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gerrit-public.fairphone.software / toolchain / llvm-project / ef84814ea94185d586045a3684c462afdc527342 / . / llvm / lib / Target / PowerPC / PPC32ISelSimple.cpp
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//===-- InstSelectSimple.cpp - A simple instruction selector for PowerPC --===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "isel"
#include "PowerPC.h"
#include "PowerPCInstrBuilder.h"
#include "PowerPCInstrInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/CodeGen/IntrinsicLowering.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/MRegisterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/InstVisitor.h"
#include "Support/Debug.h"
#include <vector>
using namespace llvm;
namespace {
/// TypeClass - Used by the PowerPC backend to group LLVM types by their basic
/// PPC Representation.
///
enum TypeClass {
cByte, cShort, cInt, cFP, cLong
};
}
/// getClass - Turn a primitive type into a "class" number which is based on the
/// size of the type, and whether or not it is floating point.
///
static inline TypeClass getClass(const Type *Ty) {
switch (Ty->getTypeID()) {
case Type::SByteTyID:
case Type::UByteTyID: return cByte; // Byte operands are class #0
case Type::ShortTyID:
case Type::UShortTyID: return cShort; // Short operands are class #1
case Type::IntTyID:
case Type::UIntTyID:
case Type::PointerTyID: return cInt; // Int's and pointers are class #2
case Type::FloatTyID:
case Type::DoubleTyID: return cFP; // Floating Point is #3
case Type::LongTyID:
case Type::ULongTyID: return cLong; // Longs are class #4
default:
assert(0 && "Invalid type to getClass!");
return cByte; // not reached
}
}
// getClassB - Just like getClass, but treat boolean values as ints.
static inline TypeClass getClassB(const Type *Ty) {
if (Ty == Type::BoolTy) return cInt;
return getClass(Ty);
}
namespace {
struct ISel : public FunctionPass, InstVisitor<ISel> {
TargetMachine &TM;
MachineFunction *F; // The function we are compiling into
Module *M; // Current module
MachineBasicBlock *BB; // The current MBB we are compiling
int VarArgsFrameIndex; // FrameIndex for start of varargs area
int ReturnAddressIndex; // FrameIndex for the return address
std::map<Value*, unsigned> RegMap; // Mapping between Val's and SSA Regs
// MBBMap - Mapping between LLVM BB -> Machine BB
std::map<const BasicBlock*, MachineBasicBlock*> MBBMap;
// AllocaMap - Mapping from fixed sized alloca instructions to the
// FrameIndex for the alloca.
std::map<AllocaInst*, unsigned> AllocaMap;
ISel(TargetMachine &tm) : TM(tm), F(0), BB(0) {}
bool doInitialization(Module &Mod) {
M = &Mod;
// Add external functions that we may call
Type *d = Type::DoubleTy;
// double fmod(double, double);
Mod.getOrInsertFunction("fmod", d, d, d, 0);
// { "__moddi3", "__divdi3", "__umoddi3", "__udivdi3" };
return false;
}
/// runOnFunction - Top level implementation of instruction selection for
/// the entire function.
///
bool runOnFunction(Function &Fn) {
// First pass over the function, lower any unknown intrinsic functions
// with the IntrinsicLowering class.
LowerUnknownIntrinsicFunctionCalls(Fn);
F = &MachineFunction::construct(&Fn, TM);
// Create all of the machine basic blocks for the function...
for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
BB = &F->front();
// Set up a frame object for the return address. This is used by the
// llvm.returnaddress & llvm.frameaddress intrinisics.
ReturnAddressIndex = F->getFrameInfo()->CreateFixedObject(4, -4);
// Copy incoming arguments off of the stack...
LoadArgumentsToVirtualRegs(Fn);
// Instruction select everything except PHI nodes
visit(Fn);
// Select the PHI nodes
SelectPHINodes();
RegMap.clear();
MBBMap.clear();
AllocaMap.clear();
F = 0;
// We always build a machine code representation for the function
return true;
}
virtual const char *getPassName() const {
return "PowerPC Simple Instruction Selection";
}
/// visitBasicBlock - This method is called when we are visiting a new basic
/// block. This simply creates a new MachineBasicBlock to emit code into
/// and adds it to the current MachineFunction. Subsequent visit* for
/// instructions will be invoked for all instructions in the basic block.
///
void visitBasicBlock(BasicBlock &LLVM_BB) {
BB = MBBMap[&LLVM_BB];
}
/// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
/// function, lowering any calls to unknown intrinsic functions into the
/// equivalent LLVM code.
///
void LowerUnknownIntrinsicFunctionCalls(Function &F);
/// LoadArgumentsToVirtualRegs - Load all of the arguments to this function
/// from the stack into virtual registers.
///
void LoadArgumentsToVirtualRegs(Function &F);
/// SelectPHINodes - Insert machine code to generate phis. This is tricky
/// because we have to generate our sources into the source basic blocks,
/// not the current one.
///
void SelectPHINodes();
// Visitation methods for various instructions. These methods simply emit
// fixed PowerPC code for each instruction.
// Control flow operators
void visitReturnInst(ReturnInst &RI);
void visitBranchInst(BranchInst &BI);
struct ValueRecord {
Value *Val;
unsigned Reg;
const Type *Ty;
ValueRecord(unsigned R, const Type *T) : Val(0), Reg(R), Ty(T) {}
ValueRecord(Value *V) : Val(V), Reg(0), Ty(V->getType()) {}
};
void doCall(const ValueRecord &Ret, MachineInstr *CallMI,
const std::vector<ValueRecord> &Args, bool isVarArg);
void visitCallInst(CallInst &I);
void visitIntrinsicCall(Intrinsic::ID ID, CallInst &I);
// Arithmetic operators
void visitSimpleBinary(BinaryOperator &B, unsigned OpcodeClass);
void visitAdd(BinaryOperator &B) { visitSimpleBinary(B, 0); }
void visitSub(BinaryOperator &B) { visitSimpleBinary(B, 1); }
void visitMul(BinaryOperator &B);
void visitDiv(BinaryOperator &B) { visitDivRem(B); }
void visitRem(BinaryOperator &B) { visitDivRem(B); }
void visitDivRem(BinaryOperator &B);
// Bitwise operators
void visitAnd(BinaryOperator &B) { visitSimpleBinary(B, 2); }
void visitOr (BinaryOperator &B) { visitSimpleBinary(B, 3); }
void visitXor(BinaryOperator &B) { visitSimpleBinary(B, 4); }
// Comparison operators...
void visitSetCondInst(SetCondInst &I);
unsigned EmitComparison(unsigned OpNum, Value *Op0, Value *Op1,
MachineBasicBlock *MBB,
MachineBasicBlock::iterator MBBI);
void visitSelectInst(SelectInst &SI);
// Memory Instructions
void visitLoadInst(LoadInst &I);
void visitStoreInst(StoreInst &I);
void visitGetElementPtrInst(GetElementPtrInst &I);
void visitAllocaInst(AllocaInst &I);
void visitMallocInst(MallocInst &I);
void visitFreeInst(FreeInst &I);
// Other operators
void visitShiftInst(ShiftInst &I);
void visitPHINode(PHINode &I) {} // PHI nodes handled by second pass
void visitCastInst(CastInst &I);
void visitVANextInst(VANextInst &I);
void visitVAArgInst(VAArgInst &I);
void visitInstruction(Instruction &I) {
std::cerr << "Cannot instruction select: " << I;
abort();
}
/// promote32 - Make a value 32-bits wide, and put it somewhere.
///
void promote32(unsigned targetReg, const ValueRecord &VR);
/// emitGEPOperation - Common code shared between visitGetElementPtrInst and
/// constant expression GEP support.
///
void emitGEPOperation(MachineBasicBlock *BB, MachineBasicBlock::iterator IP,
Value *Src, User::op_iterator IdxBegin,
User::op_iterator IdxEnd, unsigned TargetReg);
/// emitCastOperation - Common code shared between visitCastInst and
/// constant expression cast support.
///
void emitCastOperation(MachineBasicBlock *BB,MachineBasicBlock::iterator IP,
Value *Src, const Type *DestTy, unsigned TargetReg);
/// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
/// and constant expression support.
///
void emitSimpleBinaryOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1,
unsigned OperatorClass, unsigned TargetReg);
/// emitBinaryFPOperation - This method handles emission of floating point
/// Add (0), Sub (1), Mul (2), and Div (3) operations.
void emitBinaryFPOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1,
unsigned OperatorClass, unsigned TargetReg);
void emitMultiply(MachineBasicBlock *BB, MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1, unsigned TargetReg);
void doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI,
unsigned DestReg, const Type *DestTy,
unsigned Op0Reg, unsigned Op1Reg);
void doMultiplyConst(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MBBI,
unsigned DestReg, const Type *DestTy,
unsigned Op0Reg, unsigned Op1Val);
void emitDivRemOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1, bool isDiv,
unsigned TargetReg);
/// emitSetCCOperation - Common code shared between visitSetCondInst and
/// constant expression support.
///
void emitSetCCOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1, unsigned Opcode,
unsigned TargetReg);
/// emitShiftOperation - Common code shared between visitShiftInst and
/// constant expression support.
///
void emitShiftOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Op, Value *ShiftAmount, bool isLeftShift,
const Type *ResultTy, unsigned DestReg);
/// emitSelectOperation - Common code shared between visitSelectInst and the
/// constant expression support.
void emitSelectOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Cond, Value *TrueVal, Value *FalseVal,
unsigned DestReg);
/// copyConstantToRegister - Output the instructions required to put the
/// specified constant into the specified register.
///
void copyConstantToRegister(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MBBI,
Constant *C, unsigned Reg);
void emitUCOM(MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI,
unsigned LHS, unsigned RHS);
/// makeAnotherReg - This method returns the next register number we haven't
/// yet used.
///
/// Long values are handled somewhat specially. They are always allocated
/// as pairs of 32 bit integer values. The register number returned is the
/// lower 32 bits of the long value, and the regNum+1 is the upper 32 bits
/// of the long value.
///
unsigned makeAnotherReg(const Type *Ty) {
assert(dynamic_cast<const PowerPCRegisterInfo*>(TM.getRegisterInfo()) &&
"Current target doesn't have PPC reg info??");
const PowerPCRegisterInfo *MRI =
static_cast<const PowerPCRegisterInfo*>(TM.getRegisterInfo());
if (Ty == Type::LongTy || Ty == Type::ULongTy) {
const TargetRegisterClass *RC = MRI->getRegClassForType(Type::IntTy);
// Create the lower part
F->getSSARegMap()->createVirtualRegister(RC);
// Create the upper part.
return F->getSSARegMap()->createVirtualRegister(RC)-1;
}
// Add the mapping of regnumber => reg class to MachineFunction
const TargetRegisterClass *RC = MRI->getRegClassForType(Ty);
return F->getSSARegMap()->createVirtualRegister(RC);
}
/// getReg - This method turns an LLVM value into a register number.
///
unsigned getReg(Value &V) { return getReg(&V); } // Allow references
unsigned getReg(Value *V) {
// Just append to the end of the current bb.
MachineBasicBlock::iterator It = BB->end();
return getReg(V, BB, It);
}
unsigned getReg(Value *V, MachineBasicBlock *MBB,
MachineBasicBlock::iterator IPt);
/// getFixedSizedAllocaFI - Return the frame index for a fixed sized alloca
/// that is to be statically allocated with the initial stack frame
/// adjustment.
unsigned getFixedSizedAllocaFI(AllocaInst *AI);
};
}
/// dyn_castFixedAlloca - If the specified value is a fixed size alloca
/// instruction in the entry block, return it. Otherwise, return a null
/// pointer.
static AllocaInst *dyn_castFixedAlloca(Value *V) {
if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
BasicBlock *BB = AI->getParent();
if (isa<ConstantUInt>(AI->getArraySize()) && BB ==&BB->getParent()->front())
return AI;
}
return 0;
}
/// getReg - This method turns an LLVM value into a register number.
///
unsigned ISel::getReg(Value *V, MachineBasicBlock *MBB,
MachineBasicBlock::iterator IPt) {
// If this operand is a constant, emit the code to copy the constant into
// the register here...
//
if (Constant *C = dyn_cast<Constant>(V)) {
unsigned Reg = makeAnotherReg(V->getType());
copyConstantToRegister(MBB, IPt, C, Reg);
return Reg;
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// GV is located at PC + distance
unsigned CurPC = makeAnotherReg(Type::IntTy);
unsigned Reg1 = makeAnotherReg(V->getType());
unsigned Reg2 = makeAnotherReg(V->getType());
// Move PC to destination reg
BuildMI(*MBB, IPt, PPC32::MovePCtoLR, 0, CurPC);
// Move value at PC + distance into return reg
BuildMI(*MBB, IPt, PPC32::LOADHiAddr, 2, Reg1).addReg(CurPC)
.addGlobalAddress(GV);
BuildMI(*MBB, IPt, PPC32::LOADLoAddr, 2, Reg2).addReg(Reg1)
.addGlobalAddress(GV);
return Reg2;
} else if (CastInst *CI = dyn_cast<CastInst>(V)) {
// Do not emit noop casts at all.
if (getClassB(CI->getType()) == getClassB(CI->getOperand(0)->getType()))
return getReg(CI->getOperand(0), MBB, IPt);
} else if (AllocaInst *AI = dyn_castFixedAlloca(V)) {
unsigned Reg = makeAnotherReg(V->getType());
unsigned FI = getFixedSizedAllocaFI(AI);
addFrameReference(BuildMI(*MBB, IPt, PPC32::ADDI, 2, Reg), FI, 0, false);
return Reg;
}
unsigned &Reg = RegMap[V];
if (Reg == 0) {
Reg = makeAnotherReg(V->getType());
RegMap[V] = Reg;
}
return Reg;
}
/// getFixedSizedAllocaFI - Return the frame index for a fixed sized alloca
/// that is to be statically allocated with the initial stack frame
/// adjustment.
unsigned ISel::getFixedSizedAllocaFI(AllocaInst *AI) {
// Already computed this?
std::map<AllocaInst*, unsigned>::iterator I = AllocaMap.lower_bound(AI);
if (I != AllocaMap.end() && I->first == AI) return I->second;
const Type *Ty = AI->getAllocatedType();
ConstantUInt *CUI = cast<ConstantUInt>(AI->getArraySize());
unsigned TySize = TM.getTargetData().getTypeSize(Ty);
TySize *= CUI->getValue(); // Get total allocated size...
unsigned Alignment = TM.getTargetData().getTypeAlignment(Ty);
// Create a new stack object using the frame manager...
int FrameIdx = F->getFrameInfo()->CreateStackObject(TySize, Alignment);
AllocaMap.insert(I, std::make_pair(AI, FrameIdx));
return FrameIdx;
}
/// copyConstantToRegister - Output the instructions required to put the
/// specified constant into the specified register.
