_cmpneq) && | ||
|  |                 (feederReg == (unsigned)cmpOp2)) { | ||
|  |               unsigned tmp = cmpReg1; | ||
|  |               cmpReg1 = cmpOp2; | ||
|  |               cmpOp2 = tmp; | ||
|  |             } | ||
|  | 
 | ||
|  |             // Now we have swapped the operands, all we need to check is,
 | ||
|  |             // if the second operand (after swap) is the feeder.
 | ||
|  |             // And if it is, make a note.
 | ||
|  |             if (feederReg == (unsigned)cmpOp2) | ||
|  |               isSecondOpNewified = true; | ||
|  |           } | ||
|  | 
 | ||
|  |           // Now that we are moving feeder close the jump,
 | ||
|  |           // make sure we are respecting the kill values of
 | ||
|  |           // the operands of the feeder.
 | ||
|  | 
 | ||
|  |           auto TransferKills = [jmpPos,cmpPos] (MachineInstr &MI) { | ||
|  |             for (MachineOperand &MO : MI.operands()) { | ||
|  |               if (!MO.isReg() || !MO.isUse()) | ||
|  |                 continue; | ||
|  |               unsigned UseR = MO.getReg(); | ||
|  |               for (auto I = std::next(MI.getIterator()); I != jmpPos; ++I) { | ||
|  |                 if (I == cmpPos) | ||
|  |                   continue; | ||
|  |                 for (MachineOperand &Op : I->operands()) { | ||
|  |                   if (!Op.isReg() || !Op.isUse() || !Op.isKill()) | ||
|  |                     continue; | ||
|  |                   if (Op.getReg() != UseR) | ||
|  |                     continue; | ||
|  |                   // We found that there is kill of a use register
 | ||
|  |                   // Set up a kill flag on the register
 | ||
|  |                   Op.setIsKill(false); | ||
|  |                   MO.setIsKill(true); | ||
|  |                   return; | ||
|  |                 } | ||
|  |               } | ||
|  |             } | ||
|  |           }; | ||
|  | 
 | ||
|  |           TransferKills(*feederPos); | ||
|  |           TransferKills(*cmpPos); | ||
|  |           bool MO1IsKill = cmpPos->killsRegister(cmpReg1, QRI); | ||
|  |           bool MO2IsKill = isSecondOpReg && cmpPos->killsRegister(cmpOp2, QRI); | ||
|  | 
 | ||
|  |           MBB->splice(jmpPos, MI.getParent(), MI); | ||
|  |           MBB->splice(jmpPos, MI.getParent(), cmpInstr); | ||
|  |           DebugLoc dl = MI.getDebugLoc(); | ||
|  |           MachineInstr *NewMI; | ||
|  | 
 | ||
|  |           assert((isNewValueJumpCandidate(*cmpInstr)) && | ||
|  |                  "This compare is not a New Value Jump candidate."); | ||
|  |           unsigned opc = getNewValueJumpOpcode(cmpInstr, cmpOp2, | ||
|  |                                                isSecondOpNewified, | ||
|  |                                                jmpTarget, MBPI); | ||
|  |           if (invertPredicate) | ||
|  |             opc = QII->getInvertedPredicatedOpcode(opc); | ||
|  | 
 | ||
|  |           if (isSecondOpReg) | ||
|  |             NewMI = BuildMI(*MBB, jmpPos, dl, QII->get(opc)) | ||
|  |                         .addReg(cmpReg1, getKillRegState(MO1IsKill)) | ||
|  |                         .addReg(cmpOp2, getKillRegState(MO2IsKill)) | ||
|  |                         .addMBB(jmpTarget); | ||
|  | 
 | ||
|  |           else | ||
|  |             NewMI = BuildMI(*MBB, jmpPos, dl, QII->get(opc)) | ||
|  |                         .addReg(cmpReg1, getKillRegState(MO1IsKill)) | ||
|  |                         .addImm(cmpOp2) | ||
|  |                         .addMBB(jmpTarget); | ||
|  | 
 | ||
|  |           assert(NewMI && "New Value Jump Instruction Not created!"); | ||
|  |           (void)NewMI; | ||
|  |           if (cmpInstr->getOperand(0).isReg() && | ||
|  |               cmpInstr->getOperand(0).isKill()) | ||
|  |             cmpInstr->getOperand(0).setIsKill(false); | ||
|  |           if (cmpInstr->getOperand(1).isReg() && | ||
|  |               cmpInstr->getOperand(1).isKill()) | ||
|  |             cmpInstr->getOperand(1).setIsKill(false); | ||
|  |           cmpInstr->eraseFromParent(); | ||
|  |           jmpInstr->eraseFromParent(); | ||
|  |           ++nvjGenerated; | ||
|  |           ++NumNVJGenerated; | ||
|  |           break; | ||
|  |         } | ||
|  |       } | ||
|  |     } | ||
|  |   } | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | FunctionPass *llvm::createHexagonNewValueJump() { | ||
|  |   return new HexagonNewValueJump(); | ||
|  | } |