//===-- HexagonExpandPredSpillCode.cpp - Expand Predicate Spill Code ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// The Hexagon processor has no instructions that load or store predicate
// registers directly. So, when these registers must be spilled a general
// purpose register must be found and the value copied to/from it from/to
// the predicate register. This code currently does not use the register
// scavenger mechanism available in the allocator. There are two registers
// reserved to allow spilling/restoring predicate registers. One is used to
// hold the predicate value. The other is used when stack frame offsets are
// too large.
//
//===----------------------------------------------------------------------===//
#include "Hexagon.h"
#include "HexagonMachineFunctionInfo.h"
#include "HexagonSubtarget.h"
#include "HexagonTargetMachine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LatencyPriorityQueue.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/SchedulerRegistry.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
namespace llvm {
void initializeHexagonExpandPredSpillCodePass(PassRegistry&);
}
namespace {
class HexagonExpandPredSpillCode : public MachineFunctionPass {
const HexagonTargetMachine& QTM;
const HexagonSubtarget &QST;
public:
static char ID;
HexagonExpandPredSpillCode(const HexagonTargetMachine& TM) :
MachineFunctionPass(ID), QTM(TM), QST(*TM.getSubtargetImpl()) {
PassRegistry &Registry = *PassRegistry::getPassRegistry();
initializeHexagonExpandPredSpillCodePass(Registry);
}
const char *getPassName() const {
return "Hexagon Expand Predicate Spill Code";
}
bool runOnMachineFunction(MachineFunction &Fn);
};
char HexagonExpandPredSpillCode::ID = 0;
bool HexagonExpandPredSpillCode::runOnMachineFunction(MachineFunction &Fn) {
const HexagonInstrInfo *TII = QTM.getInstrInfo();
// Loop over all of the basic blocks.
for (MachineFunction::iterator MBBb = Fn.begin(), MBBe = Fn.end();
MBBb != MBBe; ++MBBb) {
MachineBasicBlock* MBB = MBBb;
// Traverse the basic block.
for (MachineBasicBlock::iterator MII = MBB->begin(); MII != MBB->end();
++MII) {
MachineInstr *MI = MII;
int Opc = MI->getOpcode();
if (Opc == Hexagon::STriw_pred) {
// STriw_pred [R30], ofst, SrcReg;
unsigned FP = MI->getOperand(0).getReg();
assert(FP == QTM.getRegisterInfo()->getFrameRegister() &&
"Not a Frame Pointer, Nor a Spill Slot");
assert(MI->getOperand(1).isImm() && "Not an offset");
int Offset = MI->getOperand(1).getImm();
int SrcReg = MI->getOperand(2).getReg();
assert(Hexagon::PredRegsRegClass.contains(SrcReg) &&
"Not a predicate register");
if (!TII->isValidOffset(Hexagon::STriw_indexed, Offset)) {
if (!TII->isValidOffset(Hexagon::ADD_ri, Offset)) {
BuildMI(*MBB, MII, MI->getDebugLoc(),
TII->get(Hexagon::CONST32_Int_Real),
HEXAGON_RESERVED_REG_1).addImm(Offset);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_rr),
HEXAGON_RESERVED_REG_1)
.addReg(FP).addReg(HEXAGON_RESERVED_REG_1);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
HEXAGON_RESERVED_REG_2).addReg(SrcReg);
BuildMI(*MBB, MII, MI->getDebugLoc(),
TII->get(Hexagon::STriw_indexed))
.addReg(HEXAGON_RESERVED_REG_1)
.addImm(0).addReg(HEXAGON_RESERVED_REG_2);
} else {
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_ri),
HEXAGON_RESERVED_REG_1).addReg(FP).addImm(Offset);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
HEXAGON_RESERVED_REG_2).addReg(SrcReg);
BuildMI(*MBB, MII, MI->getDebugLoc(),
TII->get(Hexagon::STriw_indexed))
.addReg(HEXAGON_RESERVED_REG_1)
.addImm(0)
.addReg(HEXAGON_RESERVED_REG_2);
}
} else {
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_RsPd),
HEXAGON_RESERVED_REG_2).addReg(SrcReg);
BuildMI(*MBB, MII, MI->getDebugLoc(),
TII->get(Hexagon::STriw_indexed)).
addReg(FP).addImm(Offset).addReg(HEXAGON_RESERVED_REG_2);
}
MII = MBB->erase(MI);
--MII;
} else if (Opc == Hexagon::LDriw_pred) {
// DstReg = LDriw_pred [R30], ofst.
int DstReg = MI->getOperand(0).getReg();
assert(Hexagon::PredRegsRegClass.contains(DstReg) &&
"Not a predicate register");
unsigned FP = MI->getOperand(1).getReg();
assert(FP == QTM.getRegisterInfo()->getFrameRegister() &&
"Not a Frame Pointer, Nor a Spill Slot");
assert(MI->getOperand(2).isImm() && "Not an offset");
int Offset = MI->getOperand(2).getImm();
if (!TII->isValidOffset(Hexagon::LDriw, Offset)) {
if (!TII->isValidOffset(Hexagon::ADD_ri, Offset)) {
BuildMI(*MBB, MII, MI->getDebugLoc(),
TII->get(Hexagon::CONST32_Int_Real),
HEXAGON_RESERVED_REG_1).addImm(Offset);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_rr),
HEXAGON_RESERVED_REG_1)
.addReg(FP)
.addReg(HEXAGON_RESERVED_REG_1);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
HEXAGON_RESERVED_REG_2)
.addReg(HEXAGON_RESERVED_REG_1)
.addImm(0);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
DstReg).addReg(HEXAGON_RESERVED_REG_2);
} else {
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::ADD_ri),
HEXAGON_RESERVED_REG_1).addReg(FP).addImm(Offset);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
HEXAGON_RESERVED_REG_2)
.addReg(HEXAGON_RESERVED_REG_1)
.addImm(0);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
DstReg).addReg(HEXAGON_RESERVED_REG_2);
}
} else {
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::LDriw),
HEXAGON_RESERVED_REG_2).addReg(FP).addImm(Offset);
BuildMI(*MBB, MII, MI->getDebugLoc(), TII->get(Hexagon::TFR_PdRs),
DstReg).addReg(HEXAGON_RESERVED_REG_2);
}
MII = MBB->erase(MI);
--MII;
}
}
}
return true;
}
}
//===----------------------------------------------------------------------===//
// Public Constructor Functions
//===----------------------------------------------------------------------===//
static void initializePassOnce(PassRegistry &Registry) {
const char *Name = "Hexagon Expand Predicate Spill Code";
PassInfo *PI = new PassInfo(Name, "hexagon-spill-pred",
&HexagonExpandPredSpillCode::ID,
0, false, false);
Registry.registerPass(*PI, true);
}
void llvm::initializeHexagonExpandPredSpillCodePass(PassRegistry &Registry) {
CALL_ONCE_INITIALIZATION(initializePassOnce)
}
FunctionPass*
llvm::createHexagonExpandPredSpillCode(const HexagonTargetMachine &TM) {
return new HexagonExpandPredSpillCode(TM);
}