llvm-6502/lib/Target/SparcV8/InstSelectSimple.cpp
2004-02-29 00:27:00 +00:00

153 lines
5.0 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 "llvm/Instructions.h"
#include "llvm/IntrinsicLowering.h"
#include "llvm/Pass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.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 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);
};
}
FunctionPass *llvm::createSparcV8SimpleInstructionSelector(TargetMachine &TM) {
return new V8ISel(TM);
}
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::visitReturnInst(ReturnInst &I) {
if (I.getNumOperands() == 0) {
// Just emit a 'ret' instruction
BuildMI(BB, V8::JMPLi, 2, V8::G0).addZImm(8).addReg(V8::I7);
return;
}
visitInstruction(I);
}
/// 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!");
}
}