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llvm-project/llvm/lib/Target/XCore/XCoreInstrInfo.cpp

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//===- XCoreInstrInfo.cpp - XCore Instruction Information -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the XCore implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "XCoreMachineFunctionInfo.h"
#include "XCoreInstrInfo.h"
#include "XCore.h"
#include "llvm/MC/MCContext.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#define GET_INSTRINFO_CTOR
#include "XCoreGenInstrInfo.inc"
namespace llvm {
namespace XCore {
// XCore Condition Codes
enum CondCode {
COND_TRUE,
COND_FALSE,
COND_INVALID
};
}
}
using namespace llvm;
XCoreInstrInfo::XCoreInstrInfo()
: XCoreGenInstrInfo(XCore::ADJCALLSTACKDOWN, XCore::ADJCALLSTACKUP),
RI(*this) {
}
static bool isZeroImm(const MachineOperand &op) {
return op.isImm() && op.getImm() == 0;
}
/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned
XCoreInstrInfo::isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const{
int Opcode = MI->getOpcode();
if (Opcode == XCore::LDWFI)
{
if ((MI->getOperand(1).isFI()) && // is a stack slot
(MI->getOperand(2).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(2))))
{
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned
XCoreInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
int Opcode = MI->getOpcode();
if (Opcode == XCore::STWFI)
{
if ((MI->getOperand(1).isFI()) && // is a stack slot
(MI->getOperand(2).isImm()) && // the imm is zero
(isZeroImm(MI->getOperand(2))))
{
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
//===----------------------------------------------------------------------===//
// Branch Analysis
//===----------------------------------------------------------------------===//
static inline bool IsBRU(unsigned BrOpc) {
return BrOpc == XCore::BRFU_u6
|| BrOpc == XCore::BRFU_lu6
|| BrOpc == XCore::BRBU_u6
|| BrOpc == XCore::BRBU_lu6;
}
static inline bool IsBRT(unsigned BrOpc) {
return BrOpc == XCore::BRFT_ru6
|| BrOpc == XCore::BRFT_lru6
|| BrOpc == XCore::BRBT_ru6
|| BrOpc == XCore::BRBT_lru6;
}
static inline bool IsBRF(unsigned BrOpc) {
return BrOpc == XCore::BRFF_ru6
|| BrOpc == XCore::BRFF_lru6
|| BrOpc == XCore::BRBF_ru6
|| BrOpc == XCore::BRBF_lru6;
}
static inline bool IsCondBranch(unsigned BrOpc) {
return IsBRF(BrOpc) || IsBRT(BrOpc);
}
static inline bool IsBR_JT(unsigned BrOpc) {
return BrOpc == XCore::BR_JT
|| BrOpc == XCore::BR_JT32;
}
/// GetCondFromBranchOpc - Return the XCore CC that matches
/// the correspondent Branch instruction opcode.
static XCore::CondCode GetCondFromBranchOpc(unsigned BrOpc)
{
if (IsBRT(BrOpc)) {
return XCore::COND_TRUE;
} else if (IsBRF(BrOpc)) {
return XCore::COND_FALSE;
} else {
return XCore::COND_INVALID;
}
}
/// GetCondBranchFromCond - Return the Branch instruction
/// opcode that matches the cc.
static inline unsigned GetCondBranchFromCond(XCore::CondCode CC)
{
switch (CC) {
default: llvm_unreachable("Illegal condition code!");
case XCore::COND_TRUE : return XCore::BRFT_lru6;
case XCore::COND_FALSE : return XCore::BRFF_lru6;
}
}
/// GetOppositeBranchCondition - Return the inverse of the specified
/// condition, e.g. turning COND_E to COND_NE.
static inline XCore::CondCode GetOppositeBranchCondition(XCore::CondCode CC)
{
switch (CC) {
default: llvm_unreachable("Illegal condition code!");
case XCore::COND_TRUE : return XCore::COND_FALSE;
case XCore::COND_FALSE : return XCore::COND_TRUE;
}
}
/// AnalyzeBranch - Analyze the branching code at the end of MBB, returning
/// true if it cannot be understood (e.g. it's a switch dispatch or isn't
/// implemented for a target). Upon success, this returns false and returns
/// with the following information in various cases:
///
/// 1. If this block ends with no branches (it just falls through to its succ)
/// just return false, leaving TBB/FBB null.
/// 2. If this block ends with only an unconditional branch, it sets TBB to be
/// the destination block.
/// 3. If this block ends with an conditional branch and it falls through to
/// an successor block, it sets TBB to be the branch destination block and a
/// list of operands that evaluate the condition. These
/// operands can be passed to other TargetInstrInfo methods to create new
/// branches.
/// 4. If this block ends with an conditional branch and an unconditional
/// block, it returns the 'true' destination in TBB, the 'false' destination
/// in FBB, and a list of operands that evaluate the condition. These
/// operands can be passed to other TargetInstrInfo methods to create new
/// branches.
