mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-21 18:29:46 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7873 91177308-0d34-0410-b5e6-96231b3b80d8
118 lines
4.1 KiB
C++
118 lines
4.1 KiB
C++
//===-- InstSelectPattern.cpp - A pattern matching inst selector for X86 --===//
|
|
//
|
|
// This file defines a pattern matching instruction selector for X86.
|
|
//
|
|
// FIXME: we could allocate one big array of unsigneds to use as the backing
|
|
// store for all of the nodes costs arrays.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "X86.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/DerivedTypes.h"
|
|
#include "llvm/CodeGen/SelectionDAG.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineFrameInfo.h"
|
|
#include "llvm/CodeGen/SSARegMap.h"
|
|
|
|
#include "X86RegisterInfo.h"
|
|
|
|
// Include the generated instruction selector...
|
|
#include "X86GenInstrSelector.inc"
|
|
|
|
namespace {
|
|
struct ISel : public FunctionPass, SelectionDAGTargetBuilder {
|
|
TargetMachine &TM;
|
|
ISel(TargetMachine &tm) : TM(tm) {}
|
|
int VarArgsFrameIndex; // FrameIndex for start of varargs area
|
|
|
|
bool runOnFunction(Function &Fn) {
|
|
MachineFunction &MF = MachineFunction::construct(&Fn, TM);
|
|
SelectionDAG DAG(MF, TM, *this);
|
|
|
|
std::cerr << "\n\n\n=== "
|
|
<< DAG.getMachineFunction().getFunction()->getName() << "\n";
|
|
|
|
DAG.dump();
|
|
X86ISel(DAG).generateCode();
|
|
std::cerr << "\n\n\n";
|
|
return true;
|
|
}
|
|
|
|
public: // Implementation of the SelectionDAGTargetBuilder class...
|
|
/// expandArguments - Add nodes to the DAG to indicate how to load arguments
|
|
/// off of the X86 stack.
|
|
void expandArguments(SelectionDAG &SD);
|
|
void expandCall(SelectionDAG &SD, CallInst &CI);
|
|
};
|
|
}
|
|
|
|
|
|
void ISel::expandArguments(SelectionDAG &SD) {
|
|
|
|
// Add DAG nodes to load the arguments... On entry to a function on the X86,
|
|
// the stack frame looks like this:
|
|
//
|
|
// [ESP] -- return address
|
|
// [ESP + 4] -- first argument (leftmost lexically)
|
|
// [ESP + 8] -- second argument, if first argument is four bytes in size
|
|
// ...
|
|
//
|
|
MachineFunction &F = SD.getMachineFunction();
|
|
MachineFrameInfo *MFI = F.getFrameInfo();
|
|
const Function &Fn = *F.getFunction();
|
|
|
|
unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot
|
|
for (Function::const_aiterator I = Fn.abegin(), E = Fn.aend(); I != E; ++I) {
|
|
MVT::ValueType ObjectVT = SD.getValueType(I->getType());
|
|
unsigned ArgIncrement = 4;
|
|
unsigned ObjSize;
|
|
switch (ObjectVT) {
|
|
default: assert(0 && "Unhandled argument type!");
|
|
case MVT::i8: ObjSize = 1; break;
|
|
case MVT::i16: ObjSize = 2; break;
|
|
case MVT::i32: ObjSize = 4; break;
|
|
case MVT::i64: ObjSize = ArgIncrement = 8; break;
|
|
case MVT::f32: ObjSize = 4; break;
|
|
case MVT::f64: ObjSize = ArgIncrement = 8; break;
|
|
}
|
|
// Create the frame index object for this incoming parameter...
|
|
int FI = MFI->CreateFixedObject(ObjSize, ArgOffset);
|
|
|
|
// Create the SelectionDAG nodes corresponding to a load from this parameter
|
|
SelectionDAGNode *FIN = new SelectionDAGNode(ISD::FrameIndex, MVT::i32);
|
|
FIN->addValue(new ReducedValue_FrameIndex_i32(FI));
|
|
|
|
SelectionDAGNode *Arg
|
|
= new SelectionDAGNode(ISD::Load, ObjectVT, F.begin(), FIN);
|
|
|
|
// Add the SelectionDAGNodes to the SelectionDAG... note that there is no
|
|
// reason to add chain nodes here. We know that no loads ore stores will
|
|
// ever alias these loads, so we are free to perform the load at any time in
|
|
// the function
|
|
SD.addNode(FIN);
|
|
SD.addNodeForValue(Arg, I);
|
|
|
|
ArgOffset += ArgIncrement; // Move on to the next argument...
|
|
}
|
|
|
|
// If the function takes variable number of arguments, make a frame index for
|
|
// the start of the first vararg value... for expansion of llvm.va_start.
|
|
if (Fn.getFunctionType()->isVarArg())
|
|
VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset);
|
|
}
|
|
|
|
void ISel::expandCall(SelectionDAG &SD, CallInst &CI) {
|
|
assert(0 && "ISel::expandCall not implemented!");
|
|
}
|
|
|
|
|
|
/// createX86PatternInstructionSelector - This pass converts an LLVM function
|
|
/// into a machine code representation using pattern matching and a machine
|
|
/// description file.
|
|
///
|
|
FunctionPass *createX86PatternInstructionSelector(TargetMachine &TM) {
|
|
return new ISel(TM);
|
|
}
|