///
void ISel::copyConstantToRegister(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Constant *C, unsigned R) {
if (C->getType()->isIntegral()) {
unsigned Class = getClassB(C->getType());
if (Class == cLong) {
// Copy the value into the register pair.
uint64_t Val = cast<ConstantInt>(C)->getRawValue();
unsigned hiTmp = makeAnotherReg(Type::IntTy);
unsigned loTmp = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::ADDIS, 2, loTmp).addReg(PPC32::R0)
.addImm(Val >> 48);
BuildMI(*MBB, IP, PPC32::ORI, 2, R).addReg(loTmp)
.addImm((Val >> 32) & 0xFFFF);
BuildMI(*MBB, IP, PPC32::ADDIS, 2, hiTmp).addReg(PPC32::R0)
.addImm((Val >> 16) & 0xFFFF);
BuildMI(*MBB, IP, PPC32::ORI, 2, R+1).addReg(hiTmp).addImm(Val & 0xFFFF);
return;
}
assert(Class <= cInt && "Type not handled yet!");
if (C->getType() == Type::BoolTy) {
BuildMI(*MBB, IP, PPC32::ADDI, 2, R).addReg(PPC32::R0)
.addImm(C == ConstantBool::True);
} else if (Class == cByte || Class == cShort) {
ConstantInt *CI = cast<ConstantInt>(C);
BuildMI(*MBB, IP, PPC32::ADDI, 2, R).addReg(PPC32::R0)
.addImm(CI->getRawValue());
} else {
ConstantInt *CI = cast<ConstantInt>(C);
int TheVal = CI->getRawValue() & 0xFFFFFFFF;
if (TheVal < 32768 && TheVal >= -32768) {
BuildMI(*MBB, IP, PPC32::ADDI, 2, R).addReg(PPC32::R0)
.addImm(CI->getRawValue());
} else {
unsigned TmpReg = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::ADDIS, 2, TmpReg).addReg(PPC32::R0)
.addImm(CI->getRawValue() >> 16);
BuildMI(*MBB, IP, PPC32::ORI, 2, R).addReg(TmpReg)
.addImm(CI->getRawValue() & 0xFFFF);
}
}
} else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
// We need to spill the constant to memory...
MachineConstantPool *CP = F->getConstantPool();
unsigned CPI = CP->getConstantPoolIndex(CFP);
const Type *Ty = CFP->getType();
assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
unsigned LoadOpcode = (Ty == Type::FloatTy) ? PPC32::LFS : PPC32::LFD;
addConstantPoolReference(BuildMI(*MBB, IP, LoadOpcode, 2, R), CPI);
} else if (isa<ConstantPointerNull>(C)) {
// Copy zero (null pointer) to the register.
BuildMI(*MBB, IP, PPC32::ADDI, 2, R).addReg(PPC32::R0).addImm(0);
} else if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)) {
BuildMI(*MBB, IP, PPC32::ADDIS, 2, R).addReg(PPC32::R0)
.addGlobalAddress(CPR->getValue());
BuildMI(*MBB, IP, PPC32::ORI, 2, R).addReg(PPC32::R0)
.addGlobalAddress(CPR->getValue());
} else {
std::cerr << "Offending constant: " << C << "\n";
assert(0 && "Type not handled yet!");
}
}
/// LoadArgumentsToVirtualRegs - Load all of the arguments to this function from
/// the stack into virtual registers.
///
/// FIXME: When we can calculate which args are coming in via registers
/// source them from there instead.
void ISel::LoadArgumentsToVirtualRegs(Function &Fn) {
unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
unsigned GPR_remaining = 8;
unsigned FPR_remaining = 13;
unsigned GPR_idx = 0, FPR_idx = 0;
static const unsigned GPR[] = {
PPC32::R3, PPC32::R4, PPC32::R5, PPC32::R6,
PPC32::R7, PPC32::R8, PPC32::R9, PPC32::R10,
};
static const unsigned FPR[] = {
PPC32::F1, PPC32::F2, PPC32::F3, PPC32::F4, PPC32::F5, PPC32::F6, PPC32::F7,
PPC32::F8, PPC32::F9, PPC32::F10, PPC32::F11, PPC32::F12, PPC32::F13
};
MachineFrameInfo *MFI = F->getFrameInfo();
for (Function::aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
bool ArgLive = !I->use_empty();
unsigned Reg = ArgLive ? getReg(*I) : 0;
int FI; // Frame object index
switch (getClassB(I->getType())) {
case cByte:
if (ArgLive) {
FI = MFI->CreateFixedObject(1, ArgOffset);
if (GPR_remaining > 0) {
BuildMI(BB, PPC32::OR, 2, Reg).addReg(GPR[GPR_idx])
.addReg(GPR[GPR_idx]);
} else {
addFrameReference(BuildMI(BB, PPC32::LBZ, 2, Reg), FI);
}
}
break;
case cShort:
if (ArgLive) {
FI = MFI->CreateFixedObject(2, ArgOffset);
if (GPR_remaining > 0) {
BuildMI(BB, PPC32::OR, 2, Reg).addReg(GPR[GPR_idx])
.addReg(GPR[GPR_idx]);
} else {
addFrameReference(BuildMI(BB, PPC32::LHZ, 2, Reg), FI);
}
}
break;
case cInt:
if (ArgLive) {
FI = MFI->CreateFixedObject(4, ArgOffset);
if (GPR_remaining > 0) {
BuildMI(BB, PPC32::OR, 2, Reg).addReg(GPR[GPR_idx])
.addReg(GPR[GPR_idx]);
} else {
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, Reg), FI);
}
}
break;
case cLong:
if (ArgLive) {
FI = MFI->CreateFixedObject(8, ArgOffset);
if (GPR_remaining > 1) {
BuildMI(BB, PPC32::OR, 2, Reg).addReg(GPR[GPR_idx])
.addReg(GPR[GPR_idx]);
BuildMI(BB, PPC32::OR, 2, Reg+1).addReg(GPR[GPR_idx+1])
.addReg(GPR[GPR_idx+1]);
} else {
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, Reg), FI);
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, Reg+1), FI, 4);
}
}
ArgOffset += 4; // longs require 4 additional bytes
if (GPR_remaining > 1) {
GPR_remaining--; // uses up 2 GPRs
GPR_idx++;
}
break;
case cFP:
if (ArgLive) {
unsigned Opcode;
if (I->getType() == Type::FloatTy) {
Opcode = PPC32::LFS;
FI = MFI->CreateFixedObject(4, ArgOffset);
} else {
Opcode = PPC32::LFD;
FI = MFI->CreateFixedObject(8, ArgOffset);
}
if (FPR_remaining > 0) {
BuildMI(BB, PPC32::FMR, 1, Reg).addReg(FPR[FPR_idx]);
FPR_remaining--;
FPR_idx++;
} else {
addFrameReference(BuildMI(BB, Opcode, 2, Reg), FI);
}
}
if (I->getType() == Type::DoubleTy) {
ArgOffset += 4; // doubles require 4 additional bytes
if (GPR_remaining > 0) {
GPR_remaining--; // uses up 2 GPRs
GPR_idx++;
}
}
break;
default:
assert(0 && "Unhandled argument type!");
}
ArgOffset += 4; // Each argument takes at least 4 bytes on the stack...
if (GPR_remaining > 0) {
GPR_remaining--; // uses up 2 GPRs
GPR_idx++;
}
}
// If the function takes variable number of arguments, add a frame offset for
// the start of the first vararg value... this is used to expand
// llvm.va_start.
if (Fn.getFunctionType()->isVarArg())
VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
}
/// SelectPHINodes - Insert machine code to generate phis. This is tricky
/// because we have to generate our sources into the source basic blocks, not
/// the current one.
///
void ISel::SelectPHINodes() {
const TargetInstrInfo &TII = *TM.getInstrInfo();
const Function &LF = *F->getFunction(); // The LLVM function...
for (Function::const_iterator I = LF.begin(), E = LF.end(); I != E; ++I) {
const BasicBlock *BB = I;
MachineBasicBlock &MBB = *MBBMap[I];
// Loop over all of the PHI nodes in the LLVM basic block...
MachineBasicBlock::iterator PHIInsertPoint = MBB.begin();
for (BasicBlock::const_iterator I = BB->begin();
PHINode *PN = const_cast<PHINode*>(dyn_cast<PHINode>(I)); ++I) {
// Create a new machine instr PHI node, and insert it.
unsigned PHIReg = getReg(*PN);
MachineInstr *PhiMI = BuildMI(MBB, PHIInsertPoint,
PPC32::PHI, PN->getNumOperands(), PHIReg);
MachineInstr *LongPhiMI = 0;
if (PN->getType() == Type::LongTy || PN->getType() == Type::ULongTy)
LongPhiMI = BuildMI(MBB, PHIInsertPoint,
PPC32::PHI, PN->getNumOperands(), PHIReg+1);
// PHIValues - Map of blocks to incoming virtual registers. We use this
// so that we only initialize one incoming value for a particular block,
// even if the block has multiple entries in the PHI node.
//
std::map<MachineBasicBlock*, unsigned> PHIValues;
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
MachineBasicBlock *PredMBB = MBBMap[PN->getIncomingBlock(i)];
unsigned ValReg;
std::map<MachineBasicBlock*, unsigned>::iterator EntryIt =
PHIValues.lower_bound(PredMBB);
if (EntryIt != PHIValues.end() && EntryIt->first == PredMBB) {
// We already inserted an initialization of the register for this
// predecessor. Recycle it.
ValReg = EntryIt->second;
} else {
// Get the incoming value into a virtual register.
//
Value *Val = PN->getIncomingValue(i);
// If this is a constant or GlobalValue, we may have to insert code
// into the basic block to compute it into a virtual register.
if ((isa<Constant>(Val) && !isa<ConstantExpr>(Val)) ||
isa<GlobalValue>(Val)) {
// Simple constants get emitted at the end of the basic block,
// before any terminator instructions. We "know" that the code to
// move a constant into a register will never clobber any flags.
ValReg = getReg(Val, PredMBB, PredMBB->getFirstTerminator());
} else {
// Because we don't want to clobber any values which might be in
// physical registers with the computation of this constant (which
// might be arbitrarily complex if it is a constant expression),
// just insert the computation at the top of the basic block.
MachineBasicBlock::iterator PI = PredMBB->begin();
// Skip over any PHI nodes though!
while (PI != PredMBB->end() && PI->getOpcode() == PPC32::PHI)
++PI;
ValReg = getReg(Val, PredMBB, PI);
}
// Remember that we inserted a value for this PHI for this predecessor
PHIValues.insert(EntryIt, std::make_pair(PredMBB, ValReg));
}
PhiMI->addRegOperand(ValReg);
PhiMI->addMachineBasicBlockOperand(PredMBB);
if (LongPhiMI) {
LongPhiMI->addRegOperand(ValReg+1);
LongPhiMI->addMachineBasicBlockOperand(PredMBB);
}
}
// Now that we emitted all of the incoming values for the PHI node, make
// sure to reposition the InsertPoint after the PHI that we just added.
// This is needed because we might have inserted a constant into this
// block, right after the PHI's which is before the old insert point!
PHIInsertPoint = LongPhiMI ? LongPhiMI : PhiMI;
++PHIInsertPoint;
}
}
}
// canFoldSetCCIntoBranchOrSelect - Return the setcc instruction if we can fold
// it into the conditional branch or select instruction which is the only user
// of the cc instruction. This is the case if the conditional branch is the
// only user of the setcc, and if the setcc is in the same basic block as the
// conditional branch. We also don't handle long arguments below, so we reject
// them here as well.
//
static SetCondInst *canFoldSetCCIntoBranchOrSelect(Value *V) {
if (SetCondInst *SCI = dyn_cast<SetCondInst>(V))
if (SCI->hasOneUse()) {
Instruction *User = cast<Instruction>(SCI->use_back());
if ((isa<BranchInst>(User) || isa<SelectInst>(User)) &&
SCI->getParent() == User->getParent() &&
(getClassB(SCI->getOperand(0)->getType()) != cLong ||
SCI->getOpcode() == Instruction::SetEQ ||
SCI->getOpcode() == Instruction::SetNE))
return SCI;
}
return 0;
}
// Return a fixed numbering for setcc instructions which does not depend on the
// order of the opcodes.
