llvm/lib/Target/BPF/BPFSubtarget.cpp

   1 //===-- BPFSubtarget.cpp - BPF Subtarget Information ----------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the BPF specific subclass of TargetSubtargetInfo.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "BPFSubtarget.h"
  14 #include "BPF.h"
  15 #include "BPFTargetMachine.h"
  16 #include "GISel/BPFCallLowering.h"
  17 #include "GISel/BPFLegalizerInfo.h"
  18 #include "GISel/BPFRegisterBankInfo.h"
  19 #include "llvm/MC/TargetRegistry.h"
  20 #include "llvm/TargetParser/Host.h"
  21
  22 using namespace llvm;
  23
  24 #define DEBUG_TYPE "bpf-subtarget"
  25
  26 #define GET_SUBTARGETINFO_TARGET_DESC
  27 #define GET_SUBTARGETINFO_CTOR
  28 #include "BPFGenSubtargetInfo.inc"
  29
  30 static cl::opt<bool> Disable_ldsx("disable-ldsx", cl::Hidden, cl::init(false),
  31   cl::desc("Disable ldsx insns"));
  32 static cl::opt<bool> Disable_movsx("disable-movsx", cl::Hidden, cl::init(false),
  33   cl::desc("Disable movsx insns"));
  34 static cl::opt<bool> Disable_bswap("disable-bswap", cl::Hidden, cl::init(false),
  35   cl::desc("Disable bswap insns"));
  36 static cl::opt<bool> Disable_sdiv_smod("disable-sdiv-smod", cl::Hidden,
  37   cl::init(false), cl::desc("Disable sdiv/smod insns"));
  38 static cl::opt<bool> Disable_gotol("disable-gotol", cl::Hidden, cl::init(false),
  39   cl::desc("Disable gotol insn"));
  40 static cl::opt<bool>
  41     Disable_StoreImm("disable-storeimm", cl::Hidden, cl::init(false),
  42                      cl::desc("Disable BPF_ST (immediate store) insn"));
  43
  44 void BPFSubtarget::anchor() {}
  45
  46 BPFSubtarget &BPFSubtarget::initializeSubtargetDependencies(StringRef CPU,
  47                                                             StringRef FS) {
  48   initializeEnvironment();
  49   initSubtargetFeatures(CPU, FS);
  50   ParseSubtargetFeatures(CPU, /*TuneCPU*/ CPU, FS);
  51   return *this;
  52 }
  53
  54 void BPFSubtarget::initializeEnvironment() {
  55   HasJmpExt = false;
  56   HasJmp32 = false;
  57   HasAlu32 = false;
  58   UseDwarfRIS = false;
  59   HasLdsx = false;
  60   HasMovsx = false;
  61   HasBswap = false;
  62   HasSdivSmod = false;
  63   HasGotol = false;
  64   HasStoreImm = false;
  65 }
  66
  67 void BPFSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
  68   if (CPU == "probe")
  69     CPU = sys::detail::getHostCPUNameForBPF();
  70   if (CPU == "generic" || CPU == "v1")
  71     return;
  72   if (CPU == "v2") {
  73     HasJmpExt = true;
  74     return;
  75   }
  76   if (CPU == "v3") {
  77     HasJmpExt = true;
  78     HasJmp32 = true;
  79     HasAlu32 = true;
  80     return;
  81   }
  82   if (CPU == "v4") {
  83     HasJmpExt = true;
  84     HasJmp32 = true;
  85     HasAlu32 = true;
  86     HasLdsx = !Disable_ldsx;
  87     HasMovsx = !Disable_movsx;
  88     HasBswap = !Disable_bswap;
  89     HasSdivSmod = !Disable_sdiv_smod;
  90     HasGotol = !Disable_gotol;
  91     HasStoreImm = !Disable_StoreImm;
  92     return;
  93   }
  94 }
  95
  96 BPFSubtarget::BPFSubtarget(const Triple &TT, const std::string &CPU,
  97                            const std::string &FS, const TargetMachine &TM)
  98     : BPFGenSubtargetInfo(TT, CPU, /*TuneCPU*/ CPU, FS),
  99       FrameLowering(initializeSubtargetDependencies(CPU, FS)),
 100       TLInfo(TM, *this) {
 101   IsLittleEndian = TT.isLittleEndian();
 102
 103   CallLoweringInfo.reset(new BPFCallLowering(*getTargetLowering()));
 104   Legalizer.reset(new BPFLegalizerInfo(*this));
 105   auto *RBI = new BPFRegisterBankInfo(*getRegisterInfo());
 106   RegBankInfo.reset(RBI);
 107
 108   InstSelector.reset(createBPFInstructionSelector(
 109       *static_cast<const BPFTargetMachine *>(&TM), *this, *RBI));
 110 }
 111
 112 const CallLowering *BPFSubtarget::getCallLowering() const {
 113   return CallLoweringInfo.get();
 114 }
 115
 116 InstructionSelector *BPFSubtarget::getInstructionSelector() const {
 117   return InstSelector.get();
 118 }
 119
 120 const LegalizerInfo *BPFSubtarget::getLegalizerInfo() const {
 121   return Legalizer.get();
 122 }
 123
 124 const RegisterBankInfo *BPFSubtarget::getRegBankInfo() const {
 125   return RegBankInfo.get();
 126 }