llvm-project/llvm/lib/Target/Alpha/AlphaInstrInfo.cpp

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//===- AlphaInstrInfo.cpp - Alpha Instruction Information -------*- C++ -*-===//
//
// 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 contains the Alpha implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "Alpha.h"
#include "AlphaInstrInfo.h"
#include "AlphaGenInstrInfo.inc"
#include "llvm/CodeGen/MachineInstrBuilder.h"
using namespace llvm;
AlphaInstrInfo::AlphaInstrInfo()
: TargetInstrInfo(AlphaInsts, sizeof(AlphaInsts)/sizeof(AlphaInsts[0])),
RI(*this) { }
bool AlphaInstrInfo::isMoveInstr(const MachineInstr& MI,
unsigned& sourceReg,
unsigned& destReg) const {
MachineOpCode oc = MI.getOpcode();
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if (oc == Alpha::BISr ||
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oc == Alpha::CPYSS ||
oc == Alpha::CPYST ||
oc == Alpha::CPYSSt ||
oc == Alpha::CPYSTs) {
// or r1, r2, r2
// cpys(s|t) r1 r2 r2
assert(MI.getNumOperands() >= 3 &&
MI.getOperand(0).isRegister() &&
MI.getOperand(1).isRegister() &&
MI.getOperand(2).isRegister() &&
"invalid Alpha BIS instruction!");
if (MI.getOperand(1).getReg() == MI.getOperand(2).getReg()) {
sourceReg = MI.getOperand(1).getReg();
destReg = MI.getOperand(0).getReg();
return true;
}
}
return false;
}
unsigned
AlphaInstrInfo::isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const {
switch (MI->getOpcode()) {
case Alpha::LDL:
case Alpha::LDQ:
case Alpha::LDBU:
case Alpha::LDWU:
case Alpha::LDS:
case Alpha::LDT:
if (MI->getOperand(1).isFrameIndex()) {
FrameIndex = MI->getOperand(1).getFrameIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
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unsigned
AlphaInstrInfo::isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const {
switch (MI->getOpcode()) {
case Alpha::STL:
case Alpha::STQ:
case Alpha::STB:
case Alpha::STW:
case Alpha::STS:
case Alpha::STT:
if (MI->getOperand(1).isFrameIndex()) {
FrameIndex = MI->getOperand(1).getFrameIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
static bool isAlphaIntCondCode(unsigned Opcode) {
switch (Opcode) {
case Alpha::BEQ:
case Alpha::BNE:
case Alpha::BGE:
case Alpha::BGT:
case Alpha::BLE:
case Alpha::BLT:
case Alpha::BLBC:
case Alpha::BLBS:
return true;
default:
return false;
}
}
void AlphaInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const std::vector<MachineOperand> &Cond)const{
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"Alpha branch conditions have two components!");
// One-way branch.
if (FBB == 0) {
if (Cond.empty()) // Unconditional branch
BuildMI(&MBB, get(Alpha::BR)).addMBB(TBB);
else // Conditional branch
if (isAlphaIntCondCode(Cond[0].getImm()))
BuildMI(&MBB, get(Alpha::COND_BRANCH_I))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
else
BuildMI(&MBB, get(Alpha::COND_BRANCH_F))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
return;
}
// Two-way Conditional Branch.
if (isAlphaIntCondCode(Cond[0].getImm()))
BuildMI(&MBB, get(Alpha::COND_BRANCH_I))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
else
BuildMI(&MBB, get(Alpha::COND_BRANCH_F))
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg()).addMBB(TBB);
BuildMI(&MBB, get(Alpha::BR)).addMBB(FBB);
}
static unsigned AlphaRevCondCode(unsigned Opcode) {
switch (Opcode) {
case Alpha::BEQ: return Alpha::BNE;
case Alpha::BNE: return Alpha::BEQ;
case Alpha::BGE: return Alpha::BLT;
case Alpha::BGT: return Alpha::BLE;
case Alpha::BLE: return Alpha::BGT;
case Alpha::BLT: return Alpha::BGE;
case Alpha::BLBC: return Alpha::BLBS;
case Alpha::BLBS: return Alpha::BLBC;
case Alpha::FBEQ: return Alpha::FBNE;
case Alpha::FBNE: return Alpha::FBEQ;
case Alpha::FBGE: return Alpha::FBLT;
case Alpha::FBGT: return Alpha::FBLE;
case Alpha::FBLE: return Alpha::FBGT;
case Alpha::FBLT: return Alpha::FBGE;
default:
assert(0 && "Unknown opcode");
}
}
// Branch analysis.
bool AlphaInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
std::vector<MachineOperand> &Cond) const {
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin() || !isTerminatorInstr((--I)->getOpcode()))
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() || !isTerminatorInstr((--I)->getOpcode())) {
if (LastInst->getOpcode() == Alpha::BR) {
TBB = LastInst->getOperand(0).getMachineBasicBlock();
return false;
} else if (LastInst->getOpcode() == Alpha::COND_BRANCH_I ||
LastInst->getOpcode() == Alpha::COND_BRANCH_F) {
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(2).getMachineBasicBlock();
Cond.push_back(LastInst->getOperand(0));
Cond.push_back(LastInst->getOperand(1));
return false;
}
// Otherwise, don't know what this is.
return true;
}
// 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() &&
isTerminatorInstr((--I)->getOpcode()))
return true;
// If the block ends with Alpha::BR and Alpha::COND_BRANCH_*, handle it.
if ((SecondLastInst->getOpcode() == Alpha::COND_BRANCH_I ||
SecondLastInst->getOpcode() == Alpha::COND_BRANCH_F) &&
LastInst->getOpcode() == Alpha::BR) {
TBB = SecondLastInst->getOperand(2).getMachineBasicBlock();
Cond.push_back(SecondLastInst->getOperand(0));
Cond.push_back(SecondLastInst->getOperand(1));
FBB = LastInst->getOperand(0).getMachineBasicBlock();
return false;
}
// Otherwise, can't handle this.
return true;
}
void AlphaInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin()) return;
--I;
if (I->getOpcode() != Alpha::BR &&
I->getOpcode() != Alpha::COND_BRANCH_I &&
I->getOpcode() != Alpha::COND_BRANCH_F)
return;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return;
--I;
if (I->getOpcode() != Alpha::COND_BRANCH_I &&
I->getOpcode() != Alpha::COND_BRANCH_F)
return;
// Remove the branch.
I->eraseFromParent();
}
void AlphaInstrInfo::insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const {
BuildMI(MBB, MI, get(Alpha::BISr), Alpha::R31).addReg(Alpha::R31)
.addReg(Alpha::R31);
}
bool AlphaInstrInfo::BlockHasNoFallThrough(MachineBasicBlock &MBB) const {
if (MBB.empty()) return false;
switch (MBB.back().getOpcode()) {
case Alpha::BR: // Uncond branch.
case Alpha::JMP: // Indirect branch.
return true;
default: return false;
}
}
bool AlphaInstrInfo::
ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
assert(Cond.size() == 2 && "Invalid Alpha branch opcode!");
Cond[0].setImm(AlphaRevCondCode(Cond[0].getImm()));
return false;
}