Files
clang-p2996/llvm/lib/Target/BPF/BPFMIChecking.cpp
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00

96 lines
2.7 KiB
C++

//===-------------- BPFMIChecking.cpp - MI Checking Legality -------------===//
//
// 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 pass performs checking to signal errors for certain illegal usages at
// MachineInstruction layer. Specially, the result of XADD{32,64} insn should
// not be used. The pass is done at the PreEmit pass right before the
// machine code is emitted at which point the register liveness information
// is still available.
//
//===----------------------------------------------------------------------===//
#include "BPF.h"
#include "BPFInstrInfo.h"
#include "BPFTargetMachine.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
using namespace llvm;
#define DEBUG_TYPE "bpf-mi-checking"
namespace {
struct BPFMIPreEmitChecking : public MachineFunctionPass {
static char ID;
MachineFunction *MF;
const TargetRegisterInfo *TRI;
BPFMIPreEmitChecking() : MachineFunctionPass(ID) {
initializeBPFMIPreEmitCheckingPass(*PassRegistry::getPassRegistry());
}
private:
// Initialize class variables.
void initialize(MachineFunction &MFParm);
void checkingIllegalXADD(void);
public:
// Main entry point for this pass.
bool runOnMachineFunction(MachineFunction &MF) override {
if (!skipFunction(MF.getFunction())) {
initialize(MF);
checkingIllegalXADD();
}
return false;
}
};
// Initialize class variables.
void BPFMIPreEmitChecking::initialize(MachineFunction &MFParm) {
MF = &MFParm;
TRI = MF->getSubtarget<BPFSubtarget>().getRegisterInfo();
LLVM_DEBUG(dbgs() << "*** BPF PreEmit checking pass ***\n\n");
}
void BPFMIPreEmitChecking::checkingIllegalXADD(void) {
for (MachineBasicBlock &MBB : *MF) {
for (MachineInstr &MI : MBB) {
if (MI.getOpcode() != BPF::XADD32 && MI.getOpcode() != BPF::XADD64)
continue;
LLVM_DEBUG(MI.dump());
if (!MI.allDefsAreDead()) {
DebugLoc Empty;
const DebugLoc &DL = MI.getDebugLoc();
if (DL != Empty)
report_fatal_error("line " + std::to_string(DL.getLine()) +
": Invalid usage of the XADD return value", false);
else
report_fatal_error("Invalid usage of the XADD return value", false);
}
}
}
return;
}
} // end default namespace
INITIALIZE_PASS(BPFMIPreEmitChecking, "bpf-mi-pemit-checking",
"BPF PreEmit Checking", false, false)
char BPFMIPreEmitChecking::ID = 0;
FunctionPass* llvm::createBPFMIPreEmitCheckingPass()
{
return new BPFMIPreEmitChecking();
}