//
static unsigned getSetCCNumber(unsigned Opcode) {
switch (Opcode) {
default: assert(0 && "Unknown setcc instruction!");
case Instruction::SetEQ: return 0;
case Instruction::SetNE: return 1;
case Instruction::SetLT: return 2;
case Instruction::SetGE: return 3;
case Instruction::SetGT: return 4;
case Instruction::SetLE: return 5;
}
}
static unsigned getPPCOpcodeForSetCCNumber(unsigned Opcode) {
switch (Opcode) {
default: assert(0 && "Unknown setcc instruction!");
case Instruction::SetEQ: return PPC32::BEQ;
case Instruction::SetNE: return PPC32::BNE;
case Instruction::SetLT: return PPC32::BLT;
case Instruction::SetGE: return PPC32::BGE;
case Instruction::SetGT: return PPC32::BGT;
case Instruction::SetLE: return PPC32::BLE;
}
}
static unsigned invertPPCBranchOpcode(unsigned Opcode) {
switch (Opcode) {
default: assert(0 && "Unknown PPC32 branch opcode!");
case PPC32::BEQ: return PPC32::BNE;
case PPC32::BNE: return PPC32::BEQ;
case PPC32::BLT: return PPC32::BGE;
case PPC32::BGE: return PPC32::BLT;
case PPC32::BGT: return PPC32::BLE;
case PPC32::BLE: return PPC32::BGT;
}
}
/// emitUCOM - emits an unordered FP compare.
void ISel::emitUCOM(MachineBasicBlock *MBB, MachineBasicBlock::iterator IP,
unsigned LHS, unsigned RHS) {
BuildMI(*MBB, IP, PPC32::FCMPU, 2, PPC32::CR0).addReg(LHS).addReg(RHS);
}
// EmitComparison - This function emits a comparison of the two operands,
// returning the extended setcc code to use.
unsigned ISel::EmitComparison(unsigned OpNum, Value *Op0, Value *Op1,
MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP) {
// The arguments are already supposed to be of the same type.
const Type *CompTy = Op0->getType();
unsigned Class = getClassB(CompTy);
unsigned Op0r = getReg(Op0, MBB, IP);
// Special case handling of: cmp R, i
if (isa<ConstantPointerNull>(Op1)) {
BuildMI(*MBB, IP, PPC32::CMPI, 2, PPC32::CR0).addReg(Op0r).addImm(0);
} else if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
if (Class == cByte || Class == cShort || Class == cInt) {
unsigned Op1v = CI->getRawValue();
// Mask off any upper bits of the constant, if there are any...
Op1v &= (1ULL << (8 << Class)) - 1;
// Compare immediate or promote to reg?
if (Op1v <= 32767) {
BuildMI(*MBB, IP, CompTy->isSigned() ? PPC32::CMPI : PPC32::CMPLI, 3,
PPC32::CR0).addImm(0).addReg(Op0r).addImm(Op1v);
} else {
unsigned Op1r = getReg(Op1, MBB, IP);
BuildMI(*MBB, IP, CompTy->isSigned() ? PPC32::CMP : PPC32::CMPL, 3,
PPC32::CR0).addImm(0).addReg(Op0r).addReg(Op1r);
}
return OpNum;
} else {
assert(Class == cLong && "Unknown integer class!");
unsigned LowCst = CI->getRawValue();
unsigned HiCst = CI->getRawValue() >> 32;
if (OpNum < 2) { // seteq, setne
unsigned LoTmp = Op0r;
if (LowCst != 0) {
unsigned LoLow = makeAnotherReg(Type::IntTy);
unsigned LoTmp = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::XORI, 2, LoLow).addReg(Op0r).addImm(LowCst);
BuildMI(*MBB, IP, PPC32::XORIS, 2, LoTmp).addReg(LoLow)
.addImm(LowCst >> 16);
}
unsigned HiTmp = Op0r+1;
if (HiCst != 0) {
unsigned HiLow = makeAnotherReg(Type::IntTy);
unsigned HiTmp = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::XORI, 2, HiLow).addReg(Op0r+1).addImm(HiCst);
BuildMI(*MBB, IP, PPC32::XORIS, 2, HiTmp).addReg(HiLow)
.addImm(HiCst >> 16);
}
unsigned FinalTmp = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::ORo, 2, FinalTmp).addReg(LoTmp).addReg(HiTmp);
//BuildMI(*MBB, IP, PPC32::CMPLI, 2, PPC32::CR0).addReg(FinalTmp).addImm(0);
return OpNum;
} else {
// FIXME: Not Yet Implemented
std::cerr << "EmitComparison unimplemented: Opnum >= 2\n";
abort();
return OpNum;
}
}
}
unsigned Op1r = getReg(Op1, MBB, IP);
switch (Class) {
default: assert(0 && "Unknown type class!");
case cByte:
case cShort:
case cInt:
BuildMI(*MBB, IP, CompTy->isSigned() ? PPC32::CMP : PPC32::CMPL, 2,
PPC32::CR0).addReg(Op0r).addReg(Op1r);
break;
case cFP:
emitUCOM(MBB, IP, Op0r, Op1r);
break;
case cLong:
if (OpNum < 2) { // seteq, setne
unsigned LoTmp = makeAnotherReg(Type::IntTy);
unsigned HiTmp = makeAnotherReg(Type::IntTy);
unsigned FinalTmp = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::XOR, 2, LoTmp).addReg(Op0r).addReg(Op1r);
BuildMI(*MBB, IP, PPC32::XOR, 2, HiTmp).addReg(Op0r+1).addReg(Op1r+1);
BuildMI(*MBB, IP, PPC32::ORo, 2, FinalTmp).addReg(LoTmp).addReg(HiTmp);
//BuildMI(*MBB, IP, PPC32::CMPLI, 2, PPC32::CR0).addReg(FinalTmp).addImm(0);
break; // Allow the sete or setne to be generated from flags set by OR
} else {
// FIXME: Not Yet Implemented
std::cerr << "EmitComparison (cLong) unimplemented: Opnum >= 2\n";
abort();
return OpNum;
}
}
return OpNum;
}
/// visitSetCondInst - emit code to calculate the condition via
/// EmitComparison(), and possibly store a 0 or 1 to a register as a result
///
void ISel::visitSetCondInst(SetCondInst &I) {
if (canFoldSetCCIntoBranchOrSelect(&I))
return;
unsigned Op0Reg = getReg(I.getOperand(0));
unsigned Op1Reg = getReg(I.getOperand(1));
unsigned DestReg = getReg(I);
unsigned OpNum = I.getOpcode();
const Type *Ty = I.getOperand (0)->getType();
EmitComparison(OpNum, I.getOperand(0), I.getOperand(1), BB, BB->end());
unsigned Opcode = getPPCOpcodeForSetCCNumber(OpNum);
MachineBasicBlock *thisMBB = BB;
const BasicBlock *LLVM_BB = BB->getBasicBlock();
// thisMBB:
// ...
// cmpTY cr0, r1, r2
// bCC copy1MBB
// b copy0MBB
// FIXME: we wouldn't need copy0MBB (we could fold it into thisMBB)
// if we could insert other, non-terminator instructions after the
// bCC. But MBB->getFirstTerminator() can't understand this.
MachineBasicBlock *copy1MBB = new MachineBasicBlock(LLVM_BB);
F->getBasicBlockList().push_back(copy1MBB);
BuildMI(BB, Opcode, 2).addReg(PPC32::CR0).addMBB(copy1MBB);
MachineBasicBlock *copy0MBB = new MachineBasicBlock(LLVM_BB);
F->getBasicBlockList().push_back(copy0MBB);
BuildMI(BB, PPC32::B, 1).addMBB(copy0MBB);
// Update machine-CFG edges
BB->addSuccessor(copy1MBB);
BB->addSuccessor(copy0MBB);
// copy0MBB:
// %FalseValue = li 0
// b sinkMBB
BB = copy0MBB;
unsigned FalseValue = makeAnotherReg(I.getType());
BuildMI(BB, PPC32::LI, 1, FalseValue).addZImm(0);
MachineBasicBlock *sinkMBB = new MachineBasicBlock(LLVM_BB);
F->getBasicBlockList().push_back(sinkMBB);
BuildMI(BB, PPC32::B, 1).addMBB(sinkMBB);
// Update machine-CFG edges
BB->addSuccessor(sinkMBB);
DEBUG(std::cerr << "thisMBB is at " << (void*)thisMBB << "\n");
DEBUG(std::cerr << "copy1MBB is at " << (void*)copy1MBB << "\n");
DEBUG(std::cerr << "copy0MBB is at " << (void*)copy0MBB << "\n");
DEBUG(std::cerr << "sinkMBB is at " << (void*)sinkMBB << "\n");
// copy1MBB:
// %TrueValue = li 1
// b sinkMBB
BB = copy1MBB;
unsigned TrueValue = makeAnotherReg (I.getType ());
BuildMI(BB, PPC32::LI, 1, TrueValue).addZImm(1);
BuildMI(BB, PPC32::B, 1).addMBB(sinkMBB);
// Update machine-CFG edges
BB->addSuccessor(sinkMBB);
// sinkMBB:
// %Result = phi [ %FalseValue, copy0MBB ], [ %TrueValue, copy1MBB ]
// ...
BB = sinkMBB;
BuildMI(BB, PPC32::PHI, 4, DestReg).addReg(FalseValue)
.addMBB(copy0MBB).addReg(TrueValue).addMBB(copy1MBB);
}
void ISel::visitSelectInst(SelectInst &SI) {
unsigned DestReg = getReg(SI);
MachineBasicBlock::iterator MII = BB->end();
emitSelectOperation(BB, MII, SI.getCondition(), SI.getTrueValue(),
SI.getFalseValue(), DestReg);
}
/// emitSelect - Common code shared between visitSelectInst and the constant
/// expression support.
/// FIXME: this is most likely broken in one or more ways. Namely, PowerPC has
/// no select instruction. FSEL only works for comparisons against zero.
void ISel::emitSelectOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Cond, Value *TrueVal, Value *FalseVal,
unsigned DestReg) {
unsigned SelectClass = getClassB(TrueVal->getType());
unsigned TrueReg = getReg(TrueVal, MBB, IP);
unsigned FalseReg = getReg(FalseVal, MBB, IP);
if (TrueReg == FalseReg) {
if (SelectClass == cFP) {
BuildMI(*MBB, IP, PPC32::FMR, 1, DestReg).addReg(TrueReg);
} else {
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(TrueReg).addReg(TrueReg);
}
if (SelectClass == cLong)
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg+1).addReg(TrueReg+1)
.addReg(TrueReg+1);
return;
}
unsigned CondReg = getReg(Cond, MBB, IP);
unsigned numZeros = makeAnotherReg(Type::IntTy);
unsigned falseHi = makeAnotherReg(Type::IntTy);
unsigned falseAll = makeAnotherReg(Type::IntTy);
unsigned trueAll = makeAnotherReg(Type::IntTy);
unsigned Temp1 = makeAnotherReg(Type::IntTy);
unsigned Temp2 = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::CNTLZW, 1, numZeros).addReg(CondReg);
BuildMI(*MBB, IP, PPC32::RLWINM, 4, falseHi).addReg(numZeros).addImm(26)
.addImm(0).addImm(0);
BuildMI(*MBB, IP, PPC32::SRAWI, 2, falseAll).addReg(falseHi).addImm(31);
BuildMI(*MBB, IP, PPC32::NOR, 2, trueAll).addReg(falseAll).addReg(falseAll);
BuildMI(*MBB, IP, PPC32::AND, 2, Temp1).addReg(TrueReg).addReg(trueAll);
BuildMI(*MBB, IP, PPC32::AND, 2, Temp2).addReg(FalseReg).addReg(falseAll);
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(Temp1).addReg(Temp2);
if (SelectClass == cLong) {
unsigned Temp3 = makeAnotherReg(Type::IntTy);
unsigned Temp4 = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::AND, 2, Temp3).addReg(TrueReg+1).addReg(trueAll);
BuildMI(*MBB, IP, PPC32::AND, 2, Temp4).addReg(FalseReg+1).addReg(falseAll);
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg+1).addReg(Temp3).addReg(Temp4);
}
return;
}
/// promote32 - Emit instructions to turn a narrow operand into a 32-bit-wide
/// operand, in the specified target register.
///
void ISel::promote32(unsigned targetReg, const ValueRecord &VR) {
bool isUnsigned = VR.Ty->isUnsigned() || VR.Ty == Type::BoolTy;
Value *Val = VR.Val;
const Type *Ty = VR.Ty;
if (Val) {
if (Constant *C = dyn_cast<Constant>(Val)) {
Val = ConstantExpr::getCast(C, Type::IntTy);
Ty = Type::IntTy;
}
// If this is a simple constant, just emit a load directly to avoid the copy
if (ConstantInt *CI = dyn_cast<ConstantInt>(Val)) {
int TheVal = CI->getRawValue() & 0xFFFFFFFF;
if (TheVal < 32768 && TheVal >= -32768) {
BuildMI(BB, PPC32::ADDI, 2, targetReg).addReg(PPC32::R0).addImm(TheVal);
} else {
unsigned TmpReg = makeAnotherReg(Type::IntTy);
BuildMI(BB, PPC32::ADDIS, 2, TmpReg).addReg(PPC32::R0)
.addImm(TheVal >> 16);
BuildMI(BB, PPC32::ORI, 2, targetReg).addReg(TmpReg)
.addImm(TheVal & 0xFFFF);
}
return;
}
}
// Make sure we have the register number for this value...
unsigned Reg = Val ? getReg(Val) : VR.Reg;
switch (getClassB(Ty)) {
case cByte:
// Extend value into target register (8->32)
if (isUnsigned)
BuildMI(BB, PPC32::RLWINM, 4, targetReg).addReg(Reg).addZImm(0)
.addZImm(24).addZImm(31);
else
BuildMI(BB, PPC32::EXTSB, 1, targetReg).addReg(Reg);
break;
case cShort:
// Extend value into target register (16->32)
if (isUnsigned)
BuildMI(BB, PPC32::RLWINM, 4, targetReg).addReg(Reg).addZImm(0)
.addZImm(16).addZImm(31);
else
BuildMI(BB, PPC32::EXTSH, 1, targetReg).addReg(Reg);
break;
case cInt:
// Move value into target register (32->32)
BuildMI(BB, PPC32::OR, 2, targetReg).addReg(Reg).addReg(Reg);
break;
default:
assert(0 && "Unpromotable operand class in promote32");
}
}
/// visitReturnInst - implemented with BLR
///
void ISel::visitReturnInst(ReturnInst &I) {
// Only do the processing if this is a non-void return
if (I.getNumOperands() > 0) {
Value *RetVal = I.getOperand(0);
switch (getClassB(RetVal->getType())) {
case cByte: // integral return values: extend or move into r3 and return
case cShort:
case cInt:
promote32(PPC32::R3, ValueRecord(RetVal));
break;
case cFP: { // Floats & Doubles: Return in f1
unsigned RetReg = getReg(RetVal);
BuildMI(BB, PPC32::FMR, 1, PPC32::F1).addReg(RetReg);
break;
}
case cLong: {
unsigned RetReg = getReg(RetVal);
BuildMI(BB, PPC32::OR, 2, PPC32::R3).addReg(RetReg).addReg(RetReg);
BuildMI(BB, PPC32::OR, 2, PPC32::R4).addReg(RetReg+1).addReg(RetReg+1);
break;
}
default:
visitInstruction(I);
}
}
BuildMI(BB, PPC32::BLR, 1).addImm(0);
}
// getBlockAfter - Return the basic block which occurs lexically after the
// specified one.
static inline BasicBlock *getBlockAfter(BasicBlock *BB) {
Function::iterator I = BB; ++I; // Get iterator to next block
return I != BB->getParent()->end() ? &*I : 0;
}
/// visitBranchInst - Handle conditional and unconditional branches here. Note
/// that since code layout is frozen at this point, that if we are trying to
/// jump to a block that is the immediate successor of the current block, we can
/// just make a fall-through (but we don't currently).
