llvm-6502/lib/Target/ARM/ARMFastISel.cpp
Eric Christopher 9ed58dff86 Rewrite TargetMaterializeConstant splitting it out into two functions
for integer and fp constants. Implement todo to use vfp3 instructions
to materialize easy constants if we can.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113453 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 00:19:41 +00:00

748 lines
26 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;
const ARMFunctionInfo *AFI;
// Convenience variable to avoid checking all the time.
bool isThumb;
public:
explicit ARMFastISel(FunctionLoweringInfo &funcInfo)
: FastISel(funcInfo),
TM(funcInfo.MF->getTarget()),
TII(*TM.getInstrInfo()),
TLI(*TM.getTargetLowering()) {
Subtarget = &TM.getSubtarget<ARMSubtarget>();
AFI = funcInfo.MF->getInfo<ARMFunctionInfo>();
isThumb = AFI->isThumbFunction();
}
// 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);
virtual unsigned TargetMaterializeConstant(const Constant *C);
#include "ARMGenFastISel.inc"
// Instruction selection routines.
virtual bool ARMSelectLoad(const Instruction *I);
virtual bool ARMSelectStore(const Instruction *I);
virtual bool ARMSelectBranch(const Instruction *I);
virtual bool ARMSelectCmp(const Instruction *I);
// Utility routines.
private:
bool isTypeLegal(const Type *Ty, EVT &VT);
bool isLoadTypeLegal(const Type *Ty, EVT &VT);
bool ARMEmitLoad(EVT VT, unsigned &ResultReg, unsigned Reg, int Offset);
bool ARMEmitStore(EVT VT, unsigned SrcReg, unsigned Reg, int Offset);
bool ARMLoadAlloca(const Instruction *I, EVT VT);
bool ARMStoreAlloca(const Instruction *I, unsigned SrcReg, EVT VT);
bool ARMComputeRegOffset(const Value *Obj, unsigned &Reg, int &Offset);
unsigned ARMMaterializeFP(const ConstantFP *CFP, EVT VT);
unsigned ARMMaterializeInt(const Constant *C);
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.isReg() || !MO.isDef()) continue;
if (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;
}
// For double width floating point we need to materialize two constants
// (the high and the low) into integer registers then use a move to get
// the combined constant into an FP reg.
unsigned ARMFastISel::ARMMaterializeFP(const ConstantFP *CFP, EVT VT) {
const APFloat Val = CFP->getValueAPF();
bool is64bit = VT.getSimpleVT().SimpleTy == MVT::f64;
// This checks to see if we can use VFP3 instructions to materialize
// a constant, otherwise we have to go through the constant pool.
if (TLI.isFPImmLegal(Val, VT)) {
unsigned Opc = is64bit ? ARM::FCONSTD : ARM::FCONSTS;
unsigned DestReg = createResultReg(TLI.getRegClassFor(VT));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(Opc),
DestReg)
.addFPImm(CFP));
return DestReg;
}
// No 64-bit at the moment.
if (is64bit) return 0;
// Load this from the constant pool.
unsigned DestReg = ARMMaterializeInt(cast<Constant>(CFP));
// If we have a floating point constant we expect it in a floating point
// register.
unsigned MoveReg = createResultReg(TLI.getRegClassFor(VT));
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(ARM::VMOVRS), MoveReg)
.addReg(DestReg));
return MoveReg;
}
unsigned ARMFastISel::ARMMaterializeInt(const Constant *C) {
// MachineConstantPool wants an explicit alignment.
unsigned Align = TD.getPrefTypeAlignment(C->getType());
if (Align == 0) {
// TODO: Figure out if this is correct.
Align = TD.getTypeAllocSize(C->getType());
}
unsigned Idx = MCP.getConstantPoolIndex(C, Align);
unsigned DestReg = createResultReg(TLI.getRegClassFor(MVT::i32));
if (isThumb)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(ARM::t2LDRpci))
.addReg(DestReg).addConstantPoolIndex(Idx));
else
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(ARM::LDRcp))
.addReg(DestReg).addConstantPoolIndex(Idx)
.addReg(0).addImm(0));
return DestReg;
}
unsigned ARMFastISel::TargetMaterializeConstant(const Constant *C) {
EVT VT = TLI.getValueType(C->getType(), true);
// Only handle simple types.
if (!VT.isSimple()) return 0;
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return ARMMaterializeFP(CFP, VT);
return ARMMaterializeInt(C);
}
bool ARMFastISel::isTypeLegal(const Type *Ty, EVT &VT) {
VT = TLI.getValueType(Ty, true);
// Only handle simple types.
if (VT == MVT::Other || !VT.isSimple()) return false;
// Handle all legal types, i.e. a register that will directly hold this
// value.
return TLI.isTypeLegal(VT);
}
bool ARMFastISel::isLoadTypeLegal(const Type *Ty, EVT &VT) {
if (isTypeLegal(Ty, VT)) return true;
// If this is a type than can be sign or zero-extended to a basic operation
// go ahead and accept it now.
if (VT == MVT::i8 || VT == MVT::i16)
return true;
return false;
}
// Computes the Reg+Offset to get to an object.
