llvm-6502/lib/Target/ARM/ARMFastISel.cpp
Eric Christopher cb59229a4a Add a couple of random comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111592 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-20 00:20:31 +00:00

316 lines
12 KiB
C++

//===-- ARMFastISel.cpp - ARM FastISel implementation ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ARM-specific support for the FastISel class. Some
// of the target-specific code is generated by tablegen in the file
// ARMGenFastISel.inc, which is #included here.
//
//===----------------------------------------------------------------------===//
#include "ARM.h"
#include "ARMBaseInstrInfo.h"
#include "ARMRegisterInfo.h"
#include "ARMTargetMachine.h"
#include "ARMSubtarget.h"
#include "llvm/CallingConv.h"
#include "llvm/DerivedTypes.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
static cl::opt<bool>
EnableARMFastISel("arm-fast-isel",
cl::desc("Turn on experimental ARM fast-isel support"),
cl::init(false), cl::Hidden);
namespace {
class ARMFastISel : public FastISel {
/// Subtarget - Keep a pointer to the ARMSubtarget around so that we can
/// make the right decision when generating code for different targets.
const ARMSubtarget *Subtarget;
const TargetMachine &TM;
const TargetInstrInfo &TII;
const TargetLowering &TLI;
public:
explicit ARMFastISel(FunctionLoweringInfo &funcInfo)
: FastISel(funcInfo),
TM(funcInfo.MF->getTarget()),
TII(*TM.getInstrInfo()),
TLI(*TM.getTargetLowering()) {
Subtarget = &TM.getSubtarget<ARMSubtarget>();
}
// Code from FastISel.cpp.
virtual unsigned FastEmitInst_(unsigned MachineInstOpcode,
const TargetRegisterClass *RC);
virtual unsigned FastEmitInst_r(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill);
virtual unsigned FastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill);
virtual unsigned FastEmitInst_ri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm);
virtual unsigned FastEmitInst_rf(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
const ConstantFP *FPImm);
virtual unsigned FastEmitInst_i(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
uint64_t Imm);
virtual unsigned FastEmitInst_rri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
uint64_t Imm);
virtual unsigned FastEmitInst_extractsubreg(MVT RetVT,
unsigned Op0, bool Op0IsKill,
uint32_t Idx);
// Backend specific FastISel code.
virtual bool TargetSelectInstruction(const Instruction *I);
#include "ARMGenFastISel.inc"
private:
bool DefinesOptionalPredicate(MachineInstr *MI, bool *CPSR);
const MachineInstrBuilder &AddOptionalDefs(const MachineInstrBuilder &MIB);
};
} // end anonymous namespace
// #include "ARMGenCallingConv.inc"
// DefinesOptionalPredicate - This is different from DefinesPredicate in that
// we don't care about implicit defs here, just places we'll need to add a
// default CCReg argument. Sets CPSR if we're setting CPSR instead of CCR.
bool ARMFastISel::DefinesOptionalPredicate(MachineInstr *MI, bool *CPSR) {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.hasOptionalDef())
return false;
// Look to see if our OptionalDef is defining CPSR or CCR.
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (MO.isDef() && MO.isReg() && MO.getReg() == ARM::CPSR)
*CPSR = true;
}
return true;
}
// If the machine is predicable go ahead and add the predicate operands, if
// it needs default CC operands add those.
const MachineInstrBuilder &
ARMFastISel::AddOptionalDefs(const MachineInstrBuilder &MIB) {
MachineInstr *MI = &*MIB;
// Do we use a predicate?
if (TII.isPredicable(MI))
AddDefaultPred(MIB);
// Do we optionally set a predicate? Preds is size > 0 iff the predicate
// defines CPSR. All other OptionalDefines in ARM are the CCR register.
bool CPSR = false;
if (DefinesOptionalPredicate(MI, &CPSR)) {
if (CPSR)
AddDefaultT1CC(MIB);
else
AddDefaultCC(MIB);
}
return MIB;
}
unsigned ARMFastISel::FastEmitInst_(unsigned MachineInstOpcode,
const TargetRegisterClass* RC) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg));
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_r(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addReg(Op0, Op0IsKill * RegState::Kill));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addReg(Op0, Op0IsKill * RegState::Kill));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_rr(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addReg(Op1, Op1IsKill * RegState::Kill));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addReg(Op1, Op1IsKill * RegState::Kill));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_ri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
uint64_t Imm) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addImm(Imm));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addImm(Imm));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_rf(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
const ConstantFP *FPImm) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addFPImm(FPImm));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addFPImm(FPImm));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_rri(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
unsigned Op0, bool Op0IsKill,
unsigned Op1, bool Op1IsKill,
uint64_t Imm) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addReg(Op1, Op1IsKill * RegState::Kill)
.addImm(Imm));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addReg(Op0, Op0IsKill * RegState::Kill)
.addReg(Op1, Op1IsKill * RegState::Kill)
.addImm(Imm));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_i(unsigned MachineInstOpcode,
const TargetRegisterClass *RC,
uint64_t Imm) {
unsigned ResultReg = createResultReg(RC);
const TargetInstrDesc &II = TII.get(MachineInstOpcode);
if (II.getNumDefs() >= 1)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II, ResultReg)
.addImm(Imm));
else {
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, II)
.addImm(Imm));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(TargetOpcode::COPY), ResultReg)
.addReg(II.ImplicitDefs[0]));
}
return ResultReg;
}
unsigned ARMFastISel::FastEmitInst_extractsubreg(MVT RetVT,
unsigned Op0, bool Op0IsKill,
uint32_t Idx) {
unsigned ResultReg = createResultReg(TLI.getRegClassFor(RetVT));
assert(TargetRegisterInfo::isVirtualRegister(Op0) &&
"Cannot yet extract from physregs");
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt,
DL, TII.get(TargetOpcode::COPY), ResultReg)
.addReg(Op0, getKillRegState(Op0IsKill), Idx));
return ResultReg;
}
bool ARMFastISel::TargetSelectInstruction(const Instruction *I) {
switch (I->getOpcode()) {
default: break;
}
return false;
}
namespace llvm {
llvm::FastISel *ARM::createFastISel(FunctionLoweringInfo &funcInfo) {
if (EnableARMFastISel) return new ARMFastISel(funcInfo);
return 0;
}
}