///
void ISel::visitBranchInst(BranchInst &BI) {
// Update machine-CFG edges
BB->addSuccessor (MBBMap[BI.getSuccessor(0)]);
if (BI.isConditional())
BB->addSuccessor (MBBMap[BI.getSuccessor(1)]);
BasicBlock *NextBB = getBlockAfter(BI.getParent()); // BB after current one
if (!BI.isConditional()) { // Unconditional branch?
if (BI.getSuccessor(0) != NextBB)
BuildMI(BB, PPC32::B, 1).addMBB(MBBMap[BI.getSuccessor(0)]);
return;
}
// See if we can fold the setcc into the branch itself...
SetCondInst *SCI = canFoldSetCCIntoBranchOrSelect(BI.getCondition());
if (SCI == 0) {
// Nope, cannot fold setcc into this branch. Emit a branch on a condition
// computed some other way...
unsigned condReg = getReg(BI.getCondition());
BuildMI(BB, PPC32::CMPLI, 3, PPC32::CR1).addImm(0).addReg(condReg)
.addImm(0);
if (BI.getSuccessor(1) == NextBB) {
if (BI.getSuccessor(0) != NextBB)
BuildMI(BB, PPC32::BNE, 2).addReg(PPC32::CR1)
.addMBB(MBBMap[BI.getSuccessor(0)]);
} else {
BuildMI(BB, PPC32::BNE, 2).addReg(PPC32::CR1)
.addMBB(MBBMap[BI.getSuccessor(1)]);
if (BI.getSuccessor(0) != NextBB)
BuildMI(BB, PPC32::B, 1).addMBB(MBBMap[BI.getSuccessor(0)]);
}
return;
}
unsigned OpNum = getSetCCNumber(SCI->getOpcode());
unsigned Opcode = getPPCOpcodeForSetCCNumber(SCI->getOpcode());
MachineBasicBlock::iterator MII = BB->end();
OpNum = EmitComparison(OpNum, SCI->getOperand(0), SCI->getOperand(1), BB,MII);
if (BI.getSuccessor(0) != NextBB) {
BuildMI(BB, Opcode, 2).addReg(PPC32::CR0)
.addMBB(MBBMap[BI.getSuccessor(0)]);
if (BI.getSuccessor(1) != NextBB)
BuildMI(BB, PPC32::B, 1).addMBB(MBBMap[BI.getSuccessor(1)]);
} else {
// Change to the inverse condition...
if (BI.getSuccessor(1) != NextBB) {
Opcode = invertPPCBranchOpcode(Opcode);
BuildMI(BB, Opcode, 2).addReg(PPC32::CR0)
.addMBB(MBBMap[BI.getSuccessor(1)]);
}
}
}
/// doCall - This emits an abstract call instruction, setting up the arguments
/// and the return value as appropriate. For the actual function call itself,
/// it inserts the specified CallMI instruction into the stream.
///
/// FIXME: See Documentation at the following URL for "correct" behavior
/// <http://developer.apple.com/documentation/DeveloperTools/Conceptual/MachORuntime/2rt_powerpc_abi/chapter_9_section_5.html>
void ISel::doCall(const ValueRecord &Ret, MachineInstr *CallMI,
const std::vector<ValueRecord> &Args, bool isVarArg) {
// Count how many bytes are to be pushed on the stack...
unsigned NumBytes = 0;
if (!Args.empty()) {
for (unsigned i = 0, e = Args.size(); i != e; ++i)
switch (getClassB(Args[i].Ty)) {
case cByte: case cShort: case cInt:
NumBytes += 4; break;
case cLong:
NumBytes += 8; break;
case cFP:
NumBytes += Args[i].Ty == Type::FloatTy ? 4 : 8;
break;
default: assert(0 && "Unknown class!");
}
// Adjust the stack pointer for the new arguments...
BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addImm(NumBytes);
// Arguments go on the stack in reverse order, as specified by the ABI.
unsigned ArgOffset = 0;
int GPR_remaining = 8, FPR_remaining = 13;
static const unsigned GPR[] = {
PPC32::R3, PPC32::R4, PPC32::R5, PPC32::R6,
PPC32::R7, PPC32::R8, PPC32::R9, PPC32::R10,
};
static const unsigned FPR[] = {
PPC32::F1, PPC32::F2, PPC32::F3, PPC32::F4, PPC32::F5, PPC32::F6,
PPC32::F7, PPC32::F8, PPC32::F9, PPC32::F10, PPC32::F11, PPC32::F12,
PPC32::F13
};
unsigned GPR_idx = 0, FPR_idx = 0;
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
unsigned ArgReg;
switch (getClassB(Args[i].Ty)) {
case cByte:
case cShort:
// Promote arg to 32 bits wide into a temporary register...
ArgReg = makeAnotherReg(Type::UIntTy);
promote32(ArgReg, Args[i]);
// Reg or stack?
if (GPR_remaining > 0) {
BuildMI(BB, PPC32::OR, 2, GPR[GPR_idx]).addReg(ArgReg)
.addReg(ArgReg);
} else {
BuildMI(BB, PPC32::STW, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
}
break;
case cInt:
ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
// Reg or stack?
if (GPR_remaining > 0) {
BuildMI(BB, PPC32::OR, 2, GPR[GPR_idx]).addReg(ArgReg)
.addReg(ArgReg);
} else {
BuildMI(BB, PPC32::STW, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
}
break;
case cLong:
ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
// Reg or stack?
if (GPR_remaining > 1) {
BuildMI(BB, PPC32::OR, 2, GPR[GPR_idx]).addReg(ArgReg)
.addReg(ArgReg);
BuildMI(BB, PPC32::OR, 2, GPR[GPR_idx + 1]).addReg(ArgReg+1)
.addReg(ArgReg+1);
} else {
BuildMI(BB, PPC32::STW, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
BuildMI(BB, PPC32::STW, 3).addReg(ArgReg+1).addImm(ArgOffset+4)
.addReg(PPC32::R1);
}
ArgOffset += 4; // 8 byte entry, not 4.
GPR_remaining -= 1; // uses up 2 GPRs
GPR_idx += 1;
break;
case cFP:
ArgReg = Args[i].Val ? getReg(Args[i].Val) : Args[i].Reg;
if (Args[i].Ty == Type::FloatTy) {
// Reg or stack?
if (FPR_remaining > 0) {
BuildMI(BB, PPC32::FMR, 1, FPR[FPR_idx]).addReg(ArgReg);
FPR_remaining--;
FPR_idx++;
} else {
BuildMI(BB, PPC32::STFS, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
}
assert(!isVarArg && "Cannot pass floats to vararg functions!");
} else {
assert(Args[i].Ty == Type::DoubleTy && "Unknown FP type!");
// Reg or stack?
if (FPR_remaining > 0) {
BuildMI(BB, PPC32::FMR, 1, FPR[FPR_idx]).addReg(ArgReg);
FPR_remaining--;
FPR_idx++;
// For vararg functions, must pass doubles via int regs as well
if (isVarArg) {
BuildMI(BB, PPC32::STFD, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
if (GPR_remaining > 1) {
BuildMI(BB, PPC32::LWZ, 2, GPR[GPR_idx]).addImm(ArgOffset)
.addReg(PPC32::R1);
BuildMI(BB, PPC32::LWZ, 2, GPR[GPR_idx + 1])
.addImm(ArgOffset+4).addReg(PPC32::R1);
}
}
} else {
BuildMI(BB, PPC32::STFD, 3).addReg(ArgReg).addImm(ArgOffset)
.addReg(PPC32::R1);
}
ArgOffset += 4; // 8 byte entry, not 4.
GPR_remaining--; // uses up 2 GPRs
GPR_idx++;
}
break;
default: assert(0 && "Unknown class!");
}
ArgOffset += 4;
GPR_remaining--;
GPR_idx++;
}
} else {
BuildMI(BB, PPC32::ADJCALLSTACKDOWN, 1).addImm(0);
}
BB->push_back(CallMI);
BuildMI(BB, PPC32::ADJCALLSTACKUP, 1).addImm(NumBytes);
// If there is a return value, scavenge the result from the location the call
// leaves it in...
//
if (Ret.Ty != Type::VoidTy) {
unsigned DestClass = getClassB(Ret.Ty);
switch (DestClass) {
case cByte:
case cShort:
case cInt:
// Integral results are in r3
BuildMI(BB, PPC32::OR, 2, Ret.Reg).addReg(PPC32::R3).addReg(PPC32::R3);
break;
case cFP: // Floating-point return values live in f1
BuildMI(BB, PPC32::FMR, 1, Ret.Reg).addReg(PPC32::F1);
break;
case cLong: // Long values are in r3:r4
BuildMI(BB, PPC32::OR, 2, Ret.Reg).addReg(PPC32::R3).addReg(PPC32::R3);
BuildMI(BB, PPC32::OR, 2, Ret.Reg+1).addReg(PPC32::R4).addReg(PPC32::R4);
break;
default: assert(0 && "Unknown class!");
}
}
}
/// visitCallInst - Push args on stack and do a procedure call instruction.
void ISel::visitCallInst(CallInst &CI) {
MachineInstr *TheCall;
Function *F = CI.getCalledFunction();
if (F) {
// Is it an intrinsic function call?
if (Intrinsic::ID ID = (Intrinsic::ID)F->getIntrinsicID()) {
visitIntrinsicCall(ID, CI); // Special intrinsics are not handled here
return;
}
// Emit a CALL instruction with PC-relative displacement.
TheCall = BuildMI(PPC32::CALLpcrel, 1).addGlobalAddress(F, true);
} else { // Emit an indirect call through the CTR
unsigned Reg = getReg(CI.getCalledValue());
BuildMI(PPC32::MTSPR, 2).addZImm(9).addReg(Reg);
TheCall = BuildMI(PPC32::CALLindirect, 1).addZImm(20).addZImm(0);
}
std::vector<ValueRecord> Args;
for (unsigned i = 1, e = CI.getNumOperands(); i != e; ++i)
Args.push_back(ValueRecord(CI.getOperand(i)));
unsigned DestReg = CI.getType() != Type::VoidTy ? getReg(CI) : 0;
bool isVarArg = F ? F->getFunctionType()->isVarArg() : true;
doCall(ValueRecord(DestReg, CI.getType()), TheCall, Args, isVarArg);
}
/// dyncastIsNan - Return the operand of an isnan operation if this is an isnan.
///
static Value *dyncastIsNan(Value *V) {
if (CallInst *CI = dyn_cast<CallInst>(V))
if (Function *F = CI->getCalledFunction())
if (F->getIntrinsicID() == Intrinsic::isunordered)
return CI->getOperand(1);
return 0;
}
/// isOnlyUsedByUnorderedComparisons - Return true if this value is only used by
/// or's whos operands are all calls to the isnan predicate.
static bool isOnlyUsedByUnorderedComparisons(Value *V) {
assert(dyncastIsNan(V) && "The value isn't an isnan call!");
// Check all uses, which will be or's of isnans if this predicate is true.
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
Instruction *I = cast<Instruction>(*UI);
if (I->getOpcode() != Instruction::Or) return false;
if (I->getOperand(0) != V && !dyncastIsNan(I->getOperand(0))) return false;
if (I->getOperand(1) != V && !dyncastIsNan(I->getOperand(1))) return false;
}
return true;
}
/// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
/// function, lowering any calls to unknown intrinsic functions into the
/// equivalent LLVM code.
///
void ISel::LowerUnknownIntrinsicFunctionCalls(Function &F) {
for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; )
if (CallInst *CI = dyn_cast<CallInst>(I++))
if (Function *F = CI->getCalledFunction())
switch (F->getIntrinsicID()) {
case Intrinsic::not_intrinsic:
case Intrinsic::vastart:
case Intrinsic::vacopy:
case Intrinsic::vaend:
case Intrinsic::returnaddress:
case Intrinsic::frameaddress:
// FIXME: should lower this ourselves
// case Intrinsic::isunordered:
// We directly implement these intrinsics
break;
case Intrinsic::readio: {
// On PPC, memory operations are in-order. Lower this intrinsic
// into a volatile load.
Instruction *Before = CI->getPrev();
LoadInst * LI = new LoadInst(CI->getOperand(1), "", true, CI);
CI->replaceAllUsesWith(LI);
BB->getInstList().erase(CI);
break;
}
case Intrinsic::writeio: {
// On PPC, memory operations are in-order. Lower this intrinsic
// into a volatile store.
Instruction *Before = CI->getPrev();
StoreInst *LI = new StoreInst(CI->getOperand(1),
CI->getOperand(2), true, CI);
CI->replaceAllUsesWith(LI);
BB->getInstList().erase(CI);
break;
}
default:
// All other intrinsic calls we must lower.