bool ARMFastISel::ARMComputeRegOffset(const Value *Obj, unsigned &Reg,
int &Offset) {
// Some boilerplate from the X86 FastISel.
const User *U = NULL;
unsigned Opcode = Instruction::UserOp1;
if (const Instruction *I = dyn_cast<Instruction>(Obj)) {
// Don't walk into other basic blocks; it's possible we haven't
// visited them yet, so the instructions may not yet be assigned
// virtual registers.
if (FuncInfo.MBBMap[I->getParent()] != FuncInfo.MBB)
return false;
Opcode = I->getOpcode();
U = I;
} else if (const ConstantExpr *C = dyn_cast<ConstantExpr>(Obj)) {
Opcode = C->getOpcode();
U = C;
}
if (const PointerType *Ty = dyn_cast<PointerType>(Obj->getType()))
if (Ty->getAddressSpace() > 255)
// Fast instruction selection doesn't support the special
// address spaces.
return false;
switch (Opcode) {
default:
//errs() << "Failing Opcode is: " << *Op1 << "\n";
break;
case Instruction::Alloca: {
assert(false && "Alloca should have been handled earlier!");
return false;
}
}
if (const GlobalValue *GV = dyn_cast<GlobalValue>(Obj)) {
//errs() << "Failing GV is: " << GV << "\n";
(void)GV;
return false;
}
// Try to get this in a register if nothing else has worked.
Reg = getRegForValue(Obj);
if (Reg == 0) return false;
// Since the offset may be too large for the load instruction
// get the reg+offset into a register.
// TODO: Verify the additions work, otherwise we'll need to add the
// offset instead of 0 to the instructions and do all sorts of operand
// munging.
// TODO: Optimize this somewhat.
if (Offset != 0) {
ARMCC::CondCodes Pred = ARMCC::AL;
unsigned PredReg = 0;
if (!isThumb)
emitARMRegPlusImmediate(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
Reg, Reg, Offset, Pred, PredReg,
static_cast<const ARMBaseInstrInfo&>(TII));
else {
assert(AFI->isThumb2Function());
emitT2RegPlusImmediate(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
Reg, Reg, Offset, Pred, PredReg,
static_cast<const ARMBaseInstrInfo&>(TII));
}
}
return true;
}
bool ARMFastISel::ARMLoadAlloca(const Instruction *I, EVT VT) {
Value *Op0 = I->getOperand(0);
// Verify it's an alloca.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Op0)) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
TargetRegisterClass* RC = TLI.getRegClassFor(VT);
unsigned ResultReg = createResultReg(RC);
TII.loadRegFromStackSlot(*FuncInfo.MBB, *FuncInfo.InsertPt,
ResultReg, SI->second, RC,
TM.getRegisterInfo());
UpdateValueMap(I, ResultReg);
return true;
}
}
return false;
}
bool ARMFastISel::ARMEmitLoad(EVT VT, unsigned &ResultReg,
unsigned Reg, int Offset) {
assert(VT.isSimple() && "Non-simple types are invalid here!");
unsigned Opc;
switch (VT.getSimpleVT().SimpleTy) {
default:
assert(false && "Trying to emit for an unhandled type!");
return false;
case MVT::i16:
Opc = isThumb ? ARM::tLDRH : ARM::LDRH;
VT = MVT::i32;
break;
case MVT::i8:
Opc = isThumb ? ARM::tLDRB : ARM::LDRB;
VT = MVT::i32;
break;
case MVT::i32:
Opc = isThumb ? ARM::tLDR : ARM::LDR;
break;
}
ResultReg = createResultReg(TLI.getRegClassFor(VT));
// TODO: Fix the Addressing modes so that these can share some code.
// Since this is a Thumb1 load this will work in Thumb1 or 2 mode.
if (isThumb)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg)
.addReg(Reg).addImm(Offset).addReg(0));
else
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(Opc), ResultReg)
.addReg(Reg).addReg(0).addImm(Offset));
return true;
}
bool ARMFastISel::ARMStoreAlloca(const Instruction *I, unsigned SrcReg, EVT VT){
Value *Op1 = I->getOperand(1);
// Verify it's an alloca.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Op1)) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
TargetRegisterClass* RC = TLI.getRegClassFor(VT);
assert(SrcReg != 0 && "Nothing to store!");
TII.storeRegToStackSlot(*FuncInfo.MBB, *FuncInfo.InsertPt,
SrcReg, true /*isKill*/, SI->second, RC,
TM.getRegisterInfo());
return true;
}
}
return false;
}
bool ARMFastISel::ARMEmitStore(EVT VT, unsigned SrcReg,
unsigned DstReg, int Offset) {
unsigned StrOpc;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
case MVT::i1:
case MVT::i8: StrOpc = isThumb ? ARM::tSTRB : ARM::STRB; break;
case MVT::i16: StrOpc = isThumb ? ARM::tSTRH : ARM::STRH; break;
case MVT::i32: StrOpc = isThumb ? ARM::tSTR : ARM::STR; break;
case MVT::f32:
if (!Subtarget->hasVFP2()) return false;
StrOpc = ARM::VSTRS;
break;
case MVT::f64:
if (!Subtarget->hasVFP2()) return false;
StrOpc = ARM::VSTRD;
break;
}
if (isThumb)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(StrOpc), SrcReg)
.addReg(DstReg).addImm(Offset).addReg(0));
else
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(StrOpc), SrcReg)
.addReg(DstReg).addReg(0).addImm(Offset));
return true;
}
bool ARMFastISel::ARMSelectStore(const Instruction *I) {
Value *Op0 = I->getOperand(0);
unsigned SrcReg = 0;
// Yay type legalization
EVT VT;
if (!isLoadTypeLegal(I->getOperand(0)->getType(), VT))
return false;
// Get the value to be stored into a register.
