llvm-6502/lib/Target/Sparc/SparcV8ISelSimple.cpp
Brian Gaeke 2d4fa8faac Preliminary support for getting 64-bit integer constants into registers.
Preliminary support for division. It's gross because you have to initialize
the "Y" register, which is the top 32 bits of the thing you're dividing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12732 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-07 04:00:49 +00:00

380 lines
14 KiB
C++

//===-- InstSelectSimple.cpp - A simple instruction selector for SparcV8 --===//
//
// 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.
//
//===----------------------------------------------------------------------===//
//
// This file defines a simple peephole instruction selector for the V8 target
//
//===----------------------------------------------------------------------===//
#include "SparcV8.h"
#include "SparcV8InstrInfo.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicLowering.h"
#include "llvm/Pass.h"
#include "llvm/Constants.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/SSARegMap.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Support/CFG.h"
using namespace llvm;
namespace {
struct V8ISel : public FunctionPass, public InstVisitor<V8ISel> {
TargetMachine &TM;
MachineFunction *F; // The function we are compiling into
MachineBasicBlock *BB; // The current MBB we are compiling
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;
V8ISel(TargetMachine &tm) : TM(tm), F(0), BB(0) {}
/// runOnFunction - Top level implementation of instruction selection for
/// the entire function.
///
bool runOnFunction(Function &Fn);
virtual const char *getPassName() const {
return "SparcV8 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];
}
void visitBinaryOperator(BinaryOperator &I);
void visitCallInst(CallInst &I);
void visitReturnInst(ReturnInst &RI);
void visitInstruction(Instruction &I) {
std::cerr << "Unhandled instruction: " << I;
abort();
}
/// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
/// function, lowering any calls to unknown intrinsic functions into the
/// equivalent LLVM code.
void LowerUnknownIntrinsicFunctionCalls(Function &F);
void visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI);
/// copyConstantToRegister - Output the instructions required to put the
/// specified constant into the specified register.
///
void copyConstantToRegister(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Constant *C, unsigned R);
/// 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 SparcV8RegisterInfo*>(TM.getRegisterInfo()) &&
"Current target doesn't have SparcV8 reg info??");
const SparcV8RegisterInfo *MRI =
static_cast<const SparcV8RegisterInfo*>(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);
}
unsigned getReg(Value &V) { return getReg (&V); } // allow refs.
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) {
unsigned &Reg = RegMap[V];
if (Reg == 0) {
Reg = makeAnotherReg(V->getType());
RegMap[V] = Reg;
}
// If this operand is a constant, emit the code to copy the constant into
// the register here...
//
if (Constant *C = dyn_cast<Constant>(V)) {
copyConstantToRegister(MBB, IPt, C, Reg);
RegMap.erase(V); // Assign a new name to this constant if ref'd again
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// Move the address of the global into the register
unsigned TmpReg = makeAnotherReg(V->getType());
BuildMI (*MBB, IPt, V8::SETHIi, 1, TmpReg).addGlobalAddress (GV);
BuildMI (*MBB, IPt, V8::ORri, 2, Reg).addReg (TmpReg)
.addGlobalAddress (GV);
RegMap.erase(V); // Assign a new name to this address if ref'd again
}
return Reg;
}
};
}
FunctionPass *llvm::createSparcV8SimpleInstructionSelector(TargetMachine &TM) {
return new V8ISel(TM);
}
enum TypeClass {
cByte, cShort, cInt, cLong, cFloat, cDouble
};
static TypeClass getClass (const Type *T) {
switch (T->getPrimitiveID ()) {
case Type::UByteTyID: case Type::SByteTyID: return cByte;
case Type::UShortTyID: case Type::ShortTyID: return cShort;
case Type::UIntTyID: case Type::IntTyID: return cInt;
case Type::ULongTyID: case Type::LongTyID: return cLong;
case Type::FloatTyID: return cFloat;
case Type::DoubleTyID: return cDouble;
default:
assert (0 && "Type of unknown class passed to getClass?");
return cByte;
}
}
/// copyConstantToRegister - Output the instructions required to put the
/// specified constant into the specified register.