///
/// Note that RemoveBranch and InsertBranch must be implemented to support
/// cases where this method returns success.
///
bool
XCoreInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin())
return false;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return false;
--I;
}
if (!isUnpredicatedTerminator(I))
return false;
// Get the last instruction in the block.
MachineInstr *LastInst = I;
// If there is only one terminator instruction, process it.
if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
if (IsBRU(LastInst->getOpcode())) {
TBB = LastInst->getOperand(0).getMBB();
return false;
}
XCore::CondCode BranchCode = GetCondFromBranchOpc(LastInst->getOpcode());
if (BranchCode == XCore::COND_INVALID)
return true; // Can't handle indirect branch.
// Conditional branch
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(BranchCode));
Cond.push_back(LastInst->getOperand(0));
return false;
}
// Get the instruction before it if it's a terminator.
MachineInstr *SecondLastInst = I;
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() &&
isUnpredicatedTerminator(--I))
return true;
unsigned SecondLastOpc = SecondLastInst->getOpcode();
XCore::CondCode BranchCode = GetCondFromBranchOpc(SecondLastOpc);
// If the block ends with conditional branch followed by unconditional,
// handle it.
if (BranchCode != XCore::COND_INVALID
&& IsBRU(LastInst->getOpcode())) {
TBB = SecondLastInst->getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(BranchCode));
Cond.push_back(SecondLastInst->getOperand(0));
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two unconditional branches, handle it. The second
// one is not executed, so remove it.
if (IsBRU(SecondLastInst->getOpcode()) &&
IsBRU(LastInst->getOpcode())) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// Likewise if it ends with a branch table followed by an unconditional branch.
if (IsBR_JT(SecondLastInst->getOpcode()) && IsBRU(LastInst->getOpcode())) {
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return true;
}
// Otherwise, can't handle this.
return true;
}
unsigned
XCoreInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL)const{
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"Unexpected number of components!");
if (FBB == 0) { // One way branch.
if (Cond.empty()) {
// Unconditional branch
BuildMI(&MBB, DL, get(XCore::BRFU_lu6)).addMBB(TBB);
} else {
// Conditional branch.
unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
BuildMI(&MBB, DL, get(Opc)).addReg(Cond[1].getReg())
.addMBB(TBB);
}
return 1;
}
// Two-way Conditional branch.
assert(Cond.size() == 2 && "Unexpected number of components!");
unsigned Opc = GetCondBranchFromCond((XCore::CondCode)Cond[0].getImm());
BuildMI(&MBB, DL, get(Opc)).addReg(Cond[1].getReg())
.addMBB(TBB);
BuildMI(&MBB, DL, get(XCore::BRFU_lu6)).addMBB(FBB);
return 2;
}
unsigned
XCoreInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin()) return 0;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return 0;
--I;
}
if (!IsBRU(I->getOpcode()) && !IsCondBranch(I->getOpcode()))
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (!IsCondBranch(I->getOpcode()))
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
void XCoreInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const {
bool GRDest = XCore::GRRegsRegClass.contains(DestReg);
bool GRSrc = XCore::GRRegsRegClass.contains(SrcReg);
if (GRDest && GRSrc) {
BuildMI(MBB, I, DL, get(XCore::ADD_2rus), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))
.addImm(0);
return;
}
if (GRDest && SrcReg == XCore::SP) {
BuildMI(MBB, I, DL, get(XCore::LDAWSP_ru6), DestReg).addImm(0);
return;
}
if (DestReg == XCore::SP && GRSrc) {
BuildMI(MBB, I, DL, get(XCore::SETSP_1r))
.addReg(SrcReg, getKillRegState(KillSrc));
return;
}
llvm_unreachable("Impossible reg-to-reg copy");
}
void XCoreInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill,
int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const
{
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
BuildMI(MBB, I, DL, get(XCore::STWFI))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FrameIndex)
.addImm(0);
}
void XCoreInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const
{
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
BuildMI(MBB, I, DL, get(XCore::LDWFI), DestReg)
.addFrameIndex(FrameIndex)
.addImm(0);
}
MachineInstr*
XCoreInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF, int FrameIx,
uint64_t Offset, const MDNode *MDPtr,
DebugLoc DL) const {
MachineInstrBuilder MIB = BuildMI(MF, DL, get(XCore::DBG_VALUE))
.addFrameIndex(FrameIx).addImm(0).addImm(Offset).addMetadata(MDPtr);
return &*MIB;
}
/// ReverseBranchCondition - Return the inverse opcode of the
/// specified Branch instruction.
bool XCoreInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
assert((Cond.size() == 2) &&
"Invalid XCore branch condition!");
Cond[0].setImm(GetOppositeBranchCondition((XCore::CondCode)Cond[0].getImm()));
return false;
}
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