Instruction *Before = CI->getPrev();
TM.getIntrinsicLowering().LowerIntrinsicCall(CI);
if (Before) { // Move iterator to instruction after call
I = Before; ++I;
} else {
I = BB->begin();
}
}
}
void ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) {
unsigned TmpReg1, TmpReg2, TmpReg3;
switch (ID) {
case Intrinsic::vastart:
// Get the address of the first vararg value...
TmpReg1 = getReg(CI);
addFrameReference(BuildMI(BB, PPC32::ADDI, 2, TmpReg1), VarArgsFrameIndex);
return;
case Intrinsic::vacopy:
TmpReg1 = getReg(CI);
TmpReg2 = getReg(CI.getOperand(1));
BuildMI(BB, PPC32::OR, 2, TmpReg1).addReg(TmpReg2).addReg(TmpReg2);
return;
case Intrinsic::vaend: return;
case Intrinsic::returnaddress:
case Intrinsic::frameaddress:
TmpReg1 = getReg(CI);
if (cast<Constant>(CI.getOperand(1))->isNullValue()) {
if (ID == Intrinsic::returnaddress) {
// Just load the return address
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, TmpReg1),
ReturnAddressIndex);
} else {
addFrameReference(BuildMI(BB, PPC32::ADDI, 2, TmpReg1),
ReturnAddressIndex, -4, false);
}
} else {
// Values other than zero are not implemented yet.
BuildMI(BB, PPC32::ADDI, 2, TmpReg1).addReg(PPC32::R0).addImm(0);
}
return;
#if 0
// This may be useful for supporting isunordered
case Intrinsic::isnan:
// If this is only used by 'isunordered' style comparisons, don't emit it.
if (isOnlyUsedByUnorderedComparisons(&CI)) return;
TmpReg1 = getReg(CI.getOperand(1));
emitUCOM(BB, BB->end(), TmpReg1, TmpReg1);
TmpReg2 = makeAnotherReg(Type::IntTy);
BuildMI(BB, PPC32::MFCR, TmpReg2);
TmpReg3 = getReg(CI);
BuildMI(BB, PPC32::RLWINM, 4, TmpReg3).addReg(TmpReg2).addImm(4).addImm(31).addImm(31);
return;
#endif
default: assert(0 && "Error: unknown intrinsics should have been lowered!");
}
}
/// visitSimpleBinary - Implement simple binary operators for integral types...
/// OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for Or, 4 for
/// Xor.
///
void ISel::visitSimpleBinary(BinaryOperator &B, unsigned OperatorClass) {
unsigned DestReg = getReg(B);
MachineBasicBlock::iterator MI = BB->end();
Value *Op0 = B.getOperand(0), *Op1 = B.getOperand(1);
unsigned Class = getClassB(B.getType());
emitSimpleBinaryOperation(BB, MI, Op0, Op1, OperatorClass, DestReg);
}
/// emitBinaryFPOperation - This method handles emission of floating point
/// Add (0), Sub (1), Mul (2), and Div (3) operations.
void ISel::emitBinaryFPOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1,
unsigned OperatorClass, unsigned DestReg) {
// Special case: op Reg, <const fp>
if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
// Create a constant pool entry for this constant.
MachineConstantPool *CP = F->getConstantPool();
unsigned CPI = CP->getConstantPoolIndex(Op1C);
const Type *Ty = Op1->getType();
static const unsigned OpcodeTab[][4] = {
{ PPC32::FADDS, PPC32::FSUBS, PPC32::FMULS, PPC32::FDIVS }, // Float
{ PPC32::FADD, PPC32::FSUB, PPC32::FMUL, PPC32::FDIV }, // Double
};
assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
unsigned TempReg = makeAnotherReg(Ty);
unsigned LoadOpcode = (Ty == Type::FloatTy) ? PPC32::LFS : PPC32::LFD;
addConstantPoolReference(BuildMI(*BB, IP, LoadOpcode, 2, TempReg), CPI);
unsigned Opcode = OpcodeTab[Ty != Type::FloatTy][OperatorClass];
unsigned Op0r = getReg(Op0, BB, IP);
BuildMI(*BB, IP, Opcode, DestReg).addReg(Op0r).addReg(TempReg);
return;
}
// Special case: R1 = op <const fp>, R2
if (ConstantFP *CFP = dyn_cast<ConstantFP>(Op0))
if (CFP->isExactlyValue(-0.0) && OperatorClass == 1) {
// -0.0 - X === -X
unsigned op1Reg = getReg(Op1, BB, IP);
BuildMI(*BB, IP, PPC32::FNEG, 1, DestReg).addReg(op1Reg);
return;
} else {
// R1 = op CST, R2 --> R1 = opr R2, CST
// Create a constant pool entry for this constant.
MachineConstantPool *CP = F->getConstantPool();
unsigned CPI = CP->getConstantPoolIndex(CFP);
const Type *Ty = CFP->getType();
static const unsigned OpcodeTab[][4] = {
{ PPC32::FADDS, PPC32::FSUBS, PPC32::FMULS, PPC32::FDIVS }, // Float
{ PPC32::FADD, PPC32::FSUB, PPC32::FMUL, PPC32::FDIV }, // Double
};
assert(Ty == Type::FloatTy || Ty == Type::DoubleTy && "Unknown FP type!");
unsigned TempReg = makeAnotherReg(Ty);
unsigned LoadOpcode = (Ty == Type::FloatTy) ? PPC32::LFS : PPC32::LFD;
addConstantPoolReference(BuildMI(*BB, IP, LoadOpcode, 2, TempReg), CPI);
unsigned Opcode = OpcodeTab[Ty != Type::FloatTy][OperatorClass];
unsigned Op1r = getReg(Op1, BB, IP);
BuildMI(*BB, IP, Opcode, DestReg).addReg(TempReg).addReg(Op1r);
return;
}
// General case.
static const unsigned OpcodeTab[] = {
PPC32::FADD, PPC32::FSUB, PPC32::FMUL, PPC32::FDIV
};
unsigned Opcode = OpcodeTab[OperatorClass];
unsigned Op0r = getReg(Op0, BB, IP);
unsigned Op1r = getReg(Op1, BB, IP);
BuildMI(*BB, IP, Opcode, 2, DestReg).addReg(Op0r).addReg(Op1r);
}
/// emitSimpleBinaryOperation - Implement simple binary operators for integral
/// types... OperatorClass is one of: 0 for Add, 1 for Sub, 2 for And, 3 for
/// Or, 4 for Xor.
///
/// emitSimpleBinaryOperation - Common code shared between visitSimpleBinary
/// and constant expression support.
///
void ISel::emitSimpleBinaryOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1,
unsigned OperatorClass, unsigned DestReg) {
unsigned Class = getClassB(Op0->getType());
// Arithmetic and Bitwise operators
static const unsigned OpcodeTab[] = {
PPC32::ADD, PPC32::SUB, PPC32::AND, PPC32::OR, PPC32::XOR
};
// Otherwise, code generate the full operation with a constant.
static const unsigned BottomTab[] = {
PPC32::ADDC, PPC32::SUBC, PPC32::AND, PPC32::OR, PPC32::XOR
};
static const unsigned TopTab[] = {
PPC32::ADDE, PPC32::SUBFE, PPC32::AND, PPC32::OR, PPC32::XOR
};
if (Class == cFP) {
assert(OperatorClass < 2 && "No logical ops for FP!");
emitBinaryFPOperation(MBB, IP, Op0, Op1, OperatorClass, DestReg);
return;
}
if (Op0->getType() == Type::BoolTy) {
if (OperatorClass == 3)
// If this is an or of two isnan's, emit an FP comparison directly instead
// of or'ing two isnan's together.
if (Value *LHS = dyncastIsNan(Op0))
if (Value *RHS = dyncastIsNan(Op1)) {
unsigned Op0Reg = getReg(RHS, MBB, IP), Op1Reg = getReg(LHS, MBB, IP);
unsigned TmpReg = makeAnotherReg(Type::IntTy);
emitUCOM(MBB, IP, Op0Reg, Op1Reg);
BuildMI(*MBB, IP, PPC32::MFCR, TmpReg);
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(TmpReg).addImm(4)
.addImm(31).addImm(31);
return;
}
}
// sub 0, X -> neg X
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op0))
if (OperatorClass == 1 && CI->isNullValue()) {
unsigned op1Reg = getReg(Op1, MBB, IP);
BuildMI(*MBB, IP, PPC32::NEG, 1, DestReg).addReg(op1Reg);
if (Class == cLong) {
unsigned zeroes = makeAnotherReg(Type::IntTy);
unsigned overflow = makeAnotherReg(Type::IntTy);
unsigned T = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::CNTLZW, 1, zeroes).addReg(op1Reg);
BuildMI(*MBB, IP, PPC32::RLWINM, 4, overflow).addReg(zeroes).addImm(27)
.addImm(5).addImm(31);
BuildMI(*MBB, IP, PPC32::ADD, 2, T).addReg(op1Reg+1).addReg(overflow);
BuildMI(*MBB, IP, PPC32::NEG, 1, DestReg+1).addReg(T);
}
return;
}
// Special case: op Reg, <const int>
if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
unsigned Op0r = getReg(Op0, MBB, IP);
// xor X, -1 -> not X
if (OperatorClass == 4 && Op1C->isAllOnesValue()) {
BuildMI(*MBB, IP, PPC32::NOR, 2, DestReg).addReg(Op0r).addReg(Op0r);
if (Class == cLong) // Invert the top part too
BuildMI(*MBB, IP, PPC32::NOR, 2, DestReg+1).addReg(Op0r+1)
.addReg(Op0r+1);
return;
}
unsigned Opcode = OpcodeTab[OperatorClass];
unsigned Op1r = getReg(Op1, MBB, IP);
if (Class != cLong) {
BuildMI(*MBB, IP, Opcode, 2, DestReg).addReg(Op0r).addReg(Op1r);
return;
}
// If the constant is zero in the low 32-bits, just copy the low part
// across and apply the normal 32-bit operation to the high parts. There
// will be no carry or borrow into the top.
if (cast<ConstantInt>(Op1C)->getRawValue() == 0) {
if (OperatorClass != 2) // All but and...
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(Op0r).addReg(Op0r);
else
BuildMI(*MBB, IP, PPC32::ADDI, 2, DestReg).addReg(PPC32::R0).addImm(0);
BuildMI(*MBB, IP, Opcode, 2, DestReg+1).addReg(Op0r+1).addReg(Op1r+1);
return;
}
// If this is a long value and the high or low bits have a special
// property, emit some special cases.
unsigned Op1h = cast<ConstantInt>(Op1C)->getRawValue() >> 32LL;
// If this is a logical operation and the top 32-bits are zero, just
// operate on the lower 32.
if (Op1h == 0 && OperatorClass > 1) {
BuildMI(*MBB, IP, Opcode, 2, DestReg).addReg(Op0r).addReg(Op1r);
if (OperatorClass != 2) // All but and
BuildMI(*MBB, IP, PPC32::OR, 2,DestReg+1).addReg(Op0r+1).addReg(Op0r+1);
else
BuildMI(*MBB, IP, PPC32::ADDI, 2,DestReg+1).addReg(PPC32::R0).addImm(0);
return;
}
// TODO: We could handle lots of other special cases here, such as AND'ing
// with 0xFFFFFFFF00000000 -> noop, etc.
BuildMI(*MBB, IP, BottomTab[OperatorClass], 2, DestReg).addReg(Op0r)
.addImm(Op1r);
BuildMI(*MBB, IP, TopTab[OperatorClass], 2, DestReg+1).addReg(Op0r+1)
.addImm(Op1r+1);
return;
}
unsigned Op0r = getReg(Op0, MBB, IP);
unsigned Op1r = getReg(Op1, MBB, IP);
if (Class != cLong) {
unsigned Opcode = OpcodeTab[OperatorClass];
BuildMI(*MBB, IP, Opcode, 2, DestReg).addReg(Op0r).addReg(Op1r);
} else {
BuildMI(*MBB, IP, BottomTab[OperatorClass], 2, DestReg).addReg(Op0r)
.addImm(Op1r);
BuildMI(*MBB, IP, TopTab[OperatorClass], 2, DestReg+1).addReg(Op0r+1)
.addImm(Op1r+1);
}
return;
}
/// doMultiply - Emit appropriate instructions to multiply together the
/// registers op0Reg and op1Reg, and put the result in DestReg. The type of the
/// result should be given as DestTy.
///
void ISel::doMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator MBBI,
unsigned DestReg, const Type *DestTy,
unsigned op0Reg, unsigned op1Reg) {
unsigned Class = getClass(DestTy);
switch (Class) {
case cLong:
BuildMI(*MBB, MBBI, PPC32::MULHW, 2, DestReg+1).addReg(op0Reg+1)
.addReg(op1Reg+1);
case cInt:
case cShort:
case cByte:
BuildMI(*MBB, MBBI, PPC32::MULLW, 2, DestReg).addReg(op0Reg).addReg(op1Reg);
return;
default:
assert(0 && "doMultiply cannot operate on unknown type!");
}
}
// ExactLog2 - This function solves for (Val == 1 << (N-1)) and returns N. It
// returns zero when the input is not exactly a power of two.
static unsigned ExactLog2(unsigned Val) {
if (Val == 0 || (Val & (Val-1))) return 0;
unsigned Count = 0;
while (Val != 1) {
Val >>= 1;
++Count;
}
return Count+1;
}
/// doMultiplyConst - This function is specialized to efficiently codegen an 8,
/// 16, or 32-bit integer multiply by a constant.