///
void V8ISel::copyConstantToRegister(MachineBasicBlock *MBB,
MachineBasicBlock::iterator IP,
Constant *C, unsigned R) {
if (ConstantInt *CI = dyn_cast<ConstantInt> (C)) {
unsigned Class = getClass(C->getType());
switch (Class) {
case cByte:
BuildMI (*MBB, IP, V8::ORri, 2, R).addReg (V8::G0).addImm ((uint8_t) CI->getRawValue ());
return;
case cShort: {
unsigned TmpReg = makeAnotherReg (C->getType ());
BuildMI (*MBB, IP, V8::SETHIi, 1, TmpReg).addImm (((uint16_t) CI->getRawValue ()) >> 10);
BuildMI (*MBB, IP, V8::ORri, 2, R).addReg (TmpReg).addImm (((uint16_t) CI->getRawValue ()) & 0x03ff);
return;
}
case cInt: {
unsigned TmpReg = makeAnotherReg (C->getType ());
BuildMI (*MBB, IP, V8::SETHIi, 1, TmpReg).addImm (((uint32_t) CI->getRawValue ()) >> 10);
BuildMI (*MBB, IP, V8::ORri, 2, R).addReg (TmpReg).addImm (((uint32_t) CI->getRawValue ()) & 0x03ff);
return;
}
case cLong: {
unsigned TmpReg = makeAnotherReg (Type::UIntTy);
uint32_t topHalf, bottomHalf;
topHalf = (uint32_t) (CI->getRawValue () >> 32);
bottomHalf = (uint32_t) (CI->getRawValue () & 0x0ffffffffULL);
BuildMI (*MBB, IP, V8::SETHIi, 1, TmpReg).addImm (topHalf >> 10);
BuildMI (*MBB, IP, V8::ORri, 2, R).addReg (TmpReg).addImm (topHalf & 0x03ff);
BuildMI (*MBB, IP, V8::SETHIi, 1, TmpReg).addImm (bottomHalf >> 10);
BuildMI (*MBB, IP, V8::ORri, 2, R).addReg (TmpReg).addImm (bottomHalf & 0x03ff);
return;
}
default:
std::cerr << "Offending constant: " << *C << "\n";
assert (0 && "Can't copy this kind of constant into register yet");
return;
}
}
std::cerr << "Offending constant: " << *C << "\n";
assert (0 && "Can't copy this kind of constant into register yet");
}
bool V8ISel::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 and out of fixed registers.
//LoadArgumentsToVirtualRegs(Fn);
// Instruction select everything except PHI nodes
visit(Fn);
// Select the PHI nodes
//SelectPHINodes();
RegMap.clear();
MBBMap.clear();
F = 0;
// We always build a machine code representation for the function
return true;
}
void V8ISel::visitCallInst(CallInst &I) {
assert (I.getNumOperands () == 1 && "Can't handle call args yet");
unsigned DestReg = getReg (I);
BuildMI (BB, V8::CALL, 1).addPCDisp (I.getOperand (0));
if (I.getType ()->getPrimitiveID () == Type::VoidTyID)
return;
// Deal w/ return value
switch (getClass (I.getType ())) {
case cByte:
case cShort:
case cInt:
// Schlep it over into the destination register
BuildMI (BB, V8::ORrr, 2, DestReg).addReg(V8::G0).addReg(V8::O0);
break;
default:
visitInstruction (I);
return;
}
}
void V8ISel::visitReturnInst(ReturnInst &I) {
if (I.getNumOperands () == 1) {
unsigned RetValReg = getReg (I.getOperand (0));
switch (getClass (I.getOperand (0)->getType ())) {
case cByte:
case cShort:
case cInt:
// Schlep it over into i0 (where it will become o0 after restore).
