llvm-for-llvmta/lib/Target/X86/X86TileConfig.cpp

249 lines
8.4 KiB
C++

//===-- X86TileConfig.cpp - Tile Register Configure----------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
/// \file Pass to config the shape of AMX physical registers
/// AMX register need to be configured before use. In X86PreTileConfig pass
/// the pldtilecfg instruction is inserted, however at that time we don't
/// know the shape of each physical tile registers, because the register
/// allocation is not done yet. This pass runs after egister allocation
/// pass. It collects the shape information of each physical tile register
/// and store the shape in the stack slot that is allocated for load config
/// to tile config register.
//
//===----------------------------------------------------------------------===//
#include "X86.h"
#include "X86InstrBuilder.h"
#include "X86MachineFunctionInfo.h"
#include "X86RegisterInfo.h"
#include "X86Subtarget.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TileShapeInfo.h"
#include "llvm/CodeGen/VirtRegMap.h"
#include "llvm/InitializePasses.h"
using namespace llvm;
#define DEBUG_TYPE "tile-config"
namespace {
class X86TileConfig : public MachineFunctionPass {
// context
MachineFunction *MF = nullptr;
const X86Subtarget *ST = nullptr;
const TargetRegisterInfo *TRI;
const TargetInstrInfo *TII;
MachineDominatorTree *DomTree = nullptr;
MachineRegisterInfo *MRI = nullptr;
VirtRegMap *VRM = nullptr;
LiveIntervals *LIS = nullptr;
MachineInstr *getTileConfigPoint();
void tileConfig();
public:
X86TileConfig() : MachineFunctionPass(ID) {}
/// Return the pass name.
StringRef getPassName() const override { return "Tile Register Configure"; }
/// X86TileConfig analysis usage.
void getAnalysisUsage(AnalysisUsage &AU) const override;
/// Perform register allocation.
bool runOnMachineFunction(MachineFunction &mf) override;
MachineFunctionProperties getRequiredProperties() const override {
return MachineFunctionProperties().set(
MachineFunctionProperties::Property::NoPHIs);
}
static char ID;
};
} // end anonymous namespace
char X86TileConfig::ID = 0;
INITIALIZE_PASS_BEGIN(X86TileConfig, "tileconfig", "Tile Register Configure",
false, false)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
INITIALIZE_PASS_DEPENDENCY(VirtRegMap)
INITIALIZE_PASS_END(X86TileConfig, "tileconfig", "Tile Register Configure",
false, false)
void X86TileConfig::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineDominatorTree>();
AU.addRequired<LiveIntervals>();
AU.addPreserved<SlotIndexes>();
AU.addRequired<VirtRegMap>();
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
static unsigned getTilePhysRegIndex(Register PhysReg) {
assert((PhysReg >= X86::TMM0 && X86::TMM0 <= X86::TMM7) &&
"Tile register number is invalid");
return (PhysReg - X86::TMM0);
}
static MachineInstr *
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
Register SrcReg, unsigned BitSize, int FrameIdx, int Offset,
const TargetInstrInfo *TII, const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) {
unsigned SubIdx = (BitSize == 8) ? X86::sub_8bit : X86::sub_16bit;
unsigned Opc = (BitSize == 8) ? X86::MOV8mr : X86::MOV16mr;
if (BitSize == TRI->getRegSizeInBits(*RC))
SubIdx = 0;
MachineInstr *NewMI =
addFrameReference(BuildMI(MBB, MI, DebugLoc(), TII->get(Opc)), FrameIdx,
Offset)
.addReg(SrcReg, 0, SubIdx);
return NewMI;
}
static MachineInstr *storeImmToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
int64_t Imm, unsigned BitSize,
int FrameIdx, int Offset,
const TargetInstrInfo *TII) {
unsigned Opc = (BitSize == 8) ? X86::MOV8mi : X86::MOV16mi;
return addFrameReference(BuildMI(MBB, MI, DebugLoc(), TII->get(Opc)),
FrameIdx, Offset)
.addImm(Imm);
}
MachineInstr *X86TileConfig::getTileConfigPoint() {
for (MachineBasicBlock &MBB : *MF) {
// Traverse the basic block.
for (MachineInstr &MI : MBB)
// Refer X86PreTileConfig.cpp.