///
void ISel::doMultiplyConst(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
unsigned DestReg, const Type *DestTy,
unsigned op0Reg, unsigned ConstRHS) {
unsigned Class = getClass(DestTy);
// Handle special cases here.
switch (ConstRHS) {
case 0:
BuildMI(*MBB, IP, PPC32::ADDI, 2, DestReg).addReg(PPC32::R0).addImm(0);
return;
case 1:
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(op0Reg).addReg(op0Reg);
return;
case 2:
BuildMI(*MBB, IP, PPC32::ADD, 2,DestReg).addReg(op0Reg).addReg(op0Reg);
return;
}
// If the element size is exactly a power of 2, use a shift to get it.
if (unsigned Shift = ExactLog2(ConstRHS)) {
switch (Class) {
default: assert(0 && "Unknown class for this function!");
case cByte:
case cShort:
case cInt:
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(op0Reg)
.addImm(Shift-1).addImm(0).addImm(31-Shift-1);
return;
}
}
// Most general case, emit a normal multiply...
unsigned TmpReg1 = makeAnotherReg(Type::IntTy);
unsigned TmpReg2 = makeAnotherReg(Type::IntTy);
BuildMI(*MBB, IP, PPC32::ADDIS, 2, TmpReg1).addReg(PPC32::R0)
.addImm(ConstRHS >> 16);
BuildMI(*MBB, IP, PPC32::ORI, 2, TmpReg2).addReg(TmpReg1).addImm(ConstRHS);
// Emit a MUL to multiply the register holding the index by
// elementSize, putting the result in OffsetReg.
doMultiply(MBB, IP, DestReg, DestTy, op0Reg, TmpReg2);
}
void ISel::visitMul(BinaryOperator &I) {
unsigned ResultReg = getReg(I);
Value *Op0 = I.getOperand(0);
Value *Op1 = I.getOperand(1);
MachineBasicBlock::iterator IP = BB->end();
emitMultiply(BB, IP, Op0, Op1, ResultReg);
}
void ISel::emitMultiply(MachineBasicBlock *MBB, MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1, unsigned DestReg) {
MachineBasicBlock &BB = *MBB;
TypeClass Class = getClass(Op0->getType());
// Simple scalar multiply?
unsigned Op0Reg = getReg(Op0, &BB, IP);
switch (Class) {
case cByte:
case cShort:
case cInt:
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
unsigned Val = (unsigned)CI->getRawValue(); // Isn't a 64-bit constant
doMultiplyConst(&BB, IP, DestReg, Op0->getType(), Op0Reg, Val);
} else {
unsigned Op1Reg = getReg(Op1, &BB, IP);
doMultiply(&BB, IP, DestReg, Op1->getType(), Op0Reg, Op1Reg);
}
return;
case cFP:
emitBinaryFPOperation(MBB, IP, Op0, Op1, 2, DestReg);
return;
case cLong:
break;
}
// Long value. We have to do things the hard way...
if (ConstantInt *CI = dyn_cast<ConstantInt>(Op1)) {
unsigned CLow = CI->getRawValue();
unsigned CHi = CI->getRawValue() >> 32;
if (CLow == 0) {
// If the low part of the constant is all zeros, things are simple.
BuildMI(BB, IP, PPC32::ADDI, 2, DestReg).addReg(PPC32::R0).addImm(0);
doMultiplyConst(&BB, IP, DestReg+1, Type::UIntTy, Op0Reg, CHi);
return;
}
// Multiply the two low parts
unsigned OverflowReg = 0;
if (CLow == 1) {
BuildMI(BB, IP, PPC32::OR, 2, DestReg).addReg(Op0Reg).addReg(Op0Reg);
} else {
unsigned TmpRegL = makeAnotherReg(Type::UIntTy);
unsigned Op1RegL = makeAnotherReg(Type::UIntTy);
OverflowReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, IP, PPC32::ADDIS, 2, TmpRegL).addReg(PPC32::R0)
.addImm(CLow >> 16);
BuildMI(BB, IP, PPC32::ORI, 2, Op1RegL).addReg(TmpRegL).addImm(CLow);
BuildMI(BB, IP, PPC32::MULLW, 2, DestReg).addReg(Op0Reg).addReg(Op1RegL);
BuildMI(BB, IP, PPC32::MULHW, 2, OverflowReg).addReg(Op0Reg)
.addReg(Op1RegL);
}
unsigned AHBLReg = makeAnotherReg(Type::UIntTy);
doMultiplyConst(&BB, IP, AHBLReg, Type::UIntTy, Op0Reg+1, CLow);
unsigned AHBLplusOverflowReg;
if (OverflowReg) {
AHBLplusOverflowReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, IP, PPC32::ADD, 2,
AHBLplusOverflowReg).addReg(AHBLReg).addReg(OverflowReg);
} else {
AHBLplusOverflowReg = AHBLReg;
}
if (CHi == 0) {
BuildMI(BB, IP, PPC32::OR, 2, DestReg+1).addReg(AHBLplusOverflowReg)
.addReg(AHBLplusOverflowReg);
} else {
unsigned ALBHReg = makeAnotherReg(Type::UIntTy);
doMultiplyConst(&BB, IP, ALBHReg, Type::UIntTy, Op0Reg, CHi);
BuildMI(BB, IP, PPC32::ADD, 2,
DestReg+1).addReg(AHBLplusOverflowReg).addReg(ALBHReg);
}
return;
}
// General 64x64 multiply
unsigned Op1Reg = getReg(Op1, &BB, IP);
// Multiply the two low parts...
BuildMI(BB, IP, PPC32::MULLW, 2, DestReg).addReg(Op0Reg).addReg(Op1Reg);
unsigned OverflowReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, IP, PPC32::MULHW, 2, OverflowReg).addReg(Op0Reg).addReg(Op1Reg);
unsigned AHBLReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, IP, PPC32::MULLW, 2, AHBLReg).addReg(Op0Reg+1).addReg(Op1Reg);
unsigned AHBLplusOverflowReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, IP, PPC32::ADD, 2, AHBLplusOverflowReg).addReg(AHBLReg)
.addReg(OverflowReg);
unsigned ALBHReg = makeAnotherReg(Type::UIntTy); // AL*BH
BuildMI(BB, IP, PPC32::MULLW, 2, ALBHReg).addReg(Op0Reg).addReg(Op1Reg+1);
BuildMI(BB, IP, PPC32::ADD, 2,
DestReg+1).addReg(AHBLplusOverflowReg).addReg(ALBHReg);
}
/// visitDivRem - Handle division and remainder instructions... these
/// instruction both require the same instructions to be generated, they just
/// select the result from a different register. Note that both of these
/// instructions work differently for signed and unsigned operands.
///
void ISel::visitDivRem(BinaryOperator &I) {
unsigned ResultReg = getReg(I);
Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
MachineBasicBlock::iterator IP = BB->end();
emitDivRemOperation(BB, IP, Op0, Op1, I.getOpcode() == Instruction::Div,
ResultReg);
}
void ISel::emitDivRemOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Op0, Value *Op1, bool isDiv,
unsigned ResultReg) {
const Type *Ty = Op0->getType();
unsigned Class = getClass(Ty);
switch (Class) {
case cFP: // Floating point divide
if (isDiv) {
emitBinaryFPOperation(BB, IP, Op0, Op1, 3, ResultReg);
return;
} else { // Floating point remainder...
unsigned Op0Reg = getReg(Op0, BB, IP);
unsigned Op1Reg = getReg(Op1, BB, IP);
Function *FmodFn = M->getNamedFunction("fmod");
assert(FmodFn && "fmod() does not exist in the module");
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addGlobalAddress(FmodFn, true);
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(Op0Reg, Type::DoubleTy));
Args.push_back(ValueRecord(Op1Reg, Type::DoubleTy));
doCall(ValueRecord(ResultReg, Type::DoubleTy), TheCall, Args, false);
}
return;
case cLong: {
// FIXME: Make sure the module has external function
static const char *FnName[] =
{ "__moddi3", "__divdi3", "__umoddi3", "__udivdi3" };
unsigned Op0Reg = getReg(Op0, BB, IP);
unsigned Op1Reg = getReg(Op1, BB, IP);
unsigned NameIdx = Ty->isUnsigned()*2 + isDiv;
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addExternalSymbol(FnName[NameIdx], true);
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(Op0Reg, Type::LongTy));
Args.push_back(ValueRecord(Op1Reg, Type::LongTy));
doCall(ValueRecord(ResultReg, Type::LongTy), TheCall, Args, false);
return;
}
case cByte: case cShort: case cInt:
break; // Small integrals, handled below...
default: assert(0 && "Unknown class!");
}
// Special case signed division by power of 2.
if (isDiv)
if (ConstantSInt *CI = dyn_cast<ConstantSInt>(Op1)) {
assert(Class != cLong && "This doesn't handle 64-bit divides!");
int V = CI->getValue();
if (V == 1) { // X /s 1 => X
unsigned Op0Reg = getReg(Op0, BB, IP);
BuildMI(*BB, IP, PPC32::OR, 2, ResultReg).addReg(Op0Reg).addReg(Op0Reg);
return;
}
if (V == -1) { // X /s -1 => -X
unsigned Op0Reg = getReg(Op0, BB, IP);
BuildMI(*BB, IP, PPC32::NEG, 1, ResultReg).addReg(Op0Reg);
return;
}
bool isNeg = false;
if (V < 0) { // Not a positive power of 2?
V = -V;
isNeg = true; // Maybe it's a negative power of 2.
}
if (unsigned Log = ExactLog2(V)) {
--Log;
unsigned Op0Reg = getReg(Op0, BB, IP);
unsigned TmpReg = makeAnotherReg(Op0->getType());
if (Log != 1)
BuildMI(*BB, IP, PPC32::SRAWI,2, TmpReg).addReg(Op0Reg).addImm(Log-1);
else
BuildMI(*BB, IP, PPC32::OR, 2, TmpReg).addReg(Op0Reg).addReg(Op0Reg);
unsigned TmpReg2 = makeAnotherReg(Op0->getType());
BuildMI(*BB, IP, PPC32::RLWINM, 4, TmpReg2).addReg(TmpReg).addImm(Log)
.addImm(32-Log).addImm(31);
unsigned TmpReg3 = makeAnotherReg(Op0->getType());
BuildMI(*BB, IP, PPC32::ADD, 2, TmpReg3).addReg(Op0Reg).addReg(TmpReg2);
unsigned TmpReg4 = isNeg ? makeAnotherReg(Op0->getType()) : ResultReg;
BuildMI(*BB, IP, PPC32::SRAWI, 2, TmpReg4).addReg(Op0Reg).addImm(Log);
if (isNeg)
BuildMI(*BB, IP, PPC32::NEG, 1, ResultReg).addReg(TmpReg4);
return;
}
}
unsigned Op0Reg = getReg(Op0, BB, IP);
unsigned Op1Reg = getReg(Op1, BB, IP);
if (isDiv) {
if (Ty->isSigned()) {
BuildMI(*BB, IP, PPC32::DIVW, 2, ResultReg).addReg(Op0Reg).addReg(Op1Reg);
} else {
BuildMI(*BB, IP,PPC32::DIVWU, 2, ResultReg).addReg(Op0Reg).addReg(Op1Reg);
}
} else { // Remainder
unsigned TmpReg1 = makeAnotherReg(Op0->getType());
unsigned TmpReg2 = makeAnotherReg(Op0->getType());
if (Ty->isSigned()) {
BuildMI(*BB, IP, PPC32::DIVW, 2, TmpReg1).addReg(Op0Reg).addReg(Op1Reg);
} else {
BuildMI(*BB, IP, PPC32::DIVWU, 2, TmpReg1).addReg(Op0Reg).addReg(Op1Reg);
}
BuildMI(*BB, IP, PPC32::MULLW, 2, TmpReg2).addReg(TmpReg1).addReg(Op1Reg);
BuildMI(*BB, IP, PPC32::SUBF, 2, ResultReg).addReg(TmpReg2).addReg(Op0Reg);
}
}
/// Shift instructions: 'shl', 'sar', 'shr' - Some special cases here
/// for constant immediate shift values, and for constant immediate
/// shift values equal to 1. Even the general case is sort of special,
/// because the shift amount has to be in CL, not just any old register.
///
void ISel::visitShiftInst(ShiftInst &I) {
MachineBasicBlock::iterator IP = BB->end ();
emitShiftOperation(BB, IP, I.getOperand (0), I.getOperand (1),
I.getOpcode () == Instruction::Shl, I.getType (),
getReg (I));
}
/// emitShiftOperation - Common code shared between visitShiftInst and
/// constant expression support.
///
void ISel::emitShiftOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Op, Value *ShiftAmount, bool isLeftShift,
const Type *ResultTy, unsigned DestReg) {
unsigned SrcReg = getReg (Op, MBB, IP);
bool isSigned = ResultTy->isSigned ();
unsigned Class = getClass (ResultTy);
// Longs, as usual, are handled specially...
if (Class == cLong) {
// If we have a constant shift, we can generate much more efficient code
// than otherwise...
