1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-19 11:02:59 +02:00
llvm-mirror/lib/Target/BPF/BPFSubtarget.h
Jiong Wang 1bc276c3c4 [BPF] add code-gen support for JMP32 instructions
JMP32 instructions has been added to eBPF ISA. They are 32-bit variants of
existing BPF conditional jump instructions, but the comparison happens on
low 32-bit sub-register only, therefore some unnecessary extensions could
be saved.

JMP32 instructions will only be available for -mcpu=v3. Host probe hook has
been updated accordingly.

JMP32 instructions will only be enabled in code-gen when -mattr=+alu32
enabled, meaning compiling the program using sub-register mode.

For JMP32 encoding, it is a new instruction class, and is using the
reserved eBPF class number 0x6.

This patch has been tested by compiling and running kernel bpf selftests
with JMP32 enabled.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
llvm-svn: 353384
2019-02-07 10:43:09 +00:00

93 lines
2.8 KiB
C++

//===-- BPFSubtarget.h - Define Subtarget for the BPF -----------*- C++ -*-===//
//
// 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 declares the BPF specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_BPF_BPFSUBTARGET_H
#define LLVM_LIB_TARGET_BPF_BPFSUBTARGET_H
#include "BPFFrameLowering.h"
#include "BPFISelLowering.h"
#include "BPFInstrInfo.h"
#include "BPFSelectionDAGInfo.h"
#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Target/TargetMachine.h"
#define GET_SUBTARGETINFO_HEADER
#include "BPFGenSubtargetInfo.inc"
namespace llvm {
class StringRef;
class BPFSubtarget : public BPFGenSubtargetInfo {
virtual void anchor();
BPFInstrInfo InstrInfo;
BPFFrameLowering FrameLowering;
BPFTargetLowering TLInfo;
BPFSelectionDAGInfo TSInfo;
private:
void initializeEnvironment();
void initSubtargetFeatures(StringRef CPU, StringRef FS);
bool probeJmpExt();
protected:
// unused
bool isDummyMode;
// whether the cpu supports jmp ext
bool HasJmpExt;
// whether the cpu supports jmp32 ext.
// NOTE: jmp32 is not enabled when alu32 enabled.
bool HasJmp32;
// whether the cpu supports alu32 instructions.
bool HasAlu32;
// whether we should enable MCAsmInfo DwarfUsesRelocationsAcrossSections
bool UseDwarfRIS;
public:
// This constructor initializes the data members to match that
// of the specified triple.
BPFSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
const TargetMachine &TM);
BPFSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
// ParseSubtargetFeatures - Parses features string setting specified
// subtarget options. Definition of function is auto generated by tblgen.
void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
bool getHasJmpExt() const { return HasJmpExt; }
bool getHasJmp32() const { return HasJmp32; }
bool getHasAlu32() const { return HasAlu32; }
bool getUseDwarfRIS() const { return UseDwarfRIS; }
const BPFInstrInfo *getInstrInfo() const override { return &InstrInfo; }
const BPFFrameLowering *getFrameLowering() const override {
return &FrameLowering;
}
const BPFTargetLowering *getTargetLowering() const override {
return &TLInfo;
}
const BPFSelectionDAGInfo *getSelectionDAGInfo() const override {
return &TSInfo;
}
const TargetRegisterInfo *getRegisterInfo() const override {
return &InstrInfo.getRegisterInfo();
}
};
} // End llvm namespace
#endif