// We only support one tile config for now.
if (MI.getOpcode() == X86::PLDTILECFG)
return &MI;
}
return nullptr;
}
void X86TileConfig::tileConfig() {
MachineInstr *MI = getTileConfigPoint();
if (!MI)
return;
MachineBasicBlock *MBB = MI->getParent();
int SS = MI->getOperand(1).getIndex();
BitVector PhysRegs(TRI->getNumRegs());
// Fill in the palette first.
auto *NewMI = storeImmToStackSlot(*MBB, *MI, 1, 8, SS, 0, TII);
LIS->InsertMachineInstrInMaps(*NewMI);
// Fill in the shape of each tile physical register.
for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
Register VirtReg = Register::index2VirtReg(i);
if (MRI->reg_nodbg_empty(VirtReg))
continue;
const TargetRegisterClass &RC = *MRI->getRegClass(VirtReg);
if (RC.getID() != X86::TILERegClassID)
continue;
Register PhysReg = VRM->getPhys(VirtReg);
if (PhysRegs.test(PhysReg))
continue;
PhysRegs.set(PhysReg);
ShapeT Shape = VRM->getShape(VirtReg);
Register RowReg = Shape.getRow()->getReg();
Register ColReg = Shape.getCol()->getReg();
// Here is the data format for the tile config.
// 0 palette
// 1 start_row
// 2-15 reserved, must be zero
// 16-17 tile0.colsb Tile 0 bytes per row.
// 18-19 tile1.colsb Tile 1 bytes per row.
// 20-21 tile2.colsb Tile 2 bytes per row.
// ... (sequence continues)
// 30-31 tile7.colsb Tile 7 bytes per row.
// 32-47 reserved, must be zero
// 48 tile0.rows Tile 0 rows.
// 49 tile1.rows Tile 1 rows.
// 50 tile2.rows Tile 2 rows.
// ... (sequence continues)
// 55 tile7.rows Tile 7 rows.
// 56-63 reserved, must be zero
unsigned Index = getTilePhysRegIndex(PhysReg);
int RowOffset = 48 + Index;
int ColOffset = 16 + Index * 2;
unsigned BitSize = 8;
for (const auto &Pair : {std::make_pair(RowReg, RowOffset),
std::make_pair(ColReg, ColOffset)}) {
int64_t Imm;
int ImmCount = 0;
// All def must be the same value, otherwise it is invalid MIs.
// Immediate is prefered.
for (const MachineOperand &MO : MRI->def_operands(Pair.first)) {
const auto *Inst = MO.getParent();
if (Inst->isMoveImmediate()) {
ImmCount++;
Imm = Inst->getOperand(1).getImm();
break;
}
}
auto StoreConfig = [&](int Offset) {
MachineInstr *NewMI = nullptr;
if (ImmCount)
NewMI = storeImmToStackSlot(*MBB, *MI, Imm, BitSize, SS, Offset, TII);
else {
const TargetRegisterClass *RC = MRI->getRegClass(Pair.first);
NewMI = storeRegToStackSlot(*MBB, *MI, Pair.first, BitSize, SS,
Offset, TII, RC, TRI);
}
SlotIndex SIdx = LIS->InsertMachineInstrInMaps(*NewMI);
if (!ImmCount) {
// Extend the live interval.
SmallVector<SlotIndex, 8> EndPoints = {SIdx.getRegSlot()};
LiveInterval &Int = LIS->getInterval(Pair.first);
LIS->extendToIndices(Int, EndPoints);
}
};
StoreConfig(Pair.second);
BitSize += 8;
}
}
}
bool X86TileConfig::runOnMachineFunction(MachineFunction &mf) {
MF = &mf;
MRI = &mf.getRegInfo();
ST = &mf.getSubtarget<X86Subtarget>();
TRI = ST->getRegisterInfo();
TII = mf.getSubtarget().getInstrInfo();
DomTree = &getAnalysis<MachineDominatorTree>();
VRM = &getAnalysis<VirtRegMap>();
LIS = &getAnalysis<LiveIntervals>();
if (VRM->isShapeMapEmpty())
return false;
tileConfig();
return true;
}
FunctionPass *llvm::createX86TileConfigPass() { return new X86TileConfig(); }