mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-30 02:32:08 +00:00
e11fb34381
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43249 91177308-0d34-0410-b5e6-96231b3b80d8
249 lines
8.3 KiB
C++
249 lines
8.3 KiB
C++
//===-- LowerSubregs.cpp - Subregister Lowering instruction pass ----------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by Christopher Lamb and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define DEBUG_TYPE "lowersubregs"
|
|
#include "llvm/CodeGen/Passes.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/CodeGen/MachineFunctionPass.h"
|
|
#include "llvm/CodeGen/MachineInstr.h"
|
|
#include "llvm/CodeGen/SSARegMap.h"
|
|
#include "llvm/Target/MRegisterInfo.h"
|
|
#include "llvm/Target/TargetInstrInfo.h"
|
|
#include "llvm/Target/TargetMachine.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
struct VISIBILITY_HIDDEN LowerSubregsInstructionPass
|
|
: public MachineFunctionPass {
|
|
static char ID; // Pass identification, replacement for typeid
|
|
LowerSubregsInstructionPass() : MachineFunctionPass((intptr_t)&ID) {}
|
|
|
|
const char *getPassName() const {
|
|
return "Subregister lowering instruction pass";
|
|
}
|
|
|
|
/// runOnMachineFunction - pass entry point
|
|
bool runOnMachineFunction(MachineFunction&);
|
|
|
|
bool LowerExtract(MachineInstr *MI);
|
|
bool LowerInsert(MachineInstr *MI);
|
|
};
|
|
|
|
char LowerSubregsInstructionPass::ID = 0;
|
|
}
|
|
|
|
FunctionPass *llvm::createLowerSubregsPass() {
|
|
return new LowerSubregsInstructionPass();
|
|
}
|
|
|
|
// Returns the Register Class of a physical register.
|
|
static const TargetRegisterClass *getPhysicalRegisterRegClass(
|
|
const MRegisterInfo &MRI,
|
|
unsigned reg) {
|
|
assert(MRegisterInfo::isPhysicalRegister(reg) &&
|
|
"reg must be a physical register");
|
|
// Pick the register class of the right type that contains this physreg.
|
|
for (MRegisterInfo::regclass_iterator I = MRI.regclass_begin(),
|
|
E = MRI.regclass_end(); I != E; ++I)
|
|
if ((*I)->contains(reg))
|
|
return *I;
|
|
assert(false && "Couldn't find the register class");
|
|
return 0;
|
|
}
|
|
|
|
bool LowerSubregsInstructionPass::LowerExtract(MachineInstr *MI) {
|
|
MachineBasicBlock *MBB = MI->getParent();
|
|
MachineFunction &MF = *MBB->getParent();
|
|
const MRegisterInfo &MRI = *MF.getTarget().getRegisterInfo();
|
|
|
|
assert(MI->getOperand(0).isRegister() && MI->getOperand(0).isDef() &&
|
|
MI->getOperand(1).isRegister() && MI->getOperand(1).isUse() &&
|
|
MI->getOperand(2).isImmediate() && "Malformed extract_subreg");
|
|
|
|
unsigned SuperReg = MI->getOperand(1).getReg();
|
|
unsigned SubIdx = MI->getOperand(2).getImm();
|
|
|
|
assert(MRegisterInfo::isPhysicalRegister(SuperReg) &&
|
|
"Extract supperg source must be a physical register");
|
|
unsigned SrcReg = MRI.getSubReg(SuperReg, SubIdx);
|
|
unsigned DstReg = MI->getOperand(0).getReg();
