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//===- NVPTXInstrInfo.cpp - NVPTX Instruction Information -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the NVPTX implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "NVPTXInstrInfo.h"
#include "NVPTX.h"
#include "NVPTXTargetMachine.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
using namespace llvm;
#define GET_INSTRINFO_CTOR_DTOR
#include "NVPTXGenInstrInfo.inc"
// Pin the vtable to this file.
void NVPTXInstrInfo::anchor() {}
NVPTXInstrInfo::NVPTXInstrInfo() : RegInfo() {}
void NVPTXInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, MCRegister DestReg,
MCRegister SrcReg, bool KillSrc) const {
const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
const TargetRegisterClass *DestRC = MRI.getRegClass(DestReg);
const TargetRegisterClass *SrcRC = MRI.getRegClass(SrcReg);
if (RegInfo.getRegSizeInBits(*DestRC) != RegInfo.getRegSizeInBits(*SrcRC))
report_fatal_error("Copy one register into another with a different width");
unsigned Op;
if (DestRC == &NVPTX::Int1RegsRegClass) {
Op = NVPTX::IMOV1rr;
} else if (DestRC == &NVPTX::Int16RegsRegClass) {
Op = NVPTX::IMOV16rr;
} else if (DestRC == &NVPTX::Int32RegsRegClass) {
Op = (SrcRC == &NVPTX::Int32RegsRegClass ? NVPTX::IMOV32rr
: NVPTX::BITCONVERT_32_F2I);
} else if (DestRC == &NVPTX::Int64RegsRegClass) {
Op = (SrcRC == &NVPTX::Int64RegsRegClass ? NVPTX::IMOV64rr
: NVPTX::BITCONVERT_64_F2I);
} else if (DestRC == &NVPTX::Float32RegsRegClass) {
Op = (SrcRC == &NVPTX::Float32RegsRegClass ? NVPTX::FMOV32rr
: NVPTX::BITCONVERT_32_I2F);
} else if (DestRC == &NVPTX::Float64RegsRegClass) {
Op = (SrcRC == &NVPTX::Float64RegsRegClass ? NVPTX::FMOV64rr
: NVPTX::BITCONVERT_64_I2F);
} else {
llvm_unreachable("Bad register copy");
}
BuildMI(MBB, I, DL, get(Op), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
}
/// 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 NVPTXInstrInfo::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() || !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 (LastInst.getOpcode() == NVPTX::GOTO) {
TBB = LastInst.getOperand(0).getMBB();
return false;
} else if (LastInst.getOpcode() == NVPTX::CBranch) {
// Block ends with fall-through condbranch.
TBB = LastInst.getOperand(1).getMBB();
Cond.push_back(LastInst.getOperand(0));
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 (I != MBB.begin() && isUnpredicatedTerminator(*--I))
return true;
// If the block ends with NVPTX::GOTO and NVPTX:CBranch, handle it.
if (SecondLastInst.getOpcode() == NVPTX::CBranch &&
LastInst.getOpcode() == NVPTX::GOTO) {
TBB = SecondLastInst.getOperand(1).getMBB();
Cond.push_back(SecondLastInst.getOperand(0));
FBB = LastInst.getOperand(0).getMBB();
return false;
}
// If the block ends with two NVPTX:GOTOs, handle it. The second one is not
// executed, so remove it.
if (SecondLastInst.getOpcode() == NVPTX::GOTO &&
LastInst.getOpcode() == NVPTX::GOTO) {
TBB = SecondLastInst.getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// Otherwise, can't handle this.
return true;
}
unsigned NVPTXInstrInfo::removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved) const {
assert(!BytesRemoved && "code size not handled");
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin())
return 0;
--I;
if (I->getOpcode() != NVPTX::GOTO && I->getOpcode() != NVPTX::CBranch)
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin())
return 1;
--I;
if (I->getOpcode() != NVPTX::CBranch)
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned NVPTXInstrInfo::insertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
const DebugLoc &DL,
int *BytesAdded) const {
assert(!BytesAdded && "code size not handled");
// Shouldn't be a fall through.
assert(TBB && "insertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 1 || Cond.size() == 0) &&
"NVPTX branch conditions have two components!");
// One-way branch.
if (!FBB) {
if (Cond.empty()) // Unconditional branch
BuildMI(&MBB, DL, get(NVPTX::GOTO)).addMBB(TBB);
else // Conditional branch
BuildMI(&MBB, DL, get(NVPTX::CBranch)).add(Cond[0]).addMBB(TBB);
return 1;
}
// Two-way Conditional Branch.
BuildMI(&MBB, DL, get(NVPTX::CBranch)).add(Cond[0]).addMBB(TBB);
BuildMI(&MBB, DL, get(NVPTX::GOTO)).addMBB(FBB);
return 2;
}