SrcReg = getRegForValue(Op0);
if (SrcReg == 0)
return false;
// If we're an alloca we know we have a frame index and can emit the store
// quickly.
if (ARMStoreAlloca(I, SrcReg, VT))
return true;
// Our register and offset with innocuous defaults.
unsigned Reg = 0;
int Offset = 0;
// See if we can handle this as Reg + Offset
if (!ARMComputeRegOffset(I->getOperand(1), Reg, Offset))
return false;
if (!ARMEmitStore(VT, SrcReg, Reg, Offset /* 0 */)) return false;
return false;
}
bool ARMFastISel::ARMSelectLoad(const Instruction *I) {
// Verify we have a legal type before going any further.
EVT VT;
if (!isLoadTypeLegal(I->getType(), VT))
return false;
// If we're an alloca we know we have a frame index and can emit the load
// directly in short order.
if (ARMLoadAlloca(I, VT))
return true;
// Our register and offset with innocuous defaults.
unsigned Reg = 0;
int Offset = 0;
// See if we can handle this as Reg + Offset
if (!ARMComputeRegOffset(I->getOperand(0), Reg, Offset))
return false;
unsigned ResultReg;
if (!ARMEmitLoad(VT, ResultReg, Reg, Offset /* 0 */)) return false;
UpdateValueMap(I, ResultReg);
return true;
}
bool ARMFastISel::ARMSelectBranch(const Instruction *I) {
const BranchInst *BI = cast<BranchInst>(I);
MachineBasicBlock *TBB = FuncInfo.MBBMap[BI->getSuccessor(0)];
MachineBasicBlock *FBB = FuncInfo.MBBMap[BI->getSuccessor(1)];
// Simple branch support.
unsigned CondReg = getRegForValue(BI->getCondition());
if (CondReg == 0) return false;
unsigned CmpOpc = isThumb ? ARM::t2CMPrr : ARM::CMPrr;
unsigned BrOpc = isThumb ? ARM::t2Bcc : ARM::Bcc;
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CmpOpc))
.addReg(CondReg).addReg(CondReg));
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(BrOpc))
.addMBB(TBB).addImm(ARMCC::NE).addReg(ARM::CPSR);
FastEmitBranch(FBB, DL);
FuncInfo.MBB->addSuccessor(TBB);
return true;
}
bool ARMFastISel::ARMSelectCmp(const Instruction *I) {
const CmpInst *CI = cast<CmpInst>(I);
EVT VT;
const Type *Ty = CI->getOperand(0)->getType();
if (!isTypeLegal(Ty, VT))
return false;
bool isFloat = (Ty->isDoubleTy() || Ty->isFloatTy());
if (isFloat && !Subtarget->hasVFP2())
return false;
unsigned CmpOpc;
switch (VT.getSimpleVT().SimpleTy) {
default: return false;
// TODO: Verify compares.
case MVT::f32:
CmpOpc = ARM::VCMPES;
break;
case MVT::f64:
CmpOpc = ARM::VCMPED;
break;
case MVT::i32:
CmpOpc = isThumb ? ARM::t2CMPrr : ARM::CMPrr;
break;
}
unsigned Arg1 = getRegForValue(CI->getOperand(0));
if (Arg1 == 0) return false;
unsigned Arg2 = getRegForValue(CI->getOperand(1));
if (Arg2 == 0) return false;
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(CmpOpc))
.addReg(Arg1).addReg(Arg2));
// For floating point we need to move the result to a register we can
// actually do something with.
if (isFloat)
AddOptionalDefs(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
TII.get(ARM::FMSTAT)));
return true;
}
// TODO: SoftFP support.
bool ARMFastISel::TargetSelectInstruction(const Instruction *I) {
// No Thumb-1 for now.
if (isThumb && !AFI->isThumb2Function()) return false;
switch (I->getOpcode()) {
case Instruction::Load:
return ARMSelectLoad(I);
case Instruction::Store:
return ARMSelectStore(I);
case Instruction::Br:
return ARMSelectBranch(I);
case Instruction::ICmp:
case Instruction::FCmp:
return ARMSelectCmp(I);
default: break;
}
return false;
}
namespace llvm {
llvm::FastISel *ARM::createFastISel(FunctionLoweringInfo &funcInfo) {
if (EnableARMFastISel) return new ARMFastISel(funcInfo);
return 0;
}
}