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Diffstat (limited to 'contrib/llvm/lib/Target/ARM/NEONMoveFix.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/ARM/NEONMoveFix.cpp | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/ARM/NEONMoveFix.cpp b/contrib/llvm/lib/Target/ARM/NEONMoveFix.cpp new file mode 100644 index 0000000..0a4400c --- /dev/null +++ b/contrib/llvm/lib/Target/ARM/NEONMoveFix.cpp @@ -0,0 +1,141 @@ +//===-- NEONMoveFix.cpp - Convert vfp reg-reg moves into neon ---*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "neon-mov-fix" +#include "ARM.h" +#include "ARMMachineFunctionInfo.h" +#include "ARMInstrInfo.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/raw_ostream.h" +using namespace llvm; + +STATISTIC(NumVMovs, "Number of reg-reg moves converted"); + +namespace { + struct NEONMoveFixPass : public MachineFunctionPass { + static char ID; + NEONMoveFixPass() : MachineFunctionPass(&ID) {} + + virtual bool runOnMachineFunction(MachineFunction &Fn); + + virtual const char *getPassName() const { + return "NEON reg-reg move conversion"; + } + + private: + const TargetRegisterInfo *TRI; + const ARMBaseInstrInfo *TII; + + typedef DenseMap<unsigned, const MachineInstr*> RegMap; + + bool InsertMoves(MachineBasicBlock &MBB); + }; + char NEONMoveFixPass::ID = 0; +} + +bool NEONMoveFixPass::InsertMoves(MachineBasicBlock &MBB) { + RegMap Defs; + bool Modified = false; + + // Walk over MBB tracking the def points of the registers. + MachineBasicBlock::iterator MII = MBB.begin(), E = MBB.end(); + MachineBasicBlock::iterator NextMII; + for (; MII != E; MII = NextMII) { + NextMII = llvm::next(MII); + MachineInstr *MI = &*MII; + + if (MI->getOpcode() == ARM::VMOVD && + !TII->isPredicated(MI)) { + unsigned SrcReg = MI->getOperand(1).getReg(); + // If we do not find an instruction defining the reg, this means the + // register should be live-in for this BB. It's always to better to use + // NEON reg-reg moves. + unsigned Domain = ARMII::DomainNEON; + RegMap::iterator DefMI = Defs.find(SrcReg); + if (DefMI != Defs.end()) { + Domain = DefMI->second->getDesc().TSFlags & ARMII::DomainMask; + // Instructions in general domain are subreg accesses. + // Map them to NEON reg-reg moves. + if (Domain == ARMII::DomainGeneral) + Domain = ARMII::DomainNEON; + } + + if (Domain & ARMII::DomainNEON) { + // Convert VMOVD to VMOVDneon + unsigned DestReg = MI->getOperand(0).getReg(); + + DEBUG({errs() << "vmov convert: "; MI->dump();}); + + // It's safe to ignore imp-defs / imp-uses here, since: + // - We're running late, no intelligent condegen passes should be run + // afterwards + // - The imp-defs / imp-uses are superregs only, we don't care about + // them. + AddDefaultPred(BuildMI(MBB, *MI, MI->getDebugLoc(), + TII->get(ARM::VMOVDneon), DestReg).addReg(SrcReg)); + MBB.erase(MI); + MachineBasicBlock::iterator I = prior(NextMII); + MI = &*I; + + DEBUG({errs() << " into: "; MI->dump();}); + + Modified = true; + ++NumVMovs; + } else { + assert((Domain & ARMII::DomainVFP) && "Invalid domain!"); + // Do nothing. + } + } + + // Update def information. + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + const MachineOperand& MO = MI->getOperand(i); + if (!MO.isReg() || !MO.isDef()) + continue; + unsigned MOReg = MO.getReg(); + + Defs[MOReg] = MI; + // Catch subregs as well. + for (const unsigned *R = TRI->getSubRegisters(MOReg); *R; ++R) + Defs[*R] = MI; + } + } + + return Modified; +} + +bool NEONMoveFixPass::runOnMachineFunction(MachineFunction &Fn) { + ARMFunctionInfo *AFI = Fn.getInfo<ARMFunctionInfo>(); + const TargetMachine &TM = Fn.getTarget(); + + if (AFI->isThumb1OnlyFunction()) + return false; + + TRI = TM.getRegisterInfo(); + TII = static_cast<const ARMBaseInstrInfo*>(TM.getInstrInfo()); + + bool Modified = false; + for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E; + ++MFI) { + MachineBasicBlock &MBB = *MFI; + Modified |= InsertMoves(MBB); + } + + return Modified; +} + +/// createNEONMoveFixPass - Returns an instance of the NEON reg-reg moves fix +/// pass. +FunctionPass *llvm::createNEONMoveFixPass() { + return new NEONMoveFixPass(); +} |