|
|
|
|
DOUT << "subreg: CONVERTING: " << *MI;
|
|
|
|
if (SrcReg != DstReg) {
|
|
const TargetRegisterClass *TRC = 0;
|
|
if (MRegisterInfo::isPhysicalRegister(DstReg)) {
|
|
TRC = getPhysicalRegisterRegClass(MRI, DstReg);
|
|
} else {
|
|
TRC = MF.getSSARegMap()->getRegClass(DstReg);
|
|
}
|
|
assert(TRC == getPhysicalRegisterRegClass(MRI, SrcReg) &&
|
|
"Extract subreg and Dst must be of same register class");
|
|
|
|
MRI.copyRegToReg(*MBB, MI, DstReg, SrcReg, TRC, TRC);
|
|
MachineBasicBlock::iterator dMI = MI;
|
|
DOUT << "subreg: " << *(--dMI);
|
|
}
|
|
|
|
DOUT << "\n";
|
|
MBB->remove(MI);
|
|
return true;
|
|
}
|
|
|
|
|
|
bool LowerSubregsInstructionPass::LowerInsert(MachineInstr *MI) {
|
|
MachineBasicBlock *MBB = MI->getParent();
|
|
MachineFunction &MF = *MBB->getParent();
|
|
const MRegisterInfo &MRI = *MF.getTarget().getRegisterInfo();
|
|
unsigned DstReg = 0;
|
|
unsigned SrcReg = 0;
|
|
unsigned InsReg = 0;
|
|
unsigned SubIdx = 0;
|
|
|
|
// If only have 3 operands, then the source superreg is undef
|
|
// and we can supress the copy from the undef value
|
|
if (MI->getNumOperands() == 3) {
|
|
assert((MI->getOperand(0).isRegister() && MI->getOperand(0).isDef()) &&
|
|
(MI->getOperand(1).isRegister() && MI->getOperand(1).isUse()) &&
|
|
MI->getOperand(2).isImmediate() && "Invalid extract_subreg");
|
|
DstReg = MI->getOperand(0).getReg();
|
|
SrcReg = DstReg;
|
|
InsReg = MI->getOperand(1).getReg();
|
|
SubIdx = MI->getOperand(2).getImm();
|
|
} else if (MI->getNumOperands() == 4) {
|
|
assert((MI->getOperand(0).isRegister() && MI->getOperand(0).isDef()) &&
|
|
(MI->getOperand(1).isRegister() && MI->getOperand(1).isUse()) &&
|
|
(MI->getOperand(2).isRegister() && MI->getOperand(2).isUse()) &&
|
|
MI->getOperand(3).isImmediate() && "Invalid extract_subreg");
|
|
DstReg = MI->getOperand(0).getReg();
|
|
SrcReg = MI->getOperand(1).getReg();
|
|
InsReg = MI->getOperand(2).getReg();
|
|
SubIdx = MI->getOperand(3).getImm();
|
|
} else
|
|
assert(0 && "Malformed extract_subreg");
|
|
|
|
assert(SubIdx != 0 && "Invalid index for extract_subreg");
|
|
unsigned DstSubReg = MRI.getSubReg(DstReg, SubIdx);
|
|
|
|
assert(MRegisterInfo::isPhysicalRegister(SrcReg) &&
|
|
"Insert superreg source must be in a physical register");
|
|
assert(MRegisterInfo::isPhysicalRegister(DstReg) &&
|
|
"Insert destination must be in a physical register");
|
|
assert(MRegisterInfo::isPhysicalRegister(InsReg) &&
|
|
"Inserted value must be in a physical register");
|
|
|
|
DOUT << "subreg: CONVERTING: " << *MI;
|
|
|
|
// If the inserted register is already allocated into a subregister
|
|
// of the destination, we copy the subreg into the source
|
|
// However, this is only safe if the insert instruction is the kill
|
|
// of the source register
|
|
bool revCopyOrder = MRI.isSubRegister(DstReg, InsReg);
|
|
if (revCopyOrder && InsReg != DstSubReg) {