//
if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(ShiftAmount)) {
unsigned Amount = CUI->getValue();
if (Amount < 32) {
if (isLeftShift) {
// FIXME: RLWIMI is a use-and-def of DestReg+1, but that violates SSA
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg+1).addReg(SrcReg+1)
.addImm(Amount).addImm(0).addImm(31-Amount);
BuildMI(*MBB, IP, PPC32::RLWIMI, 5).addReg(DestReg+1).addReg(SrcReg)
.addImm(Amount).addImm(32-Amount).addImm(31);
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg)
.addImm(Amount).addImm(0).addImm(31-Amount);
} else {
// FIXME: RLWIMI is a use-and-def of DestReg, but that violates SSA
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg)
.addImm(32-Amount).addImm(Amount).addImm(31);
BuildMI(*MBB, IP, PPC32::RLWIMI, 5).addReg(DestReg).addReg(SrcReg+1)
.addImm(32-Amount).addImm(0).addImm(Amount-1);
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg+1).addReg(SrcReg+1)
.addImm(32-Amount).addImm(Amount).addImm(31);
}
} else { // Shifting more than 32 bits
Amount -= 32;
if (isLeftShift) {
if (Amount != 0) {
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg+1).addReg(SrcReg)
.addImm(Amount).addImm(0).addImm(31-Amount);
} else {
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg+1).addReg(SrcReg)
.addReg(SrcReg);
}
BuildMI(*MBB, IP, PPC32::ADDI, 2,DestReg).addReg(PPC32::R0).addImm(0);
} else {
if (Amount != 0) {
if (isSigned)
BuildMI(*MBB, IP, PPC32::SRAWI, 2, DestReg).addReg(SrcReg+1)
.addImm(Amount);
else
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg+1)
.addImm(32-Amount).addImm(Amount).addImm(31);
} else {
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(SrcReg+1)
.addReg(SrcReg+1);
}
BuildMI(*MBB, IP,PPC32::ADDI,2,DestReg+1).addReg(PPC32::R0).addImm(0);
}
}
} else {
unsigned TmpReg1 = makeAnotherReg(Type::IntTy);
unsigned TmpReg2 = makeAnotherReg(Type::IntTy);
unsigned TmpReg3 = makeAnotherReg(Type::IntTy);
unsigned TmpReg4 = makeAnotherReg(Type::IntTy);
unsigned TmpReg5 = makeAnotherReg(Type::IntTy);
unsigned TmpReg6 = makeAnotherReg(Type::IntTy);
unsigned ShiftAmountReg = getReg (ShiftAmount, MBB, IP);
if (isLeftShift) {
BuildMI(*MBB, IP, PPC32::SUBFIC, 2, TmpReg1).addReg(ShiftAmountReg)
.addImm(32);
BuildMI(*MBB, IP, PPC32::SLW, 2, TmpReg2).addReg(SrcReg+1)
.addReg(ShiftAmountReg);
BuildMI(*MBB, IP, PPC32::SRW, 2,TmpReg3).addReg(SrcReg).addReg(TmpReg1);
BuildMI(*MBB, IP, PPC32::OR, 2,TmpReg4).addReg(TmpReg2).addReg(TmpReg3);
BuildMI(*MBB, IP, PPC32::ADDI, 2, TmpReg5).addReg(ShiftAmountReg)
.addImm(-32);
BuildMI(*MBB, IP, PPC32::SLW, 2,TmpReg6).addReg(SrcReg).addReg(TmpReg5);
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg+1).addReg(TmpReg4)
.addReg(TmpReg6);
BuildMI(*MBB, IP, PPC32::SLW, 2, DestReg).addReg(SrcReg)
.addReg(ShiftAmountReg);
} else {
if (isSigned) {
// FIXME: Unimplemented
// Page C-3 of the PowerPC 32bit Programming Environments Manual
std::cerr << "Unimplemented: signed right shift\n";
abort();
} else {
BuildMI(*MBB, IP, PPC32::SUBFIC, 2, TmpReg1).addReg(ShiftAmountReg)
.addImm(32);
BuildMI(*MBB, IP, PPC32::SRW, 2, TmpReg2).addReg(SrcReg)
.addReg(ShiftAmountReg);
BuildMI(*MBB, IP, PPC32::SLW, 2, TmpReg3).addReg(SrcReg+1)
.addReg(TmpReg1);
BuildMI(*MBB, IP, PPC32::OR, 2, TmpReg4).addReg(TmpReg2)
.addReg(TmpReg3);
BuildMI(*MBB, IP, PPC32::ADDI, 2, TmpReg5).addReg(ShiftAmountReg)
.addImm(-32);
BuildMI(*MBB, IP, PPC32::SRW, 2, TmpReg6).addReg(SrcReg+1)
.addReg(TmpReg5);
BuildMI(*MBB, IP, PPC32::OR, 2, DestReg).addReg(TmpReg4)
.addReg(TmpReg6);
BuildMI(*MBB, IP, PPC32::SRW, 2, DestReg+1).addReg(SrcReg+1)
.addReg(ShiftAmountReg);
}
}
}
return;
}
if (ConstantUInt *CUI = dyn_cast<ConstantUInt>(ShiftAmount)) {
// The shift amount is constant, guaranteed to be a ubyte. Get its value.
assert(CUI->getType() == Type::UByteTy && "Shift amount not a ubyte?");
unsigned Amount = CUI->getValue();
if (isLeftShift) {
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg)
.addImm(Amount).addImm(0).addImm(31-Amount);
} else {
if (isSigned) {
BuildMI(*MBB, IP, PPC32::SRAWI,2,DestReg).addReg(SrcReg).addImm(Amount);
} else {
BuildMI(*MBB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg)
.addImm(32-Amount).addImm(Amount).addImm(31);
}
}
} else { // The shift amount is non-constant.
unsigned ShiftAmountReg = getReg (ShiftAmount, MBB, IP);
if (isLeftShift) {
BuildMI(*MBB, IP, PPC32::SLW, 2, DestReg).addReg(SrcReg)
.addReg(ShiftAmountReg);
} else {
BuildMI(*MBB, IP, isSigned ? PPC32::SRAW : PPC32::SRW, 2, DestReg)
.addReg(SrcReg).addReg(ShiftAmountReg);
}
}
}
/// visitLoadInst - Implement LLVM load instructions
///
void ISel::visitLoadInst(LoadInst &I) {
static const unsigned Opcodes[] = {
PPC32::LBZ, PPC32::LHZ, PPC32::LWZ, PPC32::LFS
};
unsigned Class = getClassB(I.getType());
unsigned Opcode = Opcodes[Class];
if (I.getType() == Type::DoubleTy) Opcode = PPC32::LFD;
unsigned DestReg = getReg(I);
if (AllocaInst *AI = dyn_castFixedAlloca(I.getOperand(0))) {
unsigned FI = getFixedSizedAllocaFI(AI);
if (Class == cLong) {
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, DestReg), FI);
addFrameReference(BuildMI(BB, PPC32::LWZ, 2, DestReg+1), FI, 4);
} else {
addFrameReference(BuildMI(BB, Opcode, 2, DestReg), FI);
}
} else {
unsigned SrcAddrReg = getReg(I.getOperand(0));
if (Class == cLong) {
BuildMI(BB, PPC32::LWZ, 2, DestReg).addImm(0).addReg(SrcAddrReg);
BuildMI(BB, PPC32::LWZ, 2, DestReg+1).addImm(4).addReg(SrcAddrReg);
} else {
BuildMI(BB, Opcode, 2, DestReg).addImm(0).addReg(SrcAddrReg);
}
}
}
/// visitStoreInst - Implement LLVM store instructions
///
void ISel::visitStoreInst(StoreInst &I) {
unsigned ValReg = getReg(I.getOperand(0));
unsigned AddressReg = getReg(I.getOperand(1));
const Type *ValTy = I.getOperand(0)->getType();
unsigned Class = getClassB(ValTy);
if (Class == cLong) {
BuildMI(BB, PPC32::STW, 3).addReg(ValReg).addImm(0).addReg(AddressReg);
BuildMI(BB, PPC32::STW, 3).addReg(ValReg+1).addImm(4).addReg(AddressReg);
return;
}
static const unsigned Opcodes[] = {
PPC32::STB, PPC32::STH, PPC32::STW, PPC32::STFS
};
unsigned Opcode = Opcodes[Class];
if (ValTy == Type::DoubleTy) Opcode = PPC32::STFD;
BuildMI(BB, Opcode, 3).addReg(ValReg).addImm(0).addReg(AddressReg);
}
/// visitCastInst - Here we have various kinds of copying with or without sign
/// extension going on.
///
void ISel::visitCastInst(CastInst &CI) {
Value *Op = CI.getOperand(0);
unsigned SrcClass = getClassB(Op->getType());
unsigned DestClass = getClassB(CI.getType());
// Noop casts are not emitted: getReg will return the source operand as the
// register to use for any uses of the noop cast.
if (DestClass == SrcClass)
return;
// If this is a cast from a 32-bit integer to a Long type, and the only uses
// of the case are GEP instructions, then the cast does not need to be
// generated explicitly, it will be folded into the GEP.
if (DestClass == cLong && SrcClass == cInt) {
bool AllUsesAreGEPs = true;
for (Value::use_iterator I = CI.use_begin(), E = CI.use_end(); I != E; ++I)
if (!isa<GetElementPtrInst>(*I)) {
AllUsesAreGEPs = false;
break;
}
// No need to codegen this cast if all users are getelementptr instrs...
if (AllUsesAreGEPs) return;
}
unsigned DestReg = getReg(CI);
MachineBasicBlock::iterator MI = BB->end();
emitCastOperation(BB, MI, Op, CI.getType(), DestReg);
}
/// emitCastOperation - Common code shared between visitCastInst and constant
/// expression cast support.
///
void ISel::emitCastOperation(MachineBasicBlock *BB,
MachineBasicBlock::iterator IP,
Value *Src, const Type *DestTy,
unsigned DestReg) {
const Type *SrcTy = Src->getType();
unsigned SrcClass = getClassB(SrcTy);
unsigned DestClass = getClassB(DestTy);
unsigned SrcReg = getReg(Src, BB, IP);
// Implement casts to bool by using compare on the operand followed by set if
// not zero on the result.
if (DestTy == Type::BoolTy) {
switch (SrcClass) {
case cByte:
case cShort:
case cInt: {
unsigned TmpReg = makeAnotherReg(Type::IntTy);
BuildMI(*BB, IP, PPC32::ADDIC, 2, TmpReg).addReg(SrcReg).addImm(-1);
BuildMI(*BB, IP, PPC32::SUBFE, 2, DestReg).addReg(TmpReg).addReg(SrcReg);
break;
}
case cLong: {
unsigned TmpReg = makeAnotherReg(Type::IntTy);
unsigned SrcReg2 = makeAnotherReg(Type::IntTy);
BuildMI(*BB, IP, PPC32::OR, 2, SrcReg2).addReg(SrcReg).addReg(SrcReg+1);
BuildMI(*BB, IP, PPC32::ADDIC, 2, TmpReg).addReg(SrcReg2).addImm(-1);
BuildMI(*BB, IP, PPC32::SUBFE, 2, DestReg).addReg(TmpReg).addReg(SrcReg2);
break;
}
case cFP:
// FIXME
// Load -0.0
// Compare
// move to CR1
// Negate -0.0
// Compare
// CROR
// MFCR
// Left-align
// SRA ?
std::cerr << "Cast fp-to-bool not implemented!";
abort();
}
return;
}
// Implement casts between values of the same type class (as determined by
// getClass) by using a register-to-register move.
if (SrcClass == DestClass) {
if (SrcClass <= cInt) {
BuildMI(*BB, IP, PPC32::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else if (SrcClass == cFP && SrcTy == DestTy) {
BuildMI(*BB, IP, PPC32::FMR, 1, DestReg).addReg(SrcReg);
} else if (SrcClass == cFP) {
if (SrcTy == Type::FloatTy) { // float -> double
assert(DestTy == Type::DoubleTy && "Unknown cFP member!");
BuildMI(*BB, IP, PPC32::FMR, 1, DestReg).addReg(SrcReg);
} else { // double -> float
assert(SrcTy == Type::DoubleTy && DestTy == Type::FloatTy &&
"Unknown cFP member!");
BuildMI(*BB, IP, PPC32::FRSP, 1, DestReg).addReg(SrcReg);
}
} else if (SrcClass == cLong) {
BuildMI(*BB, IP, PPC32::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
BuildMI(*BB, IP, PPC32::OR, 2, DestReg+1).addReg(SrcReg+1)
.addReg(SrcReg+1);
} else {
assert(0 && "Cannot handle this type of cast instruction!");
abort();
}
return;
}
// Handle cast of SMALLER int to LARGER int using a move with sign extension
// or zero extension, depending on whether the source type was signed.
if (SrcClass <= cInt && (DestClass <= cInt || DestClass == cLong) &&
SrcClass < DestClass) {
bool isLong = DestClass == cLong;
if (isLong) DestClass = cInt;
bool isUnsigned = SrcTy->isUnsigned() || SrcTy == Type::BoolTy;
if (SrcClass < cInt) {
if (isUnsigned) {
unsigned shift = (SrcClass == cByte) ? 24 : 16;
BuildMI(*BB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg).addZImm(0)
.addImm(shift).addImm(31);
} else {
BuildMI(*BB, IP, (SrcClass == cByte) ? PPC32::EXTSB : PPC32::EXTSH,
1, DestReg).addReg(SrcReg);
}
} else {
BuildMI(*BB, IP, PPC32::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
}
if (isLong) { // Handle upper 32 bits as appropriate...
if (isUnsigned) // Zero out top bits...
BuildMI(*BB, IP, PPC32::ADDI, 2, DestReg+1).addReg(PPC32::R0).addImm(0);
else // Sign extend bottom half...
BuildMI(*BB, IP, PPC32::SRAWI, 2, DestReg+1).addReg(DestReg).addImm(31);
}
return;
}
// Special case long -> int ...
if (SrcClass == cLong && DestClass == cInt) {
BuildMI(*BB, IP, PPC32::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
return;
}
// Handle cast of LARGER int to SMALLER int with a clear or sign extend
if ((SrcClass <= cInt || SrcClass == cLong) && DestClass <= cInt
&& SrcClass > DestClass) {
bool isUnsigned = SrcTy->isUnsigned() || SrcTy == Type::BoolTy;
if (isUnsigned) {
unsigned shift = (SrcClass == cByte) ? 24 : 16;
BuildMI(*BB, IP, PPC32::RLWINM, 4, DestReg).addReg(SrcReg).addZImm(0)
.addImm(shift).addImm(31);
} else {
BuildMI(*BB, IP, (SrcClass == cByte) ? PPC32::EXTSB : PPC32::EXTSH, 1,
DestReg).addReg(SrcReg);
}
return;
}
// Handle casts from integer to floating point now...
if (DestClass == cFP) {
// Emit a library call for long to float conversion
if (SrcClass == cLong) {
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(SrcReg, SrcTy));
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addExternalSymbol("__floatdidf", true);
doCall(ValueRecord(DestReg, DestTy), TheCall, Args, false);
return;
}
unsigned TmpReg = makeAnotherReg(Type::IntTy);
switch (SrcTy->getTypeID()) {
case Type::BoolTyID:
case Type::SByteTyID:
BuildMI(*BB, IP, PPC32::EXTSB, 1, TmpReg).addReg(SrcReg);
break;
case Type::UByteTyID:
BuildMI(*BB, IP, PPC32::RLWINM, 4, TmpReg).addReg(SrcReg).addZImm(0)
.addImm(24).addImm(31);
break;
case Type::ShortTyID:
BuildMI(*BB, IP, PPC32::EXTSB, 1, TmpReg).addReg(SrcReg);
break;
case Type::UShortTyID:
BuildMI(*BB, IP, PPC32::RLWINM, 4, TmpReg).addReg(SrcReg).addZImm(0)
.addImm(16).addImm(31);
break;
case Type::IntTyID:
BuildMI(*BB, IP, PPC32::OR, 2, TmpReg).addReg(SrcReg).addReg(SrcReg);
break;
case Type::UIntTyID:
BuildMI(*BB, IP, PPC32::OR, 2, TmpReg).addReg(SrcReg).addReg(SrcReg);
break;
default: // No promotion needed...
break;
}
SrcReg = TmpReg;
// Spill the integer to memory and reload it from there.
