llvm-project/llvm/lib/Target/BPF/BPFSubtarget.cpp
Lucas Ste 6397e2f59e
Revert "[BPF] Allow libcalls behind a feature gate (#168442)" (#169733)
**Problem**

As mentioned in
https://github.com/llvm/llvm-project/pull/168442#pullrequestreview-3501502448
#168442, is not the right solution for the problem.

I'll follow @arsenm suggestions starting with
https://github.com/llvm/llvm-project/pull/169537 to properly allow safe
math operations and i128 support in BPF.

**Solution**

Revert #168442.
2025-12-01 11:19:39 -08:00

139 lines
4.4 KiB
C++

//===-- BPFSubtarget.cpp - BPF Subtarget 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 implements the BPF specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#include "BPFSubtarget.h"
#include "BPF.h"
#include "BPFTargetMachine.h"
#include "GISel/BPFCallLowering.h"
#include "GISel/BPFLegalizerInfo.h"
#include "GISel/BPFRegisterBankInfo.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/TargetParser/Host.h"
using namespace llvm;
#define DEBUG_TYPE "bpf-subtarget"
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "BPFGenSubtargetInfo.inc"
static cl::opt<bool> Disable_ldsx("disable-ldsx", cl::Hidden, cl::init(false),
cl::desc("Disable ldsx insns"));
static cl::opt<bool> Disable_movsx("disable-movsx", cl::Hidden, cl::init(false),
cl::desc("Disable movsx insns"));
static cl::opt<bool> Disable_bswap("disable-bswap", cl::Hidden, cl::init(false),
cl::desc("Disable bswap insns"));
static cl::opt<bool> Disable_sdiv_smod("disable-sdiv-smod", cl::Hidden,
cl::init(false), cl::desc("Disable sdiv/smod insns"));
static cl::opt<bool> Disable_gotol("disable-gotol", cl::Hidden, cl::init(false),
cl::desc("Disable gotol insn"));
static cl::opt<bool>
Disable_StoreImm("disable-storeimm", cl::Hidden, cl::init(false),
cl::desc("Disable BPF_ST (immediate store) insn"));
static cl::opt<bool> Disable_load_acq_store_rel(
"disable-load-acq-store-rel", cl::Hidden, cl::init(false),
cl::desc("Disable load-acquire and store-release insns"));
static cl::opt<bool> Disable_gotox("disable-gotox", cl::Hidden, cl::init(false),
cl::desc("Disable gotox insn"));
void BPFSubtarget::anchor() {}
BPFSubtarget &BPFSubtarget::initializeSubtargetDependencies(StringRef CPU,
StringRef FS) {
initializeEnvironment();
initSubtargetFeatures(CPU, FS);
ParseSubtargetFeatures(CPU, /*TuneCPU*/ CPU, FS);
return *this;
}
void BPFSubtarget::initializeEnvironment() {
HasJmpExt = false;
HasJmp32 = false;
HasAlu32 = false;
UseDwarfRIS = false;
HasLdsx = false;
HasMovsx = false;
HasBswap = false;
HasSdivSmod = false;
HasGotol = false;
HasStoreImm = false;
HasLoadAcqStoreRel = false;
HasGotox = false;
AllowsMisalignedMemAccess = false;
}
void BPFSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
if (CPU.empty())
CPU = "v3";
if (CPU == "probe")
CPU = sys::detail::getHostCPUNameForBPF();
if (CPU == "generic" || CPU == "v1")
return;
if (CPU == "v2") {
HasJmpExt = true;
return;
}
if (CPU == "v3") {
HasJmpExt = true;
HasJmp32 = true;
HasAlu32 = true;
return;
}
if (CPU == "v4") {
HasJmpExt = true;
HasJmp32 = true;
HasAlu32 = true;
HasLdsx = !Disable_ldsx;
HasMovsx = !Disable_movsx;
HasBswap = !Disable_bswap;
HasSdivSmod = !Disable_sdiv_smod;
HasGotol = !Disable_gotol;
HasStoreImm = !Disable_StoreImm;
HasLoadAcqStoreRel = !Disable_load_acq_store_rel;
HasGotox = !Disable_gotox;
return;
}
}
BPFSubtarget::BPFSubtarget(const Triple &TT, const std::string &CPU,
const std::string &FS, const TargetMachine &TM)
: BPFGenSubtargetInfo(TT, CPU, /*TuneCPU*/ CPU, FS),
InstrInfo(initializeSubtargetDependencies(CPU, FS)), FrameLowering(*this),
TLInfo(TM, *this) {
IsLittleEndian = TT.isLittleEndian();
CallLoweringInfo.reset(new BPFCallLowering(*getTargetLowering()));
Legalizer.reset(new BPFLegalizerInfo(*this));
auto *RBI = new BPFRegisterBankInfo(*getRegisterInfo());
RegBankInfo.reset(RBI);
InstSelector.reset(createBPFInstructionSelector(
*static_cast<const BPFTargetMachine *>(&TM), *this, *RBI));
}
const CallLowering *BPFSubtarget::getCallLowering() const {
return CallLoweringInfo.get();
}
InstructionSelector *BPFSubtarget::getInstructionSelector() const {
return InstSelector.get();
}
const LegalizerInfo *BPFSubtarget::getLegalizerInfo() const {
return Legalizer.get();
}
const RegisterBankInfo *BPFSubtarget::getRegBankInfo() const {
return RegBankInfo.get();
}