|
|
if (MI->getOperand(1).isKill()) {
|
|
DstSubReg = MRI.getSubReg(SrcReg, SubIdx);
|
|
// Insert sub-register copy
|
|
const TargetRegisterClass *TRC1 = 0;
|
|
if (MRegisterInfo::isPhysicalRegister(InsReg)) {
|
|
TRC1 = getPhysicalRegisterRegClass(MRI, InsReg);
|
|
} else {
|
|
TRC1 = MF.getSSARegMap()->getRegClass(InsReg);
|
|
}
|
|
MRI.copyRegToReg(*MBB, MI, DstSubReg, InsReg, TRC1, TRC1);
|
|
|
|
#ifndef NDEBUG
|
|
MachineBasicBlock::iterator dMI = MI;
|
|
DOUT << "subreg: " << *(--dMI);
|
|
#endif
|
|
} else {
|
|
assert(0 && "Don't know how to convert this insert");
|
|
}
|
|
}
|
|
#ifndef NDEBUG
|
|
if (InsReg == DstSubReg) {
|
|
DOUT << "subreg: Eliminated subreg copy\n";
|
|
}
|
|
#endif
|
|
|
|
if (SrcReg != DstReg) {
|
|
// Insert super-register copy
|
|
const TargetRegisterClass *TRC0 = 0;
|
|
if (MRegisterInfo::isPhysicalRegister(DstReg)) {
|
|
TRC0 = getPhysicalRegisterRegClass(MRI, DstReg);
|
|
} else {
|
|
TRC0 = MF.getSSARegMap()->getRegClass(DstReg);
|
|
}
|
|
assert(TRC0 == getPhysicalRegisterRegClass(MRI, SrcReg) &&
|
|
"Insert superreg and Dst must be of same register class");
|
|
|
|
MRI.copyRegToReg(*MBB, MI, DstReg, SrcReg, TRC0, TRC0);
|
|
|
|
#ifndef NDEBUG
|
|
MachineBasicBlock::iterator dMI = MI;
|
|
DOUT << "subreg: " << *(--dMI);
|
|
#endif
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
if (SrcReg == DstReg) {
|
|
DOUT << "subreg: Eliminated superreg copy\n";
|
|
}
|
|
#endif
|
|
|
|
if (!revCopyOrder && InsReg != DstSubReg) {
|
|
// Insert sub-register copy
|
|
const TargetRegisterClass *TRC1 = 0;
|
|
if (MRegisterInfo::isPhysicalRegister(InsReg)) {
|
|
TRC1 = getPhysicalRegisterRegClass(MRI, InsReg);
|
|
} else {
|
|
TRC1 = MF.getSSARegMap()->getRegClass(InsReg);
|
|
}
|
|
MRI.copyRegToReg(*MBB, MI, DstSubReg, InsReg, TRC1, TRC1);
|
|
|
|
#ifndef NDEBUG
|
|
MachineBasicBlock::iterator dMI = MI;
|
|
DOUT << "subreg: " << *(--dMI);
|
|
#endif
|
|
}
|
|
|
|
DOUT << "\n";
|
|
MBB->remove(MI);
|
|
return true;
|
|
}
|
|
|
|
/// runOnMachineFunction - Reduce subregister inserts and extracts to register
|
|
/// copies.
|
|
///
|
|
bool LowerSubregsInstructionPass::runOnMachineFunction(MachineFunction &MF) {
|
|
DOUT << "Machine Function\n";
|
|
|
|
bool MadeChange = false;
|
|
|
|
DOUT << "********** LOWERING SUBREG INSTRS **********\n";
|
|
DOUT << "********** Function: " << MF.getFunction()->getName() << '\n';
|
|
|
|
for (MachineFunction::iterator mbbi = MF.begin(), mbbe = MF.end();
|
|
mbbi != mbbe; ++mbbi) {
|
|
for (MachineBasicBlock::iterator mi = mbbi->begin(), me = mbbi->end();
|
|
mi != me;) {
|
|
MachineInstr *MI = mi++;
|
|
|
|
if (MI->getOpcode() == TargetInstrInfo::EXTRACT_SUBREG) {
|
|
MadeChange |= LowerExtract(MI);
|
|
} else if (MI->getOpcode() == TargetInstrInfo::INSERT_SUBREG) {
|
|
MadeChange |= LowerInsert(MI);
|
|
}
|
|
}
|
|
}
|
|
|
|
return MadeChange;
|
|
}
|