BuildMI (BB, V8::ORrr, 2, V8::I0).addReg(V8::G0).addReg(RetValReg);
break;
default:
visitInstruction (I);
return;
}
} else if (I.getNumOperands () != 1) {
visitInstruction (I);
}
// Just emit a 'retl' instruction to return.
BuildMI(BB, V8::RETL, 0);
return;
}
void V8ISel::visitBinaryOperator (BinaryOperator &I) {
unsigned DestReg = getReg (I);
unsigned Op0Reg = getReg (I.getOperand (0));
unsigned Op1Reg = getReg (I.getOperand (1));
unsigned ResultReg = makeAnotherReg (I.getType ());
// FIXME: support long, ulong, fp.
switch (I.getOpcode ()) {
case Instruction::Add:
BuildMI (BB, V8::ADDrr, 2, ResultReg).addReg (Op0Reg).addReg (Op1Reg);
break;
case Instruction::Sub:
BuildMI (BB, V8::SUBrr, 2, ResultReg).addReg (Op0Reg).addReg (Op1Reg);
break;
case Instruction::Mul: {
unsigned Opcode = I.getType ()->isSigned () ? V8::SMULrr : V8::UMULrr;
BuildMI (BB, Opcode, 2, ResultReg).addReg (Op0Reg).addReg (Op1Reg);
break;
}
case Instruction::Div: {
unsigned Opcode = I.getType ()->isSigned () ? V8::SDIVrr : V8::UDIVrr;
// Clear out the Y register (top half of LHS of divide)
BuildMI (BB, V8::WRYrr, 2, V8::Y).addReg (V8::G0).addReg (V8::G0);
BuildMI (BB, V8::NOP, 0); // WR may take up to 4 cycles to finish
BuildMI (BB, V8::NOP, 0);
BuildMI (BB, V8::NOP, 0);
BuildMI (BB, Opcode, 2, ResultReg).addReg (Op0Reg).addReg (Op1Reg);
break;
}
default:
visitInstruction (I);
return;
}
switch (getClass (I.getType ())) {
case cByte:
if (I.getType ()->isSigned ()) { // add byte
BuildMI (BB, V8::ANDri, 2, DestReg).addReg (ResultReg).addZImm (0xff);
} else { // add ubyte
unsigned TmpReg = makeAnotherReg (I.getType ());
BuildMI (BB, V8::SLLri, 2, TmpReg).addReg (ResultReg).addZImm (24);
BuildMI (BB, V8::SRAri, 2, DestReg).addReg (TmpReg).addZImm (24);
}
break;
case cShort:
if (I.getType ()->isSigned ()) { // add short
unsigned TmpReg = makeAnotherReg (I.getType ());
BuildMI (BB, V8::SLLri, 2, TmpReg).addReg (ResultReg).addZImm (16);
BuildMI (BB, V8::SRAri, 2, DestReg).addReg (TmpReg).addZImm (16);
} else { // add ushort
unsigned TmpReg = makeAnotherReg (I.getType ());
BuildMI (BB, V8::SLLri, 2, TmpReg).addReg (ResultReg).addZImm (16);
BuildMI (BB, V8::SRLri, 2, DestReg).addReg (TmpReg).addZImm (16);
}
break;
case cInt:
BuildMI (BB, V8::ORrr, 2, DestReg).addReg (V8::G0).addReg (ResultReg);
break;
default:
visitInstruction (I);
return;
}
}
/// LowerUnknownIntrinsicFunctionCalls - This performs a prepass over the
/// function, lowering any calls to unknown intrinsic functions into the
/// equivalent LLVM code.
void V8ISel::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: 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 V8ISel::visitIntrinsicCall(Intrinsic::ID ID, CallInst &CI) {
unsigned TmpReg1, TmpReg2;
switch (ID) {
default: assert(0 && "Intrinsic not supported!");
}
}