// Also spill room for a special conversion constant
int ConstantFrameIndex =
F->getFrameInfo()->CreateStackObject(Type::DoubleTy, TM.getTargetData());
int ValueFrameIdx =
F->getFrameInfo()->CreateStackObject(Type::DoubleTy, TM.getTargetData());
unsigned constantHi = makeAnotherReg(Type::IntTy);
unsigned constantLo = makeAnotherReg(Type::IntTy);
unsigned ConstF = makeAnotherReg(Type::DoubleTy);
unsigned TempF = makeAnotherReg(Type::DoubleTy);
if (!SrcTy->isSigned()) {
BuildMI(*BB, IP, PPC32::ADDIS, 2, constantHi).addReg(PPC32::R0)
.addImm(0x4330);
BuildMI(*BB, IP, PPC32::ADDI, 2, constantLo).addReg(PPC32::R0).addImm(0);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantHi),
ConstantFrameIndex);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantLo),
ConstantFrameIndex, 4);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantHi),
ValueFrameIdx);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(SrcReg),
ValueFrameIdx, 4);
addFrameReference(BuildMI(*BB, IP, PPC32::LFD, 2, ConstF),
ConstantFrameIndex);
addFrameReference(BuildMI(*BB, IP, PPC32::LFD, 2, TempF), ValueFrameIdx);
BuildMI(*BB, IP, PPC32::FSUB, 2, DestReg).addReg(TempF).addReg(ConstF);
} else {
unsigned TempLo = makeAnotherReg(Type::IntTy);
BuildMI(*BB, IP, PPC32::ADDIS, 2, constantHi).addReg(PPC32::R0)
.addImm(0x4330);
BuildMI(*BB, IP, PPC32::ADDIS, 2, constantLo).addReg(PPC32::R0)
.addImm(0x8000);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantHi),
ConstantFrameIndex);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantLo),
ConstantFrameIndex, 4);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(constantHi),
ValueFrameIdx);
BuildMI(*BB, IP, PPC32::XORIS, 2, TempLo).addReg(SrcReg).addImm(0x8000);
addFrameReference(BuildMI(*BB, IP, PPC32::STW, 3).addReg(TempLo),
ValueFrameIdx, 4);
addFrameReference(BuildMI(*BB, IP, PPC32::LFD, 2, ConstF),
ConstantFrameIndex);
addFrameReference(BuildMI(*BB, IP, PPC32::LFD, 2, TempF), ValueFrameIdx);
BuildMI(*BB, IP, PPC32::FSUB, 2, DestReg).addReg(TempF ).addReg(ConstF);
}
return;
}
// Handle casts from floating point to integer now...
if (SrcClass == cFP) {
// emit library call
if (DestClass == cLong) {
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(SrcReg, SrcTy));
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addExternalSymbol("__fixdfdi", true);
doCall(ValueRecord(DestReg, DestTy), TheCall, Args, false);
return;
}
int ValueFrameIdx =
F->getFrameInfo()->CreateStackObject(Type::DoubleTy, TM.getTargetData());
// load into 32 bit value, and then truncate as necessary
// FIXME: This is wrong for unsigned dest types
//if (DestTy->isSigned()) {
unsigned TempReg = makeAnotherReg(Type::DoubleTy);
BuildMI(*BB, IP, PPC32::FCTIWZ, 1, TempReg).addReg(SrcReg);
addFrameReference(BuildMI(*BB, IP, PPC32::STFD, 3)
.addReg(TempReg), ValueFrameIdx);
addFrameReference(BuildMI(*BB, IP, PPC32::LWZ, 2, DestReg),
ValueFrameIdx+4);
//} else {
//}
// FIXME: Truncate return value
return;
}
// Anything we haven't handled already, we can't (yet) handle at all.
assert(0 && "Unhandled cast instruction!");
abort();
}
/// visitVANextInst - Implement the va_next instruction...
///
void ISel::visitVANextInst(VANextInst &I) {
unsigned VAList = getReg(I.getOperand(0));
unsigned DestReg = getReg(I);
unsigned Size;
switch (I.getArgType()->getTypeID()) {
default:
std::cerr << I;
assert(0 && "Error: bad type for va_next instruction!");
return;
case Type::PointerTyID:
case Type::UIntTyID:
case Type::IntTyID:
Size = 4;
break;
case Type::ULongTyID:
case Type::LongTyID:
case Type::DoubleTyID:
Size = 8;
break;
}
// Increment the VAList pointer...
BuildMI(BB, PPC32::ADDI, 2, DestReg).addReg(VAList).addImm(Size);
}
void ISel::visitVAArgInst(VAArgInst &I) {
unsigned VAList = getReg(I.getOperand(0));
unsigned DestReg = getReg(I);
switch (I.getType()->getTypeID()) {
default:
std::cerr << I;
assert(0 && "Error: bad type for va_next instruction!");
return;
case Type::PointerTyID:
case Type::UIntTyID:
case Type::IntTyID:
BuildMI(BB, PPC32::LWZ, 2, DestReg).addImm(0).addReg(VAList);
break;
case Type::ULongTyID:
case Type::LongTyID:
BuildMI(BB, PPC32::LWZ, 2, DestReg).addImm(0).addReg(VAList);
BuildMI(BB, PPC32::LWZ, 2, DestReg+1).addImm(4).addReg(VAList);
break;
case Type::DoubleTyID:
BuildMI(BB, PPC32::LFD, 2, DestReg).addImm(0).addReg(VAList);
break;
}
}
/// visitGetElementPtrInst - instruction-select GEP instructions
///
void ISel::visitGetElementPtrInst(GetElementPtrInst &I) {
unsigned outputReg = getReg(I);
emitGEPOperation(BB, BB->end(), I.getOperand(0), I.op_begin()+1, I.op_end(),
outputReg);
}
void ISel::emitGEPOperation(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Value *Src, User::op_iterator IdxBegin,
User::op_iterator IdxEnd, unsigned TargetReg) {
const TargetData &TD = TM.getTargetData();
if (ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(Src))
Src = CPR->getValue();
std::vector<Value*> GEPOps;
GEPOps.resize(IdxEnd-IdxBegin+1);
GEPOps[0] = Src;
std::copy(IdxBegin, IdxEnd, GEPOps.begin()+1);
std::vector<const Type*> GEPTypes;
GEPTypes.assign(gep_type_begin(Src->getType(), IdxBegin, IdxEnd),
gep_type_end(Src->getType(), IdxBegin, IdxEnd));
// Keep emitting instructions until we consume the entire GEP instruction.
while (!GEPOps.empty()) {
if (GEPTypes.empty()) {
// Load the base pointer into a register.
unsigned Reg = getReg(Src, MBB, IP);
BuildMI(*MBB, IP, PPC32::OR, 2, TargetReg).addReg(Reg).addReg(Reg);
break; // we are now done
}
// It's an array or pointer access: [ArraySize x ElementType].
const SequentialType *SqTy = cast<SequentialType>(GEPTypes.back());
Value *idx = GEPOps.back();
GEPOps.pop_back(); // Consume a GEP operand
GEPTypes.pop_back();
// Many GEP instructions use a [cast (int/uint) to LongTy] as their
// operand. Handle this case directly now...
if (CastInst *CI = dyn_cast<CastInst>(idx))
if (CI->getOperand(0)->getType() == Type::IntTy ||
CI->getOperand(0)->getType() == Type::UIntTy)
idx = CI->getOperand(0);
// We want to add BaseReg to(idxReg * sizeof ElementType). First, we
// must find the size of the pointed-to type (Not coincidentally, the next
// type is the type of the elements in the array).
const Type *ElTy = SqTy->getElementType();
unsigned elementSize = TD.getTypeSize(ElTy);
if (idx == Constant::getNullValue(idx->getType())) {
// GEP with idx 0 is a no-op
} else if (elementSize == 1) {
// If the element size is 1, we don't have to multiply, just add
unsigned idxReg = getReg(idx, MBB, IP);
unsigned Reg = makeAnotherReg(Type::UIntTy);
BuildMI(*MBB, IP, PPC32::ADD, 2,TargetReg).addReg(Reg).addReg(idxReg);
--IP; // Insert the next instruction before this one.
TargetReg = Reg; // Codegen the rest of the GEP into this
} else {
unsigned idxReg = getReg(idx, MBB, IP);
unsigned OffsetReg = makeAnotherReg(Type::UIntTy);
// Make sure we can back the iterator up to point to the first
// instruction emitted.
MachineBasicBlock::iterator BeforeIt = IP;
if (IP == MBB->begin())
BeforeIt = MBB->end();
else
--BeforeIt;
doMultiplyConst(MBB, IP, OffsetReg, Type::IntTy, idxReg, elementSize);
// Emit an ADD to add OffsetReg to the basePtr.
unsigned Reg = makeAnotherReg(Type::UIntTy);
BuildMI(*MBB, IP, PPC32::ADD, 2, TargetReg).addReg(Reg).addReg(OffsetReg);
// Step to the first instruction of the multiply.
if (BeforeIt == MBB->end())
IP = MBB->begin();
else
IP = ++BeforeIt;
TargetReg = Reg; // Codegen the rest of the GEP into this
}
}
}
/// visitAllocaInst - If this is a fixed size alloca, allocate space from the
/// frame manager, otherwise do it the hard way.
///
void ISel::visitAllocaInst(AllocaInst &I) {
// If this is a fixed size alloca in the entry block for the function, we
// statically stack allocate the space, so we don't need to do anything here.
//
if (dyn_castFixedAlloca(&I)) return;
// Find the data size of the alloca inst's getAllocatedType.
const Type *Ty = I.getAllocatedType();
unsigned TySize = TM.getTargetData().getTypeSize(Ty);
// Create a register to hold the temporary result of multiplying the type size
// constant by the variable amount.
unsigned TotalSizeReg = makeAnotherReg(Type::UIntTy);
unsigned SrcReg1 = getReg(I.getArraySize());
// TotalSizeReg = mul <numelements>, <TypeSize>
MachineBasicBlock::iterator MBBI = BB->end();
doMultiplyConst(BB, MBBI, TotalSizeReg, Type::UIntTy, SrcReg1, TySize);
// AddedSize = add <TotalSizeReg>, 15
unsigned AddedSizeReg = makeAnotherReg(Type::UIntTy);
BuildMI(BB, PPC32::ADD, 2, AddedSizeReg).addReg(TotalSizeReg).addImm(15);
// AlignedSize = and <AddedSize>, ~15
unsigned AlignedSize = makeAnotherReg(Type::UIntTy);
BuildMI(BB, PPC32::RLWNM, 4, AlignedSize).addReg(AddedSizeReg).addImm(0)
.addImm(0).addImm(27);
// Subtract size from stack pointer, thereby allocating some space.
BuildMI(BB, PPC32::SUB, 2, PPC32::R1).addReg(PPC32::R1).addReg(AlignedSize);
// Put a pointer to the space into the result register, by copying
// the stack pointer.
BuildMI(BB, PPC32::OR, 2, getReg(I)).addReg(PPC32::R1).addReg(PPC32::R1);
// Inform the Frame Information that we have just allocated a variable-sized
// object.
F->getFrameInfo()->CreateVariableSizedObject();
}
/// visitMallocInst - Malloc instructions are code generated into direct calls
/// to the library malloc.
///
void ISel::visitMallocInst(MallocInst &I) {
unsigned AllocSize = TM.getTargetData().getTypeSize(I.getAllocatedType());
unsigned Arg;
if (ConstantUInt *C = dyn_cast<ConstantUInt>(I.getOperand(0))) {
Arg = getReg(ConstantUInt::get(Type::UIntTy, C->getValue() * AllocSize));
} else {
Arg = makeAnotherReg(Type::UIntTy);
unsigned Op0Reg = getReg(I.getOperand(0));
MachineBasicBlock::iterator MBBI = BB->end();
doMultiplyConst(BB, MBBI, Arg, Type::UIntTy, Op0Reg, AllocSize);
}
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(Arg, Type::UIntTy));
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addExternalSymbol("malloc", true);
doCall(ValueRecord(getReg(I), I.getType()), TheCall, Args, false);
}
/// visitFreeInst - Free instructions are code gen'd to call the free libc
/// function.
///
void ISel::visitFreeInst(FreeInst &I) {
std::vector<ValueRecord> Args;
Args.push_back(ValueRecord(I.getOperand(0)));
MachineInstr *TheCall =
BuildMI(PPC32::CALLpcrel, 1).addExternalSymbol("free", true);
doCall(ValueRecord(0, Type::VoidTy), TheCall, Args, false);
}
/// createPPC32SimpleInstructionSelector - This pass converts an LLVM function
/// into a machine code representation is a very simple peep-hole fashion. The
/// generated code sucks but the implementation is nice and simple.
///
FunctionPass *llvm::createPPCSimpleInstructionSelector(TargetMachine &TM) {
return new ISel(TM);
}